MRI in evaluation of white matter diseases like multiple sclerosis, leukodystrophies, demyelination, dysmyelination, ADEM, leukoencephalopathies, van der knaap disease, ALD, MLD, Krabbes disease, Leighs disease, Vanishing white matter disease, Canavan disease, Alexander disease
imaging in neurology - demyelinating diseasesNeurologyKota
This document discusses various demyelinating diseases that can be imaged in neurology. It provides images and descriptions of findings for multiple sclerosis, ADEM, NMO spectrum disorder, Susac syndrome, CLIPPERS, acute disseminated encephalomyelitis, acute hemorrhagic leukoencephalitis, acute necrotizing encephalopathy, and osmotic demyelination syndrome. It compares imaging features of MS and NMOSD that can help differentiate the two conditions. The document also discusses variants of MS like Marburg disease, Schilder disease, and Balo concentric sclerosis.
This document discusses degenerative and white matter diseases of the central nervous system. It focuses on white matter disease, describing different types including demyelinating and dysmyelinating diseases. For demyelinating diseases, it provides detailed information about multiple sclerosis (MS), including its incidence, clinical presentation, radiographic features on CT and MRI, variants like tumefactive and Marburg MS, and McDonald criteria for diagnosing MS. It also briefly discusses other causes of white matter disease like post-viral white matter disease, toxic leukoencephalopathy, vascular white matter disease, and infectious white matter diseases.
The document discusses the vascular territories of the brain. It begins by outlining some key arteries and their branches, including the internal carotid artery, circle of Willis, middle cerebral artery, anterior cerebral artery, and persistent carotid-basilar connections. It then discusses several specific arterial territories in more detail, including the territories supplied by the posterior inferior cerebellar artery, superior cerebellar artery, branches of the vertebral and basilar arteries, and the anterior choroidal artery. The document emphasizes understanding vascular anatomy and territories to aid in diagnosing different types of strokes and infarcts.
1. Canavan disease, Alexander disease, vanishing white matter disease, and megalencephalic leukoencephalopathy involve sub cortical and deep white matter and are characterized by macrocephaly. Zellweger syndrome and Kearn sayer disease involve the normocephalic deep white matter and cerebral atrophy.
2. Krabbe's disease involves the thalamus and basal ganglia with increased choline in the centrum semiovale, while adrenoleucodystrophy affects the corticospinal tract with a posterior fossa tripe layer appearance and enhancement. Maple syrup urine disease shows restricted diffusion in the internal capsule and posterior fossa.
3. Metachromatic
Its important to recognise the myelination pattern in neonates and infants. This presentation talks about the myelination pattern and imaging of white matter diseases in children.
This document provides an overview of various demyelinating diseases of the central nervous system. It begins by defining demyelinating diseases as those involving disruption of myelin, which forms an insulating sheath around axons. It then classifies and describes several specific diseases, including acute disseminated encephalomyelitis (ADEM), inflammatory demyelinating pseudotumor, multiple sclerosis (MS), neuromyelitis optica, central pontine myelinolysis, HIV encephalopathy, progressive multifocal leukoencephalopathy (PML), and others. For each disease, it discusses clinical features, magnetic resonance imaging (MRI) findings, differential diagnoses, and pathology where relevant.
The document describes the anatomy and course of the internal carotid artery (ICA). It discusses the anterior and posterior circulations fed by the ICA and vertebrobasilar trunk. Key points include the ICA coursing through the cavernous sinus and giving off branches like the ophthalmic artery. The posterior communicating artery connects the ICA to the vertebrobasilar system.
imaging in neurology - demyelinating diseasesNeurologyKota
This document discusses various demyelinating diseases that can be imaged in neurology. It provides images and descriptions of findings for multiple sclerosis, ADEM, NMO spectrum disorder, Susac syndrome, CLIPPERS, acute disseminated encephalomyelitis, acute hemorrhagic leukoencephalitis, acute necrotizing encephalopathy, and osmotic demyelination syndrome. It compares imaging features of MS and NMOSD that can help differentiate the two conditions. The document also discusses variants of MS like Marburg disease, Schilder disease, and Balo concentric sclerosis.
This document discusses degenerative and white matter diseases of the central nervous system. It focuses on white matter disease, describing different types including demyelinating and dysmyelinating diseases. For demyelinating diseases, it provides detailed information about multiple sclerosis (MS), including its incidence, clinical presentation, radiographic features on CT and MRI, variants like tumefactive and Marburg MS, and McDonald criteria for diagnosing MS. It also briefly discusses other causes of white matter disease like post-viral white matter disease, toxic leukoencephalopathy, vascular white matter disease, and infectious white matter diseases.
The document discusses the vascular territories of the brain. It begins by outlining some key arteries and their branches, including the internal carotid artery, circle of Willis, middle cerebral artery, anterior cerebral artery, and persistent carotid-basilar connections. It then discusses several specific arterial territories in more detail, including the territories supplied by the posterior inferior cerebellar artery, superior cerebellar artery, branches of the vertebral and basilar arteries, and the anterior choroidal artery. The document emphasizes understanding vascular anatomy and territories to aid in diagnosing different types of strokes and infarcts.
1. Canavan disease, Alexander disease, vanishing white matter disease, and megalencephalic leukoencephalopathy involve sub cortical and deep white matter and are characterized by macrocephaly. Zellweger syndrome and Kearn sayer disease involve the normocephalic deep white matter and cerebral atrophy.
2. Krabbe's disease involves the thalamus and basal ganglia with increased choline in the centrum semiovale, while adrenoleucodystrophy affects the corticospinal tract with a posterior fossa tripe layer appearance and enhancement. Maple syrup urine disease shows restricted diffusion in the internal capsule and posterior fossa.
3. Metachromatic
Its important to recognise the myelination pattern in neonates and infants. This presentation talks about the myelination pattern and imaging of white matter diseases in children.
This document provides an overview of various demyelinating diseases of the central nervous system. It begins by defining demyelinating diseases as those involving disruption of myelin, which forms an insulating sheath around axons. It then classifies and describes several specific diseases, including acute disseminated encephalomyelitis (ADEM), inflammatory demyelinating pseudotumor, multiple sclerosis (MS), neuromyelitis optica, central pontine myelinolysis, HIV encephalopathy, progressive multifocal leukoencephalopathy (PML), and others. For each disease, it discusses clinical features, magnetic resonance imaging (MRI) findings, differential diagnoses, and pathology where relevant.
The document describes the anatomy and course of the internal carotid artery (ICA). It discusses the anterior and posterior circulations fed by the ICA and vertebrobasilar trunk. Key points include the ICA coursing through the cavernous sinus and giving off branches like the ophthalmic artery. The posterior communicating artery connects the ICA to the vertebrobasilar system.
CRANIOVERTEBRAL JUNCTION ANATOMY, CRANIOMETRY, ANAMOLIES AND RADIOLOGY dr sum...SUMIT KUMAR
The craniovertebral junction (CVJ) refers anatomically to the occiput, atlas, axis, and their articulations and ligaments. It is a complex region forming the transition between the skull and upper cervical spine.
The document describes the normal anatomy of the CVJ bones including the occiput, atlas, and axis. It discusses the important ligaments including the occipitoatlantoaxial ligaments. Key radiological measurements and lines used to evaluate the CVJ are presented, along with classification of various congenital and acquired CVJ anomalies and their imaging appearance. Basilar invagination, basilar impression, and platybasia are distinguished.
Presentation1.pptx, radiological imaging of cerebral venous thrombosis.Abdellah Nazeer
This document provides an anatomical review of the cerebral venous system and discusses radiological imaging techniques for diagnosing cerebral venous thrombosis (CVT). It describes the normal anatomy of cerebral veins and venous sinuses that drain blood from the brain. Computed tomography and magnetic resonance imaging are effective noninvasive methods for identifying CVT. Direct signs on imaging include visualizing thrombus as hyperdense on CT or hyperintense on MRI. Indirect signs include edema, infarction, hemorrhage, and collateral vessel formation caused by venous outflow obstruction from thrombus.
In this presentation, i have explained different modalities available for radiological evaluation of cns tumors. How to approach to a radiographic image and how to approach to a patient of cns tumors radiologically.
This document provides an overview of various neuroimaging signs and findings. It describes signs seen on MRI that are characteristic of different neurological conditions. Some examples included are the "eye of tiger appearance" seen in Hallervorden-Spatz disease, the "hot-cross-bun sign" seen in various spinocerebellar ataxias, and the "putaminal slit sign" seen in multiple system atrophy. It also provides images and descriptions of signs seen in conditions like multiple sclerosis, Parkinson's disease, Wilson's disease, tuberculomas, and more. The document serves as a reference for neuroradiologists and neurologists to identify various pathologies based on their imaging appearance.
Presentation2, radiological imaging of neurodegenerative and dementai disease...Abdellah Nazeer
This document discusses radiological imaging techniques for diagnosing various neurodegenerative diseases and dementias. It provides an overview of different neurodegenerative diseases categorized by their underlying pathological processes including synucleinopathies, tauopathies, cerebral amyloidosis, spinocerebellar ataxias, and prion diseases. It then focuses on Alzheimer's disease, providing details on structural changes seen on MRI, patterns of hypometabolism on FDG-PET and amyloid deposition on amyloid PET. Imaging patterns of other diseases like vascular dementia, frontotemporal dementia, dementia with Lewy bodies, and corticobasal degeneration are also summarized.
Imaging is crucial for diagnosing and guiding management of stroke. MRI is more sensitive than CT for detecting early changes, with expedited protocols using FLAIR, T2*, and DWI answering key questions acutely. Imaging can identify the type of stroke (ischemic vs. hemorrhagic), location, age of the lesion, and potential underlying causes. Understanding the imaging appearance of strokes across time points from hyperacute to chronic is important for accurate diagnosis and treatment.
This document provides an overview of white matter diseases. It discusses:
1. Primary demyelinating diseases like multiple sclerosis and neuromyelitis optica which are characterized by loss of myelin.
2. Secondary demyelination caused by known etiologies like infections, metabolic disorders, or vascular issues which result in destruction of both axons and myelin.
3. Dysmyelinating/hypomyelinating leukodystrophies which involve defective or incomplete myelin formation, including some common causes like metachromatic leukodystrophy.
4. The clinical approach involves considering features like onset, progression, family history, involvement of other organs, and patterns
This document contains 22 radiology case spots describing various pathologies. For each spot, the document provides a brief description of the imaging findings and diagnosis. The cases cover a wide range of topics including musculoskeletal, chest, neurologic, breast and vascular pathologies. Differential diagnoses are also provided for some cases to aid in arriving at the correct diagnosis.
The document summarizes MRI findings in Wilson disease. There are 5 main patterns seen: 1) T2 hyperintense lesions that are T1 hypointense, 2) lesions hypointense in the center and hyperintense peripherally on T2, 3) T1 hyperintense and T2 iso/hypointense lesions, 4) generalized brain atrophy, and 5) specific signs like the "face of giant panda" seen in the midbrain. Lesions are typically bilateral and symmetric. Later in the disease, iron deposition can cause hypointensity. Diffusion MRI may show early restricted diffusion. Characteristic signs have high specificity for Wilson disease.
Diagnostic Imaging of Bilateral Abnormalities of the Basal Ganglia & ThalamusMohamed M.A. Zaitoun
The document discusses abnormalities of the basal ganglia and thalamus seen on MRI. It begins by describing the normal anatomy and blood supply of these structures. It then discusses various pathological changes that can be seen, including those from toxins, metabolic diseases, inherited metabolic diseases, vascular causes, infections, tumors and other miscellaneous etiologies. Specific conditions mentioned include Wilson's disease, Leigh's disease, NBIA, hepatic encephalopathy, kernicterus, hypoglycemia and nonketotic hyperglycemia. Radiologic signs for many of these conditions are also described.
Presentation1.pptx. radiological imaging of epilepsy.Abdellah Nazeer
1) Hippocampal sclerosis, characterized by hippocampal atrophy and increased signal intensity on MRI, is the most common epileptogenic abnormality found after epilepsy surgery.
2) Malformations of cortical development, including focal cortical dysplasias and heterotopias, are also common epileptogenic lesions found in surgical series, especially in patients with childhood-onset seizures.
3) In addition to structural abnormalities, low-grade gliomas and hamartomas located near the cerebral cortex are also important causes of drug-resistant epilepsy that may require surgery.
This document discusses the typical MRI findings seen in multiple sclerosis (MS). Key findings include ovoid lesions perpendicular to the ventricles known as Dawson fingers, enhancing lesions, and multiple lesions adjacent to the ventricles. Enhancement is seen for about a month after a lesion occurs. Juxtacortical lesions touching the cortex and involvement of the temporal lobe, corpus callosum, and periventricular regions are also typical of MS. Multiple lesions can be seen in the spinal cord, most often in the cervical region. Several variants of MS are also mentioned, including tumefactive MS, Balo's concentric sclerosis, and neuromyelitis optica, which is now considered a distinct
MRI imaging of brain tumors. A practical approach. hazem youssef
This document provides an overview of MRI protocols for imaging brain tumors and what each sequence reveals. It discusses how conventional sequences can identify tumors versus other lesions and provide histological information. Post-contrast T1-weighted imaging reveals enhancement patterns related to tumor angiogenesis and blood-brain barrier disruption. Perfusion MRI demonstrates neoangiogenesis which correlates with tumor grade. Susceptibility weighted imaging visualizes microvessels and intratumoral susceptibility signals associated with grading. Magnetic resonance spectroscopy identifies metabolite levels indicative of tumor type and grade. Diffusion weighted imaging correlates restricted diffusion with cellularity and tumor aggressiveness.
Imaging in inherited metabolic disordersvinothmezoss
Normal myelination of the brain proceeds from central to peripheral, inferior to superior, and posterior to anterior. Metabolic disorders can cause leukodystrophies through dysfunction of lysosomes, peroxisomes, or mitochondria. Lysosomal storage diseases like metachromatic leukodystrophy and Krabbe disease involve accumulation of myelin components due to enzyme deficiencies and appear on imaging as symmetric white matter abnormalities that progress centrifugally.
Magnetic Resonance Angiography and VenographyAnjan Dangal
Introduction to MR Angiography and Venography Procedure of Brain . Includes Indication, MRI protocol, planning and anatomy as well as brief intoduction to physics behind MRA and MRV principle.
This document discusses imaging in medial temporal lobe epilepsy. It begins by explaining why MRI is important for detecting epileptogenic lesions in refractory cases. It then describes the anatomy of medial temporal lobe structures like the hippocampus and amygdala. The document discusses how hippocampal sclerosis appears on MRI, including features like gliosis, neuronal loss, and atrophy. It also covers other imaging modalities that can help lateralize the seizure focus, such as hippocampal volumetry, relaxometry, MRS, PET, and SPECT. In conclusion, MRI is the best way to diagnose mesial temporal sclerosis by identifying hippocampal hyperintensity and atrophy.
Imaging in neurology - normal MR Angio and VenographyNeurologyKota
There are two main types of MR angiography (MRA): contrast-enhanced (CE) MRA and non-contrast enhanced MRA, which includes time-of-flight (TOF) MRA and phase contrast (PC) MRA. CE MRA uses an injected gadolinium contrast agent and is faster than non-contrast MRA. TOF MRA detects blood flow without contrast but is susceptible to artifacts. PC MRA measures blood velocity and flow direction and can quantify blood flow. MR venography (MRV) uses similar techniques as MRA to image veins and is useful for detecting cerebral venous thrombosis. Common applications of MRA and MRV include evaluation of aneurysms, neck vessels, and cerebral
This chapter defines an epileptic seizure as transient abnormal neuronal activity in the brain. Around 5% of people experience seizures in their lifetime, with incidence highest in infants and elderly adults. Epilepsy is defined as recurrent seizures and the consequences of this condition. A diagnosis of epilepsy can be made after one seizure if EEG or MRI findings indicate increased epileptogenicity. Drug-resistant epilepsy persists despite adequate treatment with two tolerated anti-seizure medications. Seizure freedom requires being seizure-free for at least one year while on medication.
The document discusses various central nervous system infections, how they can be classified, their routes of entry and imaging appearances. It covers congenital infections including TORCH infections, acquired pyogenic infections such as meningitis, abscesses and ventriculitis. It also discusses viral, parasitic and fungal infections of the CNS. For each type of infection, the causative pathogens, locations, presentations and characteristic imaging findings are outlined.
The document summarizes the cerebral venous system, including:
- Cerebral veins drain the brain and lack valves, emptying into dural venous sinuses between the dura layers.
- The major dural venous sinuses include the superior and inferior sagittal, straight, occipital, transverse, sigmoid, and cavernous sinuses.
- The sinuses receive blood from cerebral veins and CSF from arachnoid villi before draining into the internal jugular veins.
Demyelinating and inflammatory diseasesShivam Batra
Demyelinating diseases involve disruption of myelin in the central and peripheral nervous systems. Multiple sclerosis (MS) is an autoimmune demyelinating disease characterized by inflammatory demyelinating lesions throughout the white matter. MRI is useful for diagnosing MS by demonstrating dissemination of lesions in space and time. Typical MS lesions on MRI appear as oval or linear hyperintensities on T2/FLAIR images surrounding medullary veins and involving the periventricular white matter, corpus callosum, brainstem, and cortical gray matter.
Imaging of demyelinating diseases finalSunil Kumar
This document discusses pathology and imaging of multiple sclerosis. It begins by describing the composition and development of myelin and white matter in the central nervous system. It then discusses multiple sclerosis as a primary demyelinating disease characterized by plaques seen on imaging. The clinical manifestations and variants of multiple sclerosis are described. Imaging findings on CT, MRI, T1-weighted, T2-weighted, and FLAIR sequences are provided, showing the appearance of lesions in white matter and ability to detect acute inflammation.
CRANIOVERTEBRAL JUNCTION ANATOMY, CRANIOMETRY, ANAMOLIES AND RADIOLOGY dr sum...SUMIT KUMAR
The craniovertebral junction (CVJ) refers anatomically to the occiput, atlas, axis, and their articulations and ligaments. It is a complex region forming the transition between the skull and upper cervical spine.
The document describes the normal anatomy of the CVJ bones including the occiput, atlas, and axis. It discusses the important ligaments including the occipitoatlantoaxial ligaments. Key radiological measurements and lines used to evaluate the CVJ are presented, along with classification of various congenital and acquired CVJ anomalies and their imaging appearance. Basilar invagination, basilar impression, and platybasia are distinguished.
Presentation1.pptx, radiological imaging of cerebral venous thrombosis.Abdellah Nazeer
This document provides an anatomical review of the cerebral venous system and discusses radiological imaging techniques for diagnosing cerebral venous thrombosis (CVT). It describes the normal anatomy of cerebral veins and venous sinuses that drain blood from the brain. Computed tomography and magnetic resonance imaging are effective noninvasive methods for identifying CVT. Direct signs on imaging include visualizing thrombus as hyperdense on CT or hyperintense on MRI. Indirect signs include edema, infarction, hemorrhage, and collateral vessel formation caused by venous outflow obstruction from thrombus.
In this presentation, i have explained different modalities available for radiological evaluation of cns tumors. How to approach to a radiographic image and how to approach to a patient of cns tumors radiologically.
This document provides an overview of various neuroimaging signs and findings. It describes signs seen on MRI that are characteristic of different neurological conditions. Some examples included are the "eye of tiger appearance" seen in Hallervorden-Spatz disease, the "hot-cross-bun sign" seen in various spinocerebellar ataxias, and the "putaminal slit sign" seen in multiple system atrophy. It also provides images and descriptions of signs seen in conditions like multiple sclerosis, Parkinson's disease, Wilson's disease, tuberculomas, and more. The document serves as a reference for neuroradiologists and neurologists to identify various pathologies based on their imaging appearance.
Presentation2, radiological imaging of neurodegenerative and dementai disease...Abdellah Nazeer
This document discusses radiological imaging techniques for diagnosing various neurodegenerative diseases and dementias. It provides an overview of different neurodegenerative diseases categorized by their underlying pathological processes including synucleinopathies, tauopathies, cerebral amyloidosis, spinocerebellar ataxias, and prion diseases. It then focuses on Alzheimer's disease, providing details on structural changes seen on MRI, patterns of hypometabolism on FDG-PET and amyloid deposition on amyloid PET. Imaging patterns of other diseases like vascular dementia, frontotemporal dementia, dementia with Lewy bodies, and corticobasal degeneration are also summarized.
Imaging is crucial for diagnosing and guiding management of stroke. MRI is more sensitive than CT for detecting early changes, with expedited protocols using FLAIR, T2*, and DWI answering key questions acutely. Imaging can identify the type of stroke (ischemic vs. hemorrhagic), location, age of the lesion, and potential underlying causes. Understanding the imaging appearance of strokes across time points from hyperacute to chronic is important for accurate diagnosis and treatment.
This document provides an overview of white matter diseases. It discusses:
1. Primary demyelinating diseases like multiple sclerosis and neuromyelitis optica which are characterized by loss of myelin.
2. Secondary demyelination caused by known etiologies like infections, metabolic disorders, or vascular issues which result in destruction of both axons and myelin.
3. Dysmyelinating/hypomyelinating leukodystrophies which involve defective or incomplete myelin formation, including some common causes like metachromatic leukodystrophy.
4. The clinical approach involves considering features like onset, progression, family history, involvement of other organs, and patterns
This document contains 22 radiology case spots describing various pathologies. For each spot, the document provides a brief description of the imaging findings and diagnosis. The cases cover a wide range of topics including musculoskeletal, chest, neurologic, breast and vascular pathologies. Differential diagnoses are also provided for some cases to aid in arriving at the correct diagnosis.
The document summarizes MRI findings in Wilson disease. There are 5 main patterns seen: 1) T2 hyperintense lesions that are T1 hypointense, 2) lesions hypointense in the center and hyperintense peripherally on T2, 3) T1 hyperintense and T2 iso/hypointense lesions, 4) generalized brain atrophy, and 5) specific signs like the "face of giant panda" seen in the midbrain. Lesions are typically bilateral and symmetric. Later in the disease, iron deposition can cause hypointensity. Diffusion MRI may show early restricted diffusion. Characteristic signs have high specificity for Wilson disease.
Diagnostic Imaging of Bilateral Abnormalities of the Basal Ganglia & ThalamusMohamed M.A. Zaitoun
The document discusses abnormalities of the basal ganglia and thalamus seen on MRI. It begins by describing the normal anatomy and blood supply of these structures. It then discusses various pathological changes that can be seen, including those from toxins, metabolic diseases, inherited metabolic diseases, vascular causes, infections, tumors and other miscellaneous etiologies. Specific conditions mentioned include Wilson's disease, Leigh's disease, NBIA, hepatic encephalopathy, kernicterus, hypoglycemia and nonketotic hyperglycemia. Radiologic signs for many of these conditions are also described.
Presentation1.pptx. radiological imaging of epilepsy.Abdellah Nazeer
1) Hippocampal sclerosis, characterized by hippocampal atrophy and increased signal intensity on MRI, is the most common epileptogenic abnormality found after epilepsy surgery.
2) Malformations of cortical development, including focal cortical dysplasias and heterotopias, are also common epileptogenic lesions found in surgical series, especially in patients with childhood-onset seizures.
3) In addition to structural abnormalities, low-grade gliomas and hamartomas located near the cerebral cortex are also important causes of drug-resistant epilepsy that may require surgery.
This document discusses the typical MRI findings seen in multiple sclerosis (MS). Key findings include ovoid lesions perpendicular to the ventricles known as Dawson fingers, enhancing lesions, and multiple lesions adjacent to the ventricles. Enhancement is seen for about a month after a lesion occurs. Juxtacortical lesions touching the cortex and involvement of the temporal lobe, corpus callosum, and periventricular regions are also typical of MS. Multiple lesions can be seen in the spinal cord, most often in the cervical region. Several variants of MS are also mentioned, including tumefactive MS, Balo's concentric sclerosis, and neuromyelitis optica, which is now considered a distinct
MRI imaging of brain tumors. A practical approach. hazem youssef
This document provides an overview of MRI protocols for imaging brain tumors and what each sequence reveals. It discusses how conventional sequences can identify tumors versus other lesions and provide histological information. Post-contrast T1-weighted imaging reveals enhancement patterns related to tumor angiogenesis and blood-brain barrier disruption. Perfusion MRI demonstrates neoangiogenesis which correlates with tumor grade. Susceptibility weighted imaging visualizes microvessels and intratumoral susceptibility signals associated with grading. Magnetic resonance spectroscopy identifies metabolite levels indicative of tumor type and grade. Diffusion weighted imaging correlates restricted diffusion with cellularity and tumor aggressiveness.
Imaging in inherited metabolic disordersvinothmezoss
Normal myelination of the brain proceeds from central to peripheral, inferior to superior, and posterior to anterior. Metabolic disorders can cause leukodystrophies through dysfunction of lysosomes, peroxisomes, or mitochondria. Lysosomal storage diseases like metachromatic leukodystrophy and Krabbe disease involve accumulation of myelin components due to enzyme deficiencies and appear on imaging as symmetric white matter abnormalities that progress centrifugally.
Magnetic Resonance Angiography and VenographyAnjan Dangal
Introduction to MR Angiography and Venography Procedure of Brain . Includes Indication, MRI protocol, planning and anatomy as well as brief intoduction to physics behind MRA and MRV principle.
This document discusses imaging in medial temporal lobe epilepsy. It begins by explaining why MRI is important for detecting epileptogenic lesions in refractory cases. It then describes the anatomy of medial temporal lobe structures like the hippocampus and amygdala. The document discusses how hippocampal sclerosis appears on MRI, including features like gliosis, neuronal loss, and atrophy. It also covers other imaging modalities that can help lateralize the seizure focus, such as hippocampal volumetry, relaxometry, MRS, PET, and SPECT. In conclusion, MRI is the best way to diagnose mesial temporal sclerosis by identifying hippocampal hyperintensity and atrophy.
Imaging in neurology - normal MR Angio and VenographyNeurologyKota
There are two main types of MR angiography (MRA): contrast-enhanced (CE) MRA and non-contrast enhanced MRA, which includes time-of-flight (TOF) MRA and phase contrast (PC) MRA. CE MRA uses an injected gadolinium contrast agent and is faster than non-contrast MRA. TOF MRA detects blood flow without contrast but is susceptible to artifacts. PC MRA measures blood velocity and flow direction and can quantify blood flow. MR venography (MRV) uses similar techniques as MRA to image veins and is useful for detecting cerebral venous thrombosis. Common applications of MRA and MRV include evaluation of aneurysms, neck vessels, and cerebral
This chapter defines an epileptic seizure as transient abnormal neuronal activity in the brain. Around 5% of people experience seizures in their lifetime, with incidence highest in infants and elderly adults. Epilepsy is defined as recurrent seizures and the consequences of this condition. A diagnosis of epilepsy can be made after one seizure if EEG or MRI findings indicate increased epileptogenicity. Drug-resistant epilepsy persists despite adequate treatment with two tolerated anti-seizure medications. Seizure freedom requires being seizure-free for at least one year while on medication.
The document discusses various central nervous system infections, how they can be classified, their routes of entry and imaging appearances. It covers congenital infections including TORCH infections, acquired pyogenic infections such as meningitis, abscesses and ventriculitis. It also discusses viral, parasitic and fungal infections of the CNS. For each type of infection, the causative pathogens, locations, presentations and characteristic imaging findings are outlined.
The document summarizes the cerebral venous system, including:
- Cerebral veins drain the brain and lack valves, emptying into dural venous sinuses between the dura layers.
- The major dural venous sinuses include the superior and inferior sagittal, straight, occipital, transverse, sigmoid, and cavernous sinuses.
- The sinuses receive blood from cerebral veins and CSF from arachnoid villi before draining into the internal jugular veins.
Demyelinating and inflammatory diseasesShivam Batra
Demyelinating diseases involve disruption of myelin in the central and peripheral nervous systems. Multiple sclerosis (MS) is an autoimmune demyelinating disease characterized by inflammatory demyelinating lesions throughout the white matter. MRI is useful for diagnosing MS by demonstrating dissemination of lesions in space and time. Typical MS lesions on MRI appear as oval or linear hyperintensities on T2/FLAIR images surrounding medullary veins and involving the periventricular white matter, corpus callosum, brainstem, and cortical gray matter.
Imaging of demyelinating diseases finalSunil Kumar
This document discusses pathology and imaging of multiple sclerosis. It begins by describing the composition and development of myelin and white matter in the central nervous system. It then discusses multiple sclerosis as a primary demyelinating disease characterized by plaques seen on imaging. The clinical manifestations and variants of multiple sclerosis are described. Imaging findings on CT, MRI, T1-weighted, T2-weighted, and FLAIR sequences are provided, showing the appearance of lesions in white matter and ability to detect acute inflammation.
This document summarizes various pediatric white matter diseases seen on imaging. It begins by describing normal myelination patterns in the neonatal brain. It then divides white matter diseases into dysmyelinating, demyelinating, and hypomyelinating categories. Several specific diseases are described in detail, including their characteristic imaging findings. Metachromatic leukodystrophy, Krabbe disease, mucopolysaccharidoses, peroxisomal disorders, adrenoleukodystrophy, Zellweger syndrome, and mitochondrial diseases like MELAS are discussed. Common imaging patterns include abnormal white matter signal, involvement of specific tracts, sparing of U-fibers, and enhancement patterns.
This document summarizes multiple sclerosis (MS), a chronic inflammatory demyelinating disease of the central nervous system. It discusses the etiology, pathology, clinical presentation, imaging features, diagnostic criteria, variants, and differential diagnosis of MS. Key points include: MS is characterized by inflammatory demyelinating lesions ("plaques") in the brain and spinal cord; risk factors include genetic and environmental factors; clinical presentation varies from relapsing-remitting to progressive forms; MRI is important for diagnosis and demonstrates disseminated hyperintense lesions; and differential diagnosis includes ADEM, Susac syndrome, and CNS tumors.
Multiple sclerosis is a demyelinating disease of the central nervous system characterized by lesions in the brain and spinal cord. MRI is useful for diagnosis. MS lesions typically appear as hyperintense areas on T2-weighted MRI and may enhance with contrast. They have a predilection for the periventricular white matter, corpus callosum, brainstem and spinal cord. The diagnostic criteria for MS involves demonstrating lesions disseminated in time and space on MRI or other evidence of an inflammatory demyelinating process.
Diffuse astrocytomas, also referred to as low-grade infiltrative astrocytomas, are designated as WHO II tumours of the brain.
The term diffuse infiltrating means there is no identifiable border between the tumour and normal brain tissue, even though the borders may appear well-marginated on imaging.
Multiple sclerosis is a disease that destroys myelin in the central nervous system. It most commonly affects people between 20-40 years old. The disease has an uneven global distribution and both genetic and environmental factors influence risk. Symptoms vary depending on location of lesions in the brain and spinal cord but may include visual issues, motor problems, sensory changes, and more. The disease typically follows a relapsing-remitting course with exacerbations followed by periods of remission or stabilization. Diagnosis involves ruling out other possibilities and may include MRI, lumbar puncture, and examination of symptoms and clinical course.
This document discusses focal cortical dysplasia, a type of neuronal migration disorder caused by abnormal proliferation and migration of neurons during brain development. It begins by providing background on normal cortical development. It then defines focal cortical dysplasia and describes its characteristics and appearance on imaging studies. The document notes that focal cortical dysplasia is a common cause of epilepsy, especially in pediatric patients. Surgical treatment can successfully treat epilepsy in many patients with focal cortical dysplasia if the abnormal cortex is fully resected.
1. The document discusses various white matter disorders that can be seen on MRI imaging. It focuses on demyelinating diseases like multiple sclerosis (MS), neuromyelitis optica (NMO), acute disseminated encephalomyelitis (ADEM), and other related conditions.
2. MS is characterized by well-defined white matter lesions that are often ovoid or perpendicular to the ventricles. Lesions can also be seen in the corpus callosum, brainstem, spinal cord, and optic nerves. MRI is important for diagnosis and monitoring of MS.
3. NMO preferentially affects the spinal cord and optic nerves. Lesions are often longitudinally extensive in the spinal
references:
Phases and Phenotypes of Multiple Sclerosis By Orhun H. Kantarci, MD.
Diagnosis of Multiple Sclerosis By Jiwon Oh, MD, PhD, FRCPC
Nature Reviews | Disease Primers
Multiple sclerosis Massimo Filippi1,2*, Amit Bar- Or3, Fredrik Piehl4,5,6, Paolo Preziosa1,2, Alessandra Solari7, Sandra Vukusic8 and Maria A. Rocca1,2
Neuromyelitis optica spectrum disorders (NMOSD) is an autoimmune disorder of young adults' results from astrocytic aquaporin–4 (AQP–4) channelopathy. The AQP–4 IgG antibodies may be present in the context of some paraneoplastic disorders which should be suspected when NMOSD occurs in elderly patients.
This document discusses demyelinating diseases, specifically multiple sclerosis. It describes the key features of MS, including that it is a chronic disease characterized by episodes of focal neurological disorders that remit and recur over many years. The diagnosis can be uncertain early on but becomes more accurate as lesions disseminate throughout the central nervous system. The document outlines the pathogenesis of MS, which involves an autoimmune reaction triggered by viral infection that results in destruction of the myelin sheath. Diagnostics include examination of cerebrospinal fluid and MRI of the brain and spine to detect lesions. Variants such as acute disseminated encephalomyelitis are also mentioned.
1. MRI plays a key role in evaluating suspected myelopathy by identifying the cause and extent of spinal cord abnormalities.
2. Common artifacts that can mimic cord abnormalities include Gibbs artifacts and pulsation artifacts. Extrinsic compression is also considered.
3. For intrinsic cord lesions, the differential depends on acute vs nonacute onset. Acute causes include demyelination, ischemia, infection while nonacute includes neoplasm, metabolic, neurodegenerative, and inflammatory diseases.
This document discusses white matter disorders and imaging findings in multiple sclerosis (MS). It begins by describing white matter composition and how diseased myelin appears on MRI. It then covers the spectrum of white matter disorders, including demyelinating diseases like MS and dysmyelinating diseases. MS is discussed in depth, including its classification as an autoimmune demyelinating disease, prevalence, clinical presentation, and characteristic MRI findings like lesions in periventricular white matter, corpus callosum, brainstem, and spinal cord. Variants of MS like tumefactive demyelinating lesions, Marburg variant, and Balo concentric sclerosis are also summarized.
Primary brain tumors are a diverse group of neoplasms that can arise from different cells in the central nervous system. The most common primary brain tumor in adults is brain metastasis. Meningiomas are the most common non-malignant primary brain tumor, followed by pituitary and nerve sheath tumors. Gliomas account for 75% of malignant brain tumors, over half of which are glioblastomas. Primary brain tumors are classified and graded according to the WHO system, with grade I being low proliferative potential and grade IV being most malignant. Clinical features vary depending on tumor location but often include headaches, nausea, seizures, and focal neurological deficits.
Primary brain tumours are a diverse group of neoplasm arising from different cells of the central nervous system.
It accounts for about 2% of all cancers with an overall annual incidence of 22 per 1,00,000 population.
Most common brain tumour in adults is Brain Metastasis.
This document discusses several phakomatoses or neurocutaneous syndromes characterized by hamartomas of the skin, eye, central nervous system and other organs. It provides details on the clinical features, genetics, systemic and ophthalmic manifestations as well as management of specific conditions like Neurofibromatosis types 1 and 2, Von Hippel-Lindau disease, Tuberous sclerosis, Sturge-Weber syndrome, and Ataxia telangiectasia. Key aspects like characteristic tumors, genetic mutations, diagnostic criteria and treatment approaches are highlighted for each discussed syndrome.
epidemiology and pathophysiology of multiple sclerosis Balqees Majali
Multiple sclerosis (MS) is a chronic inflammatory disease that affects the central nervous system. It has four clinical forms and is more common in females than males. The exact cause is unknown but is believed to involve both genetic and environmental factors. Pathologically, MS is characterized by lesions throughout the white matter of the brain and spinal cord caused by inflammation and the loss of myelin. These lesions can be either actively demyelinating or chronically demyelinated. While the disease course and prognosis can vary between individuals, it generally involves periods of relapse followed by remission or a progressive decline over time.
Multiple sclerosis: Introduction, Risk Factors, Diagnosis and TreatmentEnriqueAlvarez93
Introduction about Multiple Sclerosis.
Risk factors affect to Multiple Sclerosis.
When to Suspect Multiple Sclerosis.
Evaluation and Diagnosis of Multiple Sclerosis.
How to treatment of Multiple Sclerosis.
Treatment of Multiple Sclerosis with Monoclonal Antibody.
TEST BANK For Community Health Nursing A Canadian Perspective, 5th Edition by...Donc Test
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Histololgy of Female Reproductive System.pptxAyeshaZaid1
Dive into an in-depth exploration of the histological structure of female reproductive system with this comprehensive lecture. Presented by Dr. Ayesha Irfan, Assistant Professor of Anatomy, this presentation covers the Gross anatomy and functional histology of the female reproductive organs. Ideal for students, educators, and anyone interested in medical science, this lecture provides clear explanations, detailed diagrams, and valuable insights into female reproductive system. Enhance your knowledge and understanding of this essential aspect of human biology.
Osteoporosis - Definition , Evaluation and Management .pdfJim Jacob Roy
Osteoporosis is an increasing cause of morbidity among the elderly.
In this document , a brief outline of osteoporosis is given , including the risk factors of osteoporosis fractures , the indications for testing bone mineral density and the management of osteoporosis
Does Over-Masturbation Contribute to Chronic Prostatitis.pptxwalterHu5
In some case, your chronic prostatitis may be related to over-masturbation. Generally, natural medicine Diuretic and Anti-inflammatory Pill can help mee get a cure.
Adhd Medication Shortage Uk - trinexpharmacy.comreignlana06
The UK is currently facing a Adhd Medication Shortage Uk, which has left many patients and their families grappling with uncertainty and frustration. ADHD, or Attention Deficit Hyperactivity Disorder, is a chronic condition that requires consistent medication to manage effectively. This shortage has highlighted the critical role these medications play in the daily lives of those affected by ADHD. Contact : +1 (747) 209 – 3649 E-mail : sales@trinexpharmacy.com
Recomendações da OMS sobre cuidados maternos e neonatais para uma experiência pós-natal positiva.
Em consonância com os ODS – Objetivos do Desenvolvimento Sustentável e a Estratégia Global para a Saúde das Mulheres, Crianças e Adolescentes, e aplicando uma abordagem baseada nos direitos humanos, os esforços de cuidados pós-natais devem expandir-se para além da cobertura e da simples sobrevivência, de modo a incluir cuidados de qualidade.
Estas diretrizes visam melhorar a qualidade dos cuidados pós-natais essenciais e de rotina prestados às mulheres e aos recém-nascidos, com o objetivo final de melhorar a saúde e o bem-estar materno e neonatal.
Uma “experiência pós-natal positiva” é um resultado importante para todas as mulheres que dão à luz e para os seus recém-nascidos, estabelecendo as bases para a melhoria da saúde e do bem-estar a curto e longo prazo. Uma experiência pós-natal positiva é definida como aquela em que as mulheres, pessoas que gestam, os recém-nascidos, os casais, os pais, os cuidadores e as famílias recebem informação consistente, garantia e apoio de profissionais de saúde motivados; e onde um sistema de saúde flexível e com recursos reconheça as necessidades das mulheres e dos bebês e respeite o seu contexto cultural.
Estas diretrizes consolidadas apresentam algumas recomendações novas e já bem fundamentadas sobre cuidados pós-natais de rotina para mulheres e neonatos que recebem cuidados no pós-parto em unidades de saúde ou na comunidade, independentemente dos recursos disponíveis.
É fornecido um conjunto abrangente de recomendações para cuidados durante o período puerperal, com ênfase nos cuidados essenciais que todas as mulheres e recém-nascidos devem receber, e com a devida atenção à qualidade dos cuidados; isto é, a entrega e a experiência do cuidado recebido. Estas diretrizes atualizam e ampliam as recomendações da OMS de 2014 sobre cuidados pós-natais da mãe e do recém-nascido e complementam as atuais diretrizes da OMS sobre a gestão de complicações pós-natais.
O estabelecimento da amamentação e o manejo das principais intercorrências é contemplada.
Recomendamos muito.
Vamos discutir essas recomendações no nosso curso de pós-graduação em Aleitamento no Instituto Ciclos.
Esta publicação só está disponível em inglês até o momento.
Prof. Marcus Renato de Carvalho
www.agostodourado.com
Basavarajeeyam is an important text for ayurvedic physician belonging to andhra pradehs. It is a popular compendium in various parts of our country as well as in andhra pradesh. The content of the text was presented in sanskrit and telugu language (Bilingual). One of the most famous book in ayurvedic pharmaceutics and therapeutics. This book contains 25 chapters called as prakaranas. Many rasaoushadis were explained, pioneer of dhatu druti, nadi pareeksha, mutra pareeksha etc. Belongs to the period of 15-16 century. New diseases like upadamsha, phiranga rogas are explained.
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These lecture slides, by Dr Sidra Arshad, offer a quick overview of the physiological basis of a normal electrocardiogram.
Learning objectives:
1. Define an electrocardiogram (ECG) and electrocardiography
2. Describe how dipoles generated by the heart produce the waveforms of the ECG
3. Describe the components of a normal electrocardiogram of a typical bipolar lead (limb II)
4. Differentiate between intervals and segments
5. Enlist some common indications for obtaining an ECG
6. Describe the flow of current around the heart during the cardiac cycle
7. Discuss the placement and polarity of the leads of electrocardiograph
8. Describe the normal electrocardiograms recorded from the limb leads and explain the physiological basis of the different records that are obtained
9. Define mean electrical vector (axis) of the heart and give the normal range
10. Define the mean QRS vector
11. Describe the axes of leads (hexagonal reference system)
12. Comprehend the vectorial analysis of the normal ECG
13. Determine the mean electrical axis of the ventricular QRS and appreciate the mean axis deviation
14. Explain the concepts of current of injury, J point, and their significance
Study Resources:
1. Chapter 11, Guyton and Hall Textbook of Medical Physiology, 14th edition
2. Chapter 9, Human Physiology - From Cells to Systems, Lauralee Sherwood, 9th edition
3. Chapter 29, Ganong’s Review of Medical Physiology, 26th edition
4. Electrocardiogram, StatPearls - https://www.ncbi.nlm.nih.gov/books/NBK549803/
5. ECG in Medical Practice by ABM Abdullah, 4th edition
6. Chapter 3, Cardiology Explained, https://www.ncbi.nlm.nih.gov/books/NBK2214/
7. ECG Basics, http://www.nataliescasebook.com/tag/e-c-g-basics
Muktapishti is a traditional Ayurvedic preparation made from Shoditha Mukta (Purified Pearl), is believed to help regulate thyroid function and reduce symptoms of hyperthyroidism due to its cooling and balancing properties. Clinical evidence on its efficacy remains limited, necessitating further research to validate its therapeutic benefits.
- Video recording of this lecture in English language: https://youtu.be/kqbnxVAZs-0
- Video recording of this lecture in Arabic language: https://youtu.be/SINlygW1Mpc
- Link to download the book free: https://nephrotube.blogspot.com/p/nephrotube-nephrology-books.html
- Link to NephroTube website: www.NephroTube.com
- Link to NephroTube social media accounts: https://nephrotube.blogspot.com/p/join-nephrotube-on-social-media.html
2. NORMAL MYELINATION
After normal myelination in utero, myelination of the neonatal brain is far from complete.
The first myelination is seen as early as the 16th week of gestation, but only really takes off from the
24th week1.
It does not reach maturity until 2 years or so. It correlates very closely to developmental milestones 3.
The progression of myelination is predictable and abides by a few simple general rules; myelination progresses
from:
1. central to peripheral
2. caudal to rostral
3. dorsal to ventral
4. sensory then motor
3. Myelination pattern on MR imaging
Myelination of the brain during infancy progresses in an orderly and predictable fashion.
At birth only certain structures are myelinated
dorsal brainstem
ventrolateral thalamus
lentiform nuclei
central corticospinal tracts
posterior portion of posterior limb of internal capsule
Subsequently different parts become myelinated, the first change is increase in T1 signal, and later decrease in T2
2 - 3 months : anterior limb of internal capsule becomes T1 bright
3 months : cerebellar white matter tracts becomes T1 bright
3 - 6 months : splenium of corpus callosum becomes T2 dark
6 months : genu of corpus callosum becomes T1 bright
8 months : subcortical white matter becomes T1 bright
8 months : genu of corpus callosum becomes T2 dark
11 months : anterior limb of internal capsule becomes T2 dark
1 year 2 months : occipital white matter becomes T2 dark
1 year 4 months : frontal white matter becomes T2 dark
1 1/2 years : majority of white matter becomes T2 dark (except terminal myelination zones adjacent to frontal
horns and periatrial regions)
2 years : almost all of white matter becomes T2 dark
8. • A wide number of diseases may affect brain white matter. This presentation will
attempt to address this wide topic by dividing brain white matter lesions into three
categories:
• 1. Demyelinating Diseases
• 2. Non-demyelinating Diseases of Adults
• 3. Dysmyelinating Disorders of Childhood
9. Demyelinating Diseases
Due to loss of myelin in previously normal white matter regions.
Multiple sclerosis (MS) is a relatively common acquired chronic relapsing demyelinating disease involving the central
nervous system. It is by definition disseminated not only in space (i.e. multiple lesions), but also in time (i.e. lesions are of
different age).
A number of clinical variants are recognised, each with specific imaging findings and clinical presentation. They include:
• classic multiple scleroris (Charcot type)
• tumefactive multiple sclerosis
• acute malignant Marburg type
• Schilder type (diffuse cerebral sclerosis)
• Balo concentric sclerosis (BCS)
Epidemiology
Presentation is usually between adolescence and the sixth decade, with a peak at approximately 35 years of age 12. There is a
strong, well recognised female predilection with a F:M ratio of 2-3:1.
Multiple sclerosis has a fascinating geographic distribution: it is rarely found in equatorial regions, with incidence gradually
increasing with distance from the equator
10. Clinical presentation is both highly variable acutely, as a result of varying plaque location as well as over time, with a
number of patterns of longitudinal disease being described 11-12:
1.relapsing–remitting
1. most common (70% of cases)
2. patients exhibit periodic symptoms with complete recovery (early on)
2.secondary progressive
1. approximately 85% of patients with relapsing-remitting MS eventually enter a secondarily progressive phase
3.primary progressive
1. uncommon (10% of cases)
2. patients do not have remissions, with neurological deterioration being relentless
4.progressive with relapses
5.benign multiple sclerosis
1. 15-50% of cases
2. defined as patients who remain functionally active for over 15 years
As is evident from this list, there is overlap, and in some cases patients can drift from one pattern to another.
Symptoms may be sensory or motor or mixed, including cranial nerve involvement, e.g.trigeminal neuralgia or optic
neuritis.
11. Pathology
The exact aetiology is poorly known although it is believed to have both genetic and acquired contributory components.
MS is believed to result from a cellular mediated autoimmune response against ones own myelin components, with loss of
oligodendrocytes, with little or no axonal degeneration.
Demyelination occurs in discrete foci, termed plaques which range in size from a few millimetres to a few centimeters and
are typically perivenular.
Each lesion goes through three pathological stages:
•early acute stage (active plaques)
• active myelin break down
• plaques appear pink and swollen
•subacute stage
• plaques become paler in colour ("chalky")
• abundant macrophages
•chronic stage (inactive plaques/gliosis)
• little or no myelin breakdown
• gliosis with associated volume loss
• appear grey/translucent
Patients serum IgG levels tend to be elevated and CSF analysis commonly shows oligoclonal bands
Associations
•a strong association with HLA-DR2 class II has been identified.
12. Radiographic features
Plaques can occur anywhere in the central nervous system. They are typically ovoid in
shape and perivenular in distribution.
CT
CT features are usually non-specific, and significant change may be seen on MRI with
an essentially normal CT scan. Features that may be present include:
•plaques can be homogeneously hypo attenuating
•brain atrophy may be evident in with long standing chronic MS
•some plaques may show contrast enhancement in the active phase
13. MRI
•T1
• lesions are typically iso- to hypointense (chronic)
• callososeptal interface may have multiple small hypointense lesions (Venus necklace) or the corpus callosum may
merely appear thinned 11
•T2: lesions are typically hyperintense.
•FLAIR
• lesions are typically hyperintense
• when arranged perpendicular to lateral ventricles, extending radially outward (best seen on parasagittal images)
they are termed Dawson fingers
• FLAIR is more sensitive than T2 in detection of juxtracortical and periventricular plaques while T2 is more
sensitive in infratentorial lesions.
•T1 C+ (Gd)
• active lesions show enhancement
• enhancement is often incomplete around the periphery (open ring sign)
•DWI/ADC: active plaques may demonstrate restricted diffusion 10-11
•MR spectroscopy: may show reduced NAA peaks within plaques
•double inversion recovery DIR: a new sequence that suppress both CSF and white matter signal and better delineation of
the plaques.
14. Location of the plaques can be
• infratentorial,
• deep white matter,
• periventricular,
• juxtacortical or
• mixed white matter-grey matter lesions.
Even on a single scan, some features are helpful in predicting relapsing-
remitting vs progressive disease.
Features favouring progressive disease include:
• large numerous plaques
• hypo intense T1 lesions
15. McDonald's criteria are MRI criteria used in the diagnosis of multiple sclerosis improves sensitivity from 46-
74%.
The diagnosis of multiple sclerosis requires establishing disease disseminated in both space and time.
• Dissemination in space
Dissemination in space requires ≥1 T2 bright lesions in two or more of the following locations 1:
• periventricular
• juxtacortical
• infratentorial
• spinal cord
if a patient has a brainstem/spinal cord syndrome, the symptomatic lesion(s) are excluded from the
criteria, not contributing to the lesion count
• Dissemination in time
Dissemination in time can be established in one of two ways:
• a new lesion when compared to a previous scan (irrespective of timing)
T2 bright lesion and/or gadolinium enhancing
• presence of asymptomatic enhancing lesion and a non-enhancing T2 bright lesion on any one scan.
16. Primary progressive multiple sclerosis (PPMS)
In addition to the above criteria, the diagnosis of primary progressive multiple sclerosis has also been
revised.
The diagnosis now requires:
• ≥1 year of disease progression (this can be determined either prospectively or retrospectively)
•plus two of the following three criteria
• brain dissemination in space ( ≥1 T2 bright lesions in ≥1 of juxtacortical, periventricular,
infratentorial areas)
• spinal cord dissemination in space (≥2 T2 bright lesions)
• positive CSF (oligoclonal bands and/or elevated IgG index)
17. 10. Advanced MR Imaging:
• A number of advanced MR imaging techniques, including diffusion imaging, MR spectroscopy
and magnetization transfer imaging have been used to better understand MS. For the most part,
these techniques have been used to diagnose MS but to better understand physiological changes
involved in disease progression.
• Diffusion tensor imaging (DTI) is an example of a technique that can help to better understand
whether normal-appearing white matter in MS patients is, in fact, normal.
• Studies using DTI have shown that normal-appearing white matter adjacent to plaques is very
abnormal in terms of diminished anisotropy values (correlating with loss of integrity of white
matter pathways). Even white matter distant from MS plaques can be seen to be similarly
altered.
18. 31-year-old man with a 10- year history of relapsing-remitting neurologic symptoms
19. Callosal Involvement with multiple sclerosis in 48-year-old woman with clinically definite
multiple sclerosis for 20 years.
21. Typical cerebral lesions of multiple
sclerosis in 64-year-old woman with
sudden onset of diplopia and ataxia
Multiple sclerosis lesion in brainstem
of 38-year-old man with bilateral
weakness and sensory symptoms in
lower extremities
22. Multiple sclerosis in 42-year-old woman with clinically definite
multiple sclerosis but no acute symptoms.
24. The differential diagnosis is dependent on the location and appearance of demyelination.
For classic (Charcot type) MS the differential can be divided into intracranial and spinal involvement.
For intracranial disease the differential includes almost all other demyelinating disease as well as:
•CNS fungal infection (e.g. Cryptococcus neoformans ) patients tend to be immunocompromised
•mucopolysaccharidosis (e.g. Hurler disease): congenital and occurs in a younger age group
•Susac syndrome
•CNS manifestations of primary antiphospholipid syndrome.
For spinal involvement the following should be considered:
•transverse myelitis
•infection
•spinal cord tumours, e.g. astrocytomas
25. Acute disseminated encephalomyelitis (ADEM)
• Can occur either on a post-infectious or post-vaccinial basis.
• The history of either of these precipitating factors is important in making the diagnosis.
• The disease can be seen in both adults and children. Compared to children, onset in adults is more often
seen as a more widespread CNS syndrome with impaired consciousness.
• Mean age of onset in childhood is approximately 7 years.
• In approximately 80%, one of the following events in the preceding 3 weeks can be found:
• upper respiratory illness or nonspecific fever (60%);
• specific viral or bacterial illness (20%); and
• immunization (10%).
• The most common infections to precede this disorder are measles, rubella and chickenpox. Neurological
illness typically progresses over the course of a week.
26. Imaging Findings:
• Typically bilateral, asymmetric lesions in central white matter varying in size from
many mm to several cm.
• Solitary, confluent or multiple lesions involving only one hemisphere can be seen in
a minority of cases.
• Thalamic or basal ganglia lesions in 25%
• Contrast enhancement seen in about 25% of cases
• Lesions are seen on MR imaging of the spinal cord in only about 1/3 of cases of
myelopathy
• On follow-up MR imaging weeks to months later, 36% have normal studies, 60%
have persistent but usually smaller lesions and 5% have new lesions.
27. MRI is far more sensitive than CT:
•T2: demonstrates regions of high signal, with surrounding oedema typically situated in subcortical
locations; the thalami and brainstem can also be involved
•T1 C+ (Gd): punctate, ring or arc enhancement (open ring sign) is often demonstrated along the leading
edge of inflammation; absence of enhancement does not exclude the diagnosis
•DWI: there can be peripheral restricted diffusion; the center of the lesion, although high on T2 and low
on T1 does not have increased restriction on DWI (c.f.cerebral abscess); nor does it demonstrate absent
signal on DWI as one would expect from a cyst, this is due to increase in extra cellular water in the region
of demyelination.
Magnetization transfer may help distinguish ADEM from MS, in that normal appearing brain (on T2
weighted images) has normal magnetization transfer ratio (MTR) and normal diffusivity, whereas in MS
both measurements are significantly decreased 3.
33. II. Non-demyelinating White Matter Diseases of Adults
1. Posterior Reversible Encephalopathy Syndrome (PRES)-
This syndrome was formerly known as hypertensive encephalopathy, but it has recently been recognized
that it can be caused by a number of entities other than simply systemic hypertension. The syndrome is an
emergency condition because patients can proceed to cerebral infarction and death if not appropriately
treated.
Treatment consists of reversal of hypertension (if present) or removal of causative agents in other cases.
The syndrome typically occurs in the following settings:
- acute rise in systemic blood pressure, which may be only moderate in degree
- pre-eclampsia or eclampsia
- following treatment with a variety of immunosuppressive agents, including cyclosporine A, cisplatin and
tacrolimus.
The pathophysiological mechanism is thought to be development of vasogenic edema due to loss of
autoregulation within cerebral blood vessels.
35. On unenhanced CT, regions of hypodensity predominating within the posterior half of the brain and
generally involving white matter up to the gray-white junction are seen.
On MR:
• T1- hypointense and T2 hyperintense lesions.
• No contrast enhancement.
• Cortical regions can occasionally be involved.
• The predilection for involvement of the posterior white matter is thought to be due to decreased
innervation of arteries of these regions by autonomic fibers compared to the remainder of the cerebral
circulation.
• On diffusion-weighted images, lesions often appear isointense, rather than having the hypointense
signal expected in vasogenic edema.
• This finding is most likely due to the net effect of a combination of elevated apparent diffusion
coefficient values on diffusion weighted images (due to vasogenic edema) and increased signal intensity
due to T2 prolongation effects (so-called “T2 shine-through effect”).
36. PRES
A 50-year-old woman 6 months post liver transplant experienced a generalized seizure and unresponsiveness. Blood
pressure at the time of the toxic event fluctuated markedly with a range between 106 and 200 mm Hg systolic and 54 and
80 mm Hg diastolic.
37. A 36-year-old man with severe type 1 diabetes and recurrent septic arthritis of the shoulder requiring frequent
debridement presented with several days of headache, nausea, and visual changes along with hypertension. Blood
pressure at toxicity was 184/111 mm Hg.
38. PROGRESSIVE MULTIFOCAL LEUKOENCEPHELOPATHY (PML)
• It is probably the best known virally induced demyelinating disease.
• It is caused by reactivation of a latent Papova virus (the JC virus) infection.
• Though generally seen in immunocompromised patients, it is found to have a strong association with
AIDS.
• The patient clinically presents with hemiparesis, homonymous hemianopia and altered mentation.
• MR is more sensitive than CT and is the imaging modality of choice in PML.
• MR reveals increased signal intensity in the subcortical or periventricular white matter of parieto
occipital region.
• Multifocal distribution pattern is seen which may be unilateral or more often bilateral and
asymmetric.
• There is absence of mass effect and enhancement due to the paucity of perivenous inflammation.
• The subcortical lesions result in a scalloped appearance due to the involvement of subcortical U
fibres.
• PML is commonly seen to involve the posterior fossa also.
42. HIV ENCEPHALOPATHY
• Human retroviruses like HIV are known to cause white matter changes which may be difficult to assess
subjectively especially in the early stages of the disease.
• HIV encephalopathy is a progressive subcortical dementia that is a form of subacute encephalitis.
• The most common neurological manifestation would be subacute encephalopathy presenting as dementia and
global cognitive impairment.
• Though CT and MRI are relatively insensitive in detecting microglial nodules early in the course of the
disease, they are very sensitive in the detection of secondary parenchymal changes.
• The hallmarks of the disease are cortical atrophy and diffuse white matter changes.
43. • The white matter demyelination is diffuse symmetric periventricular isointense on T1 and with no mass
effect or contrast enhancement.
• Cortical atrophy which indirectly suggests the involvement of cortex is the most frequent finding.
• Lesions in white matter may extend to the basal ganglia and cortex with disease progression.
• Clinical and radiological studies have shown a major contribution of basal ganglia dysfunction in the
pathogenesis of HIV dementia.
• Lesions may also be located in the brain stem, cerebellum and spinal cord.
• White matter changes in HIV is quite nonspecific and mimics PML and CMV encephalitis.
47. HERPES SIMPLEX ENCEHPALITIS (HSE) :
• HSV type 1 viral infection is the most common cause of fatal sporadic encephalitis.
• It is thought to result from reactivation of latent infection in the Gasserian ganglion thus explaining the
predilection of the disease for the temporal lobes.
• Clinical symptoms include nonspecific alteration in mental status, fever and focal neurological deficits.
EEG shows activity localized to the temporal lobe.
• Polymerase chain reaction (PCR) is a rapid way of diagnosis from the CSF but the definite diagnosis is
by brain biopsy.
• Prompt regression of symptoms seen with acyclovir therapy and hence early MRI diagnosis is essential
as antiviral therapy significantly reduces the mortality.
48. MRI
Affected areas however have a similar appearance, in terms of signal characteristics:
• T1
• may show general oedema in affected region
• if complicated by sub acute haemorrhage there may be areas of hyper intense signal
• T1 C+ (Gd)
• enhancement is usually absent early on
• later enhancement is variable in pattern 5
• gyral enhancement
• leptomeningeal enhancement
• ring enhancement
• diffuse enhancement
• T2
• hyperintensity of affected white matter and cortex
• more established haemorrhagic components may be hypo intense.
• DWI / ADC
• more sensitive than T2 weighted images
• restricted diffusion is common due to cytotoxic oedema
• GE / SWI - may demonstrate blooming if haemorrhagic (rare in neonates, common in older patients)
49. This 33 year-old female patient presented with agitation, confusion, mutism, and fever.
50. Vascular-
A. CADASIL- Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and
Leukoencephalopathy (CADASIL) is an autosomal dominant vascular dementia, linked to a gene on
chromosome 19, which presents with multiple lacunar and subcortical white matter infarctions. There
is disproportionate cortical hypometabolism. Presenile dementia and migraines develop in the third-
to-fourth decades of life.
B. Vasculitis- can caused by a wide spectrum of entities, including drug abuse, collagen vascular diseases
(e.g. systemic lupus erythematosus), granulomatous processes (e.g. sarcoidosis), and infectious causes
(e.g. syphilis).
51. The patient, a 16-year-old girl, presented with headache, optic neuritis, and fatigue.
52. MRI
• widespread confluent white matter
hyperintensities 2.
• More circumscribed hyperintense lesions are also
seen in the basal ganglia, thalamus and pons 3.
• Although the subcortical white matter can be
diffusely involved, the frontal (93%) and temporal
(86%) lobes and subinsular white matter (93%) are
classical 2.
• There is relative sparing of the occipital and
orbitofrontal subcortical white matter 2,subcortical
U-fibers and cortex
CADASIL:
53. Post-therapeutic-
This condition can follow some types of chemotherapy causing necrotizing
leukoencephalopathy (e.g., methotrexate), immunosuppressive agents (e.g.
cyclosporin A) and radiation therapy.
Radiation injury can occur at any point during the post-treatment period. In the acute
period (first few months), this is manifested clinically by hypersomnolence, and
usually has no CT or MR findings.
Early injury (occurring within the first year) is usually marked by encephalopathy,
often with focal white matter lesions on CT and MR imaging.
54. Hemorrhagic radiation injury, asymptomatic.
MR images through temporal lobes in patient who had received helium ion irradiation for nasopharyngeal
carcinoma 3 years earlier.
56. LYSOSOMAL STORAGE DISORDERS:
Lysosomes are membrane-bound cell organelles that contain a variety of hydrolytic enzymes and
aid in the digestion of phagocytosed particles.
When the activity of a specific lysosomal enzyme is deficient, a lysosomal storage disorder may result.
These disorders are classified according to what materials show abnormal accumulation in the
lysosomes (eg, sphingolipidosis, glycoproteinosis, mucopolysaccharidosis, mucolipidosis).
The underlying disorder may be diagnosed clinically with assay for the enzyme deficiency or abnormal
accumulation of material.
57. Metachromatic Leukodystrophy
Metachromatic leukodystrophy is an autosomal recessive disorder caused by a deficiency
of the lysosomal enzyme arylsulfatase A.
This enzyme is necessary for the normal metabolism of sulfatides, which are important
constituents of the myelin sheath. In metachromatic leukodystrophy, sulfatides
accumulate in various tissues, including the brain, peripheral nerves, kidneys, liver, and
gallbladder. The accumulation of sulfatides within glial cells and neurons causes the
characteristic metachromatic reaction.
Metachromatic leukodystrophy is diagnosed biochemically on the basis of an abnormally
low level of arylsulfatase A in peripheral blood leukocytes and in urine.
58. Three different types of metachromatic leukodystrophy are recognized according to
patient’s age at onset:
1. late infantile,
2. juvenile, and
3. adult.
The most common type is late infantile metachromatic leukodystrophy, which usually
manifests in children between 12 and 18 months of age and is characterized by motor
signs of peripheral neuropathy followed by deterioration in intellect, speech, and
coordination.
Within 2 years of onset, gait disturbance, quadriplegia, blindness, and decerebrate
posturing may be seen. Death occurs 6 months to 4 years after onset of symptoms.
59. • At T2-weighted MR imaging, metachromatic leukodystrophy manifests as symmetric confluent
areas of high signal intensity in the periventricular white matter with sparing of the subcortical
U fibers (Fig 1a).
• No enhancement is evident at computed tomography (CT) or MR imaging (Fig 1b).
• The tigroid and “leopard skin” patterns of demyelination, which suggest sparing of the
perivascular white matter, can be seen in the periventricular white matter and centrum
semiovale (Fig 2).
• The corpus callosum, internal capsule, and corticospinal tracts are also frequently involved.
• The cerebellar white matter may appear hyperintense at T2-weighted MR imaging.
• In the later stage of metachromatic leukodystrophy, corticosubcortical atrophy often occurs,
particularly when the subcortical white matter is involved.
63. Krabbe Disease
Krabbe disease, or globoid cell leukodystrophy, is an autosomal recessive disorder
caused by a deficiency of galactocerebroside -galactosidase, an enzyme that degrades
cerebroside, a normal constituent of myelin.
As soon as myelination commences and myelin turnover becomes necessary,
cerebrosides accumulate in the lysosomes of macrophages within the white matter,
forming the globoid cells characteristic of the disease.
The genetic basis for the enzyme defect in Krabbe disease has been traced to a faulty
gene on chromosome 14.
The diagnosis is made by demonstrating a deficiency of the enzyme in peripheral blood
leukocytes.
64. The clinical manifestation of Krabbe disease varies with patient age at onset.
Infantile, late infantile, juvenile, and adult forms are recognized.
The infantile form is the most common and manifests as hyperirritability, increased muscle
tone, fever, and developmental arrest and regression.
Disease progression is characterized by cognitive decline, myoclonus and opisthotonus, and
nystagmus.
Typically, Krabbe disease is rapidly progressive and fatal.
65. • CT performed during the initial stage of the disease may demonstrate symmetric high-attenuation foci
in the thalami, caudate nuclei, corona radiata, posterior limbs of the internal capsule, and brainstem.
• The centrum semiovale, periventricular white matter, and deep gray matter demonstrate high signal
intensity at T2-weighted MR imaging.
• The subcortical U fibers are spared until late in the disease course.
• Abnormal areas of hyperintensity may be seen in the cerebellum and pyramidal tract early in the
disease course.
• Severe progressive atrophy occurs as the disease advances.
• Mild enhancement has been described at MR imaging at the junction of the subcortical U fibers with
the underlying abnormal white matter despite the absence of an inflammatory reaction in the
pathologic specimen.
• Optic nerve hypertrophy may also occur in Krabbe disease.
68. Mucopolysaccharidosis
Mucopolysaccharidosis is caused by a deficiency of the various lysosomal enzymes involved in the
degradation of glycosaminoglycans.
Brain imaging is usually performed when hydrocephalus or spinal cord compression is suspected.
• CT and MR imaging usually reveal delayed myelination, atrophy, varying degrees of hydrocephalus, and
white matter changes.
• These changes manifest as diffuse low-attenuation areas within the cerebral hemispheric white matter at
CT and as focal and diffuse areas of low signal intensity on T1-weighted MR images and high signal
intensity on T2-weighted images (Fig 6).
• The sharply defined foci are commonly present in the corpus callosum, basal ganglia, and cerebral white
matter.
• They are isointense relative to cerebrospinal fluid with all imaging sequences and probably represent
mucopolysaccharide-filled perivascular spaces (16).
• As the disease progresses, the lesions become larger and more diffuse, reflecting the development of
infarcts and demyelination.
71. Peroxisomal Disorders
Peroxisomes are small, intracellular organelles that are involved in the oxidation of very long chain and
monounsaturated fatty acids.
Peroxisomal enzymes are also involved in gluconeogenesis, lysine metabolism, and glutaric acid
metabolism.
Peroxisomal disorders are inborn errors in cellular metabolism caused by a deficiency of one or more
of these enzymes.
ALD is a leukodystrophy caused by a single peroxisomal enzyme deficiency, whereas Zellweger
syndrome and neonatal ALD are caused by multiple enzyme defects.
72. X-linked Adrenoleukodystrophy
• X-linked ALD is a rare peroxisomal disorder that affects the white matter of the central nervous system, adrenal
cortex, and testes (17).
• The genetic defect responsible for X-linked ALD is located in Xq28, the terminal segment of the long arm of the X
chromosome.
• X-linked ALD is caused by a deficiency of a single enzyme, acyl-CoA synthesase. This deficiency prevents the
breakdown of very long chain fatty acids, which then accumulate in tissue and plasma (17).
• In the early stages of classic ALD, symmetric white matter demyelination occurs in the peritrigonal regions and
extends across the corpus callosum splenium (Figs 7, 8).
73. • Demyelination then spreads outward and cephalad as a confluent lesion until most of the cerebral white
matter is affected.
• The subcortical white matter is relatively spared in the early stage but often becomes involved in the later
stages.
• The affected cerebral white matter typically has three different zones.
The central or inner zone appears moderately hypointense at T1-weighted MR imaging and
markedly hyperintense at T2-weighted imaging. This zone corresponds to irreversible gliosis and
scarring.
The intermediate zone represents active inflammation and breakdown in the blood-brain barrier. At
T2-weighted MR imaging, this zone may appear isointense or slightly hypointense and readily
enhances after intravenous administration of contrast material (Fig 7c).
The peripheral or outer zone represents the leading edge of active demyelination; it appears
moderately hyperintense at T2-weighted MR imaging and demonstrates no enhancement (19–21).
• Symmetric abnormal areas of hyperintensity along the descending pyramidal tract are common at T2-
weighted MR imaging (Fig 9a, 9b) (21).
• Atypical cases with unilateral or predominantly frontal lobe involvement may occur (Fig 10) (22).
77. Zellweger Syndrome
Zellweger syndrome, or cerebrohepatorenal syndrome, is an autosomal recessive disorder caused
by multiple enzyme defects and characterized by liver dysfunction with jaundice, marked mental
retardation, weakness, hypotonia, and craniofacial dysmorphism (23).
It may lead to death in early childhood. The severity of disease varies and is determined by the
degree of peroxisomal activity.
Ultrasonography of the kidneys reveals small cortical cysts.
MR imaging reveals diffuse demyelination with abnormal gyration that is most severe in the
perisylvian and perirolandic regions (Fig 11). The pattern of gyral abnormality is similar to that
seen in polymicrogyria or pachygyria.
79. Diseases Caused by Mitochondrial Dysfunction
• Mitochondrial encephalopathy comprises a heterogeneous group of neuromuscular
disorders caused by a proved or proposed defect in the oxidative metabolic
pathways of energy production, probably owing to a structural or functional
mitochondrial defect (24–27).
• Some reasonably well-defined disorders include MELAS syndrome, Kearn-Sayre
syndrome, Leigh disease, and MERRF syndrome (Table 1).
80. MELAS Syndrome
(mitochondrial encephalopathy with lactic acidosis and stroke-like
episodes)
• Patients with MELAS syndrome usually appear healthy at birth with normal early development, then
exhibit delayed growth, episodic vomiting, seizures, and recurrent cerebral injuries resembling stroke.
• These stroke like events, probably the result of a proliferation of dysfunctional mitochondria in the
smooth muscle cells of small arteries, may give rise to either permanent or reversible deficits.
• The disease course is progressive with periodic acute exacerbation (27–29).
• Serum and cerebrospinal fluid lactate levels are usually elevated.
81. General features include multiple infarcts involving multiple vascular territories which may be either symmetrical
or asymmetrical. Parieto-occipital and parieto-temporal involvement is most common. Basal ganglia calcification
is seen. These features are more prominent feature in older patients. Atrophy also present.
MRI
chronic infarcts
• involving multiple vascular territories
• may be either symmetrical or asymmetrical
• parieto-occipital and parieto-temporal (most common)
acute infarcts
• swollen gyri with increased T2 signal
• may enhance
• subcortical white matter involved
• increased signal on DWI (T2 shine through) with little if any change on ADC: thought to
represent vasogenic rather than cytotoxic oedema 3
MR spectroscopy : may demonstrate elevated lactate 3
84. Leighs Disease
• Leigh disease, or subacute necrotizing encephalomyelopathy, is an inherited, progressive,
neurodegenerative disease of infancy or early childhood with variable course and prognosis (30).
• Affected infants and children typically present with hypotonia, psychomotor deterioration, ataxia,
ophthalmoplegia, ptosis, dystonia, and swallowing difficulties.
• Characteristic pathologic abnormalities include micro-cystic cavitation, vascular proliferation,
neuronal loss, and demyelination of the midbrain, basal ganglia, and cerebellar dentate nuclei and,
occasionally, of the cerebral white matter (31).
Typical MR imaging findings include symmetric putaminal involvement, which may be associated
with abnormalities of the caudate nuclei, globus pallidi, thalami, and brainstem and, less frequently, of
the cerebral cortex (Fig 13).
The cerebral white matter is rarely affected.
Enhancement may be seen at MR imaging and may correspond to the onset of acute necrosis (31).
87. Canavan Disease
Canavan disease, or spongiform leukodystrophy, is an autosomal recessive disorder
caused by a deficiency of N-acetylaspartylase, which results in an accumulation of N-
acetylaspartic acid in the urine, plasma, and brain.
It usually manifests in early infancy as hypotonia followed by spasticity, cortical
blindness, and macrocephaly (2).
Canavan disease is a rapidly progressive illness with a mean survival time of 3 years.
Definite diagnosis usually requires brain biopsy or autopsy.
88. • Canavan disease is characterized at pathologic analysis by extensive vacuolization that initially
involves the subcortical white matter, then spreads to the deep white matter (Fig 14c).
• Electron microscopy demonstrates increased water content within the glial tissue, described as
having the texture of a wet sponge, as well as dysmyelination (32,33).
• T1-weighted MR imaging demonstrates symmetric areas of homogeneous, diffuse low signal
intensity throughout the white matter, whereas T2-weighted imaging shows nearly homogeneous
high signal intensity throughout the white matter.
• The subcortical U fibers are preferentially affected early in the course of the disease.
• In rapidly progressive cases, the internal and external capsules are involved, and the cerebellar
white matter is usually affected as well.
• As the disease progresses, atrophy becomes conspicuous.
91. Pelizaeus-Merzbacher Disease
• PMD has been linked to a severe deficiency of myelin-specific lipids caused by a lack of proteolipid
protein.
• This myelin-specific proteolipid protein is necessary for oligodendrocyte differentiation and survival.
• PMD has traditionally been divided into classic and connatal forms (34,35).
• Classic PMD begins during late infancy with X-linked recessive inheritance.
• Connatal PMD is a rarer and more severe variant that begins at birth or in early infancy. The connatal
form has either X-linked or autosomal recessive inheritance.
• Patients with all forms of PMD present with clinical signs and symptoms including abnormal eye
movements, nystagmus, extrapyramidal hyperkinesias, spasticity, and slow psychomotor
development.
92. T2-weighted MR imaging reveals a nearly total lack of normal myelination with
diffuse high signal intensity that extends peripherally to involve the subcortical U
fibers, along with early involvement of the internal capsule (Fig 15).
Sometimes, the white matter demonstrates high signal intensity with small scattered
foci of more normal signal intensity, a finding that may reflect the tigroid pattern of
myelination (36).
At pathologic analysis, the involved white matter demonstrates patchy distribution of
dysmyelination with preserved myelin islands.
These findings are frequently seen along the perivascular area, thus giving rise to the
characteristic tigroid appearance (35,36).
94. Alexander Disease
• Alexander disease, or fibrinoid leukodystrophy, is characterized at pathologic analysis by massive
deposition of Rosenthal fibers (dense, eosinophilic, rodlike cytoplasmic inclusions found in astrocytes)
in the subependymal, subpial, and perivascular regions (Fig 16b) (37).
• Three clinical subgroups are recognized.
• The infantile subgroup is characterized by early onset of macrocephaly, psychomotor retardation, and
seizure. Death occurs within 2–3 years. The diagnosis is made on the basis of a combination of
macrocephaly, early onset of clinical findings, and imaging findings, but definite diagnosis usually
requires brain biopsy or autopsy.
• In the juvenile subgroup, onset of symptoms occurs between 7 and 14 years of age. Progressive bulbar
symptoms with spasticity are common.
• In the adult subgroup, onset of symptoms occurs between the 2nd and 7th decades. The symptoms and
disease course can be indistinguishable from those of classic multiple sclerosis in the adult subgroup.
95. • Alexander disease has a predilection for the frontal lobe white matter early in its course. CT
demonstrates low attenuation in the deep frontal lobe white matter.
• Enhancement is often seen near the tips of the frontal horns early in the disease course (39). The
characteristic frontal lobe areas of hyperintensity are seen at T2-weighted MR imaging.
• These hyperintense areas progress posteriorly to the parietal white matter and internal and external
capsules (Fig 16a).
• The subcortical white matter is affected early in the disease course.
• In the late stages of the disease, cysts may develop in affected regions of the brain.
97. Early MR imaging studies in a patient with presumed juvenile Alexander disease, obtained at the age of 4
years.
98. VANISHING WHITE MATTER DISEASE
Childhood ataxia with central hypomyelination (CACH)
• Vanishing white matter disease is an autosomal recessive disease, due to mutations in all five gene
subunits encoding the eukaryotic translation initiation factor eIF2B.
• This factor is a regulator of the final step of proteins production, in which mRNA is translated into
proteins under circumstances of mild stress.
• Clinically, after an initial normal or mildly delayed psychomotor development, patients show a
neurological picture whose course is chronic and progressive with additional episodes of rapid
deterioration following minor infection and minor head trauma that may lead to lethargy or coma.
• Cerebellar ataxia and spasticity are the main neurological signs.
• Optic atrophy and seizures may occur.
• Mental impairment is relatively mild, and usually less severe than motor dysfunction.
• Pathological abnormalities primarily involve the axons.
• It has been suggested that an abnormal stress reaction may cause deposition of denaturated proteins
within oligodendrocytes leading to hypomyelination, loss of myelin, and subsequent cystic degeneration
99. • MRI of vanishing white matter disease (VWMD) also has a characteristic pattern.
• It shows features of confluent cystic degeneration, white matter signal appears CSF-like with
progressive loss of white matter over time on proton density and FLAIR images.
• Regions of relative sparing include the U-fibers, corpus callosum, internal capsule, and the
anterior commissure.
• The cerebellar white matter and brainstem show variable degrees of involvement but do not
undergo cystic degeneration.
• MRS shows complete absence of all metabolites within cystic white matter.
• Few authors opine that MRI of the brain is usually diagnostic in VWM. It shows an abnormal
signal of all or almost all cerebral white matter with relatively spared U-fibers in some cases and
cystic degeneration of the affected white matter that is replaced by fluid.
101. MEGALENCEPHALIC LEUKOENCEPHALOPATHY
• Megalencephalic leukoencephalopathy (MLC) with subcortical cysts is a rare disease first
described by van der Knaap et al, in 1995.
• Megalencephalic leukoencephalopathy with subcortical cysts is a relatively new entity of
neurodegenerative disorder characterized by infantile onset macrocephaly, cerebral
leukoencephalopathy and mild neurological symptoms and an extremely slow course of
functional deterioration.
• It is a rare disease with autosomal recessive inheritance.
• In typical cases, the MR findings are often diagnostic of MLC.
102. • MR shows 'swollen white matter' and diffuse supratentorial symmetrical white matter
changes in the cerebral hemispheres with relative sparing of central white matter
structures like the corpus callosum, internal capsule, and brain stem.
• Subcortical cysts are almost always present in the anterior temporal region and are also
frequently noted in frontoparietal region.
• Grey matter is usually spared.
• Gradually the white matter swelling decreases and cerebral atrophy may set in.
• The subcortical cysts may increase in size and number
104. Predominance of the white matter abnormalities
Alexander: frontal WM ALD: parieto occipital WM KSS: sparing of PV WM MLD: PV & deep WM, leopard skin
Cortical neuronal disorder:
illdefined, broad PV rim
Hypo/ VMD: diffuse
cerebral WM
Cerebrotendinous
Xanthomatosis:
cerebellar> cerebral
Adult onset ALD: middle
cerebellar peduncles
105. Conclusions
There are many different white matter diseases, each of which has distinctive features.
MR imaging is highly sensitive in determining the presence and assessing the severity
of underlying white matter abnormalities.
Although the findings are often non-specific, systematic analysis of the finer details of
disease involvement may permit a narrower differential diagnosis, which the clinician
can then further refine with knowledge of patient history, clinical testing, and
metabolic analysis.
MR imaging has also been extensively used to monitor the natural progression of
various white matter disorders and the response to therapy.
Inferior cerebellar peduncles are bright on Tl images, but middle cerebellar peduncles remain unmyelinated, isointense to cerebral white matter & dark on Tl images. Dorsal brainstem is relatively hyperintense on Tl images compared with ventral brainstem.
Image at level of internal capsule shows hyperintensity of posterior limb compared with anterior limb. Lateral thalamus is also bright compared with remainder of thalamus.
Cerebellum has a nearly adult appearance by three months. Dorsal brain stem remains slightly hyperintense compared with ventral brainstem.
Image at level of internal capsule shows high signal in posterior limb & early, subtle high signal in anterior limb of internal capsule. Corpus callosum remains unmyelinated, but splenium will show high signal by approximately four months. Deep white matter begins myelinating around three months, appearing first in deep occipital white matter.
Image at level of internal capsule shows hyperintensity (bright) in genu & splenium of corpus callosum. Internal capsule is hyperintense throughout. At birth, only posterior limb is bright, but by three months, anterior limb is also bright.
Image at level of internal capsule shows near adult appearance on Tl images. White matter of internal capsule & corpus callosum is hyperintense compared with basal ganglia & thalamus, similar to an adult. Deep & subcortical white matter of frontal lobes appears unmyelinated compared with occipital lobes.
Image at level of internal capsule shows adult appearance on Tl images. White matter of internal capsule & corpus callosum is hyperintense compared with basal ganglia & thalamus. Globus pallidus is distinguishable as slightly hyperintense compared with putamen located laterally.
Image at level of internal capsule shows adult appearance of basal ganglia, thalamus & white matter. Corpus callosum has an adult appearance on Tl images by six months while internal capsule has adult appearance by three months.
Of note neuromyelitis optica (Devic disease) was considered a variant but is now recognised as a distinct entity.
A, First echo of T2-weighted MR sequence shows several ovoid lesions with long axes perpendicular to ventricular walls.
B, TI-weighted MR image shows hypointense lesions.
Callosal Involvement with multiple sclerosis in 48-year-old woman with clinically definite multiple sclerosis for 20 years.
A, TI-weighted midline s.gfttal MR image shows diffuse callosal atrophy.
B, Inner callosal hyperlntensfty, and multiple confluent periventricular lesions, are shown on first echo of T2-welghted series.
T2-weighted MR image shows a large area of demyelination in upper cervical spinal cord and cervicomedullary junction.
Fig 1: Multiple periventricular lesions of multiple sclerosis, with lumpy-bumpy contour, on first echo of T2-weighted MR sequence.
Fig 2: T2- weighted MR image shows lesion of multiple sclerosis in right cerebral peduncle (arrow).
A, T1-weighted MR image after administration of gadopentetate dimeglumine shows several enhancing ovoid lesions in cerebral white maSer bilaterally. Contrast enhancement defines areas of acute inflammation.
B, First echo of T2-weighted series at same level as A shows many more white matter lesions, primarily penventricular in distribution.
Axial T2 and FLAIR periventricular hyperintensity is seen involving bilateral periventricular white matter, internal capsules and splenium of corpus callosum.
T1 (A) and T2 (B) images showing extensive bilateral demyelination of white matter of frontal lobes. This 20 year woman presented with bilateral vision loss, cerebellar manifestations, and with extensive pyramidal signs.
Diffuse ill defined abnormal signal intensities are seen predominantly involving the cortices of both cerebellar hemispheres ( R> L) and cerebellar vermis, appearing homogenously hyperintense on T2 and FLAIR, hypointense on T1WI. There is minimal mass effect seen in the form of effacement of the involved sulci.
Axial T1, Coronal T1 C+, Axial FLAIR images show T2: demonstrates regions of high signal, with surrounding oedema typically situated in subcortical locations; the thalami and brainstem can also be involved T1 C+ (Gd): punctate, ring or arc enhancement (open ring sign) is often demonstrated along the leading edge of inflammation; absence of enhancement does not exclude the diagnosis
FLAIR sequence obtained the day of the toxic event demonstrates moderate vasogenic edema in the subcortical white matter of the frontal (white arrows), parietal (white curved arrows), and occipital regions (white open arrows)
Thalamic involvement is present (black arrowhead, 2B) along with the upper margin of vasogenic edema present in the pons (black arrow, 2A).
FLAIR sequence demonstrates moderate vasogenic edema in the parietal (white curved arrows) and occipital (white open arrows) cortex and white matter with linear involvement along the superior frontal sulcus (white arrows) in the mid to posterior frontal lobes bilaterally. The extreme frontal poles seem normal (3B). This pattern is consistent with the superior frontal sulcus pattern. Cerebellar involvement (white arrowheads) is also present along with vasogenic edema at the junction of the pons and midbrain on the right (black arrowhead, 3A).
Axial T2 weighted images show multifocal bilateral parietal, occipital, periventricular, subcortical U fibres, deep gray matter hyperintensities. Sagittal T1 weighted image shows posterior hypointensities. Coronal T2 weighted image shows occipital and bilateral cerebellar white matter involvement.
Axial FLAIR MR image shows hyperintense signal in the left frontal and periventricular white matter consistent with progressive multifocal leukoencephalopathy.
A and B, Axial T2-weighted images show the right frontal lobe confluent hyperintense signal abnormalities extending from the periventricular white matter to the subcortical white matter, with much milder white matter involvement in the right parietal lobe and minimal involvement of the left cerebral hemisphere.
C, Axial T1-weighted image shows corresponding low signal abnormalities in the affected white matter on the right as well as minimal mass effect on cortical sulci.
D–F, Eight weeks later, marked progression of disease is evident with extension and increasing confluence of the right frontal and parietal lobe lesions, corpus callosum involvement, and greater involvement of the left cerebral hemisphere. Also seen is an increase in white matter low signal abnormality on axial T1-weighted image. Patient died 7 days after this study. (Biopsy tract is also evident in the right cerebral hemisphere.)
Proton spectroscopy holds promise in differentiating these conditions as reduced NAA/choline and NAA/Cr ratios correlated with diffuse abnormalities on MR rather than focal lesions.
Axial FLAIR and T2 weighted images show diffuse multifocal nonspecific hyperintensities in bilateral cerebral hemispheres.
Axial T1-weighted MR image shows Symmetrical and diffuse hyperintensity of the white matter is demonstrated on axial T2-weighted MR image (b); compatible with HIV encephalopathy.
beware of T2 shine through due to vasogenic odema
This axial diffusion-weighted MR image shows high signal in the cortex of the temporal lobes and insula, much more marked on the right. Corresponding ADC map confirms restricted cortical diffusion and shows increased diffusion in the underlying white matter.
An angiopathy of small and middle sized arteries is characteristic, without atherosclerosis or amyloid deposition 3. Diagnosis requires genetic identification of the mutated gene 4.
(C, D) Axial FLAIR images through the brainstem and the cerebral white matter show multiple foci of increased signal. Systemic serum markers for vasculitis were negative. Brain biopsy confirmed primary CNS vasculitis.
Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy (CADASIL)
A and B, T2-weighted, and enhanced T1-weighted, Increased signal in right temporal white matter is consistent with focal radiation injury or tumor spread. The largest of these has a complex appearance and shows enhancement following administration of gadopentetate dimeglumine. This lesion may consist of focal necrosis or metastatic tumor, as well as hemorrhagic cerebral injury.
T2-weighted MR image demonstrates bilateral confluent areas of high signal intensity in the periventricular white matter.
classic sparing of the sub-cortical U fibers (arrowheads).
Contrast material–enhanced MR image shows lack of enhancement in the demyelinated white matter, a finding that is characteristic of metachromatic leukodystrophy.
T2-weighted MR image shows numerous linear tubular structures with low signal intensity in a radiating (“tigroid”) pattern within the demyelinated deep white matter.
T2-weighted MR image shows a punctate (leopard skin) pattern in the demyelinated centrum semiovale, a finding that suggests sparing of the perivascular white matter.
On a contrast-enhanced T1-weighted MR image, the tigroid pattern seen in a appears as numerous punctate foci of enhancement (arrows) within the demyelinated white matter, which is unenhanced and has low signal intensity (leopard skin pattern).
T2-weighted MR image shows bilateral high-signal-intensity areas in the periventricular white matter with posterior predominance. The corpus callosum is also involved (arrows).
T2-weighted MR image obtained at a lower level shows involvement of the descending pyramidal tracts of the medulla (arrows) and deep cerebellar white matter.
Opisthotonus: spasm of the muscles causing backward arching of the head, neck, and spine, as in severe tetanus, some kinds of meningitis, and strychnine poisoning.
Axial T2-weighted MR image demonstrates symmetric high-signal-intensity areas in the deep white matter. The internal and external capsules are also involved (arrowheads).
Bilateral areas of abnormal signal intensity in the thalami (arrows) are also seen.
Axial T2 weighted images show bilateral parietal, occipital, deep gray matter and cerebellar white matter hyperintensities with spared subcortical white matter.
T1-weighted MR image shows multiple well-defined areas of low signal intensity in the central and subcortical white matter.
T2-weighted MR image demonstrates multiple well-defined areas of high signal intensity in the deep and subcortical white matter.
Brain T2-weighted axial MR image demonstrating WMA, mainly found in the retrotrigonal area of the brain, and cribriform changes in both periventricular and subcortical white matter. Note also the enlarged ventricles and cortical sulci in the frontal lobe.
T2-weighted MR image shows symmetric confluent demyelination in the peritrigonal white matter and the corpus callosum.
On a T1-weighted MR image, the peritrigonal lesions appear hypointense.
Gadolinium-enhanced T1-weighted MR image reveals a characteristic enhancement pattern in the intermediate zone (arrows) representing active demyelination and inflammation.
ALD involving the corpus callosum splenium. T2-weighted MR image shows the corpus callosum splenium with diffuse high signal intensity (arrows). No abnormality of the periventricular white matter is seen.
(a, b) T2-weighted MR images show demyelination of the internal capsule, descending pyramidal tract (arrows in a, long arrows in b), and cerebellar deep white matter (short arrows in b).
(c) Gadolinium-enhanced T1-weighted MR image shows bilateral enhancement of the internal capsule and descending pyramidal tracts (arrows).
T2-weighted MR image shows involvement predominantly of the frontal lobe white matter, genu of the corpus callosum, and anterior limbs of the internal capsule (arrows).
Gadolinium-enhanced T1-weighted MR image shows linear enhancement within the involved white matter and the anterior limbs of the internal capsule (arrows).
T2-weighted MR image shows extensive areas of diffuse high signal intensity in the white matter. The gyri are broad, the sulci are shallow, and there is incomplete branching of the subcortical white matter, findings that suggest a migration anomaly with pachygyria.
On a T1-weighted MR image, the white matter abnormalities demonstrate low signal intensity.
MELAS: mitochondrial encephalopathy with lactic acidosis and stroke-like episodes
Follow-up MR images may show resolution and sub-sequent reappearance of the abnormal areas.
increased signal intensity due to T2 prolongation effects (so-called “T2 shine-through effect”).
Initial T2-weighted MR image shows a high-signal-intensity lesion in the left occipital lobe (arrows). Prominent cortical sulci are seen in the right occipital lobe, a finding that suggests cortical atrophy.
On a contrast-enhanced T1-weighted MR image, the lesion demonstrates no enhancement.
Follow-up MR image obtained 15 months later shows another lesion in the left temporal area (arrowheads).
A, T2-weighted coronal image during an acute stroke like episode shows parasagittal bilateral hyperintense lesions (arrows) at the age of 8 years.
B, T2-weighted coronal image 2 months later shows that lesions have almost entirely resolved. Cerebellar atrophy is evident.
C, T2-weighted axial image 5 years later, during a prolonged seizure, shows a new hyperintense lesion in the left parietooccipital region (arrow).
Leigh disease in a 2-year-old boy.
T2-weighted MR image shows bilateral high-signal-intensity areas in the putamen and globus pallidus (arrows).
On a T1-weighted MR image, the lesions demonstrate low signal intensity (arrows).
Axial FLAIR images show hyperintense lesions in midbrain and pons posteriorly.
T2-weighted MR image shows extensive high-signal-intensity areas throughout the white matter, resulting in gyral expansion and cortical thinning. Striking demyelination of the subcortical U fibers is also noted.
T1-weighted MR image shows demyelinated white matter with low signal intensity.
Axial T2 weighted image shows high signal in white matter typically a diffuse bilateral cerebral involvement and sub cortical U fibres.
MR spectroscopy - markedly elevated NAA and NAA:creatine ratio
T2-weighted MR image reveals almost no myelination of the cerebral white matter. The sub-cortical white matter is also involved, as are the internal and external capsules (arrow-heads).
T2-weighted MR image shows symmetric demyelination in the frontal lobe white matter. The internal and external capsules and parietal white matter are also involved.
Photomicrograph of the pathologic specimen shows deposition of Rosenthal fibers (arrows).
A and B, Extensive cerebral white matter abnormalities are seen on these T2-weighted images (B), with sparing of the occipital U fibers (arrows, B). The signal abnormality is more prominent in the frontal than in the occipital white matter. There is an irregular periventricular rim of low signal intensity (arrowheads, B). The basal ganglia and thalamus have a mildly increased signal intensity.
Within the posterior fossa, signal abnormalities are seen in the central part of the medulla, the hilus of the dentate nucleus, and the cerebellar hemispheric white matter, characteristically with the normal dentate nucleus prominently visible in between (A).
Axial T2 weighted image shows diffuse white matter hyperintensity similar to CSF intensity extending from periventricular white matter to the subcortical arcuate fibres.
Axial FLAIR image shows white matter vanished and replaced by near-CSF intensity fluid.
Axial T1 weighted image shows diffuse white matter hypointensity similar to CSF intensity.
Axial T2, T1 and FLAIR images show diffuse swelling and T2 hyperintensity of bilateral cerebral white matter and posterior internal capsule is seen. Large subcortical cysts are seen in bilateral frontal lobes.
In addition small subcentrimeter cysts are seen in bilateral caudate and lentiform nuclei.
A. Alexander disease (A) presents in many patients with predominantly frontal white matter abnormalities. Note the additional slight signal abnormalities in the basal ganglia.
B. The most frequent presentation of the cerebral form of X-linked adrenoleukodystrophy (B) is with a lesion in the parieto-occipital white matter. Note that two zones can be distinguished within the lesion.
C. Kearns-Sayre syndrome (C) is one of the disorders characterized by predominantly subcortical white matter abnormalities and relative sparing of the periventricular white matter. The disease also displays signal abnormalities in the thalamus (C).
D. Metachromatic leukodystrophy (D) primarily affects the periventricular and deep cerebral white matter, whereas the U-fibers are relatively spared. The stripes with more normal signal within the abnormal white matter are typically seen in certain lysosomal storage disorders (D).
E. Cortical neuronal degenerative disorders often have an ill-defined, broad, periventricular rim of mildly abnormal signal, as shown here in juvenile neuronal ceroid lipofuscinosis (E).
F. Diffuse cerebral white matter abnormalities are seen in childhood ataxia with central hypomyelination/vanishing white matter (F).
G. In cerebrotendinous xanthomatosis (G), the cerebellar white matter is usually more affected than the cerebral white matter. The cerebellum often also contains areas of low signal (G).
H. In patients with autosomal dominant adult onset leukoencephalopathy related to a duplication of LMNB1 (H), involvement of the middle cerebellar peduncles is frequently seen.