1) The document discusses the anatomy and physiology of the brain and central nervous system. It describes the different parts of the brain including the cerebrum, cerebellum, diencephalon, and brainstem.
2) It then discusses various brain tumors including their classification, etiology, natural history, grading, pathology, and clinical presentations depending on location.
3) Diagnostic workup is outlined including MRI, CT, CSF examination and other imaging modalities to characterize brain tumors.
MRI - Imaging modality of first choice for depicting the anatomy and pathology of the brachial plexus.
MRI - very well demonstrate the anatomy due to its inherent contrast differences between the nerves with low signal intensity and the surrounding hyperintense fat on T1-weighted images.
Challenges:
Large field of view
Other heterogeneous tissue distribution including fat, muscles, and bones.
I LOVE NEUROSURGERY INITIATIVE: Spinal Tumorswalid maani
A comprehensive presentation about spinal tumors. Some concentration on anatomy. Discussion of presentation, diagnosis and management. Plenty of images.
This is the first lecture about the anatomy of the brainstem discussing the definition of the brainstem and the anatomical relations along with the external and internal parts (in general) and listing the major functions of brainstem. Then describing the medulla oblongata with its location, external and internal functions at different levels of sections. Lastly, this lectures discusses the most important clinical syndromes affecting the medulla oblongata.
MRI - Imaging modality of first choice for depicting the anatomy and pathology of the brachial plexus.
MRI - very well demonstrate the anatomy due to its inherent contrast differences between the nerves with low signal intensity and the surrounding hyperintense fat on T1-weighted images.
Challenges:
Large field of view
Other heterogeneous tissue distribution including fat, muscles, and bones.
I LOVE NEUROSURGERY INITIATIVE: Spinal Tumorswalid maani
A comprehensive presentation about spinal tumors. Some concentration on anatomy. Discussion of presentation, diagnosis and management. Plenty of images.
This is the first lecture about the anatomy of the brainstem discussing the definition of the brainstem and the anatomical relations along with the external and internal parts (in general) and listing the major functions of brainstem. Then describing the medulla oblongata with its location, external and internal functions at different levels of sections. Lastly, this lectures discusses the most important clinical syndromes affecting the medulla oblongata.
1.Anatomy of the Medulla
2. Introduction to Brainstem Anatomy of the brainstem includes ( midbrain-pons-medulla ) is very complicated !! •It connects spinal cord to the cerebrum. • The mid brain pons, and medulla are connected to cerebellum posteriorly. •1 - ascending an descending tracts that connect brain to spinal cord. •2 - cranial nerves nuclei and their connections •3 - Reticular formation •4 - others e.g (olivarynucleus in MO tapizusbody in pons and red nucleus in MB )
3. Medulla oblongata •The medulla oblongata is the part of the brainstem between the pons and spinal cord •It extends through the foramen magnum to the level of the atlas. •Medulla is vital for our function, without medulla we die. •Above the foramen magnum it is embraced dorsally by the cerebellar hemispheres. 1.The lower end which contains the upward continuation of the central canal of the spinal cord is the ‘closed part of the medulla’, 2.The upper end, where the canal comes to the surface as the lower part of the floor of the fourth ventricle, is the ‘open part’.
4. Medulla contd….. MO is lowest 3 cm of the brainstem •it extend from the ponto- medullary junction until plane below foramina magnum for about 0.5 cm. •Medulla spinalis have a central canal which prolonged into its lower half to open in the fourth ventricle at its upper half. •CSF is encircle the MO from outside ( subarachnoid space ) and inside ( central canal ). •MO is between the two lobes of cerebellum ( anterior cerebellar notch )
5. EXTERNAL FEATURES AND RELATIONS • 3Cm long. • Located at the caudal portion of brainstem • Upper limit is cerebello-pontine angle • Transverse plane that above C1 (suboccipital) intersects upper border of atlas dorsally and centre of dens ventrally marks lower limit
6. VENTRAL SURFACE • Ventral median fissure extends from foramen coecum to caudal end of pyramid decussation • Lateral to median fissure is pyramid • Lat to pyramid is the ventrolateral sulcus (VLS) • Hypoglossal nerve rootlets emerge from VLS • Lat to VLS is olive which contains inf olivary nucleus • Inferior cerebellar peduncle connects medulla with cerebellum and forms side wall of caudal half of fourth ventricle
7. Ventral Surface Pyramid: Swelling on each side of anterior median fissure. • Composed of bundles of nerve fibers, (corticospinal fibers) originate from the precentral gyrus of the cerebral cortex. • The pyramids taper inferiorly and majority of the descending fibers decussate to the opposite side. Olive: • Olives are the anterolateral oval elevations produced by the underlying inferior olivary nuclei. • From the groove between the pyramid and the olive, the rootlets of the hypoglossal nerve emerge
8. LATERAL ASPECT • Roots of glossopharyngeal , vagus and cranial division of accessory nerves are attached to the medulla dorsal to olive.
9. Dorsal surface At dorsal surface of closed part of medulla, gracile and cuneate fasciculi continue from the spinal
You can watch the video on my you tube channel: https://youtu.be/I0FaX-iQfa0
Medulla oblongata or more simply medulla is part of brain stem which forms base of the brain stem. It contains pyramid, olive and above pyramidal structure, there is decussation of pyramids which explains why each part of brain controls opposite part of body. Adding to that medulla also has several nuclei which controls activity of cardiovascular system and respiratory system. Medulla also has nuclei for controlling reflexes of vomiting, swallowing, hiccuping, coughing and sneezing. It has also nuclei for test, hearing and balance. Medulla also contains nuclei of cranial nerve number VIII, IX, X, XI and XII.
1.Anatomy of the Medulla
2. Introduction to Brainstem Anatomy of the brainstem includes ( midbrain-pons-medulla ) is very complicated !! •It connects spinal cord to the cerebrum. • The mid brain pons, and medulla are connected to cerebellum posteriorly. •1 - ascending an descending tracts that connect brain to spinal cord. •2 - cranial nerves nuclei and their connections •3 - Reticular formation •4 - others e.g (olivarynucleus in MO tapizusbody in pons and red nucleus in MB )
3. Medulla oblongata •The medulla oblongata is the part of the brainstem between the pons and spinal cord •It extends through the foramen magnum to the level of the atlas. •Medulla is vital for our function, without medulla we die. •Above the foramen magnum it is embraced dorsally by the cerebellar hemispheres. 1.The lower end which contains the upward continuation of the central canal of the spinal cord is the ‘closed part of the medulla’, 2.The upper end, where the canal comes to the surface as the lower part of the floor of the fourth ventricle, is the ‘open part’.
4. Medulla contd….. MO is lowest 3 cm of the brainstem •it extend from the ponto- medullary junction until plane below foramina magnum for about 0.5 cm. •Medulla spinalis have a central canal which prolonged into its lower half to open in the fourth ventricle at its upper half. •CSF is encircle the MO from outside ( subarachnoid space ) and inside ( central canal ). •MO is between the two lobes of cerebellum ( anterior cerebellar notch )
5. EXTERNAL FEATURES AND RELATIONS • 3Cm long. • Located at the caudal portion of brainstem • Upper limit is cerebello-pontine angle • Transverse plane that above C1 (suboccipital) intersects upper border of atlas dorsally and centre of dens ventrally marks lower limit
6. VENTRAL SURFACE • Ventral median fissure extends from foramen coecum to caudal end of pyramid decussation • Lateral to median fissure is pyramid • Lat to pyramid is the ventrolateral sulcus (VLS) • Hypoglossal nerve rootlets emerge from VLS • Lat to VLS is olive which contains inf olivary nucleus • Inferior cerebellar peduncle connects medulla with cerebellum and forms side wall of caudal half of fourth ventricle
7. Ventral Surface Pyramid: Swelling on each side of anterior median fissure. • Composed of bundles of nerve fibers, (corticospinal fibers) originate from the precentral gyrus of the cerebral cortex. • The pyramids taper inferiorly and majority of the descending fibers decussate to the opposite side. Olive: • Olives are the anterolateral oval elevations produced by the underlying inferior olivary nuclei. • From the groove between the pyramid and the olive, the rootlets of the hypoglossal nerve emerge
8. LATERAL ASPECT • Roots of glossopharyngeal , vagus and cranial division of accessory nerves are attached to the medulla dorsal to olive.
9. Dorsal surface At dorsal surface of closed part of medulla, gracile and cuneate fasciculi continue from the spinal
You can watch the video on my you tube channel: https://youtu.be/I0FaX-iQfa0
Medulla oblongata or more simply medulla is part of brain stem which forms base of the brain stem. It contains pyramid, olive and above pyramidal structure, there is decussation of pyramids which explains why each part of brain controls opposite part of body. Adding to that medulla also has several nuclei which controls activity of cardiovascular system and respiratory system. Medulla also has nuclei for controlling reflexes of vomiting, swallowing, hiccuping, coughing and sneezing. It has also nuclei for test, hearing and balance. Medulla also contains nuclei of cranial nerve number VIII, IX, X, XI and XII.
This is the ppt that describes about organization of nerve in central nervous system. It also classify the nerves in various ways. Functions of different nerves and its characteristics are also described in this ppt.
this presentation consist of introduction to types of nerves, structure of nerve and cranial nerves. there is a detail description about, origin , course of the trigeminal nerve and its branches and the structures supplying the nerve. it also contains applied anatomy of the nerve and its importance of the nerve in oral and maxillofacial surgeries. a detail description about the examination of the trigeminal nerve is also mentioned in the presentation. hoping that it would be useful to the students and people seeking for knowledge about the trigeminal nerve.
cerebrovascular accidents - types, causes and its managementVarunMahajani
This PowerPoint presentation provides in-depth knowledge regarding cerebrovascular accidents types, stages of management, medical management, surgical management, nursing management, complications and their management
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These simplified slides by Dr. Sidra Arshad present an overview of the non-respiratory functions of the respiratory tract.
Learning objectives:
1. Enlist the non-respiratory functions of the respiratory tract
2. Briefly explain how these functions are carried out
3. Discuss the significance of dead space
4. Differentiate between minute ventilation and alveolar ventilation
5. Describe the cough and sneeze reflexes
Study Resources:
1. Chapter 39, Guyton and Hall Textbook of Medical Physiology, 14th edition
2. Chapter 34, Ganong’s Review of Medical Physiology, 26th edition
3. Chapter 17, Human Physiology by Lauralee Sherwood, 9th edition
4. Non-respiratory functions of the lungs https://academic.oup.com/bjaed/article/13/3/98/278874
These lecture slides, by Dr Sidra Arshad, offer a quick overview of 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 leads (limb II)
4. Differentiate between intervals and segments
5. Enlist some common indications for obtaining an ECG
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. ECG Basics, http://www.nataliescasebook.com/tag/e-c-g-basics
Title: Sense of Smell
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the primary categories of smells and the concept of odor blindness.
Explain the structure and location of the olfactory membrane and mucosa, including the types and roles of cells involved in olfaction.
Describe the pathway and mechanisms of olfactory signal transmission from the olfactory receptors to the brain.
Illustrate the biochemical cascade triggered by odorant binding to olfactory receptors, including the role of G-proteins and second messengers in generating an action potential.
Identify different types of olfactory disorders such as anosmia, hyposmia, hyperosmia, and dysosmia, including their potential causes.
Key Topics:
Olfactory Genes:
3% of the human genome accounts for olfactory genes.
400 genes for odorant receptors.
Olfactory Membrane:
Located in the superior part of the nasal cavity.
Medially: Folds downward along the superior septum.
Laterally: Folds over the superior turbinate and upper surface of the middle turbinate.
Total surface area: 5-10 square centimeters.
Olfactory Mucosa:
Olfactory Cells: Bipolar nerve cells derived from the CNS (100 million), with 4-25 olfactory cilia per cell.
Sustentacular Cells: Produce mucus and maintain ionic and molecular environment.
Basal Cells: Replace worn-out olfactory cells with an average lifespan of 1-2 months.
Bowman’s Gland: Secretes mucus.
Stimulation of Olfactory Cells:
Odorant dissolves in mucus and attaches to receptors on olfactory cilia.
Involves a cascade effect through G-proteins and second messengers, leading to depolarization and action potential generation in the olfactory nerve.
Quality of a Good Odorant:
Small (3-20 Carbon atoms), volatile, water-soluble, and lipid-soluble.
Facilitated by odorant-binding proteins in mucus.
Membrane Potential and Action Potential:
Resting membrane potential: -55mV.
Action potential frequency in the olfactory nerve increases with odorant strength.
Adaptation Towards the Sense of Smell:
Rapid adaptation within the first second, with further slow adaptation.
Psychological adaptation greater than receptor adaptation, involving feedback inhibition from the central nervous system.
Primary Sensations of Smell:
Camphoraceous, Musky, Floral, Pepperminty, Ethereal, Pungent, Putrid.
Odor Detection Threshold:
Examples: Hydrogen sulfide (0.0005 ppm), Methyl-mercaptan (0.002 ppm).
Some toxic substances are odorless at lethal concentrations.
Characteristics of Smell:
Odor blindness for single substances due to lack of appropriate receptor protein.
Behavioral and emotional influences of smell.
Transmission of Olfactory Signals:
From olfactory cells to glomeruli in the olfactory bulb, involving lateral inhibition.
Primitive, less old, and new olfactory systems with different path
Lung Cancer: Artificial Intelligence, Synergetics, Complex System Analysis, S...Oleg Kshivets
RESULTS: Overall life span (LS) was 2252.1±1742.5 days and cumulative 5-year survival (5YS) reached 73.2%, 10 years – 64.8%, 20 years – 42.5%. 513 LCP lived more than 5 years (LS=3124.6±1525.6 days), 148 LCP – more than 10 years (LS=5054.4±1504.1 days).199 LCP died because of LC (LS=562.7±374.5 days). 5YS of LCP after bi/lobectomies was significantly superior in comparison with LCP after pneumonectomies (78.1% vs.63.7%, P=0.00001 by log-rank test). AT significantly improved 5YS (66.3% vs. 34.8%) (P=0.00000 by log-rank test) only for LCP with N1-2. Cox modeling displayed that 5YS of LCP significantly depended on: phase transition (PT) early-invasive LC in terms of synergetics, PT N0—N12, cell ratio factors (ratio between cancer cells- CC and blood cells subpopulations), G1-3, histology, glucose, AT, blood cell circuit, prothrombin index, heparin tolerance, recalcification time (P=0.000-0.038). Neural networks, genetic algorithm selection and bootstrap simulation revealed relationships between 5YS and PT early-invasive LC (rank=1), PT N0—N12 (rank=2), thrombocytes/CC (3), erythrocytes/CC (4), eosinophils/CC (5), healthy cells/CC (6), lymphocytes/CC (7), segmented neutrophils/CC (8), stick neutrophils/CC (9), monocytes/CC (10); leucocytes/CC (11). Correct prediction of 5YS was 100% by neural networks computing (area under ROC curve=1.0; error=0.0).
CONCLUSIONS: 5YS of LCP after radical procedures significantly depended on: 1) PT early-invasive cancer; 2) PT N0--N12; 3) cell ratio factors; 4) blood cell circuit; 5) biochemical factors; 6) hemostasis system; 7) AT; 8) LC characteristics; 9) LC cell dynamics; 10) surgery type: lobectomy/pneumonectomy; 11) anthropometric data. Optimal diagnosis and treatment strategies for LC are: 1) screening and early detection of LC; 2) availability of experienced thoracic surgeons because of complexity of radical procedures; 3) aggressive en block surgery and adequate lymph node dissection for completeness; 4) precise prediction; 5) adjuvant chemoimmunoradiotherapy for LCP with unfavorable prognosis.
Ethanol (CH3CH2OH), or beverage alcohol, is a two-carbon alcohol
that is rapidly distributed in the body and brain. Ethanol alters many
neurochemical systems and has rewarding and addictive properties. It
is the oldest recreational drug and likely contributes to more morbidity,
mortality, and public health costs than all illicit drugs combined. The
5th edition of the Diagnostic and Statistical Manual of Mental Disorders
(DSM-5) integrates alcohol abuse and alcohol dependence into a single
disorder called alcohol use disorder (AUD), with mild, moderate,
and severe subclassifications (American Psychiatric Association, 2013).
In the DSM-5, all types of substance abuse and dependence have been
combined into a single substance use disorder (SUD) on a continuum
from mild to severe. A diagnosis of AUD requires that at least two of
the 11 DSM-5 behaviors be present within a 12-month period (mild
AUD: 2–3 criteria; moderate AUD: 4–5 criteria; severe AUD: 6–11 criteria).
The four main behavioral effects of AUD are impaired control over
drinking, negative social consequences, risky use, and altered physiological
effects (tolerance, withdrawal). This chapter presents an overview
of the prevalence and harmful consequences of AUD in the U.S.,
the systemic nature of the disease, neurocircuitry and stages of AUD,
comorbidities, fetal alcohol spectrum disorders, genetic risk factors, and
pharmacotherapies for AUD.
Ozempic: Preoperative Management of Patients on GLP-1 Receptor Agonists Saeid Safari
Preoperative Management of Patients on GLP-1 Receptor Agonists like Ozempic and Semiglutide
ASA GUIDELINE
NYSORA Guideline
2 Case Reports of Gastric Ultrasound
Tom Selleck Health: A Comprehensive Look at the Iconic Actor’s Wellness Journeygreendigital
Tom Selleck, an enduring figure in Hollywood. has captivated audiences for decades with his rugged charm, iconic moustache. and memorable roles in television and film. From his breakout role as Thomas Magnum in Magnum P.I. to his current portrayal of Frank Reagan in Blue Bloods. Selleck's career has spanned over 50 years. But beyond his professional achievements. fans have often been curious about Tom Selleck Health. especially as he has aged in the public eye.
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Introduction
Many have been interested in Tom Selleck health. not only because of his enduring presence on screen but also because of the challenges. and lifestyle choices he has faced and made over the years. This article delves into the various aspects of Tom Selleck health. exploring his fitness regimen, diet, mental health. and the challenges he has encountered as he ages. We'll look at how he maintains his well-being. the health issues he has faced, and his approach to ageing .
Early Life and Career
Childhood and Athletic Beginnings
Tom Selleck was born on January 29, 1945, in Detroit, Michigan, and grew up in Sherman Oaks, California. From an early age, he was involved in sports, particularly basketball. which played a significant role in his physical development. His athletic pursuits continued into college. where he attended the University of Southern California (USC) on a basketball scholarship. This early involvement in sports laid a strong foundation for his physical health and disciplined lifestyle.
Transition to Acting
Selleck's transition from an athlete to an actor came with its physical demands. His first significant role in "Magnum P.I." required him to perform various stunts and maintain a fit appearance. This role, which he played from 1980 to 1988. necessitated a rigorous fitness routine to meet the show's demands. setting the stage for his long-term commitment to health and wellness.
Fitness Regimen
Workout Routine
Tom Selleck health and fitness regimen has evolved. adapting to his changing roles and age. During his "Magnum, P.I." days. Selleck's workouts were intense and focused on building and maintaining muscle mass. His routine included weightlifting, cardiovascular exercises. and specific training for the stunts he performed on the show.
Selleck adjusted his fitness routine as he aged to suit his body's needs. Today, his workouts focus on maintaining flexibility, strength, and cardiovascular health. He incorporates low-impact exercises such as swimming, walking, and light weightlifting. This balanced approach helps him stay fit without putting undue strain on his joints and muscles.
Importance of Flexibility and Mobility
In recent years, Selleck has emphasized the importance of flexibility and mobility in his fitness regimen. Understanding the natural decline in muscle mass and joint flexibility with age. he includes stretching and yoga in his routine. These practices help prevent injuries, improve posture, and maintain mobilit
Pulmonary Thromboembolism - etilogy, types, medical- Surgical and nursing man...VarunMahajani
Disruption of blood supply to lung alveoli due to blockage of one or more pulmonary blood vessels is called as Pulmonary thromboembolism. In this presentation we will discuss its causes, types and its management in depth.
Pulmonary Thromboembolism - etilogy, types, medical- Surgical and nursing man...
Brain tumours seminar by dr pushpendra patel
1. Presented by – Dr. Pushpendra Kumar Patel
3rd year Post Graduate student
Dept. of Radiation Oncology
Regional cancer centre raipur
2. INTRODUCTION-
• A wide variety of tumours affect the brain and spine.
• Primary benign and malignant tumours arise from the various elements of the
CNS, including neurons, glia and meninges. Tumours metastasize to the CNS from
many primary sources.
• Presentation varies widely depending on relevant neuroanatomy. Prognosis
depends on histology and anatomy.
• Modern brain tumour centers use team approaches to CNS tumours, as patient
may require a combination of surgery, radiation therapy, chemotherapy and
research protocol enrollment.
3. ANATOMY OF BRAIN-
• Nervous system may be divided into-
Central nervous system –
1. Brain
2. Spinal cord
Peripheral nervous system-
1. Peripheral nerves
2. Ganglia
• The brain consist of
1. The cerebrum comprising 2 large cerebral hemisphere
2. The cerebellum
3. Diencephalon
4. Brainstem
- Midbrain
- Pons
- Medulla
4. Covering layers & CSF-
Central nervous system enveloped by- Duramatter (Pachymeninges)
Arachnoid & Piamatter (combined called as
Leptomeninges)
within them, there is subarachnoid space filled with cerebrospinal fluid.
CSF flows- Lateral ventricles
Foramen of monro
3rd ventricle
Aquiduct of sylvius (narrowest canal m.c. site of obstruction)
4th ventricle m.c location for tumor deposits
spinal canal
foramen of luschka & magendie venous circulation
6. THE CEREBRUM-
• The cerebrum made up of 2 cerebral hemisphere, partially separated from each
other by the median longitudinal fissure.
• The 2 hemisphere are connected to each other by corpus callosum.
• Each hemispere contains a cavity, called the lateral ventricle.
• Each cerebral hemisphere is divided into 4 lobes-
Frontal
Parietal
Occipital
Temporal
7. THE CEREBRUM-
Dural folds separate the two hemispheres of cerebrum (Falx cerebri) & the
cerebrum from the cerebellum & brainstem(Tentorium or Falx cerebelli)
Frontal & parietal lobes separated by sulcus – central sulcus
Frontal & temporal lobes are separated by – Sylvian fissure
Parietal & occipital lobes – calcarine sulcus
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24. Diencephalon
Dienchephalon consist of thalamus & pineal region
situated between the cerebrum & mesencephalon.
Lateral to thalamus there is internal capsule that
carries motor fibers from cortex to brainstem – spinal
cord.
Partners with the cerebrum and cerebellum to
1. Coordinate motor functions
2. Play a role in consciousness
3. Control and integrate the autonomic nervous
system
4. Regulate eating and thirst
5. Control body temperature and circadian
rhythm.
26. Brainstem
1. Midbrain-
contains tracks for nerve impulses between motor areas of the cerebral cortex to the
spinal cord. Some of the other functions that relay through the midbrain include
reflexes for the head, eyes and trunk response to visual stimuli, and impulses for
auditory stimuli (eg, the startle reflex)
27. Brainstem
2. Pons-
Serves as a bridge to connect areas of the brain to one another. The pons contains
areas that relay signals for voluntary movements, equilibrium information from the inner
ear, and areas that ( together with the medulla oblongata) help control breathing.
28. Brainstem
3. Medulla oblongata-
contains areas that control
key vital body functions:
• The cardiovascular center,
which regulates the rate
and force of the heartbeat
and the diameter of blood
vessels
• The respiratory center,
which adjust basic rhythm
of breathing.
• Reflexes for swallowing ,
sneezing, vomiting,
hiccupping, and coughing.
31. Dural venous sinus
• The cerebrum, cerebellum and
brainstem are drained by numerous
veins, which empty into the dural
venous sinuses.
• Dural venous sinuses lie between the
periosteal and meningeal layers of the
dura matter.
• All the dural venous sinuses ultimately
drain into the internal jugular vein.
• There are eleven venous sinuses in
total. The straight, superior, and inferior
sagittal sinuses are found in the falx
crebri of the dura matter.they converge
at the confluence of sinuses. The
straight sinus is a continuation of the
great cerebral and inferior saggital
sinus.
32. Dural venous sinus
• From ther confluence, the transverse
sinus continues bilaterally and curves
into sigmoid sinus to meet the
opening of the internal jugular vein.
• The cavernous sinus drains the
ophthalmic veins and can be found on
either side of the sella turcica. From
here, the blood returns to the internal
jugular vein via the superior or
inferior petrosal sinuses.
33. Tissue constituting nervous system
• The specialized cells that
constitute the nervous
system are called – neuron(
Neuron consist of cell body
gives off variable number of
processes – short branching
called dendrites and one
longer process axon.
• Neurons are supported by
special kind of connective
tissue called – neuroglia.
34. Neuroglial cells-
• Astrocytes
• Microglia
• Oligodendrocytes
Astrocytes:
These are star shaped cells present in all part
of the brain.concerned with nutrition and
blood brain barrier.
1. Fibrous astrocytes – present in white
matter
2. Protoplasmic astrocytes- present in grey
matter
Microglia:
These are the phagocytic cells which enters
the tissue of nervous system from blood.
Oligodendrocytes:
these are the cells forming myelin sheath
around the nerve fibres in central nervous
system.
35. Neuroglial cells-
Ependymal cells- columnar cells lining
the cavities of the CNS.
Schwann cells- mylinate the peripheral
system.
Satellite cells- cover the surface of
nerve cell bodies in sensory,
sympathetic and parasympathetic
ganglia.
40. Base of skull with clinically important foramen and
fissure-
The optic canals are
situated anteriorly in the
MCF.
They transmit the optic
nerves (CN II) and
ophthalmic arteries into
orbital cavities.
The superior orbital fissure
opens anteriorly into the
orbit. It transmits the CN
III, CN IV, ophthalmic
branch of the CN V1, CN
VI, ophthalmic veins and
sympathetic fibres.
41. Base of skull with clinically important foramen and
fissure-
The foramen rotundum opens into
the pterygopalatine fossa and
transmits the maxillary branch of the
trigeminal nerve.
The foamen ovale opens into the
infratemporal fossa, transmitting the
mandibular branche of trigeminal
nerve and accessory meningeal
artery.
The foramen spinosum also opens
into the infratemporal fossa. It
transmits the middle meningeal
artery, middle meningeal vein and a
meningeal branch of trigeminal nerve
(CN V3)
42. Base of skull with clinically important foramen and
fissure-
Hiatus for greater petrosal
nerve – transmit the greater
petrosal nerve(facial nerve)
Hiatus lesser petrosal nerve –
transmit the lesser petrosal
nerve (glossopharyngeal
nerve)
Carotid canal- located
posteriorly and medially to
the foramen ovale and it is
transversed by the internal
carotid artery.
The formen lacerum,wehich
is pierced by small blood
vessels.
43. Base of skull with clinically important foramen and
fissure-
Ct images-
44. Base of skull with clinically important foramen and
fissure-
Ct images-
45. Intracranial tumours-
• Although either benign or malignant, almost all brain tumours are
malignant in the sense that they may lead eventually to death if not
treated.
• In general, the incidence of primary brain tumours is higher in whites
than in blacks, and mortality Is higher in males than in females.
• It is the 20th most common malignancy worldwide and 14th most
common in india according to GLOBOCAN 2020 data.
• High mortility upto 75%.
46. Intracranial tumours-
• Intracranial tumours can be classified in different ways: primary versus secondary,
pediatric versus adult, by a cell of origin, or by location in the nervous system.
• Classification of brain tumor ( according to cell of origin)
Neuroepithelial tumor
• Glial cell origin: Astrocytoma, Oligodendroglioma, Ependymoma, Choroid plexus.
• Neuronal and mixed neuro-glial origin: Gangliocytoma, Neurocytoma, Papillary
gliomeuronal tumor, Rosette-forming glioneural tumor of the fourth ventricle.
• Embryonal tumors: Medulloblastoma, PNET.
Meningioma tumour (meningothelial cells, mesenchymal)
Tumors of hematopoietic system
• Lymphoma
• Plasmacytoma
Metastatic
48. Etiology
Occupational & environmental factors
• Prior exposure to ionizing and non-ionizing radiation (2.3% incidence of primary
brain tumors in children treated with PCI for acute leukemia.(a 22 fold increase
over expected)
• Farmers and petrochemical workers
• Chemical exposures (formaldehyde, vinyl chloride,acrylonitrile etc.)
• Cellular telephones- WHO classified radiofrequency electromagnetic fields those
emitted by wireless phones, as possibly carcinogens to humans based on limited
clinicians evidence. Increase incidence of glioma individual with greatest
cumulative lifetimes cell phone use (> 1620 hours in one study)
Hereditary syndromes
• Cowden, Turcot, Lynch & Li-Fraumeni (Gliomas)
• Gorlin(PNET), Neurofibromatosis type I & II (meningiomas, optiv nerve glioma,
schwannoma) & retinoblastoma.
• VHL (haemangioblastoma)
49. Natural history
Determined by location, grade & histology.
Majority of adult gliomas spread invasively with out forming natural capsule &
causes edema usually vasogenic but may be cytotoxic seen best on T2 weighted
images.
Edema is consequence of altered Blood-Brain-Barrier permeability.
Amount of edema is variable( in desending order- Mets, astrocytoma,
meningioma, oligodendroglioma.
High grade neoplasm metastasize by seeding the subarachnoid and ventricular
spaces. Because of gravity or flow.these metastatic deposits are often present in
the caudal portion of the spinal canal.
Tumors that have propensity for csf spread – medulloblastoma, germ cell tumors
& CNS lymphoma.
Extracranial mets from primary brain tumours are rare but can occure –
medulloblastoma, germonomas & high grade astrocytomas.
50. Grading of adult brain tumors
WHO grade I Low proliferative potential, a frequently discrete
nature, and the possibility of cure following surgical
resection alone.
WHO grade II Generally infiltrating and low in mitotic activity but
recur more frequently than grade I malignant tumor
after local therapy. Some tumor types tend to
progress to higher grades of malignancy.
WHO grade III Anaplastic histology & infiltrative, usually treated
with aggressive adjuvant therapy.
WHO grade IV Mitotically active, necrosis-prone, microvascular
proliferation & generally associated with a rapid pre
& post- operative progression & fatal outcomes,
usually treated with aggressive adjuvant therapy.
51. Pathology
Primary intracranial tumors are of ecto- and mesodermal origin and arise from
the brain, cranial nerves, meninges, pituitary, pineal and vascular elements.
In 2016, the WHO revised its classification system for pathologic subtypes of CNS
tumors to combine histology with molecular parameter such as:
• IDH 1 mutation
• 1p19q codeletion
• H3 K27M mutation
• RELA fusion for ependymoma
WNT and SHH activation for medulloblastoma
52.
53.
54.
55.
56. Clinical presentation
Classified as generalised & focal-
1. Focal neurologic deficit- weakness ,laryngeal dysfunction etc.
2. Headache (classically morning headache) & sensory loss more
prevalent in fast growing high grade tumors.
3. Seizures – low grade tumors
4. Increased ICT – cushing triade(HTN, bradycardia & respiratory
irregularity). Long term raised ICT causes optic atrophy blindness.
59. Diagnostic work up
Complete history and physical examination
Solitery brain lesion with lung cancer, breast cancer, colon cancer or melanoma
can be metastatic.
Magnetic resonance imaging with gadolinium is IOC.
• T1 images – demonstrating anatomy & areas of contrast enhancement.
• T2 images & FLAIR(Fluid atenuated Inversion Recovery) – sensitive for detecting
edema & infiltrative tumor.
• Diffusion, perfusion & spectroscopic sequence- post treatment
pseudoprogression. Used to distinguish tumour from necrosis or
pseudoprogression.
Neuraxis imaging – for high risk of CSF spread. Post operative period- arachnoiditis
& blood products in the CSF can mimic leptomeningeal mets. So MRI should be
done after 3 weeks of surgery.
60. MRI
T1WI T2WI FLAIR
CSF DARK BRIGHT DARK
FAT BRIGHT DARK BRIGHT
SOLID MASS DARK BRIGHT BRIGHT
EDEMA DARK BRIGHT BRIGHT
CYST DARK BRIGHT DARK
61. MRI
High-grade glioma –high-grade gliomas are typically hypointense masses on
T1- weighted images that enhance heterogeneously following contrast infusion.
62. MRI
Low-grade glioma –low-grade gliomas in adult generally appear as T2/FLAIR
hyperintense, expansile lesion involving both cortex and underlying white
matter .
63. MRI
Meningioma – on MRI, a
typical meningioma is an
extra-axial, dural-based
mass that is isointense or
hypointense to gray
matter on T1 and
isointense or hyperintense
on T2-weighted images.
64. MRI
Brain metastases – brain metastases typically appear as rounded, well-
circumscribed masses that enhance after administration of contrast.
65. Diagnostic work up
CT scan where MRI is contraindicated
Newer imaging modalities-
• FDG PET-CT is approved in USA, FLT and F-DOPA are being evaluated
Cerebrospinal fluid examination
• Medulloblastoma, ependymoma, choroid plexus carcinoma, lymphoma, and
some embryonal pineal and suprasellar region tumors high likelihood of
spreading to CSF.
• Done for staging in medulloblastoma, germ cell tumour & primary CNS
lymphoma. Done after 3 weeks of surgery.
• CSF spread findings- CSF pressure- >150 mm of H2O at the lumber level in
laterally positioned patient
Elevated protein level- >40 mg/dl
Reduced glucose level – below <50 mg/ml
66.
67. Diagnostic work up
Biopsy
When biopsy is not indicated
Known active systemic cancer and multiple lesion that are radiographically
consistent with brain metastasis.
Brainstem glioma
Optic nerve meningioma
HIV positive patients with CT or MRI findings consistent with primary CNS
lymphoma (PCNSL)
Positive Epsteine-Barr virus PCR in the CSF
Patients with secretory germ cell tumors.
71. General management
Cerebral edema
Glucocorticoid are used to control neurologic signs and symptoms
Dexamethasone 2-4 mg twice daily. It is preferred due its minimal
mineralocorticoid activity. It should be tapered to prevent rebound cerebral
edema.(allows pituitary adrenal axis to recover)
Seizures
Anticonvulsants, such as levetiracetum, lacosamide, lamotrigine, and
pregabalin are preferred. Carbamazepine, phenobarbital & phenytoin also
used.
Prophylactic anticonvulsants use (In patients who have never experienced a
seizure) remains controversial because there is lack of data.
For raised ICT
Venous thromboembolic disease
72. Surgery
Surgical procedures
Biopsy
Total resection for cure
Surgical debulking
CSF diversion
Re-resection
Others- placement of chemothereupy, brachytherapy devices & catheters for
interstitial drug delivery.
Note that some radio/chemosensitive such as PCNSL aggressive resection is
unnecessary.
Operative technique-
• ultrasound, CT & MRI guidance system.
• Endoscopic flouroscent tumour localising by usisng 5 aminolevulenic acid.
• Sterotactic biopsy/Intra operative diagnosis
• LASER interstitial thermal therapy (LITT)
73. Surgery
Extent of surgery
Gross total resection
>90% : Total or near total
51-90% : Subtotal resection
11-50% : Partial resection
<10% : Biopsy
74. Radiation therapy
Radiobiologic considerations underlying tissue injury
• The process of radiation injury depends on
• Technical factors- dose, volume, fraction size, specific target cell population
• Secondary mechanism of expression of injury- vascular leak causing edema,
vascular epithelial loss- resulting hypoxia injury, resulting gliosis.
• Host factor- inherent radiosensitivity of different organs within brain(ex. Optic
chiasm, hypothalamus, lacrimal gland, lenses are sensitive to radiation than
others)
75. Radiation therapy
Radiobiologic considerations underlying tissue injury
Functional perturbation- endothelial cells often becomes manifeste as early T2
signal abnormality on MRI – possibly due to disruption of Blood-Brain-Barrier
& edema formation.
Metabolic perturbation- observed in PET CT may reflect oligodendroglioma
demylination.
Vascular perturbation
Late injury reported as tolerance dose at either 5% or 50% risk level at 5
yrs.(TD 5/5 or 50/5)
For whole brain fractionated radiotherapy at 2Gy/fraction it is 60 & 70Gy.
For partial brain radiation – 70 & 80Gy
QUANTEC(quantitative analysis of normal tissue effect in the clinic)- estimated
5% & 10% rate of symptomatic necrosis at 72 & 90Gy (2Gy/fraction)
76. Radiation therapy
Klatzo specified two categories of cerebral edema – vasogenic and cytotoxic edema. The term
cellular edema refers to cytotoxic edema and is preferable to the latter; Fishman accepts these two
categories but adds a third, which he calls interstitial cerebral edema. Rarely is the separation into
distinct categories possible, there is often overlap between the various types of edema.
Vasogenic cerebral edema refers to the influx of fluid and solutes into the brain through an
incompetent blood-brain-barrier (BBB). This is the most common type of brain edema and results
from increased permeability of the capillary endothelial cells, the white matter is primarily affected.
Breakdown in the blood-brain barrier allows movement of proteins from the intravascular space
through the capillary wall into the extracellular space.
Cellular (cytotoxic) cerebral edema refers to a cellular swelling. It is seen in conditions like head
injury and hypoxia. It results from the swelling of brain cells, most likely due to the release of toxic
factors from neutrophils and/bacteria. Cytotoxic edema is caused by swelling of glia, neurons,
endothelial cells and begins within minutes after an insult. Cytotoxic edema affects predominantly
the gray matter.
Interstitial edema is seen in hydrocephalus when outflow of CSF is obstructed and
intraventricular pressure increases. The result is movement of sodium and water across the
ventricular wall into the paraventricular space. Interstitial cerebral edema occurring during
meningitis is due largely to obstruction of normal CSF pathways, with a resulting increase in the
resistance to CSF outflow.
77. Radiation therapy
General concept- pertinent anatomic landmark:
External auditory meatus define anatomic reference points- reid base line &
Frankfort horizontal plane.
• Reid base line- drawn from the inferior margine of the orbit(orbitale point) to
the auricular point (center of the orifice of the external acoustic meatus) and
extending backward to the center of the occipital bone.
• Frankfort horizontal plane- plane determined the highest point on the upper
margine of the opening of each external auditory canal and the low point on
the lower margine of the orbit.
78.
79. Radiation therapy
General concept- pertinent anatomic landmark:
Lateral radiograph- sella turcica is centrally located marks the lower border of
the medial telencephalon & diencephalon.
Hypothalamic structure- 1cm superior to sellar floor & optic canal runs at
most 1 cm superior & 1 cm anterior to that point.
Pineal body- (tentorial notch) 1cm posterior & 3 cm superior to ext.auditory
meatus.
Cribriform plate- most inferior part of anterior cranial fossa.(inferior border of
WBRT fields)
80. Radiation therapy
Treatment setup- head preferably fully flex /extended neck or use
noncoplanar fields & IMRT.
• Target volume definition – CTV expansion should not transverse anatomically.
Inclusion of bony skull is unnecessary unless direct tumour extension.
82. Radiation therapy
Partial brain irradiation- which includes treatment of the tumor or tumor
bed and surrounding margin, and some healthy brain tissue subject to
incidental irradiation.
Whole beain radiotherapy- in which the entire brain and brainstem are
irradiated. In case of brain mets also in PCNSL & component of CSI.
Parallel opposed lateral portals used. Inferior field border- inferior to
cribriform plate, the middle cranial fossa & foramen magnum.safty margine
1 cm taken.
Anterior border- 3 cm posterior to the ipsilateral eyelid to exclude
contralateral lense.
83. Radiation therapy
Cranio-spinal irradiation- Craniospinal Irradiation (CSI) is a technique used
in radiation therapy to deliver a prescribed amount of radiaion to the entire cranial-
spinal axis used in treatment of medulloblastoma and other brain tumors, which
tend to spread via Cerebrospinal Fluid (CSF). Generally in CSI for
medulloblastoma of two laterally opposed cranial fields, are matched to a posterior
spine field with the potential for dose in homogeneity at the junctions. Hence,
elder children and adults frequently require two posterior spine fields which lead
to additional junctions and planning complexity.treatment fields include the brain
to thecal sac.
Stereotactic radiosurgery (SRS)- very precise form of therapeutic
radiation that can be used to treat abnormalities in the brain and spine,
including cancer, epilepsy, trigeminal neuralgia and arteriovenous
malformations.
Fractionated stereotactic radiotherapy- process in which the total dose
of stereotactic radiation is divided into several smaller doses of radiation,
on separate days of treatment.
84. Radiation therapy
Brachytherapy-
Selection criteria
Tumor confined to one hemisphere
No transcallosal or subependymal spread
Small size (<5 to 6 cm)
Well circumscribed on CT or MRI
Accessible location for the implant
Procedure :
A ballon based system, gliasite, placed into the cavity at the time of surgery
Ballon is filled with organically bound iodine-125.
Treatment is completed within 3 to 7 days.
Direct infusion of radioimmunoglobulins has been used in primary and
recurrent brain gliomas.
85. Chemotherapy and targeted agents
CNS tumors are resistent to most chemotheraoeutic agents as they are unable to
cross BBB.
Alkylating agents such as BCNU (carmustine) and CCNU (lomustine) cross the BBB,
but prolonged use causes myelotoxicity and pulmonary fibrosis
Procarbazine has similar efficacy but is better tolerated
Temozolamide (TMZ), has excellent bioavailability and is the only agent to
demonstrate a survival benefit for glioblastoma and anaplastic astrocytoma.
Radiation therapy with immediate chemotherapy (PCV) prolongs survival in
patients with anaplastic oligodendroglioma and high-risk low-grade gliomas.
Implantation of slow-release chemotherapy waters into a tumor resection cavity
or convection-enhanced drug (CED) delivery have been used to bypass BBB.
VEGF pathway inhibitor bevacizumab is the only targated agent approved for
GBM.
Two large randomized trials of bevacizumab for the treatment of newely
diagmosed GBM improved PFS but failed to improve OS.
86. Toxicity
General symptoms:
Fatigue
Headache
Drowsiness
Dermatitis
Alopecia
Nausea and vomiting (raised ICP, posterior fossa or brainstem irradiation)
Otitis externa (if ear in the field)
87. Acute toxicity
Transient worsening of pretreatment deficits may develop during the course of
radiotherapy, and further acute toxicities may manifiest up to 6 weeks following
completion of irradiation.
These symptoms are consequence of a transient peritumoral edema and usually
respond to a short increase of corticosteroids.
Sub acute toxicity
Toxicity that develops during the 6-week to 6-month period following irradiation
is attributed to changes in capillary permeability as well as transient
demyelination due to damage to oligodendroglial cells.
Symptom include : headache, somnolence and fatigability
88. Late toxicity
Late sequele of radiotherapy appear from 6 months to many years following
treatment and are usually irreversible and progressive.
They are thought to be due to white matter damage from vascular injury,
demyelination And necrosis.
The most serious late reaction to radiotherapy is radiation necrosis, which has a
peak incidence at 3 years.
89. Follow up
Periodic MRIs are used to detect tumor recurrence/ treatment response.
Assessment of cognitive functioning and quality of life.
Monitoring of for neuroendocrine and ophthalmologic side effects.