Hydrocephalus project

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Hydrocephalus project

  1. 1. Hydrocephalus in Paediatric By:Hieder A`ala 601 1
  2. 2. Cerebro-Spinal Fluid (CSF) Definition: is a clear bodily fluid that occupies the subarachnoid space in the brain (the space between the skull and the cerebral cortex—more specifically, between the arachnoid and pia layers of the meninges). It is a very pure saline solution with microglia and acts as a "cushion" or buffer for the cortex. 2
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  4. 4. Physiology Cerebrospinal fluid also occupies the ventricular system of the brain and the spinal cord. It is a prime example of the separation of brain function from the rest of the body, as all CSF is generated locally in the brain. It is produced by the choroid plexus which is formed by specialized ependymal cells. The choroid plexus enter the lateral ventricles through the choroid fissure, along the line of the fimbria/fornix, and the third and fourth ventricle through their roofs. The CSF formed by the choroid plexuses in the ventricles, circulates through the interventricular foramina (foramen of Monro) into the third ventricle and then via the mesencephalic duct (cerebral aqueduct) into the fourth ventricle, whence it exits through two lateral apertures (foramina of Luschka) and one median aperture (foramen of Magendie). It then flows through the cerebromedullary cistern down the spinal cord and over the cerebral hemispheres. 4
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  6. 6. Physiology Traditionally, it has been thought that CSF returns to the vascular system by entering the dural venous sinuses via the arachnoid granulations. However, some have suggested that CSF flow along the cranial nerves and spinal nerve roots allow it into the lymphatic channels and that this flow may play a substantial role in CSF reabsorbtion, particularly in the neonate (in which arachnoid granulations are sparsely distributed). The cerebrospinal fluid is produced by the ventricles (mostly the lateral ventricles) at a rate of 500 ml/day. Since the volume that may be contained by the brain is of 150 ml, it is frequently replaced (3-4 times per day turnover), exceeding amounts getting into the blood. This continuous flow through the ventricular system into the subarachnoid space and finally exiting into the venous system provides somewhat of a "sink" that reduces the concentration of larger, lipoinsoluble molecules penetrating into the brain and CSF. The CSF contains approximately 0.3% plasma proteins, also being 15 to 40 mg/dL, depending on sampling site. 6
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  8. 8. What is Hydrocephalus? The term hydrocephalus is derived from the Greek words “hydro” meaning water and “cephalus” meaning head. As the name implies, (water head) it is a condition in which the primary characteristic is excessive accumulation of fluid in the brain. The excessive accumulation of (CSF) cerebrospinal fluid results in an abnormal dilatation of the spaces in the brain called ventricles. This dilatation causes potentially harmful pressure on the tissue of the brain. 8
  9. 9. Aetiology of hydrocephalus 9
  10. 10. classifications of Hydrocephalus We will classify causes of hydrocephalus into two forms according to two principles.1-according to relation or comminucation between the ventricular system and the venous sinuses (i.e. obstructive or non-obstructive).2-according to the nature of the aetiology whether acquired or congenital. 10
  11. 11. 1st classificationA-Obstructive (non-communicating) This type of hydrocephalus results from an obstruction within the ventricular system of the brain that prevents CSF from flowing or “communicating” within the brain. The most common type is a narrowing of a channel in the brain that connects two ventricles together. 11
  12. 12. 1st classificationB-Non-obstructive (communicating)This type results fromproblems with theproduction orabsorption of CSF. Themost common is causedby bleeding into thesubarachnoid space inthe brain. 12
  13. 13. 2nd classificationA-Congenital causes in infants and children  Stenoses of the aqueduct of Sylvius due to malformation: This is responsible for 10% of all cases of hydrocephalus in newborns.  Dandy-Walker malformation: This affects 2-4% of newborns with hydrocephalus.  Arnold-Chiari malformation type 1 and type 2 and type three  Agenesis of the foramen of Monro  Congenital toxoplasmosis  Bickers-Adams syndrome: This is an X-linked hydrocephalus accounting for 7% of cases in males. It is characterized by stenosis of the aqueduct of Sylvius, severe mental retardation, and in 50% by an adduction-flexion deformity of the thumb 13
  14. 14. 2nd classificationB-Acquired causes in infants and children Mass lesions account for 20% of all cases of hydrocephalus in children. These are usually tumors (eg, medulloblastoma, astrocytoma), but cysts, abscesses, or hematoma also can be the cause. Intraventricular hemorrhage can be related to prematurity, head injury, or rupture of a vascular malformation. Infections: Meningitis (especially bacterial) and, in some geographic areas, cysticercosis can cause hydrocephalus. Increased venous sinus pressure: This can be related to achondroplasia, some craniostenoses, or venous thrombosis. Iatrogenic: Hypervitaminosis A, by increasing secretion of CSF or by increasing permeability of the blood-brain barrier, can lead to hydrocephalus. Idiopathic 14
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  16. 16. Some important definitions CHIARI MALFORMATION TYPE I:  DISPLACEMENT OF CEREBELLAR TONSILS INTO THE CERVICAL CANAL.  GIVES SYMPTOMS IN ADOLESCENCE OR ADULT LIFE. (HEADACHE, NECK PAIN)  NO HYDROCEPHALUS TYPE II :  DISPLACEMENT OF INFERIOR VERMIS, PONS, AND MEDULLA INTO CERVICAL CANAL  PROGRESSIVE HYDROCEPHALUS AND MYELOMENINGOCELE.  ELONGATION OF THE 4TH VENTRICLE. 16
  17. 17. Some important definitions DANDY-WALKER SYNDROME1. CYSTIC EXPANSION OF THE 4TH VENTRICLE IN THE POSTERIOR FOSSA.2. DEVELOPMENTAL FAILURE OF ROOF OF 4TH VENTRICLE DURING EMBRYOGENESIS.3. 90 % HAVE HYDROCEPHALUS4. PROMINENT OCCIPUT 17
  18. 18. Other types of Hydrocephalus Two other forms of hydrocephalus which don’t fit distinctly into those categories are hydrocephalus ex-vacuo, and normal pressure hydrocephalus. N.B.: * Ex-vacuo occurs when there is damage to the brain caused by stroke of a traumatic injury. * Normal pressure hydrocephalus commonly occurs in the elderly, due to aging. The triad (Hakim triad) of gait instability, urinary incontinence and dementia is a relatively typical manifestation of the distinct entity normal pressure hydrocephalus (NPH). The triad can easily be remembered as "Wacky, Wet, and Wobbly!" 18
  19. 19. Some important definitions IVH DEFINITION:  BLEEDING IN SUBEPENDIMAL GERMINAL MATRIX WITH/WITHOUT EXTENSION INTO VENTRICLES AND BRAIN PARENCHYMA INCIDENCE:  IN PREMATURES 25 - 40 % 19
  20. 20. Some important definitions PATHOLOGY:  INTRAVASCULAR  VASCULAR  EXTRAVASCULAR COMPLICATIONS:  HYDROCEPHALUS  20 % IN MODERATE BLEEDS  65-100 % IN LARGE BLEEDS 20
  21. 21. Pathophysiology Pathological basis of clinical picture:1. increased intracranial tension (ICP).2. Age of onset.3. Type of hydrocephalus (obs. or non obs.)4. Closure of fontanels and sutures of the skull5. Associated disorders.6. Treatment.( relapsing of the symptoms due to complication associated with treatment ) 21
  22. 22. Pathophysiology ICP rises if production of CSF exceeds absorption. This occurs if CSF is overproduced, resistance to CSF flow is increased, or venous sinus pressure is increased. CSF production falls as ICP rises. Compensation may occur through transventricular absorption of CSF and also by absorption along nerve root sleeves. Temporal and frontal horns dilate first, often asymmetrically. This may result in elevation of the corpus callosum, stretching or perforation of the septum pellucidum, thinning of the cerebral mantle, or enlargement of the third ventricle downward into the pituitary fossa (which may cause pituitary dysfunction). 22
  23. 23. Pathophysiology Age of onsetThere are three groups in which hydrocephalus can develop:1. Fetuses (diagnosed antenataly )2. Infants .3. Children.Each group has its own criteria of hydrocephalus Type of hydrocephalus (obs.or non obs.) 23
  24. 24. Pathophysiology Closure of fontanels and sutures of the skull : As there is limited space for expansion in the skull, CSF pressure (as total intracranial pressure) effects the arterial profusion to the brain. When CSF pressure is elevated, cerebral blood flow may be diminished . 24
  25. 25. Pathophysiology Associated disorders. ( see later )Meningitis, ventriculaitis , meningeocele , cerebellar herniation ..etc. Treatment as option, time of intervention , modality , complications and rate of recurrence . 25
  26. 26. Pathophysiology As there is limited space for expansion in the skull, CSF pressure (as total intracranial pressure) effects the arterial profusion to the brain. When CSF pressure is elevated, cerebral blood flow may be diminished . 26
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  28. 28. Mortality/Morbidity Mortality : In untreated hydrocephalus, death may occur by tonsillar herniation secondary to raised ICP with compression of the brain stem and subsequent respiratory arrest. Morbidity:1. Shunt dependence occurs in 75%2. frequent hospitalizations for scheduled shunt revisions .3. Poor development of cognitive function in infants and children4. Visual loss can complicate untreated hydrocephalus and may persist after treatment 28
  29. 29. Male : Female Sex: Generally, incidence is equal in males and females. The exception is Bickers-Adams syndrome, an X-linked hydrocephalus transmitted by females and manifested in males. NPH has a slight male preponderance. 29
  30. 30. 30
  31. 31. Fetal hydrocephalus. During antenatal care , Fetal ventriculomegaly can be detected through ultrasound (sonogram) towards the end of the first trimester. Evaluation of the brain and cranial structure is part of the routine ultrasound examination done by many obstetricians as part of their prenatal care. If the condition is detected on ultrasound, the patient may undergo a fetal brain MRI (magnetic resonance imaging) to determine the severity of the finding. 31
  32. 32. Sonographic demonstration Fetal hydrocephalus: gross enlargement of the lateral ventricles, thinning of the cortex, asymmetric choroid plexuses. 32
  33. 33. Infants Symptoms Poor feeding  Irritability  Reduced activity  Vomiting 33
  34. 34. Infants Signs Head enlargement: Head circumference is in the 98th percentile for the age or greater.(remember h.c. to the age) Dysjunction of sutures: This can be seen or palpated. Dilated scalp veins: The scalp is thin and shiny with easily visible veins.(why?) Tense fontanelle: The anterior fontanelle in infants who are held erect and are not crying may be excessively tense. Setting-sun sign: In infants it is characteristic of increased ICP. Both ocular globes are deviated downward, the upper lids are retracted, and the white sclerae may be visible above the iris. Increased limb tone: Spasticity preferentially affects the lower limbs. The cause is stretching of the periventricular pyramidal tract fibers by hydrocephalus. 34
  35. 35. Children Symptoms Slowing of mental capacity Headaches (initially in the morning) that are more significant than in infants because of skull rigidity Neck pain suggesting tonsillar herniation Vomiting, more significant in the morning Blurred vision - Consequence of papilledema and later of optic atrophy Double vision - Related to unilateral or bilateral sixth nerve palsy Stunted growth and sexual maturation from third ventricle dilatation: This can lead to obesity and to precocious or delayed onset of puberty. Difficulty in walking secondary to spasticity: This affects the lower limbs preferentially because the periventricular pyramidal tract is stretched by the hydrocephalus. Drowsiness 35
  36. 36. Children Signs Papilledema: if the raised ICP is not treated, this can lead to optic atrophy and vision loss. Failure of upward gaze: This is due to pressure on the tectal plate through the suprapineal recess. Macewen sign: A "cracked pot" sound is noted on percussion of the head. Tapping with the fingertips on the skull may show abnormal sounds associated with thinning and separation of skull bones. Unsteady gait: This is related to spasticity in the lower extremities. Large head: Sutures are closed, but chronic increased ICP will lead to progressive abnormal head growth. 36 Unilateral or bilateral sixth nerve palsy is secondary to
  37. 37. Certain pics. 37
  38. 38. Certain pics 38
  39. 39. Differential diagnosis  Macrocephaly Macrocephaly means a large head—greater than 2 standard deviations from the normal distribution; 2% of the “normal” population has macrocephaly. Investigation of such individuals may show an abnormality causing macrocephaly, but many are normal, often with a familial tendency for a large head. When asked to evaluate a large head in an otherwise normal child, first ask the parents for their hat sizes. The causes of a large head include hydrocephalus (an excessive volume of CSF in the skull), megalencephaly (enlargement of the brain), thickening of the skull, and hemorrhage into the subdural or epidural spaces. Hydrocephalus is the main cause of macrocephaly at birth in which intracranial pressure is increased 39
  40. 40. Differential diagnosis1- extracranial causes:Cephalhematoma, subgleal hemorrhage .2- cranial causes: Anemia Cleidocranial dysostosis Craniometaphyseal dysplasia of Pyle Epiphyseal dysplasia Hyperphosphatemia Leontiasis ossea Orodigitofacial dysostosis Osteogenesis imperfecta OsteopetrosisPyknodysostosis Rickets Russell dwarf3-intracranial causes :Megalencephaly , hydrocephalus and strugg – Webber syndrome . 40
  41. 41. Work up1-Imaging Studies• CT scan of the head• MRI scan of head• Fetal and neonatal cranial ultrasound2-Diagnostic Procedures• Lumbar puncture 41
  42. 42. Work up imaging studies CT scan of the head delineates the degree of ventriculomegaly and, in many cases, the etiology. When performed with contrast, it can show infection and tumors causing obstruction. It also helps with operative planning. Ventricles usually are dilated proximal to the point of obstruction. In pseudotumor cerebri, the CT scan findings usually are normal. 42
  43. 43. Work up imaging studies Perform MRI scan of head in most, if not all, congenital cases of hydrocephalus. This delineates the extent of associated brain anomalies such as corpus callosum agenesis, Chiari malformations, disorders of neuronal migration, and vascular malformations. 43
  44. 44. Work up Imaging studies Fetal and neonatal cranial ultrasound is a good study for monitoring ventricular size and intraventricular hemorrhage in the neonatal ICU setting. Certainly, prior to treatment, perform other imaging studies. 44
  45. 45. Imaging studies Noncommunicating obstructive hydrocephalus caused by obstruction of the foramina of Luschka and Magendie. This MRI sagittal image demonstrates dilatation of lateral ventricles with stretching of corpus callosum and dilatation of the fourth ventricle. 45
  46. 46. Imaging studies Noncommunicating obstructive hydrocephalus caused by obstruction of foramina of Luschka and Magendie. This MRI axial image demonstrates dilatation of the lateral ventricles. 46
  47. 47. Imaging studies Non-communicating obstructive hydrocephalus caused by obstruction of foramina of Luschka and Magendie. This MRI axial image demonstrates fourth ventricle dilatation. 47
  48. 48. Imaging studies Dandy-Walker malformation. CT shows cystic dilation of the fourth ventricle and partial agenesis of the cerebellar vermis 48
  49. 49. Imaging studies Aqueductal stenosis. CT shows marked enlargement of the third ventricle (arrow) and the lateral ventricles. 49
  50. 50. Imaging studies Chiari I malformation : Sagittal C-T1W MR image of the brain shows a downward herniation of the cerebellar tonsils without associated syrinx. 50
  51. 51. Imaging studies Chiari II malformation : Axial FSE T2W MR image of the brain shows colpocephaly. 51
  52. 52. Imaging studiesMR images demonstrating a massively dilated ventricular system withcongenital hydrocephalus secondary to acqueductal stenosis. The sagittal image(left) shows a normal-appearing fourth ventricle. The tremendous enlargement of the lateral ventricles has led to compression of the cerebral mantle with only the frontal lobes being visible (right). 52
  53. 53. Work up Diagnostic Procedures Lumbar puncture can be used to measure intracranial pressure, but it should only be performed after imaging studies rule out an obstruction. Spinal fluid can show the type and severity of infection ( i.e. in meningitis ) 53
  54. 54. TREATMENT Medical therapy : Indications: In transient conditions, such as meningitis, or neonatal intraventricular hemorrhage . Modalities :1. Acetazolamide (25 mg/kg/d in 3 doses): Careful monitoring of respiratory status and electrolytes is crucial. Treatment beyond 6 months is not recommended.2. Furosemide (1 mg/kg/d in 3 doses): Again, electrolyte balance and fluid balance need to be monitored carefully. 54
  55. 55. Treatment3-Lumbar punctures: In neonates recovering from intraventricular hemorrhage, serial lumbar punctures can resolve hydrocephalus in some cases. If possible, this is the preferred method of treatment.4-Removal of the underlying cause resolves hydrocephalus in most cases 55
  56. 56. Treatment Surgical therapy Principle of surgical intervention :Relief increased ICP by diversion the exessive CSF from ventricular system into an absorptive surface out side the brain such as pleura or peritoneum or into the atria of the heart…….this is called shunt operation The most indication for shunt operation is progressive hydrocephalus . 56
  57. 57. Treatment Contraindications:1. The patient in whom a successful surgery would not affect the outcome (eg, a child with hydranencephaly) or cortical thickenning is less than one cm.2. Arrested hydrocephalus is defined as a rare condition in which the neurologic status of the patient is stable in the presence of stable ventriculomegaly.3. Benign hydrocephalus of infancy is found in neonates and young infants. The children are asymptomatic, and head growth is normal. CT scan shows mildly enlarged ventricles and subarachnoid spaces. 57
  58. 58. Treatment Types of shunts :1. Third ventriculostomy2. Ventriculoperitoneal shunting (the common procedure ) .3. Ventriculoatrial shunting .4. Ventriculopleural shunting .5. Torkildsen shunts or internal shunts .6. Lumboperitoneal shunts . 58
  59. 59. Treatment 59
  60. 60. Treatment 60
  61. 61. Follow-up care Perform CT scan for baseline at 2-4 weeks postsurgery. Monitor all children with shunts every 6-12 months. Carefully monitor head growth in infants. Check distal tubing length with plain radiographs when the child grows. Appropriate specialists should carefully assess child development. What happens to ventricular size in patients who have a third ventriculostomy or Torkildsen shunt is not known. Other methods of assessment of patency need to be used, such as MRI flow studies and clinical evaluations (eg, detailed funduscopic examinations). 61
  62. 62. COMPLICATIONS1. Infection is the most feared complication2. Subdural hematomas .3. Shunt failure is mostly due to suboptimal proximal catheter placement .4. Overdrainage is more common in lumboperitoneal shunts .5. Slit ventricle syndrome . 62
  63. 63. Shunt failure 63
  64. 64. PROGNOSIS In general, outcome is good. A typical patient should return to baseline after shunting. The neurologic function of children is optimized with shunting. The best long-term results in the most carefully selected patients are no better than 60% in normal pressure hydrocephalus. Few complete recoveries occur. Often, gait and incontinence respond to shunting, but dementia responds less frequently. Often, various other neurologic abnormalities associated with hydrocephalus are the limiting factor in patient recovery. Examples are migrational abnormalities and postinfectious hydrocephalus. 64
  65. 65. Before and After 65
  66. 66. 66
  67. 67. THE END 67

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