Hydrocephalus in children -_ Final.pptx

Large Head

1. Hydrocephalus

2. Hydrocephalus Is not a specific disease; Represents a diverse group of conditions that result from: impaired circulation and absorption of CSF or, in rare circumstances, from increased production of CSF by a choroid plexus papilloma

3. CAUSES OF HYDROCEPHALUS COMMUNICATING Achondroplasia Basilar impression   Benign enlargement of subarachnoid space Choroid plexus papilloma Meningeal malignancy Meningitis Posthemorrhagic NONCOMMUNICATING Aqueductal stenosis    Infectious* X-linked Mitochondrial Autosomal recessive Autosomal dominant L1CAM mutations Chiari malformation Dandy-Walker malformation Klippel-Feil syndrome Mass lesions    Abscess Hematoma Tumors and neurocutaneous disorders Vein of Galen malformation Walker-Warburg syndrome

4. Source of CSF By the choroid plexus, primarily in the ventricular system By extrachoroidal sources, Approximately 25%, including the capillary endothelium within the brain parenchyma

5. Autonomic effect on CSF production Stimulation of the adrenergic system diminishes CSF production, Excitation of the cholinergic nerves can double the normal CSF production rate.

6. Volume of CSF In a normal child, about 20  mL /hr of CSF is produced. The total volume of CSF approximates 50  mL in an infant and 150  mL in an adult. Most of the CSF is extraventricular .

7. Location of choroid plexus which is situated in the lateral, 3rd, and 4th ventricles.

8. Size of aqueduct of Sylvius About 3 mm long 2 mm in diameter in a child,

9. Basal cystern s

10. The clinical presentation of hydrocephalus Is variable and depends on many factors, including: The age at onset, The nature of the lesion causing obstruction, The duration and rate of increase of the intracranial pressure (ICP).

11. The clinical presentation of hydrocephalus In an infant An accelerated rate of enlargement of the head is the most prominent sign. The anterior fontanel is wide open and bulging , The scalp veins are dilated. The forehead is broad , The eyes might deviate downward because of impingement of the dilated suprapineal recess on the tectum , producing the setting-sun eye sign. Long-tract signs including brisk tendon reflexes, spasticity, clonus (particularly in the lower extremities), and Babinski sign are common owing to stretching and disruption of the corticospinal fibers originating from the leg region of the motor cortex.

12. The clinical presentation of hydrocephalus In an older child The cranial sutures are partially closed so that the signs of hydrocephalus may be subtler . Irritability, lethargy, poor appetite, and vomiting are common to both age groups, Headache is a prominent symptom in older patients. A gradual change in personality and deterioration in academic productivity suggest a slowly progressive form of hydrocephalus. With regard to other clinical signs, serial measurements of the head circumference often indicate an increased velocity of growth. Percussion of the skull might produce a cracked pot sound or MacEwen's sign , indicating separation of the sutures. A foreshortened occiput suggests Chiari malformation, and a prominent occiput suggests the Dandy-Walker malformation. Papilledema , abducens nerve palsies, and pyramidal tract signs , which are most evident in the lower extremities, are apparent in many cases.

13. Chiari malformation consists of two major subgroups.

14. Type I of chiari malformation Typically produces symptoms during adolescence or adult life Is usually not associated with hydrocephalus . Patients complain of recurrent headache , neck pain , urinary frequency , and progressive lower extremity spasticity. The deformity consists of displacement of the cerebellar tonsils into the cervical canal

15. Pathogenesis of Type I of chiari malformation Is unknown, A prevailing theory suggests that obstruction of the caudal portion of the 4th ventricle during fetal development is responsible. Other theories include tethering of the cord or additional anomalies ( syrinx ).

16. The type II Chiari malformation Is characterized by progressive hydrocephalus with a myelomeningocele .

17. Pathogenesis of type II Chiari malformation Represents an anomaly of the hindbrain, probably owing to a failure of pontine flexure during embryogenesis, and results in elongation of the 4th ventricle and kinking of the brainstem, with displacement of the inferior vermis , pons , and medulla into the cervical canal

18. Sign & symptoms in The type II Chiari malformation Approximately 10% of type II malformations produce symptoms during infancy , consisting of: stridor , weak cry, and apnea , which may be relieved by shunting or by decompression of the posterior fossa . A more indolent form consists of abnormalities of gait , spasticity , and increasing incoordination during childhood.

19. The Dandy-Walker malformation Consists of: A cystic expansion of the 4th ventricle in the posterior fossa Midline cerebellar hypoplasia , which results from a developmental failure of the roof of the 4th ventricle during embryogenesis

20. Clinical findings in Dandy-Walker malformation Approximately 90% of patients have hydrocephalus , A significant number of children have associated anomalies, including agenesis of the posterior cerebellar vermis and corpus callosum . Infants present with a rapid increase in head size and a prominent occiput . Transillumination of the skull may be positive. Most children have evidence of long-tract signs, cerebellar ataxia, and delayed motor and cognitive milestones, probably due to the associated structural anomalies.

21. Management of Dandy-Walker malformation By shunting the cystic cavity (and on occasion the ventricles as well) in the presence of hydrocephalus.

22. Investigation of a child with hydrocephalus Begins with the history. Familial cases suggest : X-linked or autosomal hydrocephalus secondary to aqueductal stenosis . A past history of: Prematurity with intracranial hemorrhage, Meningitis, Mumps encephalitis. Multiple Cafe-au- lait spots and other clinical features of neurofibromatosis point to aqueductal stenosis

23. Examination in hydrocephalus Careful inspection, palpation, and auscultation of the skull and spine. The occipitofrontal head circumference is recorded and compared with previous measurements. The size and configuration of the anterior fontanel are noted, The back is inspected for abnormal midline skin lesions, including tufts of hair, lipoma , or angioma that might suggest spinal dysraphism . The presence of a prominent forehead or abnormalities in the shape of the occiput can suggest the pathogenesis of the hydrocephalus. A cranial bruit is audible in association with many cases of vein of Galen arteriovenous malformation. Transillumination of the skull is positive with : Massive dilatation of the ventricular system The Dandy-Walker syndrome. Inspection of the eyegrounds is mandatory because the finding of chorioretinitis suggests an intrauterine infection, such as toxoplasmosis, as a cause of the hydrocephalus. Papilledema is observed in older children but is rarely present in infants because the cranial sutures separate as a result of the increased pressure.

24. Plain skull films typically show Separation of the sutures, Erosion of the posterior clinoids in an older child, An increase in convolutional markings (beaten-silver appearance) with long-standing increased ICP.

25. The most important studies to identify the specific cause and severity of hydrocephalus in an infant The CT scan and/or MRI along with ultrasonography

26. The head might appear enlarged and can be confused with hydrocephalus secondary to a thickened cranium resulting from Chronic anemia, Rickets, Osteogenesis imperfecta , Epiphyseal dysplasia.

27. Chronic subdural collections can produce bilateral parietal bone prominence. In addition, cerebral gigantism and neurofibromatosis are characterized by increased brain mass.

28. Various metabolic and degenerative disorders of the CNS produce megalencephaly lysosomal diseases ( Tay -Sachs, gangliosidosis , and the mucopolysaccharidoses ), The aminoacidurias ( maple syrup urine disease), The leukodystrophies ( metachromatic leukodystrophy , Alexander disease, Canavan disease ).

29. Megalencephaly An anatomic disorder of brain growth defined as a brain weight:volume ratio >98th percentile for age (or ≥2 standard deviations [SD] above the mean) that is usually accompanied by macrocephaly (an occipitofrontal circumference [OFC] >98th percentile).

30. Causes of megalencephaly Various storage and degenerative diseases Anatomic and genetic causes. On the other hand, in >100 syndromes macrocephaly a known feature.

31. Benign familial megalencephaly . The most common cause of anatomic megalencephaly . Easily diagnosed by careful family history and measurement of the parents’ head circumferences (OFCs).

32. Familial megalencephaly An autosomal dominant trait Is characterized by: Delayed motor milestones and hypotonia But normal or near-normal intelligence. Measurement of parents’ head circumferences is necessary to establish the diagnosis.

33. Anatomic megalencephaly Usually apparent at birth , and head growth continues to run parallel to the upper percentiles. Sometimes, in some syndromes , increased OFC is the presenting sign. Neuroimaging is critical in identifying the various structural and gyral abnormalities seen in syndromic macrocephaly and determining whether anatomic megalencephaly exists.

34. Common megalencephaly -associated macrocephaly syndromes Syndromes with prenatal and/or postnatal somatic overgrowth such as: Sotos , Simpson- Golabi - Behmel , fragile X, Weaver, M-CMTC, the macrocephaly -capillary malformation (M-CM) syndrome ( previousiy termed macrocephaly cutis marmorata telangiectatica congenita , or CMTC); Bannayan - Ruvalcaba -Riley syndromes syndromes without somatic overgrowth such as: FG, Greig cephalopolysyndactyly , acrocallosal , Gorlin syndromes

35. Simpson- Golabi - Behmel syndrome (SGBS) An X-linked complex congenital overgrowth syndrome characterized by: Macroglossia , Macrosomia , Renal and skeletal abnormalities, An increased risk of embryonal tumors. Macrocephaly is often congenital. Patients may have hypotonia and mild developmental delay, although most have normal intelligence. Most cases of SGBS are due to mutations or deletions of the glypicall-3 (CPC3) gene at Xq26, a member of a multigene family encoding at least six distinct glycosylphosphatidylinositol -linked cell-surface heparan sulfate proteoglycans (HSPGs); these act as co-receptors for multiple families of growth factors that have been shown to regulate cell proliferation, differentiation, and patterning, including that of the brain . [

36. SGBS type 2 An X-linked mental retardation syndrome with: Macrocephaly ( ofcs +2 to +6 SD above the mean) Ciliary dysfunction , manifesting as recurrent respiratory tract infections, with abnormal functional studies of the respiratory cilia. Recently, a family with this syndrome co-segregating with a frameshift mutation in the oral-facial-digital type 1 (OFDJ) gene was reported

37. Sotos syndrome (cerebral gigantism) The most common megalencephalic syndrome , With 50% of patients having prenatal macrocephaly and 100% of patients having macrocephaly by age 1 yr. Early postnatal overgrowth normalizes by adulthood. Facial features Hypotonia , poor coordination, and speech delay are common. Most children show mental retardation, ranging from mild to severe .

38. Facial features of soto High forehead with frontal bossing, Sparse hair in the frontoparietal region, Downslanting palpebral fissures, Apparent hypertelorism , Long narrow face, Prominent mandible, Malar flushing.

39. Weaver syndrome A condition that involves: Tall stature with or without a large head size ( macrocephaly ), A variable degree of intellectual disability (usually mild), Characteristic facial features. joint deformities called contractures that restrict the movement of affected joints

40. Characteristic facial features of weaver syndrome Broad forehead; Widely spaced eyes ( hypertelorism ); Large, low-set ears; A dimpled chin, A small lower jaw ( micrognathia ).

41. HYDRANENCEPHALY May be confused with hydrocephalus. The cerebral hemispheres are absent or represented by membranous sacs with remnants of frontal, temporal, or occipital cortex dispersed over the membrane. The midbrain and brainstem are relatively intact.

42. The cause of hydranencephaly Is unknown , but bilateral occlusion of the internal carotid arteries during early fetal development would explain most of the pathologic abnormalities.

43. Clinical findings in hydranencephaly Affected infants can have a normal or enlarged head circumference at birth that grows at an excessive rate postnatally . Transillumination shows an absence of the cerebral hemispheres. The child is irritable, feeds poorly, develops seizures and spastic quadriparesis , and has little or no cognitive development. A ventriculoperitoneal shunt prevents massive enlargement of the cranium.

44. Therapy for hydrocephalus Depends on the cause. Medical management , including the use of acetazolamide and furosemide , can provide temporary relief by reducing the rate of CSF production, but long-term results have been disappointing . Most cases of hydrocephalus require extracranial shunts, particularly a ventriculoperitoneal shunt. Endoscopic third ventriculostomy has evolved as a viable approach and criteria have been developed for its use, but the procedure might need to be repeated to be effective. Ventricular shunting may be avoided with this approach. The results of intrauterine surgical management of fetal hydrocephalus have been poor (possibly because of the high rate of associated cerebral malformations in addition to the hydrocephalus) except for some promise in cases of hydrocephalus associated with fetal meningomyelocele .

45. The major complications of shunting Occlusion ( characterized by headache, papilledema , emesis, mental status changes) Bacterial infection (fever, headache, meningismus ), usually caused by Staphylococcus epidermidis . With meticulous preparation, the shunt infection rate can be reduced to <5%.

46. Prognosis of hydrocephalus Depends on the cause of the dilated ventricles and not on the size of the cortical mantle at the time of operative intervention, except in cases in which the cortical mantle has been severely compressed and stretched. The visual evoked potential latencies are delayed and take some time to recover after correction of the hydrocephalus. Although most hydrocephalic children are pleasant and mild mannered, some children show aggressive and delinquent behavior. Accelerated pubertal development in patients with shunted hydrocephalus or myelomeningocele is relatively common, possibly because of increased gonadotropin secretion in response to increased ICP.

47. Hydrocephalic children are at increased risk for various developmental disabilities The mean intelligence quotient is reduced compared with the general population, particularly for performance tasks as compared with verbal abilities. Many children have abnormalities in memory function. Vision problems are common, including: Strabismus, Visuospatial abnormalities, Visual field defects, Optic atrophy with decreased acuity secondary to increased ICP.

48. Thank You