1. Dr Shreedhar Paudel May, 2009
CNS DISORDERS CONT….
Dr Shreedhar Paudel
May, 2009

2. Hydrocephalus Increased amount of CSF in the ventricles of the brain
Increase CSF pressure
Ventricular dilatation
Due to imbalance between production and absorption of CSF

4. Hydrocephalus…. CSF physiology
Secreted at the choroid plexus of the ventricles
Absorbed at arachnoid villi and channeled into the venous circulation
720 ml CSF is secreted in a day

5. CSF Circulation
It is produced in the brain by modified ependymal cells in the choroid plexus (approx %),
The remainder is formed around blood vessels and along ventricular walls
It circulates from the choroid plexus through the interventricular foramina (foramen of Monro) into the third ventricle,
Then through the cerebral aqueduct (aqueduct of Sylvius) into the fourth ventricle, where it exits through two lateral apertures (foramina of Luschka) and one median aperture (foramen of Magendie)
It then flows through the cerebellomedullary cistern down the spinal cord and over the cerebral hemispheres.

6. CSF Circulation..
Traditionally, it has been thought that CSF returns to the vascular system by entering the dural venous sinuses via the arachnoid granulations/villi. However, there is suggestion that the CSF flow along the cranial nerves and spinal nerve roots allow it into the lymphatic channels; this flow may play a substantial role in CSF reabsorbtion, particularly in the neonate, in which arachnoid granulations are sparsely distributed.

7. Hydrocephalus… Types Communicating Hydrocephalus
No blockage in the CSF flow
Non-communicating Hydrocephalus
Blockage of CSF flow
Commonly at the level of aqueduct or foramina of Luschaka and Magendie

8. Hydrocephalus… Causes Congenital Hydrocephalus
Intrauterine infection of TORCH
Intraventricular hemorrhage
Congenital malformations like
Aqueductal stenosis
Dandy-Walker syndrome
Arnold-Chiari syndrome

9. Dandy-Walker malformation
Characterized by
Agenesis or hypoplasia of the cerebellar vermis,
Cystic dilatation of the fourth ventricle,
Enlargement of the posterior fossa.
Approximately 70-90% of patients have hydrocephalus, which often develops postnatally
Dandy-Walker malformation may be associated with atresia of the foramen of Magendie and, possibly, the foramen of Luschka

10. Arnold-Chiari Syndrome
A downward displacement of the cerebellar tonsils and the medulla through the foramen magnum.
Portions of cerebellum and brain stem herniate into cervical spinal canal

11. Types of Arnold-Chiari Malformation
Type I: generally asymptomatic during childhood, but often manifests with headaches and cerebellar symptoms.
Type II: usually accompanied by a myelomeningocele leading to partial or complete paralysis below the spinal defect. Abnormal development of the cerebellar vermis and medulla occur, and they both descend into the foramen magnum. Hydrocephalus is also nearly always present.
Type III causes severe neurological defects. It is associated with an encephalocele
Type IV involves a failure of brain development

12. Hydrocephalus…. Causes… Acquired Hydrocephalus Pyogenic meningitis
Tuberculosis
Post intra-ventricular hemorrhage
Posterior fossa tumors : medulloblastoma, astrocytoma, ependymoma
Intracranial/intraventricular hemorrhage

13. Hydrocephalus…. Hydrocephalus Ex Vacuo
also called normal pressure hydrocephalus
Ventricular dilatation due to cerebral atrophy
No increase in CSF pressure

14. Clinical features Inappropriate enlargement of head size
Delayed closure of fontanel and sutures
Prominent forehead
Prominent scalp veins
Sunset sign in eyes
Signs and symptoms of raised ICP
Personality and behavioral changes

16. Hydrocephalus…. Diagnosis Serial measurement of head circumference
(An increase in head circumference more than cm in every 2 weeks in first 3 months of life-diagnostic)
-USG head
-CT/ MRI of head

17. Differential diagnosis of large head
Megalencephaly: Hurler’s syndrome, metachromatic leukodystrophy, Tay Sach’s disease
No signs of raised ICP
Ventricles are not enlarged
Normal CSF pressure
Chronic subdural hematoma
Familial macrocephaly

18. Treatment of Hydrocephalus
General nursing care
Medical management to decrease CSF volume and CSF pressure : Acetazolamide, oral Glycerol
Management of raised ICP
Treatment of the cause
Surgical treatment : ventriculo-peritoneal shunt, removal of the cause of obstruction

19. Neural Tube Defects
Congenital structural anomalies characterized by failure of proper closure of neural tube and covering mesoderm and ectoderm

20. Neural Tube Defects Very common structural congenital anomaly
Incidence is 1.5 per 1,000 live births
Risk in second sibling is 5 per live 100 births

21. Neural Tube Defects Etiology Decreased maternal folate intake
Multifactorial inheritance
Other maternal risk factors including alcohol, radiation exposure, DM, Valproate, Carbamazepine and zinc deficiency
Chromosomal abnormalities like trisomy of 13 and 15

22. Neural Tube Defects Clinical features Commonest defect is spina bifida
Others might be anencephaly, encephalocele….
Defect will be obvious at birth
Commonly associated with other anomalies
Lower body paralysis
Bowel and bladder dysfunction
Learning disabilities
Hydrocephalus

24. Neural Tube Defects (NTD)
Spina bifida
Spina bifida occulta: the mildest form of spina bifida (occulta means hidden). Most children with this type of defect never have any health problems, and the spinal cord is often unaffected.

25. Spina bifida
Meningocele : involves the meninges, the membranes responsible for covering and protecting the brain and spinal cord. If the meninges push through the hole in the vertebrae, the sac is called a meningocele.

26. Spina bifida..
Myelomeningocele : the most severe form of spina bifida. It occurs when the meninges push through the hole in the back, and the spinal cord also pushes though. Most babies who are born with this type of spina bifida also have hydrocephalus,

27. Spina bifida..
Because of the abnormal development of and damage to the spinal cord, a child with myelomeningocele typically has some paralysis. The degree of paralysis largely depends on where the opening occurs in the spine. The higher the opening is on the back, the more severe the paralysis tends to be.

28. Diagnosis of NTD
Prenatal diagnosis
Alpha fetoprotein level in maternal serum between weeks of pregnancy
Amniocentesis for alpha fetoprotein level in amniotic fluid in early pregnancy
USG of the fetus

29. Diagnosis of NTD Postnatal diagnosis USG of head, sac, kidney
CXR and X-Ray spine
C/S of the leaking CSF and swab C/S from the lesion
Routine investigations

30. Treatment of NTD Multidisciplinary approach PEDIATRICIAN
NEUROLOGIST/ NEUROSURGEON
UROLOGIST
ORTHOPEDIC SURGEON
PHYSIOTHERAPIST
SOCIAL WORKER
PSYCHIATRIST

31. Treatment of NTD Decision of treatment depends on Degree of paralysis
Presence of hydrocephalus
Kyphosis
Other congenital anomalies
Evidence of infection of CNS

32. Treatment of NTD Surgery
EARLY CLOSURE PREVENTS NEUROLOGICAL DETERIORATION
OPEN LESION WITH CSF LEAK SHOULD BE CLOSED WITHIN 24 HOURS
CLOSED LESION SHOULD BE REPAIRED WITHIN 48 HOURS
INFECTED LESION SHOULD BE REPAIRED ONLY AFTER CSF BECOMES STERILE ( should be given parenteral antibiotics)

33. Treatment of NTD Lorber’s criteria for selective surgery
Surgery is not done in case of
Severe paraplegia at or below L3 level
Kyphosis/ scoliosis
Gross hydrocephalus
Associated gross anomalies
Intracerebral birth injuries
Neonatal ventriculitis before closure of the back
90% would die within the neonatal period

34. Prevention
Folic acid supplementation to all pregnant women– 0.4 mg/ day
If there is history of previous birth of NTD babies then 5 mg/ day folic acid
Counseling of the family with previous child with NTD
Risk of recurrence- 3.5% with 1 affected child
10% with 2 affected child
25% with 3 affected child
Folate supplementation reduces recurrence risk by 70%