cns

1. Hydrocephalus

2. hydrocephalusslus
A condition in which excess CSF
builds up within the cerebral
ventricles due to :
Increased production or decreased
absorption of CSF.

3. CSF Circulation
Volume: 50 ml in infants -150 ml in an adult
Formation: by
1- Choroid plexus .
Circulation:
1- Lat. Ventricle → 3rd ventricle (more CSF is
added) → Cerebral aqueduct → 4th ventricle
(more CSF is added) → Foramina of L and
Magendi ----- Subarachnoid space.
----------- Arachnoid villi.

4. Causes of hydrocephalus
Obstructive (noncommunicating) hydrocephalus.
Due to obstruction within the ventricular system.
Nonobstructive or communicating hydrocephalus.
Dysfunction in absorption or secretion of CSF.
No obstruction within the ventricular system.

5. Causes of obstructive hydrocephalus
1. Obstruction of aqueduct of sylvius :
 Congenital atresia: may be sex linked recessive ( males)
 NF-1
2- Obstruction of Foramen of monro
3- Obstruction of Foramina of luscka and Magendi
Dandy Walker malformation
4- Obstruction from outside of any foraminae by a SOL
5- Obstruction from inside of any foraminae by :
 Post hemorrhagic (specially in premature)
 Post meningitis ( T.B , pneumocci , mumps)
6- Arnold Chiari malformation type - II
Progressive hydrocephalus & myelomeningocele.
7- Congenital TORCH infection : toxoplasmosis
8-Papilloma of the choroid plexus
9- Defect in CST absorption by A Villi : meningitis Leukemic infilterate

6. Congenital atresia of aqueduct of sylvius :

8. ( Dandy Walker malformation).
Figure 1. Prominent occiput and macrocephaly in an infant with Dandy-Walker
Prominent occiput and
macrocephaly in an infant with
Dandy-Walker malformation
Dandy-Walker malformation: midsagittal
(A) and axial (B) T1-weighted magnetic
resonance images reveal hypoplastic
cerebellum, elevated tentorium, and large
posterior fossa cyst in continuation with the
fourth ventricle.

9. Symptoms & signs
Mainly due to ↑ ICP
 Poor feeding
 Irritability
 Reduced activity
 High pitched cry
 Vomiting
 Seizures
 Accelerated head growth
In older patients
 Headache
 Change in personality
 Academic deterioration

10. Diagnosis
• In infant:
Head signs are marked as cranial sutures are still opened
 Large head with progressive increase in size (increase
head circumference on serial measurment)
 Fontanels are widely opened and bulging
 Suture are widely separated
 Dilated scalp veins
 Eyes deviated downwards ( sunset appearance)
 Skull percussion: cracked pot sound ( macewen sign)
 Craniotabes
 Back of skull : promeninet occiput in Dandy walker
foreshortened occiput in Arnold chiari

11. Diagnosis
 Vomiting
 Squint
 Delayed motor milestones
 Pyramidal tract lesion signs are common specially in LL
 In advanced cases mental deterioration and optic
atrophy

12. Diagnosis
3. General examination:
 Back of spine for tuft of hair, lipoma or angioma in spina
bifida
 Meningeomyelocele in Arnold chiari malformation
 Cerebellar ataxia in Dandy walker malformation
 Fundus examination for chorioretinitis in toxoplasmosis
 A cranial bruit is audible in association with many cases
of vein of Galen arteriovenous malformation

13. Diagnosis
• In older child:
Marked neurologic manifestations as sutures are not
easily separated with subsequent marked increase in
intracranial tension
 Bursting headache severe in the morning
 Blurring of vision
 Projectile vomiting ( unrelated to meals not preceded by
nausea)
 Bradycardia and hypertension
 Papilledema

14. Investigations
1. Cranial X-ray
 Before closure of sutures –
 Wide fontanels, wide separation of suture
 Craniofacial disproportion with large cranium
 After closure of sutures increase intra cranial
tension and an increase in convolutional
markings (beaten silver appearance)
2. Ultrasound - through the anterior fontanelle.
3. CT or MRI – diagnostic can detect ventricular
dilatation
- may detect the cause
4. Transillumination of the skull is positive with
massive dilatation of the ventricular system or in
the Dandy-Walker syndrome

15. Cranial X-ray

17. CT –SCAN of hydrocephalus

18. Treatment
• Therapy for hydrocephalus depends on the cause.
 Medical management, including the use of acetazolamide and
furosemide, may provide temporary relief by reducing the rate of
CSF production, but long-term results have been disappointing.
 Most cases of hydrocephalus require extracranial shunts,
ventriculoatrial (VA) & ventriculoperitoneal (VP)
The major complications of shunting are occlusion (characterized by
headache, papilledema, emesis, mental status changes) and
bacterial infection (fever, headache, meningismus), usually due to
Staphylococcus epidermidis

19. Extracranial shunts

20. Endoscopic third
ventriculostomy
• Endoscopic third ventriculostomy (ETV) : an opening is created in the floor of the third
ventricle using an endoscope placed within the ventricular system through a burr hole.
Treatment of obstructive hydrocephalus secondary to congenital aqueductal stenosis, .

21. PROGNOSIS.
 This depends on the cause of the dilated ventricles
 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.
 Visual problems are common, including strabismus,, visual field defects,
and optic atrophy with decreased acuity secondary to increased ICP.
 Some children show aggressive 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.
 It is imperative that hydrocephalic children receive long-term follow-up in a
multidisciplinary setting.