Hydrocephalus

 Hydrocephalus

Imbalance between the production and absorption of cerebrospinal fluid.

Chacterized by abnormal increase in volume of cerebrospinal fluid intracranial cavity.

Resulting inlargement of infants head 

Enlarged ventricles and filled fluid ventricles.

CSF Pathway

CSF produced by choroid plexus in lateral ventricles of brain. (1st and 2 nd ventricles)

Flow to 3rd ventricle

Through Cerebral aqueduct

Flow to 4th ventricles

Through median apertures, lateral apertures 

Cisterna of subarachnoid space

CSF finally reabsorbed into venous sinuses by arachnid villi.

Classification of Hydrocephalus

1. Non-communicating or obstructive hydrocephalus

(Obstruction in flow of CSF)

2. Communicating or non-obstructive hydrocephalus

1. Non-communicating or obstructive hydrocephalus

Obstruction of CSF, within ventricles and subarachnoid space.

Resulting in disrupt with circulation and obstruction of CSF 

1. Congenital causes

Stenosis of aqueduct of sylvius

Meningomyelocele

Dandy-walker syndrome

Arnold-chiari malformation

2.  Acquired causes

During neonatal period and early infancy

1. Infection caused by rubella, cytomegalovirus, toxoplasmosis (opportunistic infection).

2. Spontaneous intracranial hemorrhage

3. Intracranial tumors such as-

Medulloblastoma, Craniopharyngioma, Astrocytoma

4. Head injury

2. Communicating non- obstructive hydrocephalus

Normal flow of CSF, within ventricular system but interference outside the ventricles causing decrease absorption of CSF in subarachnoid villi.

Causes- 

1. Subarachnoid hemorrhage

2. Meningitis

3. Toxoplasmosis 

4. Cytomegalovirus

5. Diseases of connective tissue such as Hurler's syndrome.

Clinical features

1. Enlargement of Skull; accumulation of CSF in ventricles leading to enlargement of Skull/ depressed face.

2. Dilation of cranial sutures; cranial sutures become widely separated

3. Closure anterior frontanelle delayed

4. Bulging fontanele

5. High pitch cry due to increased ICP

6. Poor feeding

7. Macewen's sign

Tapping (percussion) skull near junction of frontal, temporal and parietal bone - produce hallow or cracked pot sound.

6. Scalp vein prominent and scalp appear shiny.

7. Sun setting sign

Eyes focused, depressed downward

8. Restless/ irritable/ sluggish pupillary response to light 

9. Vomiting

10. Spasticity of lower limb.

11. Failure to thrive

Clinical features in older children

No enlargement of head but increased ICP resulting in -

1. Headache in awakening in morning

2. Nausea and vomiting

3. Irritability and high pitch cry

4. Lethargy

5. Apathy

6. Confusion

7. Affected motor ability

Diagnostic evaluation

1. Increase head circumference - show increased ICP

2. CT scan /MRI scan - reveals ventricular enlargement or dilation, may structural defect, if present.

3. Ultrasound or Echoencephalography

4. X-ray shows large skull with wide cranial sutures.

Management

1. Relief of Hydrocephalus or reducing Increased intracranial pressure

2. Osmotic diuretic - Acetazolamide and frusemide to reduce rate of CSF production.

Surgical Management

Shunt helps in removing excessive CSF from ventricle and reducing the increased intracranial pressure.

1. Ventriculoperitoneal shunt; from ventricles to peritoneal cavity

2. Ventriculoatrial shunt; from ventricles to left atrium

3. Ventriculopleural shunt; from ventricles to pleural cavity

4. Ventriculoureteric shunt; from ventricles to ureters

Complication arise with shunt -

1. Kinking; twist

2. Separation or plugging of shunt tubing

3. Infection of shunt lead to ventriculitis and septicemia