Hydrocephalus Treatment

Core Principle

1. Surgical Treatment

Ventriculoperitoneal (VP) Shunt — Primary Approach

• A catheter is inserted into the lateral ventricle (preferably the anterior horn of the right ventricle, where there is no choroid plexus) to reduce catheter blockage.
• CSF is diverted to the peritoneal cavity via a tube with a one-way pressure-sensitive valve.
• This is the most common shunt type in both adults and children.

• Meticulous aseptic technique + peri/postoperative antibiotics reduce infection risk.
• Adjustable valves allow the opening pressure to be modified non-invasively after placement.
• Anti-siphon devices prevent excessive CSF drainage when the patient is upright (important in the "slit ventricle" syndrome in children).

Ventriculoatrial (VA) Shunt

• CSF diverted to the right atrium — less common.
• Rare complications include pulmonary hypertension, pulmonary embolism, and nephritis (due to low-grade Staphylococcal infection of the shunt).

Endoscopic Third Ventriculostomy (ETV)

• The floor of the third ventricle is perforated endoscopically, creating an alternative CSF drainage pathway.
• Best suited for obstructive (non-communicating) hydrocephalus.
• Can be effective for shunt failure, though long-term results when used as a primary approach have been mixed.
• "Puncture of the floor of the third ventricle by endoscopic techniques ('third ventriculostomy') has been explored as an alternative to shunting... sometimes an effective treatment of shunt failure" — Adams and Victor's Principles of Neurology

2. Normal-Pressure Hydrocephalus (NPH)

Patient Selection for VP Shunt (Algorithm)

1. FLAIR MRI — look for: enlarged ventricles (especially temporal horns), transependymal CSF absorption, and disproportionate cortical atrophy relative to age.
2. Large-volume LP (tap test) — remove 30–50 mL CSF and observe gait over several days.
   • Gait improvement → proceed to VP shunt (good predictor of response).
   • Patients with extensive white-matter changes likely have lacunar state or vascular parkinsonism and may not benefit from shunting.
3. Other methods: ICP monitoring, CSF infusion tests, cisternography, regional cerebral blood flow (increased CBF after CSF removal predicts shunt response).

Algorithm for VP Shunt Selection in NPH — Bradley and Daroff's Neurology

Outcomes

• Approximately 80% improvement in carefully selected patients (some series).
• Gait disturbance responds better and faster than cognitive impairment.
• Clinical improvement may occur within weeks; ventricular shrinkage usually follows within 1–2 weeks of shunting.

3. Infantile and Childhood Hydrocephalus

• ~72% of shunted hydrocephalic children achieve IQ 70–100; a minority achieve normal intellect.
• Whether to shunt all hydrocephalic infants soon after birth remains controversial, as outcomes vary.

4. Acute / Emergency Hydrocephalus

• Caused by obstructive masses (colloid cyst of the third ventricle, ependymoma, cerebellar hemorrhage/infarction, intraventricular cysticercosis).
• Emergency external ventricular drain (EVD) or urgent VP shunt placement to decompress.
• Cerebellar hemorrhage compressing the brainstem: ventricular catheter for decompression → posterior fossa craniectomy to remove the mass.

5. Medical Management

• Acetazolamide (carbonic anhydrase inhibitor) — reduces CSF production; used in NPH and posthemorrhagic hydrocephalus of prematurity but clinical effects have been minimal in controlled trials.
• Steroids — useful when hydrocephalus is caused by inflammation (e.g., neurosarcoidosis, neurocysticercosis).
• Medical treatment is not definitive; most cases ultimately require surgical intervention.

6. Shunt Complications