Hydrocephalus

• Derived from two Greek words
  • Hydro - water
  • Kefale - head
• Literally means “water in the head”
• Hydrocephalus is the abnormal enlargement of the brain ventricles due to the excessive accumulation of CSF
• This may be as a result of:
  • Excessive production of CSF
  • Disturbance in the flow of CSF
  • Defective absorption of CSF

• The incidence of congenital hydrocephalus is 3 per 1,000 live births (United States)
• M:F (1:1)
• NPH has a slight male preponderance (M:F; 1.3:1)

• Normal CSF production is 0.20-0.35 mL/min
• About 20 mL/hr
• 450-500 mL/day
• CSF is produced majorly by the choroid plexus, which is located within the ventricular system, but also by the ependymal lining of the ventricles and dural sleeve around cranial nerves.
• About 150 mL in the ventricles, subarachnoid space, and basal cisterns at a time
• Turnover is three times per day
• Absorbed into the venous sinuses via the arachnoid villi

Functions of CSF

• Mechanical cushion (buoyancy)
• Source of nutrients
• Transport medium for waste products
• Control of homeostasis

• Excessive CSF accumulation as a result of:
  • Increased production
  • Obstruction of CSF pathways
  • Impairment of absorption
• Monro-Kellie Doctrine
  • Older children and adults

• Communicating or Non-Communicating
• Congenital or Acquired
• Infantile or Adult
• Normal Pressure Hydrocephalus (NPH)

Non-Communicating Hydrocephalus

• No communication between the ventricular system and subarachnoid space

Communicating Hydrocephalus

• There is communication throughout the ventricular system

Congenital

• Aqueductal Stenosis
• Chiari Malformation
• Dandy-Walker Syndrome
• Congenital Absence of Arachnoid Granulations
• Vein of Galen Malformation

Acquired

Infective

• Meningitis (bacterial, TB)
• Ventriculitis

Neoplastic

• Choroid Papilloma
• Medulloblastoma
• Ependymoma
• Glioma

Intracranial Hemorrhage

• IVH (Intraventricular Hemorrhage)
• SAH (Subarachnoid Hemorrhage)

Clinical features of hydrocephalus depend on:

• Patient's age
• Duration/Rapidity of onset

Neonates and Infants

• Increasing head circumference
• Delayed developmental milestones
• Loss of already achieved milestones
• Poor feeding
• Irritability
• Reduced activity
• Vomiting

Older Children

• Headaches
• Vomiting
• Blurred vision
• Poor school performance
• Difficulty in walking and loss of previously attained milestones
• Drowsiness

Adults

• Headaches
• Nausea and vomiting
• Blurred vision and visual loss
• Difficulty in walking
• Drowsiness
• Cognitive deterioration
• Incontinence (urinary first, fecal later if condition remains untreated)

Normal Pressure Hydrocephalus

• Normal pressure hydrocephalus (NPH) usually occurs in patients older than 60 years
• Enlarged ventricles but no sign of raised ICP
• Normal CSF pressure at lumbar puncture (LP)
• Absence of papilledema
• The classic Hakim triad of symptoms includes:
  • Gait apraxia
  • Incontinence
  • Dementia

Physical Examination

• Head enlargement (macrocephaly)
• Craniofacial disproportion in favor of the cranium
• Dilated scalp veins
• Sun setting eye appearance
• OFC (Occipital Frontal Circumference)
• Fontanelles (patency, diameter, topography, tension, etc.)
• Sutural diastasis
• Light fixation and visual tracking
• Neck control
• Increased limb tone and reflexes
• Papilledema
• Examine other parts of the body (VACTERL H)
• Macewen sign: A "cracked pot" sound is noted on percussion of the head.
• Transillumination
• If on shunt, further examination
• If spina bifida, further examination

• Magnetic resonance imaging (MRI)
• Computed tomography (CT) scan
• Ultrasonography through the anterior fontanelles in infants (TFUSS)
• CSF analysis
• E, U, Cr (Electrolytes, Urea, Creatinine)
• FBC (Full blood count)

Shunting

• Ventriculoperitoneal
• Ventriculoatrial
• Ventriculopleural
• Ventriculocisternal (Torkildsen procedure)
• Lumboperitoneal

Endoscopic Third Ventriculostomy

• Used for non-communicating hydrocephalus

Others

• Tumour excision
• Medical treatment
• Ventricular tap

Medical treatment is used when surgical intervention is not feasible yet:

• Decreasing CSF secretion by the choroid plexus – (Acetazolamide, 100 mg/kg/day and Furosemide, 1 mg/kg/day)
• Increasing CSF reabsorption - Isosorbide (effectiveness is questionable)

Related to progression of hydrocephalus

• Visual changes leading to blindness
• Cognitive dysfunction

Complications of VP Shunt

• Intraop/Postop: Cranial/Abdominal complications
• Procedural/shunt malfunction/Infective/hemorrhage/Underdrainage/Overdrainage:
  • Intracerebral hematoma (from direct brain injury), subdural hematoma (from overdrainage)
  • Shunt infection, meningitis, encephalitis, ventriculitis, skull osteomyelitis, shunt tract infection
  • Gut perforation, peritonitis, intraabdominal abscess, intussusception, volvulus, CSF ascites, hydrocele, hernia, abdominal pseudocyst
  • Shunt migration, disconnection, blockage, kinking
• Ventriculoatrial (VA) shunt: Sepsis, shunt embolus, arrhythmias, endocarditis, pulmonary hypertension

Shunt Infection

• 5-15% of all shunt procedures get infected
• 70% occur within 1 month
• Commonest organism is Staphylococcus epidermidis (70%)
• Others include Staphylococcus aureus, Enterococci, Streptococci, GNB (Gram-negative bacilli)

Management of Shunt Infection

• CSF analysis/microscopy culture sensitivity
• IV antibiotics
• External drainage
• Change of shunt

Paediatrics

• Hydraencephaly
• Subgaleal hematoma
• Soto disease
• Familial

Adults

• Alzheimer disease

Arrested Hydrocephalus

• Mild or moderate ventriculomegaly (ventricular size remains stable)
• CSF pressure is normal, no raised ICP
• No new neurological deficits
• Advancing psychomotor development with age

Hydrocephalus Ex-vacuo

• Ventricular enlargement
• Dilatation of sulci
• No obstruction in CSF pathway
• CSF pressure is normal
• Seen in cerebral atrophy

• Long-term outcome is directly related to the cause of hydrocephalus and promptness of management.

• Hydrocephalus remains a common condition in neurosurgical services.
• Early recognition and management can prevent neurological sequelae.