Hydrocephalus

CT scan picture of Hydrocephalus
showing enlarged ventricles.


What is hydrocephalus?
Hydrocephalus is defined as the accumulation of excessive fluid in the brain. The fluid is actually cerebrospinal fluid which is normally present in the cranium and protects the brain. In hydrocephalus the excessive cerebrospinal fluid is present in the dilated spaces of the brain (ventricles) and compresses the normal brain. Hence normal brain function is lost. Incidence of hydrocephalus is 0.9 to 1.8 per thousand live births.

What are the types of hydrocephalus?
Hydrocephalus may be congenital (that is present during birth) or may be acquired any time after birth. Congenital hydrocephalus is usually of non communicating type. This means that there is some obstruction in the pathway of flow of the cerebrospinal fluid. Hydrocephalus which is acquired after birth (in conditions like tuberculous infection of the brain or bleeding inside the brain) is usually communicating type. Here the defect lies in the faulty absorption of the cerebrospinal fluid from the brain.

What are the causes of hydrocephalus?
Hydrocephalus is either due to excessive production or defective absorption of brain fluid. In both the cases, there is accumulation of fluid in the brain causing hydrocephalus.
The common causes are:

• Babies with congenital birth defects of the spinal cord.
• Chiari type 1 malformation (a kind malformation in the brain).
• Aqueductal stenosis (block in the pathway of flow of the brain fluid).
• Congenitally inherited.
• Following tuberculous infection of the brain.
• Neurocysticercosis (infection of the brain).
• Post hemorrhagic (bleeding inside the brain).
• In some types of brain tumor.
• In some types of spinal cord tumor.

What are the symptoms of hydrocephalus?
In young children there is rapid enlargement of the head. The head will be abnormally large compared to other children of similar age. The child will be irritable and head control will not be there. The skin over the head will be very thin and shiny. The child may have sun setting sign in the eyes (the eye ball cannot move up).There may be difficulty in breathing. There will be cognitive impairment and delayed developmental milestones. In older children and adults, there will be severe headache, nausea, vomiting, difficulty in walking and blurring of vision.

How do you diagnose hydrocephalus?
The physician usually can diagnose hydrocephalus after thorough neurological examination. The head circumference is usually more for the age of the patient. Radiological investigations like ultrasound, CT scan, MRI scan of the head are helpful in accurate diagnosis. The scan reveals the dilated spaces containing excessive fluid compressing the brain.

What are the treatment options available?
Treatment for hydrocephalus is mainly surgical. However in the waiting period for surgery drugs like acetazolamide and furosemide are helpful. The main purpose of surgery is to divert the excess fluid in the brain outside to either in the abdominal cavity or in the pleural space (this is the space inside the chest cavity). The fluid is drained by a tube made of silastic material. The procedure commonly performed is called ventriculo-peritoneal shunt. There are various types of shunt tubes available in the market and the operating neurosurgeon usually selects which one to use. Complications of surgery include infection, bleeding inside the brain, over drainage of the brain fluid, obstruction of the shunt tube and breakage of the shunt tube. In some few selected cases of hydrocephalus, newer technique called endoscopic third ventriculostomy can be done.

What is the prognosis of hydrocephalus after surgery?
Patient needs supportive care from the parents and the care takers. The child will be mentally impaired and needs proper vocational training. Team work is needed comprising of the treating physician, physiotherapist and rehabilitation specialists.

Did you know?
Hydrocephalus is defined as the accumulation of excessive fluid in the brain. The fluid is actually cerebrospinal fluid which is normally present in the cranium and protects the brain. In hydrocephalus the excessive cerebrospinal fluid is present in the dilated spaces of the brain (ventricles) and compresses the normal brain.