Hydrocephalus
An excess of cerebrospinal fluid within the skull, also known as “water on the brain.” This condition is often present at birth in association with other abnormalities, especially SPINA BIFIDA. Untreated, the condition will progress to extreme sleepiness, seizures, and severe brain damage, and it may be fatal in a few weeks.
Cause
Hydrocephalus is caused by the excessive formation of spinal fluid, by a blockage of this fluid, or both. It may be present at birth or develop after a severe head injury, brain hemorrhage, infection (such as MENINGITIS), or brain tumor.
Symptoms
If the condition is present at birth, the symptoms include an enlarged head that continues to grow at an excessively fast rate, because the baby’s skull bones are not rigid, and they expand to accommodate the fluid. Other symptoms may include leg rigidity, EPILEPSY, irritability, lethargy, vomiting, and absence of reflexes.
If the condition occurs later in childhood, the skull cannot swell and the symptoms will be caused by a rising pressure within the skull characterized by HEADACHE, vomiting, loss of coordination, and deteriorating mental function.
Diagnosis
The condition is diagnosed with computerized axial tomography (CAT) or magnetic resonance imaging (MRI) brain scans, which can reveal the location and nature of the problem.
Treatment
Excess fluid can usually be drained away by using a shunt from the brain to another part of the body (such as the lining of the abdomen), where it can be absorbed by the body. The shunt is inserted into the brain through a hole in the skull; sometimes, the device will be left in place indefinitely.
In older children, treatment may be aimed at resolving the underlying condition (head injury, brain hemorrhage, infection, or tumor).
