An abnormal amount of cerebrespinal fluid, usually under increased pressure, under the skull. The term "water on the brain" is a non-medical term sometimes used to describe the condition.
Hydrocephalus is sometimes associated with other spinal abnormalities such as Spina Bifida.
The condition may be congenital (present at birth) or may develop as a result of major head injury, brain haemorrhage, infection (meningitis for example), or a tumour.
Hydrocephalus is caused by excessive formation of cerebrospinal fluid, by a block in the circulation of this fluid, or both.
Skull enlargement is due to pressure from excess fluid within the cavities of the brain. To prevent brain damage, the fluid must be drained by means of a tube inserted through a hole made in the skull.
When the condition is congenital, the main feature is an enlarged head that continues to grow at an abnormally fast rate because the bones are not rigid and expand to accomodate the fluid. Other features are the rigidity of the legs, epilepsy, irritability <Note: You try smiling with the mother and father of all headaches <g>>, lethargy, vomiting, and the absence of normal reflex actions. <Of course if the condition is coupled with Spina Bifida these reactions, certainly below the waist, are likely to be absent anyway.> If the condition is not treated, it progresses to extreme drowsiness, severe brain damage, and seizures, which may lead to the baby's death within a matter of weeks.
When the condition occurs later in childhood or adulthood, the skull is no longer flexible and symptoms are caused by raised pressure within the skull. Symptoms include headache, vomiting, loss of coordination <yet another handy excuse for typos <s>>, and deterioration of the normal mental functions <no I'm not lagged my Spitz Holter valve has packed up <G>>.
<Note: Another symptom is an increase in vocabulary. Veering toward the profane as the subject of the condition makes known their displeasure at the newfound circumstances. To whit a blinding headache as if they had just downed 14 bottles of Stoly and a crate of Scotch>
Diagnosis and Treatment
CT Scanning or MRI show the location and nature of any obstruction. In most cases treatment aims to drain excess fluid away from the brain to another part of the body, such as the peritoneal cavity (lining of the abdomen) where it can be absorbed.
Drainage is achieved by means of a valve and shunt (tube) <The Spitz Holter which I have fitted is the most common I believe>, which is inserted into the brain through a hole made in the skull. In some cases the shunt must be left in place for an indefinite period <read Life or thereabouts>.
In older children or adults, treatment is sometimes only for the underlying cause.
This has been a personalised look at Hydrocephalus based on an entry in a medical encyclopaedia. For a specific look at an offical site, which is still pitched at an acceptable level, please visit the ASBAH Hydrocephalus page.