There are several treatments to be considered when treating an individual with hydrocephalus. The first question should be whether the hydrocephalus does in fact need treating. In the case of an infant with generous ventricular size, there should be a clear trend of accelerated head growth. Typically, an infant's pediatrician should be measuring the child's head circumference at each office visit. This information is then plotted on a chart that contains the expected growth curves for the head. If a child's head is growing too fast, it becomes very apparent on the chart, and further studies are then indicated. Not uncommonly, massive hydrocephalus will be seen on the CAT scan. The size of the fluid spaces is not predictive of future brain function.
With regard to older children, headaches, lethargy, nausea and poor appetite, abnormal eye movements and declining school performance bring them to the doctor's office. When examined, the child may exhibit signs such as swelling of the eye's nerve (papilledema), or an inability to look upward. Studies such as CAT or MRI scans can then be ordered to evaluate the size of the ventricles.
The CAT or MRI scan is then studied. When the ventricles are enlarged, the cause is searched for. In the case of obstructive hydrocephalus, an unequal enlargement of the ventricles will point to the location of the obstruction. Causative factors for the obstruction are then searched for. Tumors or blood clots can obstruct the CSF pathways, and their removal can often reestablish a normal CSF flow pathway. Obstruction at the aqueduct or the outlets of the fourth ventricle can often be treated by surgically creating a new outlet for the ventricles through the floor of the third ventricle (see QuickTime view). Blockage of the foramen of Monroe with a resultant trapped lateral ventricle can be treated by surgically creating a window through the curtain of tissue separating the two lateral ventricles (septal fenestration).
When the CAT or MRI scans show a hydrocephalus that cannot be dealt with using one of the above techniques, a permanent diversionary device needs to be surgically implanted to draw the fluid out of the ventricles and carry it to some other cavity within the body where it will be reabsorbed into the bloodstream. Such a device is called a shunt.