Chronic headache in the shunt-dependent adolescent with nearly normal ventricular volume: diagnosis and treatment.

The shunt-dependent adolescent will occasionally manifest shunt malfunction by intermittent or chronic headache without any obvious signs of increased intracranial pressure (ICP). A small percentage of these patients will have nearly normal ventricular volume, making the diagnosis and treatment difficult. The authors present a comprehensive approach to this problem that uses computerized axial tomography (CT), ICP monitoring, positive contrast or isotope shunt scan, shunt revision, subtemporal craniectomy, or medical management as the individual situation dictates. The CT scan identifies patients with nearly normal ventricular volume. ICP monitoring then determines whether there is shunt malfunction. The shunt scan aids in localization of the malfunction. For distal obstruction, a simple revision is performed. When proximal shunt malfunction occurs, either subtemporal craniectomy or revision is carried out. It has been documented that occasionally ICP is episodically increased in the absence of shunt malfunction. This is secondary to abnormal brain compliance, and subtemporal craniectomy alone or in conjunction with corticosteroids is curative. This comprehensive approach is designed to provide a method for recognizing and treating intermittently increased ICP in the shunt-dependent child.