Chronic headache associated with a functioning shunt: usefulness of pressure monitoring. Chronic headaches in a shunt-dependent patient with small ventricles has long been treated with little or no regard to intracranial pressure. In this study, pressure monitoring on 12 such patients demonstrated that they fell into three distinct categories: 3 had headaches caused by intracranial hypertension, 2 had headaches from hypotension, and 7 showed no relation of symptoms to pressure. As therapeutic procedures for treating these three categories are entirely different and sometimes opposing, it is clear that intracranial pressure monitoring is essential to successful management of this complaint. 