Cerebral blood flow during plateau waves in a patient with benign intracranial hypertension--case report.

A 50-year-old male presented with benign intracranial hypertension (BIH). He was admitted to our hospital for headache and papilledema. The diagnosis was BIH as continuous monitoring of lumbar cerebrospinal fluid pressure (CSFP) showed high basal pressure with intermittent plateau waves. Ten months after successful ventriculoperitoneal shunting, he presented with headache again due to shunt malfunction. CSFP monitoring showed the same findings as before. Regional cerebral blood flow (rCBF) was measured by positron emission tomography (PET) using the 15O-labeled water autoradiographic method with simultaneous recording of lumbar CSFP. The rCBF values of the cerebral cortex, white matter, thalamus, cerebellar cortex, and pons were evaluated during both the plateau waves and the intervals. In spite of severely reduced cerebral perfusion pressure, rCBF during the plateau waves was not reduced when compared with the rCBF of normal volunteers in all regions. This result might explain why patients with BIH show no impairment of consciousness or focal signs during the plateau waves.