[Benign intracranial hypertension and continuous CSF pressure monitoring: case report]

The authors report a case of benign intracranial hypertension (BIH) treated with a ventriculoperitoneal shunt. A 62-year-old man was referred to the Kobe City General Hospital with several episodes of transient visual obscuration. Neurological examination on admission revealed bilateral papilledema and a right lower quadrantic homonymous hemianopsia. Computed tomography (CT) showed normalized ventricles and a low-density area in the left occipital lobe without mass effects. From the findings of magnetic resonance images (MRIs) the occipital lesion was diagnosed as a chronic intracerebral hematoma. Because the hematoma did not show mass effects. BIH was suspected to be responsible for the papilledema. In spite of intravenous administration of dexamethasone and glycerol for a week, a lumbar puncture showed an opening pressure of 360mm H2O. Several subsequent lumbar punctures failed to improve intracranial hypertension. The mean opening pressure of the last 6 punctures was 392mm H2O. The mean terminal pressure dropped to 32mm H2O after removal of 10m/ of cerebrospinal fluid (CSF). A spinal subarachnoid drainage was inserted at the level of L4-L5 interspace for continuous CSF pressure monitoring. The mean CSF pressure ranged from 20 to 40mmHg. The continuous recording showed typical B waves frequently and plateau waves (A waves) occasionally. Removal of only 8m/ of CSF caused significant pressure reduction immediately. Then, pressure returned to the predrainage level about 35 minutes later. These findings supported the diagnosis of BIH. A ventriculoperitoneal shunt was inserted, which resulted in rapid and complete resolution of the papilledema. Postoperative CSF monitoring returned to normal pressure and waves. This case emphasizes the usefulness of continuous CSF pressure recording for the diagnosis and subsequent therapy of BIH.