Normal pressure "herniation".

INTRODUCTION

Hydrocephalus with normal intracranial pressure has rarely been reported to result in herniation.

METHODS

Case report.

RESULTS

A 52-year-old man became acutely comatose with extensor posturing and ventriculomegaly 17 days after experiencing a primary ventricular hemorrhage. An external ventricular drain revealed normal intracranial pressure. After 24 hours without improvement with the drain set at a level of 5 mm H2O, negative-pressure siphoning (50 mL of cerebrospinal fluid [CSF] removed) reduced ventricular size and led to dramatic clinical recovery.

CONCLUSION

Normal pressure hydrocephalus can result in delayed brainstem herniation after ventricular hemorrhage. CSF siphoning in these patients can reverse the syndrome.