Dementia associated with normal pressure hydrocephalus

The aim of this study is to sum up our current knowledge on the so-called 'normal pressure hydrocephalus' syndrome. It is based upon a review of the literature dealing with the subject and an original series of 32 cases with suspected hydrocephalic dementia that were surgically treated at our institution by cerebrospinal fluid (CSF) ventriculoatrial or peritoneal shunt. The results of surgery were considered in relation to clinical history and different diagnostic examinations: CT scan, magnetic resonance imaging, isotope and/or computed cisternography, constant infusion manometric test and intraventricular pressure recording. Intracranial pressure (ICP) was analyzed during both resting conditions and spontaneously (REM phase of sleep) or artificially induced (jugular compression and intraventricular CSF mock infusion) increases. The ventricular enlargement and the slope of the intracranial elastance seem to provide the most reliable data for diagnosis and surgical prognosis.