CEREBROSPINAL-FLUID SHUNTING IN IDIOPATHIC NORMAL-PRESSURE HYDROCEPHALUS OF THE ELDERLY - EFFECT OF PERIVENTRICULAR AND DEEP WHITE-MATTER LESIONS

OBJECTIVE: We investigated the effect of periventricular and deep whit e matter lesions (DWMLs) on outcome after cerebrospinal fluid shunting in a prospective series of elderly patients with idiopathic normal-pr essure hydrocephalus. METHODS: White matter lesions were assessed with T2-weighted magnetic resonance scans according to a standard protocol in 41 patients with idiopathic normal-pressure hydrocephalus of the e lderly who underwent subsequent shunting. In all patients, the diagnos is of idiopathic normal-pressure hydrocephalus had been established pr eoperatively by clinical and diagnostic investigations. RESULTS: At a mean follow-up of 16 months, clinical improvement was observed in 37 o f 41 patients (90%). There was no persistent morbidity related to surg ery. The degree of overall clinical improvement was negatively correla ted with the extension of periventricular lesions (correlation coeffic ient r=-0.324 [P=0.004]) and DWMLs (correlation coefficient r=-0.373 [ P=0.02]). This negative correlation was also noted when the analysis w as conducted separately for each of the cardinal symptoms (gait distur bance, cognitive impairment, and urinary incontinence). There was no c onsistent pattern of periventricular and DWMLs in the four patients wh o failed to respond to shunting. CONCLUSION: Periventricular and DWMLs of varying degrees are common findings on magnetic resonance scans of patients with idiopathic normal-pressure hydrocephalus, individuals w ith DWMLs suggestive of concomitant vascular encephalopathy may also b enefit from cerebrospinal fluid diversion. Although, in general, the d egree of improvement depends on the severity of periventricular and DW MLs, patients with more extensive WMLs still may derive clinical benef it from the operation.