Clinical Study A prospective study of ventriculo-peritoneal shunting for idiopathic normal pressure hydrocephalus George Razay a, * , Anthea Vreugdenhil a , John Liddell b a Department of Medicine, Launceston General Hospital, University of Tasmania, PO Box 1963, Launceston, Tasmania 7250, Australia b Royal Hobart Hospital, University of Tasmania, Hobart, Australia. article info Article history: Received 16 January 2008 Accepted 14 December 2008 Keywords: Normal pressure hydrocephalus Dementia Balance Neurosurgery Ventriculo-peritoneal shunting abstract Idiopathic normal pressure hydrocephalus (INPH) is a potentially treatable form of dementia but its diag- nosis is difficult and the effectiveness of shunting remains controversial. This study investigates the clin- ical outcomes of ventriculo-peritoneal shunting in a controlled trial of 33 consecutive patients with INPH. Mean age was 77.2 years (range 58–92 years) and the duration of symptoms was 4.6 years (3 months–14 years). Nineteen patients underwent shunt surgery. At 3–4 months follow-up, patients who had under- gone shunt surgery, compared to those who had not (controls), had significantly better global change rat- ings (median Clinician’s Interview Based Impression of Change with Carer Input rating of 2 [moderately improved] versus 6 [moderately worsened], respectively, p < 0.001), had increased Mini Mental State Examination scores by 5 points (p < 0.001) and were 6.3 s faster on the Timed ‘‘up and go” test (p = 0.008). We conclude that ventriculo-peritoneal shunting is associated with improved clinical out- comes for patients with INPH. Crown Copyright Ó 2009 Published by Elsevier Ltd. All rights reserved. 1. Introduction Idiopathic normal pressure hydrocephalus (INPH) is one of the few potentially treatable causes of dementia, but our understand- ing of the condition remains poor. The clinical and radiological diagnosis of INPH is notoriously difficult, especially in the elderly. The diagnosis is based on the presence of the clinical triad, first de- scribed by Adam and Hakim in 1965, 1 of progressive gait disorder, dementia and urinary disturbance in the presence of dilated ventri- cles out of proportion to any sulcal enlargement. However, no definitive method exists to confirm the diagnosis and the only way to prove the diagnosis is to show improvement following cere- brospinal fluid (CSF) diversion, most commonly by the surgical insertion of a ventriculo-peritoneal shunt. Moreover, studies of the outcome of shunting for INPH have been few, with variable success rates and without controls. 2 We have, therefore, investigated the clinical outcomes of ventri- culo-peritoneal shunting for patients with INPH in a non-random- ised, open-labelled, controlled trial using primary and secondary efficacy measures. 2. Methods Thirty-three consecutive patients diagnosed with probable INPH were enrolled in the study over a 4 year period from the Launceston General Hospital Memory Disorders Clinic, Launceston, Tasmania. The diagnostic inclusion criteria included: (i) mild cog- nitive impairment or dementia, 3 and/or gait disorder; (ii) enlarged ventricles on brain imaging, regardless of the presence of cerebral atrophy or white matter ischaemic lesions; and (iii) ventricular sta- sis on a CSF flow study (cisternography) over 48 hours. Cisternog- raphy assesses CSF flow by visualising the ventricular conducting system and evaluating CSF absorption and clearance. 4 The diagno- sis was made by the first investigator, a geriatrician. Patients were informed about the study at the time of diagnosis. The intention was to treat the entire cohort with a shunt and there were no exclusion criteria for shunting other than patient refusal to accept surgery. Nineteen patients were referred for neurosurgical assess- ment and all underwent shunt surgery, having a ventriculo-perito- neal shunt with an adjustable valve inserted. Ten patients declined a referral for assessment for surgery after consultation with family. Four patients who elected to proceed with surgery but were still on the waiting list were also included in the control group for the analysis. All patients had CSF testing for Creutzfeldt-Jakob disease and had negative results. Clinical outcomes were measured at baseline and at 3–4 months follow-up by assessors independent of the investigation team. The primary efficacy measure was the Clinician’s Interview Based Impression of Change with Carer Input (CIBIC-plus) rating scale. 5 This scale was used to assess change in global ratings, as well as cognitive, balance and gait, and urinary functioning. Scores ranged from 1 to 7 (1, markedly improved relative to baseline; 4, no change; 7, markedly worse). Secondary efficacy measures 0967-5868/$ - see front matter Crown Copyright Ó 2009 Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.jocn.2008.12.007 * Corresponding author. Tel.: +61 3 6348 7111; fax: +61 3 6348 7090. E-mail address: george.razay@dhhs.tas.gov.au (G. Razay). Journal of Clinical Neuroscience 16 (2009) 1180–1183 Contents lists available at ScienceDirect Journal of Clinical Neuroscience journal homepage: www.elsevier.com/locate/jocn