Mortality and risk of dementia in normal-pressure hydrocephalus: A population study

Abstract

Introduction: We examined mortality, dementia, and progression of hydrocephalic symptoms among untreated individuals with idiopathic normal-pressure hydrocephalus (iNPH) in a population-based sample.

Methods: A total of 1235 persons were examined between 1986 and 2012. Shunted individuals were excluded. We examined 53 persons with hydrocephalic ventricular enlargement (probable iNPH: n = 24, asymptomatic or possible iNPH: n = 29). Comparisons were made with individuals without hydrocephalic ventricular enlargement.

Results: The 5-year mortality was 87.5% among those with probable iNPH. The hazard ratio (HR) for death was 3.8 (95% confidence interval [CI]: 2.5-6.0) for probable iNPH. Those with possible iNPH and asymptomatic hydrocephalic ventricular enlargement had increased risk of developing dementia, HR 2.8 (95% CI: 1.5-5.2). Only two individuals with hydrocephalic ventricular enlargement remained asymptomatic.

Discussion: In the present sample, persons with clinical and imaging signs of iNPH had excess mortality and an increased risk of dementia. The data also suggest that radiological signs of iNPH might be more important than previously supposed.

Keywords: Dementia; Epidemiology; Long-term outcome; Mortality; Natural course; Normal-pressure hydrocephalus; Outcome.