Blake's pouch cyst-like imaging abnormalities in idiopathic normal pressure hydrocephalus

Abstract

Objective

Blake's pouch cyst is a cause of congenital non-communicating hydrocephalus. Recent study revealed that adult onset communicating normal pressure hydrocephalus sometimes accompanied by Blake's pouch cyst-like imaging abnormalities. However, relationships between two disease entities remains uncovered. The aim of this study was to investigate the prevalence of Blake's pouch cyst-like imaging abnormalities in idiopathic normal pressure hydrocephalus and their impact on the clinical features.

Methods

First, we investigated the existence of Blake's pouch cyst-like imaging abnormalities in 46 idiopathic normal pressure hydrocephalus patients (mean age 76.8 ± 5.2 years old; 28 women) and 247 normal controls (mean age 65.2 ± 4.0 years old; 120 women). Second, the demographic, clinical and imaging characteristics were compared between idiopathic normal pressure hydrocephalus with and without Blake's pouch cyst-like imaging abnormalities.

Results

Blake's pouch cyst-like imaging abnormalities were more prevalent in idiopathic normal pressure hydrocephalus patients (17.4 %) than in the normal population (2.4 %). Idiopathic normal pressure hydrocephalus with Blake's pouch cyst-like imaging abnormalities showed a trend toward a younger onset than those without Blake's pouch cyst-like imaging abnormalities, while clinical features, including the response to cerebrospinal fluid tap test and shunt treatment, did not differ between two groups.

Conclusions

Incomplete cerebrospinal fluid obstruction associated with Blake's pouch cyst-like imaging abnormalities may be a cause of idiopathic normal pressure hydrocephalus.