Non-obstructive hydrocephalus associated with intracranial schwannomas: hyperproteinorrhachia as an etiopathological factor?

Abstract

This series illustrates the association of communicating hydrocephalus with intracranial non-obstructive schwannomas. This association has commonly been observed, however it has only been reported once previously. Moreover, in all the patients we present, hyperproteinorrhachia was a common denominator. This finding may therefore be the underlying mechanism for hydrocephalus. Seven patients presenting with intracranial schwannomas along with non-obstructive hydrocephalus and hyperproteinorrhachia are reported. Six had a vestibular schwannoma and presented with a unilateral deafness and various degrees of gait disturbance, urinary incontinence and neuropsychological impairment. Due to their advanced ages, these patients underwent a ventriculo-peritoneal shunt, and their symptoms related to hydrocephalus resolved. One patient that suffered from hemifacial dysesthesia and memory deficits presented with a non-obstructive trigeminal schwannoma. In this case the tumour was removed and the hydrocephalus was consequently reversed, and the CSF protein content normalized. The constant finding of hyperproteinorrhachia in all these patients suggests that a high CSF protein content may be the underlying cause of hydrocephalus through a speculative mechanism of decreased CSF resorption.