Insights into the pathogenesis of normal-pressure hydrocephalus

Abstract

Normal-pressure hydrocephalus (NPH) is a poorly defined clinical syndrome, classically characterized by the phenotypic triad of gait instability, cognitive impairment, and urinary incontinence, accompanied by neuroimaging evidence of ventriculomegaly and disproportionally enlarged subarachnoid space hydrocephalus and normal intracranial pressure.1,2 The diagnosis of this syndrome is complex since the characterizing symptoms are highly nonspecific and occur together in fewer than two thirds of NPH patients. In addition, a growing body of evidence supports the observation that NPH patients often have a coexistent neurodegenerative disorder that may be a concurrent or sole cause of both clinical symptoms and ventriculomegaly. This may be the main cause for the short-lived benefits secondary to an NPH-targeted therapeutic intervention, such as the placement of a ventriculoperitoneal shunt.2