Idiopathic normal pressure hydrocephalus

Abstract

Idiopathic normal pressure hydrocephalus (INPH) is characterized by the clinical triad of gait disturbance, cognitive dysfunction, and urinary symptoms, observed in the context of enlargement of the cerebral ventricular system. Mean age of onset is approximately 60 years, which complicates the diagnosis since there is the potential for multiple age-related comorbidities in this population. Typically, gait disturbance is the presenting symptom that brings an individual to medical attention, but cognitive decline can be the initial symptom in some cases. NPH is an important diagnostic entity for the neuropsychologist working with older adults to be familiar with, since it is one of the few progressive cognitive disturbances that can be effectively treated. The current standard of care treatment is placement of a ventriculoperitoneal shunt, which can lead to reversal of symptoms, but shunt surgery is not without complications and careful patient selection is prudent. The neuropsychologist can be a key contributor in clinical settings for diagnostic considerations and in the evaluation of treatment response. In this chapter, we present a discussion of the clinical presentation and characteristic features of INPH, explore recent evidence-based diagnostic criteria, and provide guidelines for neuropsychological evaluation of INPH. A case example documenting post-shunt recovery of function is presented.