Natural History, Treatment Outcomes and Quality of Life in Idiopathic Normal Pressure Hydrocephalus (iNPH)

Background: The natural history and treatment outcomes in adult patients with hydrocephalus is a broad and heterogeneous topic that encompasses the natural history of the various subtypes of adult hydrocephalus with or without treatment; their surgical operative results, including symptom improvements, treatment failure, short- and long-term complications, and reoperations; and morbidity, mortality, and patient-centered health-related quality of life (HRQoL). Objective, Methods, and Materials: The objective of this review is to present a current update on the natural history and treatment outcomes, including QoL, for adults with hydrocephalus with a focus on patients with idiopathic normal pressure hydrocephalus (iNPH). A nonsystematic review of relevant literature was summarized. Results and Conclusions: The natural history for untreated patients with iNPH is poor, with both increased mortality and morbidity. It is strongly recommended that practitioners follow established guidelines to select patients with suspected iNPH while using objective measures of gait, balance, and cognition for consideration of treatment with a CSF shunt. Other factors such as patient-related medical comorbidities or frailty may need to be factored into the decision-making process before surgical treatment is offered. As a rule, failure to select patients based on the identified guidelines will result in a significantly lower positive response to treatment with a CSF shunt. Over 90% of iNPH patients who undergo CSF-shunt treatment demonstrate symptomatic relief after surgery, and long-term studies have shown that in most patients, the clinical improvements are long-lasting, with over 70% demonstrating improvement longer than 6 years after treatment. There is no evidence to support the routine use of endoscopic third ventriculostomy (ETV) to treat patients with iNPH. There is limited data regarding HRQoL in patients with iNPH. In addition to objective measures of outcomes focused on gait and cognition, it is equally important for future studies to assess patient-centered subjective measures of HRQoL.