Idiopathic Normal Pressure Hydrocephalus: A Review And A Proposed Role For

IDIOPATHIC NORMAL PRESSURE HYDROCEPHALUS: A REVIEW AND A PROPOSED ROLE FOR PATIENT-REPORTED OUTCOMES. Conor W. Grady (Sponsored by Charles C. Matouk). Department of Neurosurgery, Yale University, School of Medicine, New Haven, CT. Despite nearly five decades of experience treating idiopathic normal pressure hydrocephalus (iNPH), there is still no consensus amongst care providers as to how to reliably identify patients with suspected iNPH who will benefit from shunt surgery, or how to measure post-operative symptom improvement. We performed a selective review of the literature, focusing especially on the role of neuroimaging in aiding in the diagnosis of iNPH, and the various clinical scales that have historically been used to assess outcome. Further, we tested the hypothesis that patient-reported outcomes (PROs) will demonstrate effectiveness of shunt surgery for the relief of iNPH symptoms consistent with that demonstrated through the application of clinical scales. To do this, we performed a retrospective analysis of one provider’s experience treating patients with suspected iNPH, scoring outcomes based on patient-reported change in symptom severity. All patients treated for suspected iNPH between January 2012 and January 2014 with at least one month of follow-up and documented responses to direct questioning about preversus post-surgical symptom severity were included. Twenty-one patients were included in total. 100% of patients reported improvement in at least one of the three cardinal symptoms of gait disturbance, urinary incontinence, or cognitive impairment following shunt implantation. Gait, urinary, and cognitive symptoms individually improved 95%, 84%, and 89%, respectively. There was a significantly higher rate of improvement in any (i.e. at least one) symptom domain using PROs compared to historical data obtained through evaluation with clinical scales. There was no statistically significant difference between improvements in each individual symptom domain. PROs produce results that are largely consistent with data obtained by clinical scales, and can be used as one metric of patient improvement following shunt surgery for iNPH.