Protocolizing the Workup for Idiopathic Normal Pressure Hydrocephalus Improves Outcomes

Abstract

BackgroundThe workup for idiopathic normal pressure hydrocephalus (INPH) can be difficult to coordinate, and determining appropriate patients for ventriculoperitoneal shunting can be challenging. Therefore, we hypothesized that implementing a formalized protocol can improve patient selection for a shunt. In conjunction with neurology and neurosurgery, we instituted a standardized means of assessing patients whose presentation is concerning for INPH and compared their workup with similar patients seen without the Protocol (i.e., preprotocol [PP]) regarding baseline characteristics, assessment, and outcomes.MethodsTwenty-six PP patients were compared with 40 Protocol patients on measures, including baseline deficits, workup, neurosurgical evaluation, and response to shunt.ResultsAverage age was similar between groups, and the percentage of patients who had a decline in gait, cognition, and/or incontinence was not statistically different (p > 0.05). Significantly more Protocol patients underwent high-volume lumbar puncture (HVLP; 97.5%; PP, 61.5%; p < 0.001) and received formalized gait assessment with the Gait Scale (90%; PP, 0%, p < 0.001) and standardized cognitive testing (95%; PP, 38.5%; p < 0.001). Significantly more Protocol patients had no improvement after HVLP (33.3%; PP, 6.25%; p < 0.045); subsequently, fewer got shunted (57.5%; PP, 84.6%; p < 0.030). More Protocol patients who were shunted reported gait improvement (100%; PP, 72.7%; p = 0.009), although there was no difference in cognition (59.2%; PP, 82.6%; p = 0.108) or incontinence (18.2%; PP, 39.1%; p = 0.189).ConclusionsImplementing an INPH Protocol leads to standardized and more extensive assessment and better patient selection for and subsequent outcomes from shunting, specifically regarding gait.