Normal pressure hydrocephalus

Abstract

Normal pressure hydrocephalus (NPH) is a communicating hydrocephalus often resulting from impaired reabsorption of CSF into the venous sinuses due to previous meningitis, encephalitis, subarachnoid hemorrhage, or trauma.1 Many cases, however, remain idiopathic. While the classic diagnostic triad of gait disturbance, cognitive decline, and urinary incontinence suggest NPH, these symptoms are not specific, occurring in many advanced age conditions. Therefore, it is imperative to evaluate the patient carefully and thoroughly before referring for shunt placement. To help increase the chance of an accurate diagnosis and a shunt-responsive result, I suggest a few clinical pearls to consider. In NPH, motor pyramidal fibers that originate deep in the interhemispheric fissure are stretched traveling around the expanding ventricles to the internal capsule and spinal cord. The result is impaired motor control of the lower extremities and urinary bladder sphincter, gait apraxia, urinary urgency, and eventually incontinence. Gait apraxia is manifested by symptoms of feet clumsiness, slow or shuffling and wider-based gait, reduced floor clearance (magnetic gait), reduced initiation of foot movements, and slowness arising from a chair. The motor fibers serving the upper extremities and face originate more laterally in the motor cortex and therefore are less affected by stretching …