25 - Normal Pressure Hydrocephalus

Summary

Normal pressure hydrocephalus (NPH) is clinical syndrome of dementia, gait disturbance, and urinary incontinence that progresses over a period of weeks to years. Urinary incontinence, a late symptom, occurs in less than 50% of patients. If untreated, NPH progresses resulting in an inability to stand, akinetic rigidity, and withdrawn behavior. The differential diagnosis includes Parkinson's disease, bifrontal brain disease due to tumor, metastases, cerebral infarction, aqueductal stenosis, metabolic encephalopathy, and Alzheimer's disease. When NPH is suspected clinically, computerized tomography (with contrast enhancement) reveals ventriculomegaly, minimal or absence of cortical atrophy, periventricular lucencies, and nearly normal-sized subarachnoid space. Magnetic resonance imaging (MRI) is the study of choice to evaluate ventriculomegaly and functional imaging of cerebrospinal fluid (CSF) flow. The role of the emergency physician is to consider the diagnosis of NPH in patients with dementia and gait disturbance and to initiate appropriate referral.