The value of clinical findings in the detection of normal pressure hydrocephalus.

We conducted a retrospective study of 627 individuals with dementia to determine whether clinical characteristics could identify individuals with normal pressure hydrocephalus (NPH) on computed tomography (CT) brain scanning. Fifty (8%) individuals had classical clinical characteristics of NPH: dementia, urinary incontinence, and gait disturbance. When this clinical trial was present, 12% of individuals had NPH on CT scan; when absent, only 3% had NPH. The clinical findings identified individuals with a 4-fold increase (p less than .001) of NPH on CT scan. Of the 50 individuals with the clinical trial, 6 had both clinical and CT scan findings consistent with NPH; 2 of these had shunt surgery, and 1 improved clinically. None of the 577 individuals without clinical findings had shunt surgery performed, including those with CT scan abnormalities consistent with NPH. We conclude that clinical characteristics can be used to identify individuals who need CT scanning for detection of NPH.