Ventricular volume and cognitive deficit: a computed tomographic study.

A group of 35 patients with presumptive diagnosis of Alzheimer disease and 29 normal volunteer spouse controls, all over the age of 60, underwent medical and neurologic evaluation, an extensive psychometric battery, and CT scanning. CT ventricular volume was derived for each CT section by algorithm summation of the number of pixels within a user-defined cerebrospinal fluid range. Composite ventricular volume for each patient, obtained by summation of the individual section ventricular volumes, was corrected for brain size by dividing by the sum of the five largest brain section volumes. For the normal group, composite ventricular volume thus derived was 5.2% and for the impaired group 7.5%; the 44% difference was significant (p less than .009). Increasing ventricular volume was significantly associated with increasing severity of cognitive impairment (p less than .05).