Prediction of outcome in senile dementia--a computed tomography study.

Forty patients suffering from senile dementia who had been subjected to detailed clinical and psychological assessment and computed tomography (CT) were followed up for a mean period of 28.78 months. All but one were traced. The deceased (27) were compared with the survivors (12). All males had died at follow-up. The mean age was not statistically significant, but the survivors differed significantly from the deceased in having performed better on a number of clinical and psychological tests, particularly those involving speech functions and constructional ability. Measures of ventricular size and cortical atrophy were not of predictive value, but a new technique of measuring radiological density showed that this was significantly lower in the right parietal region in the original CT scans of those who subsequently died. The study confirms that clinical involvement of the parietal lobes is an indication of poor prognosis and reports the first radiological support for this view. It also suggests that a more directly quantitative approach to computed tomography may yield results which are more useful than those obtained from visual reconstructions.