POSTURAL AND GAIT DISTURBANCE CORRELATED WITH DECREASED FRONTAL CEREBRAL BLOOD-FLOW IN ALZHEIMER-DISEASE

In a group of 45 patients with Alzheimer disease (AD) and 15 control s ubjects, we studied the relationship between parameters showing postur al and gait disturbance and regional cerebral blood flow (rCBF) measur ed with N-isopropyl-p-[I-123]iodoamphetamine single photon emission co mputed tomography at different clinical stages. Patients with AD with mild dementia exhibited only increased postural sway associated with a reduced mean value of rCBF in the cortex. At a moderate stage, the re duced mean values of rCBF in the cortex and in the frontal lobe were a ssociated with increased postural sv;ay and stride length variability and with decreased stride length. At a severe stage, reduced rCBF in t he basal ganglia and in the frontal lobe additionally were associated with increased postural sway, double support lime, and stride length v ariability, and with decreased walking speed and stride length. In mul tiple regression analysis, there was a high contribution by rCBF in th e frontal lobe to account for postural and gait disturbance in AD. We propose that impaired frontal lobe circulation is an important factor causing postural and gait disturbance as AD progresses.