Relationship between blood flow kinetics and severity of Alzheimer's disease: Assessment of severity using a questionnaire-type examination, Alzheimer's disease assessment scale, cognitive sub-scale (ADAS(cog))

We assessed hemokinetics associated with changes in Alzheimer's disease (AD ) severity in 90 AD patients by researching the relationship between AD Ass essment Scale, cognitive sub-scale (ADAS(cog)) scores and regional cerebral blood flow (rCBF). In the present study, we employed the questionnaire-typ e ADAS(cog) examination to accurately assess the severity of AD. Between fi ve groups classified on the basis of ADAS(cog) score, significant differenc es were observed in parietal, lateral temporal and superior frontal rCBF. I n addition, in parietal and lateral temporal regions, significant correlati ons were also observed between ADAS(cog) score and rCBF. In superior fronta l rCBF, significant differences were noted only between group 5 (greater th an or equal to 40 ADAS(cog) points) and each of the other groups; there was no significant correlation between rCBF and ADAS(cog) score. Thus, we prop ose the following mechanism for blood flow kinetics associated with changed severity: In an early stage of AD, blood flow in the medial temporal corte x is impaired, and gradually involves the temporoparietal regions. While th e medial temporal impairment of blood flow reaches a plateau, temporopariet al blood flow continues to be impaired well into a severe stage, at which p oint blood flow impairment in the frontal region is initiated. Copyright (C) 2001 S. Karger AG, Basel.