Onset Patterns and Initial Symptoms of Dementia with Lewy Bodies: Possible Pathophysiological Diversities Deduced from a SPECT Study

BACKGROUND/AIMS: The aim of this study was to investigate onset patterns and initial symptoms in patients with dementia with Lewy bodies (DLB) and their association with SPECT findings. METHODS: We studied 29 probable and 12 possible DLB patients. Onset was defined as ‘acute’ when symptoms (in various combinations) present within a few weeks or ‘chronic’ when a few symptoms present and progress during a longer period of time. Initial symptoms were dichotomized into ‘cognitive’ and ‘non-cognitive’. We conducted voxel-to-voxel statistical analyses of SPECT, and uptake deviations from age-matched controls were depicted with Z-scores. RESULTS: In acute patients, decreases were more apparent in the bilateral frontal and temporal lobes, whereas chronic patients showed decreases in the bilateral occipital, posterior cingulate and precuneal regions. Differences in the left frontal and left posterior cingulate were significant and those in the left temporal region showed a tendency toward significance. Patients with cognitive symptoms demonstrated more marked decreases in the bilateral temporal, parietal, occipital, cingulate and precuneal regions. Differences in the left parietal area reached significance and the total decreases were larger in patients with cognitive than non-cognitive symptoms, with a trend toward significance. CONCLUSIONS: The multiplicity of onset patterns and initial symptoms may possibly be based on pathophysiological diversities in DLB.