Diffuse Lewy body disease: neurochemical, neuropathological and behavioralcorrelations

We investigated cholinergic, serotonergic and noradrenergic neurochemical m arkers in frontal pole, temporal pole and amygdala of neuropathologically a nd behaviorally characterized demented individuals with Lewy bodies (DLB) a nd matched non-demented, non-heart disease controls. Subjects with DLB were also grouped according to the absence or presence of AD neuropathology and antemortem psychiatric symptoms. The presence of concomitant AD did not af fect the number of Lewy bodies (LB) in a brain region. Higher levels of LB were associated with ante-mortem psychiatric symptoms in DLB. Choline acety ltransferase activity was decreased in DLB subjects regardless of the local presence of Lewy bodies, concomitant AD, or psychiatric symptoms. Acetylch olinesterase activity was reduced in DLB and related to the presence of LB, but not AD neuropathology or psychiatric symptoms. Muscarinic binding (QNB ) and serotonin uptake (imipramine) sites were increased in DLB, whereas se rotonergic binding sites were reduced (ketanserine) or variably altered dep ending on brain region (serotonin) in DLB. Regionally specific increases in MAO-A and MAO-B activity were identified in DLB. The neurochemical differe nces between DLB and controls, and AD and controls are numerous, but suffic ient overlap deters strongly suggesting that DLB and AD are two different d isease states.