Cortical PIB binding in Lewy body disease is associated with Alzheimer-like characteristics.

About one fourth of Lewy body disease (LBD) patients show cortical beta-amyloid load, basically a hallmark of Alzheimer disease (AD). Using [11C]PIB-PET, we tested whether LBD patients with beta-amyloid burden differ from those without with respect to demographic, clinical, biochemical and genetic parameters. Thirty-five LBD subjects (9 patients with Lewy body dementia, DLB; 12 demented Parkinson patients, PDD; 14 non-demented PD, PDND) underwent [11C]PIB-PET, and were classified as either PIB(+) or PIB(-) according to cortical PIB uptake. PIB+ and PIB(-) patients were then compared according to demographic, clinical, biochemical and genetic parameters. None of the PDND, but four PDD and four DLB subjects were PIB+. In PIB+ subjects, ApoE4 prevalence was higher, CSF Abeta42 levels were lower and, among demented patients, PIB-binding was associated with a lower MMSE score. Motor symptoms were not associated with PIB binding. Thus, LBD patients with cortical beta-amyloid show characteristics usually observed in AD.