White matter hyperintensities and cortical acetylcholinesterase activity in parkinsonian dementia.

Objective – To investigate the relationship between the severity of white matter hyperintensities (WMH) and cortical acetylcholinesterase (AChE) activity in parkinsonian dementia (PDem). Methods – PDem ( n = 11) and control subjects ( n = 14) underwent [11C]methyl-4-piperidinyl propionate (11C-PMP) AChE brain positron emission tomography and magnetic resonance (MR) imaging. Presence of WMH on proton density and T2 MR images was scored using a modified version of the semi-quantitative rating scale by Scheltens et al. [ J Neurol Sci 114 (1993)]. Results – Analysis demonstrated significantly lower mean cortical 11C-PMP k3 hydrolysis rates in PDem (−19.9%) when compared with control subjects ( P < 0.0001). PDem subjects had higher mean severity of WMH (+20.1%) when compared with control subjects ( P < 0.05). When WMH severity was entered into the analysis of variance model, there was no significant co-variate effect on cortical AChE activity ( F = 0.24, ns). Conclusions – The concomitant presence of mild to moderate WMH in patients with PDem does not have a significant effect on cortical AChE activity. [ABSTRACT FROM AUTHOR]