Subcortical whiter matter hyperintensities within the cholinergic pathways of patients with dementia and parkinsonism

Background and purpose White matter hyperintensities (WMHs) in the cholinergic pathways are associated with cognitive performance in Alzheimer's disease (AD) and Parkinson disease dementia (PDD). This study aimed to evaluate the relationship between loss of white matter cholinergic pathways and cognitive function in patients with AD, diffuse Lewy body disease (DLB), and PDD. Methods The subjects included 20 patients with AD, 17 with DLB, 21 with PDD, and 20 healthy controls. The extent of WMHs within cholinergic pathways was assessed using the Cholinergic Pathways Hyperintensities Scale (CHIPS) and was compared among the different diseases. Results The mean CHIPS scores were similar among the three dementia groups (AD vs. DLB vs. PDD = 34.6 ± 17.9 vs. 32.4 ± 14.1 vs. 31.8 ± 14.5, p = 0.781 by ANCOVA) and higher than those of controls (11.5 ± 7.6, p = 0.001 by ANCOVA). Conclusions Losses of cholinergic pathways were similar among AD, DLB, and PDD groups, and more severe cognitive dysfunction was associated with elevated WMHs. These findings suggest that interruption of acetylcholine pathways may be related to cognitive dysfunction in these three diseases, even though they have different pathological mechanisms.