The combination of atherosclerosis and macroscopic infarcts, along with Lewy body (LB) pathology, leads to a more severe form of parkinsonism in older adults, according to study findings published in the journal Neurology.
Researchers conducted a postmortem analysis of individuals from 3 longitudinal community-based aging studies who underwent annual clinical evaluation to assess parkinsonian signs and reported on a possible synergistic effect between LB and cerebrovascular disease (CVD) pathologies.
A total of 1753 participants were included in the analysis, where LB was identified in 26% (n=449/1753) and CVD pathology indicators were observed in 80% (n=1401/1753) of older adults.
Out of the total, 33% (n=572/1753) had moderate-to-severe atherosclerosis, 32% (n=555/1753) had moderate-to-severe arteriolosclerosis, 35% (n=616/1753) had moderate-to-severe cerebral amyloid angiopathy, 36% (n=624/1753) had macroscopic infarcts, and 30% (n=535/1753) had microscopic infarcts.
A total of 66 participants were excluded for being diagnosed with Parkinson disease.
At baseline, the 2 groups were similar, with 68% of participants being women (n=1188/1753). The average (SD) age at death was 89 (6.7) years.
The LB and the following CVD pathologies: atherosclerosis, arteriolosclerosis, and macroscopic infarcts, were found to be independently associated with the severity of global parkinsonism near the end of life.
Atherosclerosis had the strongest association (β=0.373, SE=0.079, P <.001), followed by LB (β=0.318, SE=0.08, P <.001), macroscopic infarcts (β=0.333, SE=0.077, P <.001), and arteriolosclerosis (β=0.253, SE=0.078, P =.001).
Presence of macroscopic infarcts was associated with a higher estimate for severe parkinsonism (β=0.463, SE=0.168, P =.006), suggesting that LB may contribute to more severe parkinsonism in individuals with macroscopic infarcts.
Significant associations were also observed between atherosclerosis and LBs (β=0.371, SE=0.173, P =.032).
Similar findings were also observed for parkinsonian gait as the outcome, including macroscopic infarcts (β=0.662, SE=0.239, P =.005) and atherosclerosis (β=0.509, SE=0.246, P =.038).
A limitation of this study includes its cross-sectional nature which does not allow for examiners to establish a clear cause and effect relationship.
“Further studies specifically focusing on understanding mechanisms by which vascular and LB interact may thus be useful in the development and interpretation of future treatment,” the researchers concluded.
Agrawal S, Leurgans SE, Sukriti N, et al. Effects of cerebrovascular and lewy body pathology on parkinsonian signs in community-dwelling older adults. Neurology. Published online July 12, 2023. doi:10.1212/WNL.0000000000207497.