WASHINGTON — Lewy body pathology—the accumulation of α-synuclein protein—appears to be associated with cerebral atherosclerosis.
In a study of 403 preserved brains, those with moderate to severe cerebral atherosclerosis were more than twice as likely to also have Lewy bodies present as were those with no cerebral atherosclerosis.
This association between cerebral atherosclerosis and Lewy body burden was discovered by examining brains from the Columbia University Medical Center databank. The brains were obtained between 1990 and 2007. Neuropathologic evaluation of Lewy bodies involved immunostaining with ubiquitin or α-synuclein. Degree of cerebral atherosclerosis was determined by gross rating of the Circle of Willis, according to Dr. Nikolaos Scarmeas, of the Taub Institute at Columbia University, New York, and his colleagues.
Lewy bodies were present in roughly a quarter of the brains (26%). Patients with Lewy bodies died at an older age on average than did those without the pathology—78 years vs. 75 years. Those with Lewy bodies were also slightly more educated—16 years vs. 14 years. Lewy bodies were more likely to be found in men (66%). Changes associated with Alzheimer's disease (AD) were found in roughly half of those with and without Lewy bodies.
Cerebral atherosclerosis was classified as not present, mild, or moderate to severe. No atherosclerosis was found in 31%, mild atherosclerosis in 36%, and moderate to severe in 33%. Atherosclerosis appeared more frequently with increasing age—68 years for those without, 76 years for those with mild, and 82 years for those with moderate to severe.
The presence of AD-related changes increased with increasing cerebral atherosclerosis—44% of those with none, 56% of those with mild, and 64% of those with moderate to severe, they reported.
The researchers used logistic regression analysis to determine if the presence of mild or moderate to severe cerebral atherosclerosis was predictive of the presence of Lewy bodies in the brain. In the unadjusted model, those with both mild (OR 1.25) and moderate to severe (OR 2.38) atherosclerosis were more likely to have Lewy bodies, versus patients without atherosclerosis, as seen in this study presented as a poster at the annual meeting of the American Neurological Association.
After adjustment for gender, age at death, and AD pathologic changes, those with mild atherosclerosis were only slightly more likely to have Lewy bodies (OR 1.07). Those with moderate to severe atherosclerosis were still more than twice as likely to have them (OR 2.20).
In addition, “stratified analyses indicated that the association between Lewy bodies and atherosclerosis was stronger in women and in patients without AD pathological changes,” the researchers wrote.
The researchers also examined the effect of restricting their analyses to include only more recent cases—those cases that used α-synuclein immunostaining. However, this restriction did not affect the associations.