July 13, 2026

@michaelokun

Do DBS candidates have less Lewy body pathology in their brains? Biopsies taken during the DBS procedure could inform this question. Buxbaum Grice and colleagues describe in a new paper in npj Parkinson's Disease the results from the Sinai Living Brain study. They examined tiny prefrontal cortex biopsies obtained during deep brain stimulation (DBS) surgery and reported that Lewy body pathology was largely absent, despite these individuals having longstanding Parkinson's disease. This was an intriguing observation in a cohort of carefully screened folks who had DBS for Parkinson’s disease. Key points: - Nearly all prefrontal cortex biopsies from Parkinson's disease patients undergoing DBS showed no detectable Lewy body pathology despite years of disease and significant motor symptoms. - In contrast, postmortem brains from individuals w/ Parkinson's disease showed abundant Lewy body pathology in the same brain region. - The results suggest that individuals pre-selected for DBS through careful multidisciplinary screening may have less Lewy body pathology. My take: Multidisciplinary screening is important to the success of DBS therapy and one wonders whether exclusion of participants w/ more severe cognitive dysfunction impacted their findings. This paper reminds us that Parkinson's disease is not one disease. We have long appreciated that the biology, symptoms and progression differ from one person to another and that the biology evolves over time. Future work linking neuropsychological findings, brain pathology, biomarkers and clinical phenotypes could shed light on this issue. Also, for the few folks with gene mutations associated w/ their Parkinson’s this could also account for some decrease in Lewy pathology. As always, one study should not change clinical practice, however it should change the questions we ask next. DBS candidates may represent a subgroup w/ relatively preserved cortical brain tissue despite many years of motor symptoms. These cases are heavily screened for dementia prior to and after referral for DBS.