WOMEN with Parkinson’s disease may be more prone to Alzheimer’s-related brain changes than men, according to autopsy research presented today at the European Academy of Neurology Congress 2026, with female patients carrying markedly more amyloid plaque despite similar cognitive outcomes.
Sex Differences in Parkinson’s and Alzheimer’s Pathology
Parkinson’s disease and Alzheimer’s disease often co-occur in older adults, yet sex differences in Alzheimer’s-related pathology among people with Parkinson’s disease have been little studied. Researchers set out to address that gap, asking whether women and men with Parkinson’s accumulate amyloid plaque, a defining marker of Alzheimer’s, to differing degrees.
Study Design and Neuropathological Assessment
Investigators from Mayo Clinic Arizona analysed 230 autopsy-confirmed Parkinson’s disease cases from the Arizona Study of Aging and Neurodegenerative Disorders and Brain and Body Donation Program. Participants had undergone annual clinical assessments during life, including cognitive testing, followed by comprehensive neuropathological examination after death. This observational clinicopathological design compared amyloid plaque measures and dementia rates between the sexes.
Amyloid Burden Higher in Women
Across several measures, female patients carried more amyloid than males. Their mean cortical total plaque scores reached 6.5 out of 15, against 4.9 in men (p=0.045), and neuritic plaque density was likewise higher at 1.7 versus 1.3 out of 3 (p=0.035). A high plaque burden was present in 56.8% of women but only 39.7% of men (p=0.015). Crucially, this gap held after accounting for age at death and the APOE ε4 risk gene, leaving women more than twice as likely to fall into the high-burden group (odds ratio 2.18; 95% CI 1.17 to 4.06; p=0.014). Even so, the two sexes showed no significant difference in Alzheimer’s dementia rates or cognitive test scores.
Implications and Future Research
Lead author Dr Erika Driver-Dunckley said the results suggest women may be more vulnerable to amyloid-driven pathology in Parkinson’s disease, mirroring patterns seen in Alzheimer’s. The greater plaque load would be expected to worsen cognition, yet no such effect emerged. “It may be that a larger study would pick up cognitive differences related to the increased plaque load,” she suggested. The authors called for further clinicopathological studies to confirm the findings and to unpick the biological mechanisms behind these sex differences in women with Parkinson’s disease.
Reference
Driver-Dunckley E et al. Greater burden of Alzheimer’s co-pathology in women with Parkinson’s disease. Abstract A-26-16751. EAN Congress, 27-30 June, 2026.
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