Risk of Cognitive Decline in Women with Parkinson’s Disease Is Reduced by Early Age at Menarche

Background: Parkinson’s disease (PD) is a neurodegenerative disorder affecting men morefrequently than women, a difference that might be due to many factors, including sexualhormones. Estrogens seem to confer a protective effect on the nigrostriatal pathway in experimental studies but their effects on cognition in patients with PD are unknown. Aim: Toinvestigate the impact of the exogenous and endogenous estrogens on cognitive impairmentin women with PD. Methods and materials: We recruited and consecutively interviewedoutpatient women affected by PD. Each patient underwent a cognitive assessment via theMontreal Cognitive Assessment scale (MoCA), an anamnestic collection of the reproductivelifespan variables and clinical features. We investigated if some of the reproductive lifespanvariables investigated could predict cognition outcomes in post-menopausal women withPD. Results: A total of 90 women with PD were recruited. Women with MoCA ≥ 26 (n = 27)had a lower median age at menarche (11 [11,12] vs. 13 [12–14], p < 0.0001), lower diseaseduration in years (8.3 [6.1–12.7] vs. 9.4 [6–12.7], p = 0.6), and less advanced disease (1 [1,2]vs. 2 [1–3], p = 0.02). Among all the reproductive life-span variables, only earlier age atmenarche significantly predicted higher scores on MoCA (aOR = 0.5 [0.3–0.8], p = 0.005). Noother clinical and reproductive factors have been shown to have an influence on cognitivescores. Conclusions: Age at menarche correlated with cognitive outcomes. Our studysuggests that earlier exposure to endogenous estrogens during a phase of developmentand plasticity of the brain might preserve women with PD from cognitive decline.