Objective: To investigate whether sex affects cognition in patients with de-novo Parkinson’s disease (PD).

Background: Sex differences in PD are common and may be due to effects of estrogen on dopaminergic pathways (Al Sweidi et al., 2012). Additionally, male sex is associated with a higher risk for PD dementia (PDD). Longitudinal data suggest that female PD patients have a slower progression for cognitive impairment (Cholerton et al., 2018). As PD patients present with various cognitive deficits, even at the early stages of PD, cognitive profiles may also be different in men and women at the time of diagnosis.

Methods: Data of 424 de novo PD patients (145 female, 34.2%) with cognitive testing from the PPMI were analyzed. All patients had a Hoehn-Yahr Stage of 1 or 2. Cognitive testing consisted of Montreal Cognitive Assessment (MoCA), verbal fluency (VF), Symbol Digit Modalities Test (SDMT), Judgment of Line Orientation (JLO), Letter Number Sequencing (LNS) and Hopkins Verbal Learning Test (HVLT). Data on Movement Disorders Society-Unified Parkinson’s Disease Rating Scale (MDS-UPDRS), and striatal dopamine transporter (DAT) binding ratios were also compared between groups.

Results: There were no significant differences in age, years of education, DAT binding ratios and disease features between groups [table 1]. All cognitive tests, except for LNS, were significantly different. Female patients had higher scores in MoCA, VF, SDMT, and HVLT; whereas male patients had significantly higher scores in JLO [table 2].

Conclusions: Our findings indicate that sex has differential effects on cognition in PD. Female PD patients performed better in executive functioning, processing speed, and memory. Male PD patients scored higher on the visuospatial task, in line with prior studies of mild cognitive impairment reporting visuospatial domains are affected more in females with PD. Our findings support the notion that the underlying mechanism for cognitive deterioration in PD may differ in men and women. Female sex appears to have a beneficial effect for cognition in PD even in early stages, which may be due to estrogen. Future studies should focus on the sex related mechanisms which may be behind this difference in cognition.

References: Al Sweidi S, Sanchez MG, Bourque M, Morissette M, Dluzen D, Di Paolo T. Oestrogen receptors and signalling pathways: implications for neuroprotective effects of sex steroids in Parkinson’s disease. J. Neuroendocrinol., 24 (1) (2012), 48-61. Cholerton B, Johnson CO, Fish B, Quinn JF, Chung KA, Peterson-Hiller AL, Rosenthal LS, Dawson TM, Albert MS, Hu SC, Mata IF, Leverenz JB, Poston KL, Montine TJ, Zabetian CP, Edwards KL. Sex differences in progression to mild cognitive impairment and dementia in Parkinson’s disease, Parkinsonism and Related Disorders (2018), https://doi.org/10.1016/j.parkreldis.2018.02.007.

« Back to 2018 International Congress

MDS Abstracts - https://www.mdsabstracts.org/abstract/sex-differences-in-cognitive-performance-in-de-novo-parkinsons-disease/