To determine if there are gender differences in distribution of Lewy Body pathology among individuals with Parkinson’s disease (PD).

There is increasing evidence that gender is an important factor in cognitive functioning in PD. One study found that women performed better on verbal learning and memory, whereas men had better visuospatial functioning (1). We hypothesized that gender differences may exist in the brain distribution of Lewy bodies (LB), potentially explaining these cognitive differences.

We evaluated individuals with a pathological diagnosis of PD, defined by the presence of LBs, from the autopsy program of the Johns Hopkins Morris K. Udall Parkinson’s Disease Research Center, which has been ongoing since 1999. First, we conducted a logistic regression to determine if LB distribution, classified as: limited to the brainstem only, extending to the limbic region, or extending into the neocortex, differed between males and females with PD when controlling for age, education, illness duration and cognitive status (normal, MCI, dementia) (n=188). Then, we conducted a Mann-Whitney analysis to determine if there was a gender difference in LB severity score (0-4) in the following brain regions: Frontal Lobe, Anterior Cingulate, Temporal Lobe, Amygdala, Locus Coeruleus (LC), Transentorhinal, Nucleus Basalis, Cranial Nerves IX and X, and Substantia Nigra for individuals with PD and a diagnosis of possible, probable or definite dementia (n=133).

We saw no association between gender and LB distribution when classified as brainstem, limbic or neocortex. However, women have a higher LB severity score in the Frontal lobe, Amygdala, and LC (n=102,p=0.04; n=80, p=0.04; n=76, p=0.02, respectively).

In this analysis, women were found to have higher LB severity scores in three major brain regions that affect cognition. Further investigation is required to determine whether the differences in scores for these brain regions correspond to specific gender differences in the cognitive characteristics of PD.