Progressive supranuclear palsy: phenotypic sex differences in a clinical cohort

We examined sex-based differences in phenotypic expression among a consecutive clinical series of 121 individuals diagnosed with probable progressive supranuclear palsy (PSP). For both men (44%) and women (56%), the age at symptomatic onset (66.2 and 68.5 years, respectively) and disease duration (4.6 and 4.3 years, respectively) were similar. The overwhelming majority of sex-based comparisons showed no significant difference on a variety of demographic, historical, and clinical characteristics, as well as measures of disease progression. The only differences observed were that men had significantly worse tremor as measured by the Unified Parkinson's Disease Rating Scale tremor subscore (0.9 for men and 0.3 for women, P<0.01) and men had a significantly higher mean body mass index (BMI; 28.2 for men and 25.1 for women, P=0.01), although these differences were not significant after Bonferroni correction. In general, the disease phenotype was similar between men and women, suggesting that sex may have little or no influence on the development, expression, or progression of the PSP phenotype.