Gender differences in non-motor symptoms in early, drug naïve Parkinson's disease

Gender differences in brain structure and function may lead to differences in the clinical expression of neurological diseases, including Parkinson's disease (PD). Few studies reported gender-related differences in the burden of non-motor symptoms (NMS) in treated PD patients, but this matter has not been previously explored in drug-naïve PD patients. This study is to assess gender differences in the prevalence of NMS in a large sample of early, drug-naïve PD patients compared with age and sex-matched healthy controls. Two hundred early, drug-naïve PD patients and ninety-three age and sex-matched healthy controls were included in the study. Frequency of NMS was evaluated by means of the Non-Motor Symptoms Questionnaire. The difference in gender distribution of NMS was evaluated with the χ (2) exact test; multiple comparisons were corrected with the Benjamini-Hochberg method. Male PD patients complained of problems having sex and taste/smelling difficulties significantly more frequently than female PD patients. Furthermore, men with PD complained more frequently of dribbling, sadness/blues, loss of interest, anxiety, acting during dreams, and taste/smelling difficulties as compared to healthy control men, while female PD patients reported more frequently loss of interest and anxiety as compared with healthy control women. This study shows specific sex-related patterns of NMS in drug-naïve PD. In contrast with previous data, female PD patients did not present higher prevalence of mood symptoms as compared to male PD patients. Comparison with healthy controls showed that some NMS classically present in premotor and early stage of disease (i.e., acting out during dreams, taste/smelling difficulties) are more frequent in male than in female patients.