Nonmotor symptoms in Parkin gene-related parkinsonism

The aim of the study was to explore the prevalence and differences of nonmotor symptoms (NMSs) in patients with young-onset Parkinson's disease (YOPD) with and without mutations in the Parkin gene and late-onset Parkinson's disease (LOPD). Twenty-seven patients with YOPD and 27 with LOPD, as well as 16 patients with homozygous or compound heterozygote Parkin mutations filled in the nonmotor symptoms questionnaire, a 30-item self-completed questionnaire that addresses various NMSs. Overall, NMSs were more prevalent in YOPD (12.07 ± 3.9; P = 0.009) and LOPD (13.26 ± 5.8; P = 0.001) compared with Parkin mutation carriers (7.38 ± 4.2). Dribbling of saliva, vivid dreams, loss of smell, and urinary urgency were more prevalent in YOPD compared with Parkin mutation carriers. Only anxiety was more prevalent in the latter. Apart from anxiety, NMSs appear to be less prevalent in Parkin gene-related parkinsonism. Although these results need further study, the presented data might be helpful in the clinical recognition of specific phenotypes and genotypes in YOPD. The data are in keeping with a different pathological disease process in Parkin generelated parkinsonism.