Nonmotor symptoms and quality of life in Parkinson’s disease with different motor subtypes

OBJECTIVE To explore the differences in the features and impact on quality of life (QOL) of nonmotor symptoms (NMS) of the tremor dominant (TD) and non-tremor dominant (NTD) subtypes of Parkinson's disease (PD) and elucidate the characteristic NMS and determinants of QOL for the subtypes. METHODS This cross-sectional study included 77 patients with PD. The NMS questionnaire was used to assess the range and prevalence of NMS. The modified Hoehn and Yahr staging and the unified PD rating scale (UPDRS) were used to assess symptom severity. Cognitive abilities were investigated using the mini-mental status examination (MMSE). Emotional state was assessed using the Hamilton depression scale (HAMD) and the Hamilton anxiety scale (HAMA) and QOL was evaluated using the Parkinson's disease questionnaire-39 (PDQ-39). RESULTS Overall, 39 (50.65%) patients were classified as the TD subtype, and 38 (49.35%) were classified as the NTD subtype. Patients with NTD subtype presented a significantly higher number of NMS total scores (P = 0.007) and significantly higher score in the cognition domain of PDQ-39 (P = 0.021) than patients with TD subtype. Patients with NTD subtype had significantly higher NMS prevalence than patients with TD subtype with constipation (P = 0.021), incomplete bowel emptying (P = 0.050), anxiety (P = 0.030), daytime sleepiness (P = 0.017) and intense vivid dreams (P = 0.016). The predictors for the NTD subtype were intense vivid dreams (P = 0.012), anxiety (P = 0.030) and constipation (P = 0.044). The UPDRS, NMS total, and MMSE scores were the determinants of QOL in patients with PD (P < 0.05). CONCLUSION The NMS is a prominent manifestation of PD. Patients with the NTD subtype had a higher prevalence of NMS than those with the TD subtype and intense vivid dreams, anxiety and constipation were characteristic of the NTD subtype. NMS is one of the important factors that determine the QOL of patients with PD especially those with the NTD subtype.