Sexual dysfunction is associated with postural instability gait difficulty subtype of Parkinson's disease.

The pathophysiology of the postural instability gait difficulty (PIGD) subtype of Parkinson's disease (PD) is unclear. Information on the spectrum of non-motor symptoms (NMS) in PIGD phenotype is limited. Our objective is to compare the spectrum of NMS in PIGD subtype compared to non-PIGD subgroup in PD patients and to determine predictive factors that are associated with PIGD phenotype. A total of 432 PD patients comprising 158 PIGD and 274 non-PIGD patients were recruited. NMS burden (frequency and severity) was assessed using non-motor symptom scale (NMSS). In the univariable analysis, NMSS total score (P = 0.0132), NMSS domain 3 (mood/apathy) score (P = 0.0108), NMSS domain 5 (attention/memory) score (P = 0.0048) and NMSS domain 8 (sexual function) score (P = 0.0052) were significantly higher in the PIGD group than in the non-PIGD group. Using multivariable logistic regression, UPDRS tremor score, UPDRS PIGD score, H&Y staging score and NMSS domain 8 (sexual function) score were found to be significantly different in the PIGD group compared to the non-PIGD group. We disclosed for the first time that PIGD patients demonstrated a greater overall NMS burden and sexual dysfunction and was an independent predictor of PIGD phenotype. Early intervention of sexual dysfunction symptoms in PIGD patients may improve their clinical management.