Urodynamic mechanisms underlying overactive bladder symptoms in patients with Parkinson disease

Purpose: To assess the urodynamic findings in patients with Parkinson disease (PD) with overactive bladder symptoms. Methods: We performed a retrospective chart review of all PD patients who were seen in an outpatient clinic for lower urinary tract symptoms (LUTS) between 2010 and 2017 in a single-institution. Only patients who complained of overactive bladder (OAB) symptoms and underwent a video-urodynamic study for these symptoms were included. We excluded patients with neurological disorders other than PD and patients with voiding LUTS but without OAB symptoms. Results: We included 42 patients (29 men, 13 women, 74.5 ± 8.1 years old). Seven patients (16.7%) had a postvoid residual (PVR) bladder volume > 100 mL and only one reported incomplete bladder emptying. Detrusor overactivity (DO) was found in all 42 patients (100%) and was terminal in 19 (45.2%) and phasic in 22 patients (52.4%). Eighteen patients had detrusor underactivity (DU) (42.3%). Later age of PD diagnosis was the only parameter associated with DU (P = 0.02). Patients with bladder outlet obstruction (BOO) were younger than patients without BOO (70.1 years vs. 76.5 years, P = 0.004), had later first sensation of bladder filling (173.5 mL vs. 120.3 mL, P = 0.02) and first involuntary detrusor contraction (226.4 mL vs. 130.4 mL, P = 0.009). Conclusions: DO is almost universal in all patients with PD complaining of OAB symptoms (97.1%). However, a significant percentage of patients also had BOO (36.8%), DU (47%), and increased PVR (16.7%) indicating that neurogenic DO may not be the only cause of OAB symptoms in PD patients.