Parkinson’s disease (PD) is the second-most common degenerative neurologic disease worldwide. Overactive bladder (OAB) is prevalent in this population, with lower urinary tract symptoms (LUTS) present in 27-85% of PD patients. [1] OAB/LUTS can be challenging to treat due to risks associated with polypharmacy (anticholinergics) and difficulty with self-catheterization in cases of retention (Onabotulinumtoxin-A). Sacral neuromodulation (SNM) is an attractive treatment option, especially with the recent introduction of MRI conditional technology, but remains understudied in PD. The largest study of SNM in PD was a retrospective chart review of 15 patients, which found that 60% of patients progressed to permanent implant. [2] We have utilized SNM in PD patients for some time, therefore, the aim of our study was to assess the safety, efficacy and long-term outcomes of SNM in the PD population.

We performed a retrospective chart review of PD patients who underwent peripheral nerve evaluation (PNE) or Stage 1 SNM from 2000-2020 at a single academic institution. Patients were included if they were greater than 18 years of age, had received a formal diagnosis of PD by a neurologist before the SNM was performed, and had failed or were not candidates for first, second and other third line treatment options for the treatment of OAB. Primary outcome was progression to permanent implant with ≥50% improvement of urinary symptoms. The impact of PD stage and pre-procedural urodynamic (UDS) parameters on test-phase outcome was assessed with Fisher’s exact and Wilcoxin rank sum tests. UDS parameters included PVR (ml), PdetQmax (cm H2O), presence of detrusor overactivity (DO) contractions, Qmax (ml/sec), Bladder Outlet Obstruction Index (BOOI), bladder capacity (ml), and presence of DSD. PD severity was defined using the Nor Hoehn and Yahr (NHY) staging system, which is one of the most common rating scales used to describe the progression and severity of PD and utilizes five stages. Long term efficacy was assessed using Wilcoxon matched-pairs test looking at change in urinary symptoms (frequency, nocturia, incontinence episodes, pad use) documented at available follow-up visits and further need for treatment.

Thirty-four patients underwent test phase SNM (7 PNE, 27 Stage 1). 20/34 (59%) patients were male with a mean age of 72 (SD 7) years and median follow-up of 11 [IQR 5.8, 29.8] months. Indications included refractory OAB (30/34) with or without urgency urinary incontinence (UUI) and non-obstructive urinary retention (4/34). Overall, 82% (28/34) of patients proceeded to permanent implant and 71% (5/7) of PNEs were successful. Median NYH PD stage was 2 [IQR 1.6, 3]. Test-phase success did not differ based on PD disease severity or UDS parameters. In patients with OAB/UUI who progressed to permanent implant, 83% (24/28) experienced subjective improvement in their urgency and there was a statistically significant improvement in their urinary symptoms (frequency, nocturia, urge incontinence episodes and pads/day) from baseline (Figure I). Most (68%) patients were able to discontinue OAB medications post-implant, and 62.5% did not require further treatment. Overall lead revision rate was 14% (4/28) and 3 devices required removal.

PD patients had a high rate of SNM test phase success with 83% of patients progressing to permanent implant. PNE success with fluoroscopy in patients with urgency-frequency syndrome, UUI, and/or fecal incontinence has been documented in a recently published study to be 76.5% [3], which is comparable to the 71% PNE success found in our results. This suggests that PNE can be considered for initial test-phase evaluation in PD patients. Patients continued to have improvement in their urinary symptoms after implantation documented at their follow-up visits, with only 3 devices requiring removal and the majority of patients not requiring further treatment of their OAB/UUI.

SNM is an efficacious treatment option for OAB in PD patients with a high percentage of patients having improvement in their urinary symptoms. No UDS parameters were found to predict which patients would progress to permanent implantation.

Sakakibara R, Panicker J, Finazzi-Agro E, et al: A guideline for the management of bladder dysfunction in Parkinson’s disease and other gait disorders. Neurourol. Urodyn. 2016; 35: 551–563.
Greenberg DR, Sohlberg EM, Zhang CA, et al: Sacral Nerve Stimulation in Parkinson’s Disease Patients with Overactive Bladder Symptoms. Urology 2020.
Kocher NJ, Derisavifard S, Rueb J, et al: Predictive factors of PNE success in a contemporary series: A single institution experience. Neurourol Urodyn 2021; 40: 376–383.