Effects of subthalamic nucleus stimulation on urodynamic findings in patients with Parkinson’s disease
Journal of Neurology
Finazzi-Agro, E., A. Peppe, et al. (2003) Effects of subthalamic nucleus stimulation on urodynamic findings in patients with Parkinson’s disease Journal of Neurology, 169(4): 1388-91
These authors suggest that approximately 60% of patients with PD have bladder dysfunction. 45-93% of those patients have difficulty with detrusor hyperreflexia (involuntary contractions of the bladder causing reduced capacity and early desire to void, also known as overactive bladder). They studied 5 patients with PD (3 men, 2 women, mean age 63, and mean disease duration 15 years) and DBS STN (9-12 months prior). All of the patients presented with urinary symptoms (frequency, urgency, and urge incontinence). They measured urination during the ON and OFF (30 minutes after turning stimulator off) phases. Statistical considerations were made due to such a small sample size. They found that patients had increased bladder capacity and reflex volume (a specific measure of bladder volume) during the ON phase than the OFF. They also found decreased detrusor hyperreflexia but not significantly so, which was thought to be due to the small number of patients studied. It is notable that all patients reported improvement in their motor symptoms and 3 of the 5 reported they felt as though they had improvement in bladder functioning as a result of the DBS STN. As noted in other studies the cause of bladder dysfunction in PD is unclear, but these authors suggest that the basal ganglia (area in the brain affected by PD), dopamine receptors (areas in the brain that respond to certain chemicals), and prefrontal areas of the brain are implicated in bladder functioning. They conclude that DBS STN seems to be effective for bladder dysfunction but suggest future research needs to continue to evaluate bladder functioning in patients with PD.