Effects of subthalamic nucleus stimulation on urodynamic findings in patients with Parkinson's disease.

PURPOSE Although the effects of subthalamic nucleus stimulation on the control of motor symptoms in patients with Parkinson's disease have been demonstrated, to our knowledge there are no data on effects of this treatment on voiding. We evaluated differences in urodynamic findings in patients with Parkinson's disease during on and off subthalamic nucleus stimulation status. MATERIALS AND METHODS We evaluated 3 males and 2 females with Parkinson's disease. All patients had undergone surgical bilateral implantation of subthalamic nucleus electrodes 4 to 9 months before our observation. Urodynamic evaluation was performed during chronic subthalamic nucleus stimulation and 30 minutes after turning off the stimulators. Certain parameters were evaluated, including bladder compliance and capacity, first desire to void volume, bladder volume of appearance (reflex volume) and amplitude of detrusor hyperreflexic contractions, maximum flow, detrusor pressure at maximum flow and detrusor-sphincter coordination. Results were compared statistically. RESULTS Statistically significant differences in urodynamic data obtained during on and off subthalamic nucleus stimulation status were noted. In particular bladder capacity and reflex volume were increased for on status (median 320 versus 130 ml., p = 0.043 and 250 versus 110, p = 0.043, respectively). The amplitude of detrusor hyperreflexic contractions was decreased for on status but the difference was not significant (median 23 versus 37 cm. H2O, p = 0.223). No differences were noted in the other urodynamic parameters considered during the filling and voiding phases. CONCLUSIONS Our experience shows that subthalamic nucleus stimulation seems to be effective for decreasing detrusor hyperreflexia in Parkinson's disease cases. This finding confirms a role for basal ganglia in voiding control.