Shifting from constant-voltage to constant-current in Parkinson's disease patients with chronic stimulation

Objective. To evaluate safety and efficacy of shifting stimulation settings from constant-voltage (CV) to constant-current (CC) programming in patients with Parkinson disease (PD) and chronic subthalamic nucleus deep brain stimulation (STN DBS). Methods. 20 PD patients with chronic STN DBS set in CV programming were shifted to CC and followed for three months; the other stimulation settings and the medication regimen remained unchanged. Side effects, motor, non-motor, executive functions and impedance were assessed at baseline and during follow-up. Results. No adverse events were observed at time of change in programming or during CC stimulation. Motor and non-motor measures remained unchanged at follow-up despite impedance decreased. Compared to baseline, cognitive assessment showed improvement of inhibition processes. Conclusions. The shifting strategy was well tolerated and the clinical outcome was maintained with no need to adjust stimulation settings or medications notwithstanding a decrease of impedance. Improvement of inhibition processes towards normality is an important feature to consider.