Effect of Deep Brain Stimulation on Gait of Patients With Parkinson's Disease Depending on Electrode Location in Subthalamic Area

Deep brain stimulation of STN (subthalamic nucleus) at high frequencies generally improved gait in parkinsonian patients. However, sometimes the investigators observed a gait aggravation either with using high voltage and high frequencies, either because of suboptimal placement of electrode inside Forel H2 field. The most frequent hypothesise to explain this gait aggravation is a modulation of the activity of pedunculopontine nucleus due to a diffusion of the electric stimulation current to the fibbers going near STN area. The primary purpose of this study is to compare the effect of deep brain stimulation with high frequency versus low frequency on gait of patients whatever the electrodes placement (STN ou Forel fields) and whatever the medication condition (with or without treatment).