Subthalamic Steering for Therapy Optimization in Parkinson's Disease

Subthalamic Steering for Therapy Optimization in Parkinson's Disease

Twenty patients with idiopathic Parkinson's disease (PD) will be included into this single center randomized controlled double-blind clinical trial (RCT) in a cross-over design. The treatment consists of two different stimulation settings using (i) conventional omnidirectional stimulation of the subthalamic nucleus [STN_O] as active comparator and (ii) directional steering of STN stimulation via a segmented electrode contact [STN_D].

Twenty PD patients will be enrolled in this cross-over double-blind RCT to evaluate both the safety and efficacy of directional STN stimulation [STN_D] compared with standard omnidirectional STN stimulation [STN_O]. The primary outcome measure is objectively quantified muscle rigidity of the upper extremity, i.e., surface EMG recordings of the biceps and triceps muscle during standardized extension/flexion of the elbow joint (Levin et al., 2009) assessed 6 months after implantation in cross-over design. The trial is designed to detect with an 80% power a change of 0.27 mA of the therapeutic stimulation threshold with two-tailed P < 0.05 (Wilcoxon rank sum test). Secondary outcome measures address clinical motor, non-motor, neurocognitive and neuropsychiatric symptoms, freezing of gait, and quality of life. Visits are scheduled at weeks 1 (V1), 6 (V2), 24 (V3), 27 (V4), and 30 (V5) from baseline (V0).

Inclusion Criteria:

• Written informed consent
• Idiopathic Parkinson's disease (according to the "British Brain Bank criteria" (Hughes, 1992) including genetic forms

Exclusion Criteria:

• Cognitive impairment (Mini Mental State Exam < 20)
• Suicidality, Psychosis
• Other severe pathological chronic condition that might confound treatment effects or interpretation of the data
• Pregnancy