Subthalamic Nucleus Deep Brain Stimulation Improves Kinetic Tremor in Parkinson's Disease

Area of Science:

• Neurology
• Neurosurgery
• Movement Disorders

Background:

• Resting tremor is a hallmark of Parkinson's disease (PD), but action tremor, particularly kinetic tremor, also affects patients.
• Subthalamic nucleus deep brain stimulation (STN-DBS) is established for PD motor symptoms, yet its impact on action tremor remains less clear.

Purpose of the Study:

• To assess the efficacy of STN-DBS in improving resting, postural, and kinetic tremor in Parkinson's disease patients.
• To specifically investigate the effectiveness of STN-DBS on kinetic tremor, a less understood subtype.

Main Methods:

• Analysis of data from Parkinson's disease patients undergoing bilateral STN-DBS.
• Assessment using the Movement Disorders Society-Unified Parkinson's Disease Rating Scale (MDS-UPDRS) OFF-medication, both OFF- and ON-stimulation, 6-12 months post-surgery.
• Statistical analysis included Wilcoxon signed-rank tests, effect size calculations, sensitivity analyses, and a systematic literature review.

Main Results:

• Bilateral STN-DBS demonstrated significant improvement across all tremor subtypes (resting, postural, kinetic) (P < 0.001).
• Very large effect sizes (Cohen's d > 1.00) were observed for all tremor subtypes.
• Mean improvement percentages were comparable: resting (71.3%), postural (64.6%), and kinetic (65.1%). Complete tremor resolution rates were also consistent across subtypes (50.2%-55.8%).

Conclusions:

• Bilateral STN-DBS is effective in improving all tremor subtypes in Parkinson's disease patients.
• The treatment shows equal efficacy for resting, postural, and kinetic tremor, suggesting broad benefits for tremor management in PD.