One Side or Two? A Systematic Review of Deep Brain Stimulation Approaches in Movement Disorders

Area of Science:

• Neurosurgery
• Neurology
• Medical Technology

Background:

• Deep brain stimulation (DBS) is a standard treatment for Parkinson's disease (PD) and essential tremor (ET).
• The choice between unilateral and bilateral DBS strategies remains debated, influenced by patient-specific factors and cost.
• Optimal surgical approach requires careful consideration of clinical presentation and patient preference.

Purpose of the Study:

• To compare motor score improvements between unilateral and bilateral DBS procedures.
• To evaluate adverse events (AEs) and incremental benefits of unilateral versus bilateral DBS.
• To analyze the rationale and outcomes for pursuing second-side DBS surgery.

Main Methods:

• Systematic review of studies on unilateral or bilateral (simultaneous/staged) DBS.
• Inclusion of studies published between 1999 and 2025.
• Focus on patient outcomes, safety, and efficacy for movement disorders.

Main Results:

• Unilateral DBS for PD (STN/GPi) improved motor scores by up to 37%; bilateral DBS improved scores by up to 66%.
• Unilateral DBS for ET (VIM) improved hand tremor by up to 89%; bilateral DBS provided additional contralateral improvement.
• Bilateral VIM DBS increased AEs like gait issues and dysarthria; staged surgeries had longer durations and more revisions.

Conclusions:

• Bilateral DBS demonstrates superior long-term efficacy for both Parkinson's disease and essential tremor.
• Individualized treatment planning is crucial for optimizing DBS outcomes.
• While bilateral DBS offers greater benefits, potential AEs and procedural complexities must be managed.