Extradural motor cortex stimulation in Parkinson's disease

Area of Science:

• Neurosurgery
• Neurology
• Movement Disorders

Background:

• Advanced Parkinson's disease (PD) presents challenges for deep brain stimulation (DBS) candidates.
• Extradural motor cortex stimulation (EMCS) is an alternative surgical approach for select PD patients.
• EMCS targets motor cortex for potential therapeutic effects in PD.

Purpose of the Study:

• To evaluate the efficacy of EMCS in patients with advanced PD and motor fluctuations/dyskinesia.
• To assess objective and subjective outcomes 6 months after EMCS surgery.
• To determine if EMCS offers a viable alternative for PD patients ineligible for DBS.

Main Methods:

• Five PD patients meeting CAPSIT criteria for DBS (except age >70) underwent left hemisphere EMCS.
• Patients were assessed preoperatively and 6 months post-surgery, with and without medication and stimulation.
• Outcome measures included UPDRS, AIMS, medication dosage, and subjective patient reports.

Main Results:

• No significant mean changes were observed in objective outcome measures post-EMCS.
• A trend towards reduced daily medication intake (-30%) and dyskinesia scores (AIMS, -19%) was noted.
• Three patients reported reduced "OFF" time, and four reported subjective benefits in stability and gait.

Conclusions:

• EMCS did not provide significant objective benefits in this cohort of advanced PD patients.
• Subjective improvements, particularly in axial symptoms like stability and gait, were reported by some patients.
• EMCS may offer limited symptomatic relief for specific PD symptoms in carefully selected individuals.