Motor cortical stimulation for parkinsonism in multiple system atrophy

Area of Science:

• Neuroscience
• Neurosurgery

Background:

• Parkinsonism involves motor cortex dysfunction, responsive to basal ganglia surgery.
• Transcranial magnetic stimulation offers transient relief for Parkinson disease bradykinesia and gait issues.
• Direct cortical stimulation has shown potential in refractory Parkinson disease cases.

Purpose of the Study:

• To assess the effectiveness of motor cortical stimulation for treating refractory parkinsonism in multiple system atrophy (MSA).

Main Methods:

• Five patients diagnosed with MSA and predominant parkinsonism underwent subdural motor cortical stimulation surgery.
• Evaluated changes in activities of daily living and motor subscores using the Unified Parkinson's Disease Rating Scale.
• Compared baseline scores with those at 3 to 6 months post-surgery, after medication withdrawal.

Main Results:

• Motor scores declined in all patients post-surgery, despite stimulation adjustments.
• Activities of daily living scores worsened by 9.7% (P=.37), and motor scores worsened by 25.6% (P=.06).
• Three patients reported subjective benefit and desired continued stimulation, though objective measures showed decline.

Conclusions:

• Motor cortical stimulation, with the tested parameters, did not improve motor disability in MSA patients.
• Observed worsening of motor scores is likely attributable to the natural progression of the disease.
• The procedure was generally safe, with no long-term adverse effects reported, apart from one seizure during programming.