Electrophysiological changes in the acute phase after deep brain stimulation surgery.

Area of Science:

• Neuroscience
• Biomedical Engineering
• Neurological Surgery

Background:

• Sensing-enabled deep brain stimulation (DBS) necessitates understanding long-term biomarker dynamics for treatment optimization.
• The microlesion effect causes transient post-operative clinical improvement.
• Optimal timing for electrophysiology-based DBS programming remains unclear, despite beta band activity being a bradykinesia biomarker.

Purpose of the Study:

• Investigate the impact of the microlesion effect on chronic biomarker recordings.
• Determine the stabilization time point of biomarker dynamics post-surgery.

Main Methods:

• Continuous subthalamic peak biomarker power recording for 40 days in 12 Parkinson's disease patients.
• Analysis of daily changes in mean peak power and complexity.
• Comparison of power spectral density at rest between immediate post-operative and 3-month follow-up periods.
• Pallidal recordings in 2 dystonia patients.

Main Results:

• Mean peak power increased postoperatively, stabilizing between 22-29 days.
• Peak power complexity stabilized around the same time, showing reduced recurrence states and laminarity.
• Biomarker activity significantly increased at 3-month follow-up compared to the early post-operative phase.
• Clinical reflection of microlesion effect: reduced medication needs before chronic stimulation.

Conclusions:

• The transient microlesion effect involves reduced beta band power and neural signal complexity, stabilizing by the first month post-surgery.
• These changes likely represent local neuronal adaptation.
• Findings are crucial for timing electrophysiology-supported DBS programming, including contact selection and adaptive algorithms.