Multi-parametric analysis assists in STN localization in Parkinson's patients

Area of Science:

• Neurosurgery
• Neuroscience
• Biomedical Engineering

Background:

• Subthalamic nucleus (STN) localization for deep brain stimulation (DBS) in Parkinson's disease (PD) typically relies on MRI and atlases, refined intraoperatively by electrophysiological mapping (IOA).
• Intraoperative multi-unit activity (IOA) is time-consuming and subjective, highlighting a need for more efficient and objective methods.

Purpose of the Study:

• To evaluate the utility of high-frequency multi-unit background activity (MUA) and local field potentials (LFP) in accurately identifying STN borders.
• To compare the effectiveness of MUA and LFP with traditional IOA for STN localization.

Main Methods:

• Retrospective single-center study involving 18 leads in 10 PD patients undergoing STN DBS.
• Comparison of IOA (gold standard), MUA (>500Hz), and LFP (5-500Hz) in detecting STN borders.
• Analysis using Bland-Altman statistics and correlation coefficients to assess agreement between methods.

Main Results:

• Both MUA and LFP showed characteristic increases upon entering the STN, correlating with dorsal and ventral borders.
• Minimal differences were observed between IOA and MUA/LFP border detection (mean differences < 0.30mm).
• High correlations were found between IOA and MUA (0.86–0.97) and IOA and LFP (0.78–0.88), indicating strong agreement.

Conclusions:

• MUA and LFP exhibit distinct elevations within the STN compared to adjacent tissues.
• These electrophysiological signals serve as rapid, real-time, objective, and dependable markers for STN border identification.
• MUA and LFP offer a promising alternative to subjective IOA for STN targeting in DBS procedures.