Localization of subthalamic nucleus borders using macroelectrode local field potential recordings.

Area of Science:

• Neurosurgery
• Neuroscience
• Biomedical Engineering

Background:

• Deep brain stimulation (DBS) targeting the subthalamic nucleus (STN) effectively treats Parkinson's disease motor symptoms.
• Accurate intraoperative STN localization is crucial but remains technically challenging.

Purpose of the Study:

• To investigate the utility of local field potential (LFP) activity recorded from DBS macroelectrodes for identifying STN borders.
• To compare LFP-based STN border localization with microelectrode-derived single-unit activity (MER-SUA) predictions.

Main Methods:

• LFPs were recorded from DBS macroelectrodes during STN trajectory in six Parkinson's disease patients.
• Frequency-vs-depth maps of LFP activity were analyzed in different sub-bands.
• STN borders identified by LFPs were compared to neurosurgeon predictions based on MER-SUA.

Main Results:

• Significant differences were observed between MER-SUA and macroelectrode LFP recordings for the dorsal STN border in beta (-1.00 ±0.84 mm) and gamma (-0.42 ±1.07 mm) frequency bands.
• The root-mean-square (RMS) of these distances were 1.26 mm (beta) and 1.06 mm (gamma).
• Analysis of other sub-bands did not reliably identify the caudal STN border.

Conclusions:

• Macrodelectrode-derived LFP recordings show potential as an alternative method for STN border identification during DBS surgery.
• LFP analysis, particularly in beta and gamma bands, may aid in improving the precision of STN targeting.