Local field potentials for target localization in centromedian deep brain stimulation for epilepsy

Area of Science:

• Neuroscience
• Neurology
• Biomedical Engineering

Background:

• Thalamic deep brain stimulation (DBS) is a treatment for drug-resistant epilepsy (DRE).
• Accurate targeting of the centromedian-parafascicular (CM-Pf) nucleus is crucial for effective DBS.
• Physiological confirmation of CM-Pf targeting is needed.

Purpose of the Study:

• To evaluate local field potential (LFP) spectral profiles as a "spectral fingerprint" for confirming CM-Pf targeting in thalamic DBS for DRE.
• To investigate the association between LFP spectral patterns and anatomical contact localization within the thalamus.

Main Methods:

• Retrospective analysis of 10 patients (20 leads) who underwent CM-DBS for DRE.
• Co-registration of postoperative CT and preoperative MRI, normalized to MNI space using Lead-DBS software.
• Analysis of LFP spectral content from BrainSense™ Survey recordings to identify prominent peaks in canonical frequency bands (theta, alpha, beta).

Main Results:

• A dual-peak spectral profile (theta/low alpha and high beta bands) was identified in 80% of contacts localized to the CM/CM-Pf region (p < 0.001).
• Single-peak profiles did not show significant association with specific nuclei (p = 0.871).
• Contacts in other thalamic nuclei showed different spectral profiles (narrow 10-15 Hz peaks or triple-peak profiles).

Conclusions:

• A dual-band spectral pattern (theta/low alpha and high beta peaks) is associated with the CM-Pf region.
• This finding supports the use of LFP recordings as a physiological marker for target engagement in thalamic DBS.
• Future research could develop a spectral atlas to refine CM-Pf targeting for DRE treatment.