Oscillatory network markers of subcallosal cingulate deep brain stimulation for depression

Area of Science:

• Neuroscience
• Biomarkers
• Brain Stimulation

Background:

• Treatment-resistant depression (TRD) poses a significant clinical challenge.
• Subcallosal cingulate deep brain stimulation (SCC-DBS) is an emerging therapy for TRD.
• Understanding the neural mechanisms of SCC-DBS is crucial for optimizing treatment.

Purpose of the Study:

• To identify region-specific oscillatory modulations differentiating TRD patients from healthy controls.
• To identify oscillatory modulations that distinguish TRD treatment responders from non-responders during SCC-DBS.
• To explore the impact of stimulation intensity and frequency on oscillatory activity.

Main Methods:

• Magnetoencephalography (MEG) data were collected from 16 individuals with SCC-DBS for TRD and 25 healthy subjects.
• Oscillatory power analyses were performed to identify brain region-specific modulations.
• Analyses examined differences between TRD patients (SCC-DBS OFF) and controls, and between responders and non-responders (SCC-DBS ON).

Main Results:

• Increased alpha (8-12 Hz) and decreased gamma (32-116 Hz) power in default mode, central executive, and somatomotor networks, Broca's area, and lingual gyrus differentiated responders from non-responders.
• Low stimulation frequency showed stronger oscillatory modulation effects than increased stimulation intensity.
• These findings implicate brain regions involved in emotional control, motor control, and speech-vision-memory interactions.

Conclusions:

• Identified electrophysiological biomarkers (alpha and gamma power modulations) can predict SCC-DBS treatment response in TRD.
• These biomarkers offer potential as functional proxies for therapy optimization.
• Stimulation frequency, particularly lower frequencies, may be a key parameter for enhancing therapeutic effects in non-responders.