Autonomic arousal elicited by subcallosal cingulate stimulation is explained by white matter connectivity

Area of Science:

• Neuroscience
• Neurosurgery
• Psychiatry

Background:

• Subcallosal cingulate deep brain stimulation (SCC DBS) is an experimental treatment for severe depression.
• Intraoperative stimulation can elicit acute behavioral responses, but accompanying physiological changes are not well-described.

Purpose of the Study:

• To investigate physiological readouts during SCC DBS for depression.
• To associate these physiological changes with anatomical substrates.

Main Methods:

• Nine patients with treatment-resistant depression underwent intraoperative SCC DBS.
• Autonomic responses (heart rate, skin conductance) were recorded during sham-controlled, double-blind stimulation.
• Probabilistic tractography mapped connectivity between stimulated contacts and mood regulation network regions.

Main Results:

• Acute SCC stimulation increased sympathetic autonomic response within seconds.
• These autonomic changes correlated with the salience of behavioral responses.
• Connectivity to the midcingulate cortex was identified as the primary pathway for autonomic responsivity.

Conclusions:

• Acute SCC stimulation induces observable autonomic and behavioral changes during surgery.
• These intraoperative phenomena are linked to networks involved in long-term antidepressant effects.
• Combining autonomic recordings, behavioral observation, and anatomical mapping aids in understanding SCC DBS mechanisms.