Functional topography of the ventral striatum and anterior limb of the internal capsule determined by electrical stimulation of awake patients.

OBJECTIVE

To assess the behavioral and subjective effects of acute electrical stimulation along the anterior limb of the internal capsule (ALIC) and ventral striatum (VS).

METHODS

Intraoperative awake electrical stimulation and postoperative programming was performed in a group of 6 patients with major depressive disorder (MDD) undergoing bilateral deep brain stimulation of the ALIC and VS areas.

RESULTS

Electrical stimulation of the VS area acutely produced changes in mood as well as alertness, anxiety, dizziness, sensation of warmth and "flushing". Stimulation of the ventral capsule area just dorsal to the anterior commissure was associated with increments in mood, sensation of energy and alertness, laughing, calmness and talkative behavior. Behavioral effects were less commonly observed with stimulation of the dorsal region of the ALIC.

CONCLUSION

Acute behavioral and subjective responses can be consistently obtained from stimulation in the ventral ALIC and VS region. Positive changes in mood and anxiety were reproducibly elicited in the ventral ALIC area.

SIGNIFICANCE

Intraoperative awake stimulation and postoperative programming of patients undergoing DBS for MDD provide unique opportunities to explore the subjective responses and behavioral phenomena related to electrical stimulation of the area spanning from the dorsal ALIC to the ventral striatum.