3389 electrode

After the Medtronic 3,389 electrodes were permanently implanted, both awake and asleep groups received intravenous propofol general anesthesia again. Impulse generator (IPG) was implanted in the right subclavian subcutaneous package and connected to extended electrodes on the same day. Patients were sent to neurosurgery intensive care unit (ICU) for tracheal extubation and recovery after surgery. Within 24 h after the operation, brain computed tomography (CT) scanning was performed for each patient to exclude intracranial complications and preliminarily evaluate the position of the electrodes (Figure 1B). About 1 week after surgery, postoperative 1.5 T MRI brain imaging was scanned for evaluating the final position of the electrodes by image fusion.

The DBS procedure was conducted using standard means. Electrodes were implanted under local anaesthetic using a stereotactic frame affixed to the patient’s head (Cosman–Roberts–Wells (CRW) frame). With the frame in place, each patient was scanned using CT, which was subsequently fused with a pre-procedural MRI scan for treatment targeting. The DBS electrodes were placed dorso-ventrally down the ALIC to the target site. The target site was 1 mm posterior to the posterior edge of the AC, 4–5 mm lateral to the midline and 2.5–3 mm below the AC–posterior commissure line. This site corresponds to the BNST at the posterior border of the nucleus accumbens, lateral and dorsal to the anterior regions of the hypothalamus. The patients were implanted using Medtronic 3389 electrodes with 1.5 mm contacts and 0.5 mm spacing.

Implantation of DBS leads was performed according to standard stereotactic procedures using frame‐based magnetic resonance imaging (MRI) for target determination, under local anesthesia. Participants underwent bilateral implantation of quadripolar 3389 electrodes (Medtronic, Minnesota, USA), spaced 0.5 mm apart and 1.5 mm long (Fig. 2). The surgical target (of the electrode tip) was the NAc as identified on MRI. Stereotactic atlases place this 7 mm lateral to the midline, 3 mm anterior to the anterior border of the anterior commissure, and 4 mm inferior to the intercommissural line. The two ventral contacts were targeted in the center of the NAc (E0, E1, E8, E9). Intra‐operative test stimulation was conducted to assess mood and behavior. The electrodes were connected via subcutaneous extensions to Activa PC, or RC stimulator (Medtronic, Minnesota, USA) placed in the infraclavicular pocket, under general anesthesia. Post‐operative computed tomography (CT) fused with pre‐operative MRI verified the position of the implanted electrodes. DBS was switched on 2 days following the surgery.