Non-Invasive Vagal Nerve Stimulation in Opioid Use Disorders

"Stimulation of vagus nerve with active device. Participants will be administered nVNS using the electroCore GammaCore-S non-invasive VNS device. The intensity of the stimulus will be adjusted by the user, to the maximum tolerable level to ensure nVNS without causing excessive pain, the burst frequency to 5 kHz, and the envelope frequency to 25 Hz.~The duration of delivery will be 2 minutes, and the beginning will coincide with initiation of acquisition of the HR-PET scan which will be 90 seconds in duration; following an additional 8 minutes, a second VNS delivery will be administered, in conjunction with which another scan will be obtained."

Injection of radiolabelled water. H2\[15-O\] is a radioactive material. Each patient will have eight H2\[15-O\] blood flow scans. For each O-15 water scan 20 mCi of H2\[15O\] will be injected as an intravenous bolus.

"Sham stimulation of vagus during opioid cue exposure. Each subject in the SHAM group will undergo the action of administering the intervention, but the device will be programmed such that the stimulation will not activate the vagus nerve."