Poster No:
78
Submission Type:
Abstract Submission
Authors:
Bashar Badran1, Xiaolong Peng2, John Robinson2, Falon Sutton2, Marion Wood3, Dillon Connolly2, Andrew Manett2, Ethan Ashley2, Baron Short2, Viswanathan Ramakrishnan2, Jeffrey Borckardt2
Institutions:
1Medical University of South Carolina, Charleston, SC, 2MUSC, Charleston, SC, 3College of Charleston, Charleston, SC
First Author:
Co-Author(s):
Introduction:
Recently, a form of noninvasive neuromodulation known transcutaneous auricular neurostimulation (tAN) has emerged as a promising form of brain stimulation. Although preliminary findings suggest tAN is safe and effective in reducing opioid withdrawal symptoms, the mechanism at which it achieves this is unknown. Furthermore, the optimal stimulation parameters (frequency, ear stimulation target) are still unclear. In this prospective neuroimaging study, we use a novel concurrent tAN/fMRI paradigm to administer tAN within the MRI scanner in various settings and targets to activate auricular cranial nerves both independently and concurrently. We aim to understand whether combining stimulation at multiple ear sites produces greater neurophysiologic effects than stimulating solely the auricular branch of the vagus nerve (ABVN) or the auricular trigeminal nerve (ATN) alone.
Methods:
Up to 96 healthy adult participants will attend a single experimental visit during which they will receive ear stimulation at one of three active conditions (ATN, ABVN, COMBO) and at two sham conditions (earlobe 15Hz, earlobe 100Hz). Enrolled participants will first have a baseline stimulation calibration conducted after which participants will be placed in the MRI scanner and electrodes will be connected to the MRI-compatible stimulation system. 8 minutes of stimulation will be delivered to the various ear targets in a 30s ON/OFF block design while acquiring high-resolution functional imaging. The fMRI data was processed to obtain the first-level task activation maps for each participant at each stimulation frequency. A one-sample t-test was then performed to generate the mean task activation maps.
Results:
To date, we have enrolled n=39 (mean age +/-SD = 37.1 +/-13.2 years, n=28 female), and in this analysis, we present blinded data from the first 20 participants. All three active tAN conditions showed positive brain activations in the supramarginal gyrus, while ABVN and combo tAN have higher brain activity in the anterior insular compared to tragus tAN (one sample t-test, p <0.05). Moreover, combo tAN also revealed strong deactivation in the primary sensorimotor area. In contrast, sham conditions (both 15Hz and 100Hz) induced brain activities have a similar spatial pattern, including positive brain activation in the temporoparietal junction (TPJ), insular, ventral lateral prefrontal cortex, and posterior temporal lobe. However, stimulation at 100Hz resulted in an overall higher intensity of activation compared to 15Hz.
Conclusions:
This NIH Heal Initiative study is part of a five-year mission to understand how to create non-opioid treatments for pain and reduce opioid dependence. Using functional MRI acquired concurrently during neurostimulation allows us to map the specific auricular dermatomes that may have biologic impacts, and determine whether specific parameters may optimally recruit brain areas in the pain network. Although still early with a small sample size to date, there are likely identifiable differences between ear stimulation targets and understanding these differences will allow us to optimize tAN for pain disorders.
Brain Stimulation:
Non-Invasive Stimulation Methods Other 1
Novel Imaging Acquisition Methods:
BOLD fMRI 2
Perception, Attention and Motor Behavior:
Perception: Pain and Visceral
Keywords:
FUNCTIONAL MRI
1|2Indicates the priority used for review
Provide references using author date format
Jenkins DD, Khodaparast N, O’Leary GH, Washburn SN, Covalin A, Badran BW. Transcutaneous auricular neurostimulation (tAN): a novel adjuvant treatment in neonatal opioid withdrawal syndrome. Frontiers in Human Neuroscience. 2021 Mar 8;15:648556.