Design and Validation of a Closed-Loop, Motor-Activated Auricular Vagus Nerve Stimulation (MAAVNS) System for Neurorehabilitation

Link to Study: Cook et al. 2020

Highlights

•A motor-activated auricular vagus nerve stimulation (MAAVNS) system effectively and consistently pairs stimulation with oromotor activation generated by a nutritive suck in neonates.

•Using a closed-loop system to deliver transcutaneous auricular vagus nerve stimulation allows for more uniform delivery of treatment across multiple operators.

•MAAVNS is feasible and may become a promising tool for both adult and pediatric neuromodulation-based rehabilitation.

Abstract

Background

Studies have found that pairing vagus nerve stimulation (VNS) with motor activity accelerates cortical reorganization and, and this synchronous pairing may enhance motor recovery.

Objective

To develop and validate a motor-activated auricular vagus nerve stimulation (MAAVNS) system as a potential neurorehabilitation tool.

Methods

We created MAAVNS and validated its function as part of an ongoing clinical trial investigating whether taVNS-paired rehabilitation enhances oromotor learning. We compared 3 different MAAVNS EMG electrode configurations in 3 neonates. The active lead was placed over the buccinator muscle. Reference lead placements were orbital, temporal or frontal.

Results

The frontal reference lead produced the highest sensitivity (0.87±0.07 (n=8)) and specificity (0.64±0.13 (n=8)). Oral sucking reliably triggers MAAVNS stimulation with high confidence.

Conclusion

EMG electrodes placed on target orofacial muscles can effectively trigger taVNS stimuli in infants in a closed loop fashion.