Transcutaneous Auricular Vagus Nerve Stimulation (taVNS) for Inflammation and Depression Following SCI

Summary

Spinal cord injury (SCI) has been shown to be associated with impairment to the autonomic nervous system in the form of reduced activity of a key nerve known as the vagus nerve. As the vagus nerve has an important role in regulating inflammation and is associated with depression, it may represent a key mechanism which contributes to chronic inflammation and depression following SCI.

A technique known as transcutaneous auricular vagus nerve stimulation (taVNS) can stimulate the vagus nerve non-invasively through an electrode applied on the skin of the ear. This technique has been shown to effectively reduce inflammation and improve symptoms of depression in other populations without any serious adverse events. However, it has not been assessed in individuals with SCI.

The primary objective of this study is to assess the efficacy of taVNS therapy for the treatment of inflammation and depression. Autonomic function as assessed by measures of heart rate variability (HRV) will also be assessed to quantify changes in vagal tone. The study will be conducted over a 2-year period, with 44 individuals with SCI and depression participating. Participants will be randomly assigned to receive either active taVNS or a placebo (sham) treatment over a 30-day period.

The researchers will assess changes in depression symptoms, autonomic function (heart rate variability), and biomarkers related to inflammation at baseline and 30-days. Safety and adherence will also be evaluated to confirm the feasibility for long-term use.

This study aims to explore a novel and non-invasive treatment strategy for depression in individuals with spinal cord injury. If taVNS is found to be safe, effective, and feasible for SCI patients, it could offer a simple, cost-effective way to address chronic inflammation and depression in this population.

Conditions

• Spinal Cord Injury
• Depression

Interventions

DEVICE

Active Transcutaneous Auricular Vagus Nerve Stimulation

Stimulation will target the auricular branch of the vagus nerve by applying stimulation to the cymba conchae region of the ear using the tVNS R device (taVNS Technologies, Erlangen, Germany). To achieve adequate stimulation while avoiding unpleasant or painful sensations, the stimulation intensity will be gradually increased in increments of 0.1mA until the subjective pain threshold is reached, and then reduced to a stimulus intensity just below the individuals pain threshold (expected range based on prior studies 1 - 3.2mA). Pulse width will be set at 100μs and frequency will be set at 25Hz. Parameters will be set for the duration of the intervention consisting of 4 hours of daily stimulation for a period of 30 days.

DEVICE

Sham Transcutaneous Auricular Vagus Nerve Stimulation

Stimulation will target the ear lobe using the NEMOS® taVNS device (taVNS Technologies, Erlangen, Germany). To achieve adequate stimulation while avoiding unpleasant or painful sensations, the stimulation intensity will be gradually increased in increments of 0.1mA until the subjective pain threshold is reached, and then reduced to a stimulus intensity just below the individuals pain threshold (expected range based on prior studies 1 - 3.2mA). Pulse width will be set at 100μs and frequency will be set at 25Hz. Participants will perform 4 hours of stimulation per day for a period of 30 days. Stimulation will be applied to the ear lobe in order to ensure participant feel the stimulation while avoiding activation of the vagus nerve.

Sponsors & Collaborators

• London Health Sciences Centre Research Institute OR Lawson Research Institute of St. Joseph's

  lead OTHER

Principal Investigators

• David J Allison, PhD. · London Health Sciences Centre Research Institute OR Lawson Research Institute of St. Joseph's

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

SINGLE

Model

PARALLEL

Eligibility

Min Age

18 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2025-01-27

Primary Completion

2026-04-30

Completion

2026-08-30

Countries

• Canada

Study Locations