Impact of Transcutaneous Vagal Nerve Stimulation (Tvns) Priming on Therapy Outcomes for People With Aphasia

Research Objectives

To investigate the impact of tVNS on therapy outcomes for aphasia.

Design

A double-blind, crossover intervention study design was used to allow for both within-subject and between-subject comparison of tVNS vs. sham condition. Participants were randomly assigned to either the active tVNS priming condition or the sham priming condition for the first half of treatment (5-6 weeks) and switched condition for the second half with the sham group then receiving active tVNS and the formerly active tVNS group receiving sham stimulation.

Setting

University of Maryland Hearing and Speech Clinic, College Park, MD.

Participants

Participants with aphasia due to stroke were recruited from the Washington, DC area; Participants were ineligible if they had certain medical conditions (eg. cancer) or implanted devices (e.g. pacemaker). Participants with a history of cardiac disease or seizures required medical clearance out of an abundance of caution. Participants were excluded for severe apraxia of speech, cognitive deficits and hearing loss. Eight participants (3m, 5f) with mild to moderate aphasia completed the study, 7 did not meet inclusion criteria, withdrew or were disrupted. No one dropped due to adverse events. Participants ranged from 22 to 75 years-old (avg. 52.9) and were between 7 months and 15 years post-onset.

Interventions

Participants received five minutes of either active or sham tVNS via an earbud prior to word-finding therapy.

Main Outcome Measures

The Western Aphasia Battery, Test of Word Finding in Adults, Boston Naming Test, F-A-S Task, Communication Confidence Rating Scale for Aphasia were completed at baseline, midterm, and post-treatment.

Results

Results are still being collected but suggest that tVNS priming may have only minimal impact on outcomes; recent work from other labs suggests that tVNS at the moment of encoding may have stronger impact, whereas priming may be more facilitative of retrieval.

Conclusions

TVNS is a low cost, safe, accessible modality with the potential to improve aphasia outcomes, but further work is needed to identify if and how it can be best used with this population.

Author(s) Disclosures

See individual author disclosures.