Transcutaneous Cervical Vagus Nerve Stimulation Induces Changes in the Electroencephalogram and Heart Rate Variability of Healthy Dogs, a Pilot Study

Gibrann Castillo; Luis Gaitero; Sonja Fonfara; Christopher J Czura; Gabrielle Monteith; Fiona James

doi:10.3389/fvets.2022.878962

Transcutaneous Cervical Vagus Nerve Stimulation Induces Changes in the Electroencephalogram and Heart Rate Variability of Healthy Dogs, a Pilot Study

Front Vet Sci. 2022 Jun 13:9:878962. doi: 10.3389/fvets.2022.878962. eCollection 2022.

Authors

Gibrann Castillo¹, Luis Gaitero¹, Sonja Fonfara¹, Christopher J Czura², Gabrielle Monteith¹, Fiona James¹

Affiliations

¹ Department of Clinical Studies, Ontario Veterinary College, University of Guelph, Guelph, ON, Canada.
² Convergent Medical Technologies, Inc., Oyster Bay, NY, United States.

Abstract

Transcutaneous cervical vagus nerve stimulation (tcVNS) has been used to treat epilepsy in people and dogs. Objective electroencephalographic (EEG) and heart rate variability (HRV) data associated with tcVNS have been reported in people. The question remained whether EEG and electrocardiography (ECG) would detect changes in brain activity and HRV, respectively, after tcVNS in dogs. Simultaneous EEG and Holter recordings, from 6 client-owned healthy dogs were compared for differences pre- and post- tcVNS in frequency band power analysis (EEG) and HRV. The feasibility and tolerance of the patients to the tcVNS were also noted. In a general linear mixed model, the average power per channel per frequency band was found to be significantly different pre- and post-stimulation in the theta (p = 0.02) and alpha bands (p = 0.04). The pooled power spectral analysis detected a significant decrease in the alpha (p < 0.01), theta (p = 0.01) and beta (p = 0.035) frequencies post-stimulation. No significant interaction was observed between dog, attitude, and stimulation in the multivariate model, neither within the same dog nor between individuals. There was a significant increase in the HRV measured by the standard deviation of the inter-beat (SDNN) index (p < 0.01) and a decrease in mean heart rate (p < 0.01) after tcVNS. The tcVNS was found to be well-tolerated. The results of this pilot study suggest that EEG and ECG can detect changes in brain activity and HRV associated with tcVNS in healthy dogs. Larger randomized controlled studies are required to confirm the results of this study and to assess tcVNS potential therapeutic value.

Keywords: SDNN index; frequency band analysis; heart rate variability; power spectral analysis; transcutaneous cervical vagus nerve stimulation; vagus nerve stimulation.