Transcutaneous vagus nerve stimulation: retrospective assessment of cardiac safety in a pilot study.
BACKGROUND
Vagus nerve stimulation has been successfully used as a treatment strategy for epilepsy and affective disorders for years. Transcutaneous vagus nerve stimulation (tVNS) is a new non-invasive method to stimulate the vagus nerve, which has been shown to modulate neuronal activity in distinct brain areas.


OBJECTIVE
Here we report effects of tVNS on cardiac function from a pilot study, which was conducted to evaluate the feasibility and safety of tVNS for the treatment of chronic tinnitus.


METHODS
Twenty-four patients with chronic tinnitus underwent treatment with tVNS over 3-10 weeks in an open single-armed pilot study. Safety criteria and practical usability of the neurostimulating device were to investigate by clinical examination and electrocardiography at baseline and at several visits during and after tVNS treatment (week 2, 4, 8, 16, and 24).


RESULTS
Two adverse cardiac events (one classified as a severe adverse event) were registered but considered very unlikely to have been caused by the tVNS device. Retrospective analyses of electrocardiographic parameters revealed a trend toward shortening of the QRS complex after tVNS.


CONCLUSIONS
To our knowledge this is one of the first studies investigating feasibility and safety of tVNS in a clinical sample. In those subjects with no known pre-existing cardiac pathology, preliminary data do not indicate arrhythmic effects of tVNS.
Department of Psychiatry and Psychotherapy, University of Regensburg Regensburg, Germany.
Peter M
PM
Kreuzer
Michael
M
Landgrebe
Oliver
O
Husser
Markus
M
Resch
Martin
M
Schecklmann
Florian
F
Geisreiter
Timm B
TB
Poeppl
Sarah Julia
SJ
Prasser
Goeran
G
Hajak
Berthold
B
Langguth