Objective: This TBS sham-controlled study aimed to evaluate the effects of intermittent TBS (iTBS) and continuous TBS (cTBS) upon ipsilateral hearing thresholds after stimulation on the left auditory cortex.
Methods: Sixty healthy adults, aged between 19 and 32 years (median of 23 years), were randomly distributed into three groups and underwent iTBS, cTBS or sham stimulation. Each double-blind experimental session comprised two pure tone audiometric evaluations per subject, before and after stimulation. To assess volunteer safety, a follow-up of at least 48 hours was implemented.
Results: The iTBS group mean thresholds displayed a tendency to decrease after stimulation, predominantly in the 500 Hz-6000 Hz interval and group comparisons revealed significant differences between the iTBS and sham groups for 500 Hz (p = 0.041) and between the iTBS and cTBS groups for 4000 Hz (p = 0.038). Neither relevant side effects nor any significant hearing threshold impairment after active or sham stimulation were found.
Conclusions: A single stimulation session led to an effective neuromodulation of the auditory cortex, reflected in lower thresholds when using iTBS.
Significance: These encouraging results with this safe noninvasive tool suggest that iTBS may have the potential to positively influence hearing thresholds.
Keywords: Audiometry; Auditory cortex; Auditory threshold; Safety; Theta burst stimulation; Transcranial magnetic stimulation.
Copyright © 2019 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.