Can theta burst stimulation safely influence auditory hearing thresholds in healthy young adults?

Abstract

ObjectiveThis 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. MethodsSixty 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. ResultsThe 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. ConclusionsA single stimulation session led to an effective neuromodulation of the auditory cortex, reflected in lower thresholds when using iTBS. SignificanceThese encouraging results with this safe noninvasive tool suggest that iTBS may have the potential to positively influence hearing thresholds.