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


CICS-Health Sciences Research Centre, University of Beira Interior, Covilhã 6200-506, Portugal; University of Beira Interior - Department of Mathematics, Covilhã 6200-506, Portugal. Electronic address: [Email]


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.
CONCLUSIONS : These encouraging results with this safe noninvasive tool suggest that iTBS may have the potential to positively influence hearing thresholds.


Audiometry,Auditory cortex,Auditory threshold,Safety,Theta burst stimulation,Transcranial magnetic stimulation,