Journal article
Glutamate is down-regulated and tinnitus loudness-levels decreased following rTMS over auditory cortex of the left hemisphere: A prospective randomized single-blinded sham-controlled cross-over study
Hearing research, Vol.358, pp.59-73
02/2018
DOI: 10.1016/j.heares.2017.10.017
Abstract
Using a prospective randomized single-blinded sham-controlled cross-over design, we studied the efficacy of low frequency (1-Hz) repetitive transcranial magnetic stimulation (rTMS) over auditory cortex of the left temporal lobe as an experimental treatment modality for noise-induced tinnitus. Pre/post outcome measures for sham vs. active rTMS conditions included differential changes in tinnitus loudness, self-perceived changes in the Tinnitus Handicap Questionnaire (THQ), and neurochemical changes of brain metabolite concentrations using single voxel proton magnetic resonance spectroscopy (1H-MRS) obtained from left and right auditory cortical areas. While no subject in our sample had complete abatement of their tinnitus percept, active but not sham rTMS significantly reduced the loudness level of the tinnitus perception on the order of 4.5 dB; improved subscales in several content areas on the THQ, and down regulated (reduced) glutamate concentrations specific to the auditory cortex of the left temporal lobe that was stimulated.
In addition, significant pair-wise correlations were observed among questionnaire variables, metabolite variables, questionnaire-metabolite variables, and metabolite-loudness variables. As part of this correlation analysis, we demonstrate for the first time that active rTMS produced a down regulation in the excitatory neurotransmitter glutamate that was highly correlated (r = 0.77, p < 0.05) with a reduction in tinnitus loudness levels measured psychoacoustically with a magnitude estimation procedure. Overall, this study provides unique information on neurochemical, psychoacoustic, and questionnaire-related profiles which emphasizes the emerging fields of perceptual and cognitive MRS and provides a perspective on a new frontier in auditory and tinnitus-related research.
•This study evaluated perceptual, neurochemical, and questionnaire-based data after 5 sequential days of active or sham rTMS.•Active rTMS produced a down regulation in glutamate that correlated highly with a reduction in tinnitus-loudness levels.•After active rTMS, improvements were also noted in various subscales and total scores of the Tinnitus Handicap Questionnaire.
Details
- Title: Subtitle
- Glutamate is down-regulated and tinnitus loudness-levels decreased following rTMS over auditory cortex of the left hemisphere: A prospective randomized single-blinded sham-controlled cross-over study
- Creators
- Anthony T Cacace - Wayne State UniversityJiani Hu - Wayne State UniversityStephen Romero - Union CollegeYang Xuan - Wayne State UniversityRobert F Burkard - University at Buffalo, State University of New YorkRichard S Tyler - University of Iowa
- Resource Type
- Journal article
- Publication Details
- Hearing research, Vol.358, pp.59-73
- DOI
- 10.1016/j.heares.2017.10.017
- ISSN
- 0378-5955
- eISSN
- 1878-5891
- Publisher
- Elsevier B.V
- Grant note
- DOI: 10.13039/100006710, name: Wayne State University
- Language
- English
- Date published
- 02/2018
- Academic Unit
- Communication Sciences and Disorders; Otolaryngology
- Record Identifier
- 9984258746102771
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