Steady-state auditory evoked fields reflect long-term effects of repetitive transcranial magnetic stimulation in tinnitus Lieber Po-Hung Li a,b,c,d,⇑ , An-Suey Shiao a,c , Cheng-Ta Li a,b,e,f , Po-Lei Lee g , Chou-Ming Cheng d , Chih-Cher Chou d , Jen-Chuen Hsieh b,d,e a Faculty of Medicine, National Yang-Ming University, Taipei, Taiwan b Institute of Brain Science, National Yang-Ming University, Taipei, Taiwan c Department of Otolaryngology, Cheng Hsin General Hospital, Taipei, Taiwan d Integrated Brain Research Laboratory, Department of Medical Research and Education, Taipei Veterans General Hospital, Taipei, Taiwan e Brain Research Center, National Yang-Ming University, Taipei, Taiwan f Department of Psychiatry, Taipei Veterans General Hospital, Taipei, Taiwan g Department of Electrical Engineering, National Central University, Chung-Li, Taiwan article info Article history: Accepted 1 May 2019 Available online 11 June 2019 Keywords: Idiopathic sudden sensorineural hearing loss (ISSNHL) Magnetoencephalography (MEG) Repetitive transcranial magnetic stimulation (rTMS) Steady-state auditory evoked fields (SSAEFs) Tinnitus highlights  Long-term effects of rTMS on steady-state auditory evoked fields (SSAEFs) in tinnitus are unknown.  We report that SSAEFs remained decreased for one month after rTMS.  SSAEFs may serve as a biomarker for long-term effects of rTMS on tinnitus. abstract Objectives: Evidence of plastic changes in tinnitus has been demonstrated in functional brain imaging. Although repetitive transcranial magnetic stimulation (rTMS) has been shown to decrease steady-state auditory evoked fields (SSAEFs) in tinnitus, the long-term consequence remained unknown. In addition, association between plastic changes as reflected by hemispheric asymmetry and tinnitus handicap inven- tory (THI) before and after rTMS have not been addressed. Methods: Twelve tinnitus patients received rTMS and 12 received sham stimulation. Another 12 healthy participants served as the normal hearing controls. Patients responded to the THI before the 1st session and at one month after the final session of rTMS/sham stimulation. Changes in brain activity were assessed by measuring SSAEFs. Results: SSAEFs remained decreased one month after rTMS compared to before treatment, along with a significant reduction in THI score. There was no significant effect between the index of hemispheric asymmetry and THI score. Conclusions: The current study objectively demonstrated the long-term effects of rTMS on tinnitus using SSAEFs. A longitudinal study to develop an index using SSAEFs to assess the subjective severity of tinnitus is warranted. Significance: This study suggests the possible use of SSAEFs to assess the long-term effects of rTMS on tinnitus. Ó 2019 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved. 1. Introduction Tinnitus, a symptom of unknown pathogenesis, causes various degrees of distress and prognoses. It affects about 10–15% of adults, and has a profound impact on the quality of life in 1–3% of the general population (Heller, 2003; Vio and Holme, 2005; Tunkel et al., 2014). Treatment includes a variety of modalities and/or medications, however the outcomes tend to be unsatisfac- tory. The pathophysiology possibly involves cochlear damage fol- lowed by functional reorganization of the auditory cortices, which in turn may lead to impaired optimization between inhibi- tion and excitation of central auditory processing (Lockwood https://doi.org/10.1016/j.clinph.2019.05.022 1388-2457/Ó 2019 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved. ⇑ Corresponding author at: Department of Otolaryngology, Cheng Hsin General Hospital, No. 45, Cheng Hsin St Pai-Tou, Taipei 112, Taiwan. Fax: +886 2 28263645. E-mail address: phli@gm.ym.edu.tw (L.P.-H. Li). Clinical Neurophysiology 130 (2019) 1665–1672 Contents lists available at ScienceDirect Clinical Neurophysiology journal homepage: www.elsevier.com/locate/clinph