Table 1.
Non-randomized studies: Summary of characteristics, protocols, results, and conclusions in 4 studies utilizing rTMS on patients with tinnitus without randomization.
| Author | Year | Subject Number |
Primary Baseline Evaluation | rTMS Protocol (Session Number, Frequency, Amount of Stimuli) | Location of Treatment | Primary Evaluation of Outcome | Results | Conclusions |
|---|---|---|---|---|---|---|---|---|
| Wang et al. [41] |
2016 | -289 patients with chronic tinnitus -30 healthy control |
-Tinnitus loudness determined by visual analog scale (VAS) -Hearing level with audiometer -Tinnitus loudness evaluated with TinniTest audiometer |
-Underwent repetitive magnetic transcranial stimulation (rTMS) over the left temporoparietal cortex region. -Stimuli consisted of 1000 stimuli at 1 hertz (Hz) daily and 110% of the motor cortex threshold for 5 consecutive days per week for 2 weeks (10 sessions total). -Control received same treatment |
-Left temporoparietal cortex | -VAS score after last treatment | -rTMS showed an effect in 138 of the patients (47.8%) and no effect in 151 patients (52.2%) in the active group. -VAS average prior was 5.5 and 2.7 after -Significant tinnitus suppression found in patients with shorter tinnitus duration, normal hearing, and without sleep disturbance. |
-rTMS resulted in a significant reduction in tinnitus loudness -Study states imaging would help determine the best site of treatment |
| Poeppl et al. [34] |
2018 | -60 patients with chronic tinnitus -0 control |
-MRI immediately before treatment -Tinnitus Questionnaire (TQ) |
-Underwent 10 consecutive days with 10 sessions -Patients received rTMS of the left DLPFC (40 trains with 50 stimuli; 25 s intertrain interval; 20 Hz; 110% resting motor threshold (RMT)), followed by low-frequency rTMS (2000 Stimuli; 1 Hz; 110% RMT) of the left temporal cortex. |
-Left dorsolateral prefrontal cortex (DLPFC) and left temporal cortex (TC) | -Magnetic resonance imaging (MRI) after last treatment -Responders classified as scoring 5 points fewer on tinnitus questionnaire |
-Assessed for longitudinal gray matter changes and structural connectivity -Longitudinal mesoscopic gray matter changes of DLPFC, left operculo-insular, and right inferior temporal Cortex (ITC) in responders (n = 22) but not in non-responders (n = 38) -Increased connectivity in DLPFC–insula and insula–ITC in responders. Weak DLPFC–insula connectivity and no insula–ITC connectivity in non-responders. |
-Results support the role of non-auditory brain regions in tinnitus and as possible therapeutic targets in rTMS. |
| Kan et al. [42] |
2019 | -11 patients with idiopathic tinnitus -11 healthy controls |
-Tinnitus handicap inventory (THI) and VAS -Positron emission tomography (PET) scans before treatment for regions of increased activity in idiopathic tinnitus compared to controls |
-1000 TMS pulses at a frequency of 1 Hz for a total of 30 min for 10 consecutive days, once a day | -Left temporoparietal cortex | -Tinnitus handicap inventory (THI) score -VAS score -PET scan -All after last treatment |
-No significant statistical difference before and after treatment regarding THI score (t = 1.019, p = 0.342 > 0.05) and VAS (t = 0.00, p = 1.0 > 0.05). -Posttreatment PET scan showed increased activities in the right parahippocampal gyrus, right superior temporal gyrus, right superior frontal gyrus, anterior insula, left inferior parietal lobule, and left precentral gyrus. -Decreased activities were noted in the left postcentral gyrus and left inferior temporal gyrus (ITG) |
-Noted limitations by small sample size -Left temporoparietal cortex alone may not be sufficient |
| Yang et al. [13] |
2021 | -199 patients with tinnitus identified in a retrospective review | -THI and VAS | -Each patient underwent 10 sessions, 5 sessions a week for 2 weeks -2000 stimuli per session of 1 Hz |
-Left temporal cortex and left prefrontal cortex | -At 3-month follow-up THI and VAS reevaluated. -A reduction in THI score by more than 6 points and VAS by 1 or more from the baseline result was considered effective |
-62.3% of all patients responded based on THI scores and 66.3% based on VAS score. -Patients with shorter duration of illness (1 week) responded the best to treatment with a rate of 82.8% versus 57.6%, 53.5%, and 67.2% for patients of 1-week to 1-month, 1-month to 1-year, and over 1-year duration |
-rTMS is effective in treating tinnitus, but the efficacy is dependent on the duration of symptoms prior to treatment |