Combination of gaps in noise detection and visual analog scale for measuring tinnitus components in patients treated with repetitive transcranial magnetic stimulation

Effect of Ipsilateral, Contralateral or Bilateral Repetitive Transcranial Magnetic Stimulation in Patients with Lateralized Tinnitus: A Placebo-Controlled Randomized Study

The relative benefit of ipsilateral, contralateral, and bilateral repetitive transcranial magnetic stimulation (rTMS) for tinnitus treatment remains unclear, especially for patients with lateralized tinnitus. In this study, we compared outcomes after 10 sessions of 1-Hz rTMS at 110% of resting motor threshold over a two-week period. In total, 104 right-handed patients with lateralized subjective tinnitus were randomly divided into four groups according to rTMS treatment: Left (n = 29), Right (n = 23), Bilateral (n = 30), and Sham stimulation (n = 22). Outcomes included estimates of tinnitus severity, psychological state, and psychoacoustic measures. Patients with left- or right-sided tinnitus were similarly distributed across treatment groups. There were no significant changes in outcome measures for the Right or Sham treatment groups. For the Left and Bilateral groups, tinnitus severity was significantly lower after treatment (p < 0.05). The reduction in tinnitus severity was largest for ipsilateral treatment in the Left group. The overall response rate was 56.1% for the Left group, 46.7% for the Bilateral group, 8.3% for the Right group, and 8.3% for the Sham group. For the Left and Bilateral groups, the response rate was larger for patients with left- than right-sided tinnitus. Changes in tinnitus severity were best predicted by changes in anxiety, depression, and the loudness of the tinnitus. The results suggests that rTMS on the left temporoparietal cortex is more effective for patients with left-sided than with right-sided tinnitus.

Repetitive transcranial magnetic stimulation on chronic tinnitus: a systematic review and meta-analysis

BACKGROUND

Although the clinical efficacy and safety of repetitive transcranial magnetic stimulation (rTMS) in the treatment of chronic tinnitus have been frequently examined, the results remain contradictory. Therefore, we performed a systematic review and meta-analysed clinical trials examining the effects of rTMS to evaluate its clinical efficacy and safety.

METHODS

Studies of rTMS for chronic tinnitus were retrieved from PubMed, Embase, and Cochrane Library through April 2020. Review Manager 5.3 software was employed for data synthesis, and Stata 13.0 software was used for analyses of publication bias and sensitivity.

RESULTS

Twenty-nine randomized studies involving 1228 chronic tinnitus patients were included. Compared with sham-rTMS, rTMS exhibited significant improvements in the tinnitus handicap inventory (THI) scores at 1 week (mean difference [MD]: - 7.92, 95% confidence interval [CI]: - 14.18, - 1.66), 1 month (MD: -8.52, 95% CI: - 12.49, - 4.55), and 6 months (MD: -6.53, 95% CI: - 11.406, - 1.66) post intervention; there were significant mean changes in THI scores at 1 month (MD: -14.86, 95% CI: - 21.42, - 8.29) and 6 months (MD: -16.37, 95% CI: - 20.64, - 12.11) post intervention, and the tinnitus questionnaire (TQ) score at 1 week post intervention (MD: -8.54, 95% CI: - 15.56, - 1.52). Nonsignificant efficacy of rTMS was found regarding the THI score 2 weeks post intervention (MD: -1.51, 95% CI: - 13.42, - 10.40); the mean change in TQ scores 1 month post intervention (MD: -3.67, 95% CI: - 8.56, 1.22); TQ scores 1 (MD: -8.97, 95% CI: - 20.41, 2.48) and 6 months (MD: -7.02, 95% CI: - 18.18, 4.13) post intervention; and adverse events (odds ratios [OR]: 1.11, 95% CI: 0.51, 2.42). Egger's and Begg's tests indicated no publication bias (P = 0.925).

CONCLUSION

This meta-analysis demonstrated that rTMS is effective for chronic tinnitus; however, its safety needs more validation. Restrained by the insufficient number of included studies and the small sample size, more large randomized double-blind multi-centre trials are needed for further verification.

Low-Frequency Repetitive Transcranial Magnetic Stimulation for the Treatment of Chronic Tinnitus: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background

Chronic tinnitus affects approximately 10-15% of the population. Low-frequency repetitive transcranial magnetic stimulation (rTMS) has been considered as a promising and well-tolerated therapeutic strategy for chronic tinnitus. However, a recent large-scale multicenter clinical trial showed a negative result.

Objective

This systematic review is aimed at assessing the efficacy and safety of low-frequency rTMS in chronic tinnitus.

Methods

We searched PubMed, Embase, and Cochrane Library for randomized controlled studies of rTMS treatment of chronic tinnitus. A pooled analysis of standardized mean difference (SMD) was performed with 95% confidence intervals (CI).

Results

Ten RCTs involving 567 participants were included in this review. Compared with sham stimulation, rTMS showed no significant efficacy in tinnitus severity and disability measured by Tinnitus Handicap Inventory (THI) in short-term (SMD = −0.04, 95% CI -0.23 to 0.16, P = 0.72), medium-term (SMD = −0.13, 95% CI -0.43 to 0.17, P = 0.41), and long-term (SMD = −0.16, 95% CI -0.38 to 0.05, P = 0.14) follow-up. Tinnitus severity and disability measured by Tinnitus Questionnaire (TQ) also showed no significant improvement in short-term (SMD = −0.11, 95% CI -0.31 to 0.10, P = 0.30), medium-term (SMD = −0.10, 95% CI -0.37 to 0.16, P = 0.44), and long-term (SMD = −0.20, 95% CI -0.40 to 0.01, P = 0.06) follow-up. Additionally, no statistically significant difference was shown in the changes of tinnitus loudness assessed by a visual analogue scale (VAS) between rTMS and sham groups in the short-term (SMD = −0.28, 95% CI -0.59 to 0.02, P = 0.07), medium-term (SMD = −0.26, 95% CI -0.59 to 0.07, P = 0.13), and long-term (SMD = −0.20, 95% CI -0.53 to 0.13, P = 0.24) follow-up. Few mild or moderate adverse events were observed in both the rTMS and sham groups.

Conclusion

Low-frequency rTMS is well tolerated but not effective in treating chronic tinnitus based on the current analysis of pooled data. Further studies with modified and uniform protocols are required to investigate the potential benefit of rTMS in chronic tinnitus.

Evidence-based guidelines on the therapeutic use of repetitive transcranial magnetic stimulation (rTMS): An update (2014-2018)

A group of European experts reappraised the guidelines on the therapeutic efficacy of repetitive transcranial magnetic stimulation (rTMS) previously published in 2014 [Lefaucheur et al., Clin Neurophysiol 2014;125:2150-206]. These updated recommendations take into account all rTMS publications, including data prior to 2014, as well as currently reviewed literature until the end of 2018. Level A evidence (definite efficacy) was reached for: high-frequency (HF) rTMS of the primary motor cortex (M1) contralateral to the painful side for neuropathic pain; HF-rTMS of the left dorsolateral prefrontal cortex (DLPFC) using a figure-of-8 or a H1-coil for depression; low-frequency (LF) rTMS of contralesional M1 for hand motor recovery in the post-acute stage of stroke. Level B evidence (probable efficacy) was reached for: HF-rTMS of the left M1 or DLPFC for improving quality of life or pain, respectively, in fibromyalgia; HF-rTMS of bilateral M1 regions or the left DLPFC for improving motor impairment or depression, respectively, in Parkinson's disease; HF-rTMS of ipsilesional M1 for promoting motor recovery at the post-acute stage of stroke; intermittent theta burst stimulation targeted to the leg motor cortex for lower limb spasticity in multiple sclerosis; HF-rTMS of the right DLPFC in posttraumatic stress disorder; LF-rTMS of the right inferior frontal gyrus in chronic post-stroke non-fluent aphasia; LF-rTMS of the right DLPFC in depression; and bihemispheric stimulation of the DLPFC combining right-sided LF-rTMS (or continuous theta burst stimulation) and left-sided HF-rTMS (or intermittent theta burst stimulation) in depression. Level A/B evidence is not reached concerning efficacy of rTMS in any other condition. The current recommendations are based on the differences reached in therapeutic efficacy of real vs. sham rTMS protocols, replicated in a sufficient number of independent studies. This does not mean that the benefit produced by rTMS inevitably reaches a level of clinical relevance.

RTMS parameters in tinnitus trials: a systematic review

Over the past few years extensive body of research was produced investigating the effects of repetitive transcranial magnetic stimulation (rTMS) for the treatment of chronic tinnitus with heterogeneous results. This heterogeneity is exemplified by two recently published large-scale clinical trials reporting different outcomes. Technical aspects of rTMS were suspected as a potential source for this incongruency. The aim of this systematic review is to examine the overall efficacy as well as to identify possible technical factors relevant for the effectiveness of rTMS tinnitus trials. Via a literature search appropriate original research papers were identified and rTMS parameters were extracted from each study arm for subsequent statistical analysis with respect to observed effects (significant vs. not significant pre-post rTMS effects). Our findings indicate that verum rTMS is superior to sham rTMS as demonstrated by the proportion of significant pre-post contrasts. Some relevant rTMS parameters (e.g., pulse waveform) are not reported. Lower rTMS stimulation intensity was associated with significant effects in verum rTMS arms. An additional stimulation of the DLPFC to the temporal cortex was not found to promote efficacy. Future research should consider differential effects of rTMS induced by technical parameters and strive for an exhaustive reporting of relevant rTMS parameters.

Changes in tinnitus after vestibular schwannoma surgery

We designed a prospective study to evaluate changes in tinnitus after vestibular schwannoma (VS) surgery. Subjects included 41 patients who were diagnosed with a VS and underwent translabyrinthine microsurgery (TLM) between January 2015 and May 2016. All patients underwent related examinations and were asked to answer the Tinnitus Handicap Inventory (THI) scale and a visual analog scale (VAS) of tinnitus severity both pre- and postoperatively. Of the 41 patients, 31 (75.6%) suffered from tinnitus before surgery. Microsurgery was associated with an overall decrease in tinnitus (p < 0.001). There was a significant improvement in THI and VAS scores after surgery (p = 0.001 and p = 0.005, respectively). The decrease in THI scores in the low-frequency group was significantly larger than that of the mid- and high-frequency groups after surgery (p = 0.034 and p = 0.001, respectively). The loudness of tinnitus decreased significantly after surgery (p = 0.031). Tinnitus in patients with VS improved after TLM. Patients with mid-/high-frequency tinnitus and louder tinnitus preoperatively seemed to have a worse prognosis than those with low-frequency and quieter tinnitus.