PurposeTinnitus is a very common symptom of vestibular schwannoma, present in 45 to 80% of patients. We evaluated changes in tinnitus after translabyrinthine microsurgery (TLM) or gamma knife radiosurgery (GKS).Materials and MethodsAmong 78 patients with vestibular schwannoma who underwent TLM or GKS at Severance Hospital from 2009-2012, 46 patients with pre- or postoperative tinnitus who agreed to participate were enrolled. Pure tone audiometry, tinnitus handicap inventory (THI), visual analogue scale (VAS) scores for loudness, awareness, and annoyance were measured before and after treatment. Changes of THI and VAS were analysed and compared according to treatment modality, tumour volume, and preoperative residual hearing.ResultsIn the TLM group (n=27), vestibulocochlear nerves were definitely cut. There was a higher rate of tinnitus improvement in TLM group (52%) than GKS group (16%, p=0.016). The GKS group had a significantly higher rate of tinnitus worsening (74%) than TLM group (11%, p<0.001). Mean scores of THI and VAS scores significantly decreased in the TLM group in contrast to significant increases in the GKS group. Tumor volume and preoperative hearing did not affect the changes in THI or VAS.ConclusionGKS can save vestibulocochlear nerve continuity but may damage the cochlea, cochlear nerve and can cause worsening tinnitus. In cases where hearing preservation is not intended, microsurgery with vestibulocochlear neurectomy during tumor removal can sometimes relieve or prevent tinnitus.

Daily application of 1-Hz rTMS to the temporoparietal area is safe and has long-term beneficial effects. The laterality of stimulation is not the decisive factor.

Quality of life is higher after microsurgery than after radiosurgery. One specific management strategy cannot always guarantee the better quality of life. The functional status and personality traits of the patient should be considered, as well as tumor size and location when choosing a management option.

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Repetitive transcranial magnetic stimulation (rTMS) and transcutaneous direct current stimulation (tDCS) are non-invasive treatments for chronic tinnitus based on neuromodulation of cortical activity. Both are considered effective, but with heterogeneous results due to lack of established protocols. Because the target groups for both modalities overlap, it is difficult to recommend one of them. We tried to unify the inclusion criteria and treatment schedules to compare the two modalities. The medical charts of 36 patients who underwent rTMS as part of clinical routine were reviewed and data for 34 patients who underwent tDCS about 7 years later were collected prospectively. Both groups had chronic unilateral tinnitus refractory to medication. Patients were treated for 5 consecutive days, and tinnitus symptoms were evaluated by survey both at the end of the treatment schedule and 1 month after the treatment. The ratio of responders who showed >20% reduction in tinnitus handicap inventory scores were compared. At the end of the treatment, the rTMS group showed a rapid response compared to the tDCS group (rTMS, 30.6%; tDCS, 12.1%; p = 0.054). However, both groups showed a significant and similar reduction in tinnitus symptoms 1 month after the treatment (rTMS, 47.2%; tDCS, 36.4%; p = 0.618). As both groups showed comparable results for tinnitus reduction, tDCS may be superior in terms of cost-effectiveness.