Clinical Characteristics and Correlation of Hearing Outcomes Following Varying Courses of Repetitive Transcranial Magnetic Stimulation for Idiopathic Sudden Sensorineural Hearing Loss: A Prospective Clinical Study

<b>Objective</b>: We aimed to explore the efficacy of repetitive transcranial magnetic stimulation (rTMS) for idiopathic sudden sensorineural hearing loss (ISSNHL) and evaluate the correlation between treatment courses of rTMS and hearing outcomes. <b>Methods</b>: A prospective observational study was conducted at West China Fourth Hospital, Sichuan University, from January 2018 to January 2025. The study enrolled 339 patients (342 affected ears) diagnosed with ISSNHL. Among them, 67 patients (group A) received standard therapy combined with rTMS, while the control group (group B) received conventional therapy only. To verify the correlation between different treatment courses of rTMS and hearing outcomes, patients in Group A were divided into Group A1 (treatment courses ≤ 10) and Group A2 (treatment courses > 10). Hearing thresholds and clinical characteristics were evaluated at admission, discharge day and 6 months post-treatment. The SDRG's criteria were used for the grading of hearing recovery. <b>Results</b>: Tinnitus (79.89% vs. 75.32%, <i>p</i> = 0.361) and sleep disorders (33.70% vs. 41.14%, <i>p</i> = 0.178) were highly prevalent among patients in group A and group B. 1 Hz rTMS significantly improved these symptoms (PSQI: 52.32% vs. 44.44%, <i>p</i> = 0.032; THI: 16.67 ± 19.41 vs. 8.22 ± 12.77, <i>p</i> = 0.002). Compared to high-tone hearing loss patients, those with low-tone loss in groupA2 showed a more rapid improvement (250 Hz: 17.66 ± 16.59 vs. 14.09 ± 15.58, <i>p</i> = 0.041; 500 Hz: 21.20 ± 18.03 vs. 17.31 ± 16.24, <i>p</i> = 0.036) than grouA1, with benefits sustained at 6-month follow-up (250 Hz: 27.79 ± 18.74 vs. 22.71 ± 18.31, <i>p</i> = 0.012; 500 Hz: 31.89 ± 19.73 vs. 26.49 ± 20.08, <i>p</i> = 0.013). <b>Conclusions</b>: rTMS at 1 Hz, administered in courses > 10 sessions, demonstrated both short-term and long-term beneficial effects in the ISSNHL. Those with low-tone hearing loss exhibit better recovery but a higher chance of relapse than high-tone loss patients. As a non-invasive approach with minimal side effects, rTMS is suitable for routine ISSNHL treatment.