A retrospective descriptive study of unilateral subjective paroxysmal tinnitus: Clinical characteristics and exploratory findings on carbamazepine

OBJECTIVE: To descriptively characterize a retrospective case series of patients with unilateral subjective paroxysmal tinnitus, and to explore the potential therapeutic effects of carbamazepine as hypothesis-generating observations. METHODS: A retrospective review was conducted of 829 patients who presented with tinnitus as their primary complaint. Patients diagnosed with unilateral subjective paroxysmal tinnitus were included, and those who received treatment with carbamazepine were analyzed in detail. Data regarding patient demographics, tinnitus characteristics, accompanying symptoms, magnetic resonance imaging (MRI) findings, and treatment responses to carbamazepine were analyzed. RESULTS: Forty-eight patients (5.8%) were identified as having paroxysmal tinnitus. Eight of these patients had causes unrelated to neurovascular compression. The remaining 40 patients (4.8%; 20 males, 20 females; mean age 63.5 years) presented with unilateral subjective tinnitus. Among them, 18 (2.2%) underwent treatment with carbamazepine. Among the carbamazepine-treated patients, vestibular symptoms were the most frequently reported accompanying symptom, noted in 14 patients (77.8%). MRI revealed arterial compression of the eighth cranial nerve in 2 patients (11.1%) and vascular-nerve contact in 10 patients (55.6%). Treatment with carbamazepine resulted in complete symptom resolution in 6 patients, partial improvement in 10, and no confirmed effect in 2, yielding an overall improvement rate of 88.9%. CONCLUSION: In this retrospective case series, we described the heterogeneous clinical features of unilateral subjective paroxysmal tinnitus. While symptom improvement was observed among carbamazepine-treated cases regardless of MRI findings, the presence of an untreated subgroup, lack of a control group, and limitations of outcome measures warrant caution against causal claims of efficacy. Future studies with prospective comparative designs and validated quality-of-life endpoints are needed.