[Diagnosis and outcome analysis of diseases characterized by recurrent low-frequency sensorineural deafness]

Objective:The aim of this study was to explore the clinical features, hearing prognosis and differential diagnosis of recurrent low frequency sensorineural hearing loss （RLFD） . Method:The clinical characteristics, clinical manifestations, audiological examination and auxiliary examination of RLFD patients were retrospectively analyzed. We summarized clinical features, draw the pure tone audiometry curves, and analyze the diagnosis of RLFD. Result:Forty-seven patients （53 ears） with RLFD had a hearing review time of 1-124 months. The course of disease ranged from 3 to 320 months with an average course of 29 months. ①The incidence of tinnitus in the accompanying symptoms was 93.6%（44 cases）, and the ear suffocation was 83.0%（39 cases）, 38.3% （18 cases） of the patients developed vestibular symptoms during the course of the disease. ②During the observation period, 27 cases（57.4%） were diagnosed with related diseases: 7 cases（14.9%） Meniere's disease, 6 cases（12.8%） vestibular migraine, 2 cases（4.3%） with Meniere's disease and migraine, and 1 case（2.1%） with idiopathic intracranial hypotension 11 cases（23.4%） were possible cochlear migraine; ③Migraine-related RLFD had a younger onset age, more common in women; ④83.0%（44 ears）of the affected ears had stable or improved low-frequency hearing during the observation period, 17.0%（9 ears）of the affected ears experienced low-frequency hearing; ⑤18.9%（10 ears）of the affected ears had high-frequency hearing loss; ⑥RLFD had 6 types of audiological outcomes: low-frequency improvement combined with high-frequency stability; low-frequency stability combined with high-frequency stability; low frequency progress combined with high frequency stability type; low frequency improvement combined with high frequency progress type; low frequency stability combined with high frequency progress type; low frequency progress combined with high frequency progress type; ⑦Rising type hearing curve low frequency hearing prognosis is good, mountain type and descending low frequency hearing prognosis is poor. Conclusion:Tinnitus and ear stuffiness are the early symptoms and the most disturbing symptoms in patients with RLFD. The mechanism of Migraine may play an important role in the pathogenesis of RLFD. The rare causes such as intracranial hypotension syndrome should not be ignored. Most of the patients with RLFD had stable or improved hearing after long-term fluctuation, but some patients with low or high frequency hearing might decline. The type of initial hearing curve was a prognostic factor. Long-term hearing follow-up is helpful for prognosis evaluation.