Clinical observations on acute low-tone sensorineural hearing loss. Survey and analysis of 137 patients.

We retrospectively analyzed the clinical records of 137 patients who were treated at our clinic for acute low-tone sensorineural hearing loss of unknown cause over a period of 8 years. The analyses of the clinical records indicated the following clinical characteristics: female preponderance; peak incidence during the fourth decade of life; frequent accompanying tinnitus, sensation of ear fullness, and/ or autophony; suspicion of bilateral involvement; and association with autonomic imbalance. The hearing in most of the patients completely recovered, but some selected patients experienced fluctuating hearing loss or progression to Meniere's disease. Our results suggest that a subgroup of patients with severe initial hearing loss should be carefully followed up, although it is difficult to predict the outcome of this disorder.