Idiopathic sudden sensorineural hearing loss

Sudden sensorineural hearing loss is one of the most controversial unsolved mysteries in Otolaryngology. Lack of a universally accepted definition of sudden sensorineural hearing loss, insufficient knowledge of pathogenesis, lack of a standard method for evaluating the patients, in addition to a high spontaneous recovery rate, all complicate the study of sensorineural hearing loss and the investigation of different treatment modalities.

To study the clinical manifestation and prognostic factors, which influence the recovery of hearing in sudden sensorineural hearing loss.

Patients with idiopathic sudden sensorineural hearing loss who were admitted to Srinagarind Hospital from January 1994 to December 1998 were included. The clinical manifestations, audiograms and investigations of these patients were analysed.

Of the fifty-six patients, who met the criterion, 34 were females and 22 males. The average age of onset was 43.7 years (SD = 13.46, range = 13-66 years). The onset of hearing loss was sudden in 50 per cent of cases, whereas, 46.4 per cent of cases were noted on awakening in the morning and the remainder had rapidly progressive hearing loss. The hearing loss was unilateral in 92.9 per cent of cases. 96.4 per cent of the patients had tinnitus and 66.1 per cent of the patients had vertigo. 64.3 per cent of the patients had some degree of recovery (complete recovery in 28.6% and partial recovery in 35.7%). The severity of hearing loss significantly influenced the outcome of the patients.

Approximately two-thirds of the patients with idiopathic sudden hearing loss had some degree of recovery. Among contributing factors, only the severity of hearing loss significantly influenced the prognosis.