Sudden Deafness with Further Progression of Hearing Loss.

We analyzed 14 patients who showed a further progression of hearing loss after an initial examination of 214 patients with sudden deafness. They were divided into 2 groups based on the type of hearing loss progression. Group I consisted of six patients who displayed a rapid progression after increased hearing loss had begun. Group II consisted of eight patients who showed transient hearing improvement before an increase in hearing loss. The clinical features of the 14 patients were from a earlier visit to the clinics experiencing dizziness and/or vertigo with less recovery of hearing loss than the other patients. However, more than 60% of the 14 patients showed complete recovery or a marked hearing improvement. The predominant type of hearing loss was high tone loss at the initial audiological assessment in both groups. The flat type hearing loss was usually noted at the time when the patients experienced their greatest hearing loss. Although the details of the etiology of hearing loss progression remain unclear, group I was thought to be the slow type sudden deafness, whereas the deterioration of hearing loss in group II may be due to a circulatory disturbance of the inner ear.