Abstract
Seven patients who experienced a rapid onset of simultaneous sensorineural hearing loss with predominantly low tone impairment were seen during one three-month period. No previous report of a similar situation was found in the literature.
Brain stem emcephalitis, due to viral infection, was suspected as the primary cause for the following reasons: 1) all cases occurred within a three-month period: 2) endemic incidence: 3) hive of the seven patients reported previous cold symptoms, excessive work or headache: 4) simultaneous involvement of other cranial nerves (V, VII) in one case.
All patients were given vitamin B12, prednisolone, and careful instructions to avoid excess physical activity. Five patients, who were seen within seven days after the onset, showed complete improvement in hearing in both ears. The other two, who visited on ten days after the onset, showed partial or no improvement. The interval between the onset of symptoms and the beginning of treatment seemed to be the most important prognostic factor.
