Appropriateness of magnetic resonance imaging in sudden sensorineural hearing loss.

Idiopathic sudden sensorineural hearing loss is an enigmatic condition of unknown cause. Although the treatment for sudden sensorineural hearing loss is controversial, the evaluation for a cause should not be. All patients are evaluated with a complete history, physical examination, audiologic examination, and blood draw to evaluate complete blood count, general chemistry screen, thyroid function test results, erythrocyte sedimentation rate, and fluorescent treponemal antibody absorbance. Magnetic resonance imaging with gadolinium contrast is essential in the evaluation of idiopathic sudden sensorineural hearing loss, even if there is a complete response to either treatment or no treatment. During the last year we treated 16 patients for idiopathic sudden sensorineural hearing loss with our protocol of intravenous dextran/Hypaque or oral high-dose steroids. Fifteen patients were evaluated immediately before treatment with a magnetic resonance imaging scan. An additional patient had been treated successfully with high-dose steroids at an outside institution and came in for an evaluation. Of these 16 patients, 3 (18.75%) were found to have significant pathologic conditions on magnetic resonance imaging scan. The patient who had been treated successfully on the outside was noted to have a 5-mm intracanalicular acoustic neuroma, the second patient was found to have a multiple sclerosis lesion at the level of the superior olive, and the third patient, who had had a normal magnetic resonance imaging scan 18 months previously, was now found to have a large 4- to 5-cm meningioma in the cerebellopontine angle. We believe it is essential that all patients with idiopathic sudden sensorineural hearing loss be evaluated at some point during their treatment with a magnetic resonance imaging scan with gadolinium contrast.