No abstract

A prospective study of electrocochleography in patients with clinically suspected perilymph fistula was undertaken to determine its predictive value in that disorder. One hundred forty-four patients suspected of having perilymph fistula had electrocochleography performed--34 of these (39 ears) had exploratory tympanotomy. Of the 19 ears with normal preoperative summating potential/action potential (SP/AP) ratio, ten had perilymph fistula identified at the time of surgery. Of the 20 ears with abnormal SP/AP ratio, 16 had perilymph fistula confirmed at exploration, 18 had resolution of symptoms after oval window and round membrane grafting, and only one ear had postoperative persistence of the abnormal SP/AP ratio. This study suggests that an abnormal SP/AP ratio is not only predictive of endolymphatic hydrops, but also of perilymph fistula (both problems of inner ear fluid imbalance). This study also suggests that, while abnormal SP/AP ratio is fairly specific for inner ear fluid imbalance, it is not sensitive.

The purpose of this study was to determine if the menstrual cycle influences the amplitude of transient (TEOAEs) and distortion-product (DPOAEs) otoacoustic emissions. Thirteen normal-hearing, normal-cycling females were monitored weekly for 12 weeks. TEOAE and DPOAE amplitudes were analyzed to determine if amplitude changes could be detected and correlated to phases of the menstrual cycle. No systematic amplitude changes were observed, demonstrating that evoked OAEs are unaffected by physiologic changes associated with the menstrual cycle. Abbreviations: ABR = auditory brainstem response, DPOAEs = distortion product otoacoustic emissions, OAEs = otoacoustic emissions, RMANOVA = repeated measures analysis of variance, SOAEs = spontaneous otoacoustic emissions, TEOAEs = transient evoked otoacoustic emissions

Susac syndrome is a readily recognized but often misdiagnosed disorder almost exclusively affecting women in the 20- to 40–year age range. Characterized by the clinical triad of encephalopathy, branch retinal artery occlusions, and sensorineural hearing loss, patients with Susac syndrome are often misdiagnosed with multiple sclerosis (MS). Unlike MS, however, the disease process extends over a 1- to 2–year period and then goes into remission. This presentation describes the progression of symptoms of a patient eventually diagnosed with Susac syndrome. Abbreviations: ALD = assistive listening device, EEG = electroencephalogram, MRI = magnetic resonance imaging, MS = multiple sclerosis