Neuroaudiological Effects in a Case of Fatal Dimethylmercury Poisoning

OBJECTIVE:The audiological examination of this patient was to determine the degree and type of hearing loss that was incurred from apparent dimethylmercury poisoning. DESIGN:This was a single subject case study design. Audiologic tests were selected to help determine sensory from neural and/or central auditory system dysfunction. RESULTS:This patient demonstrated an inability to understand speech, both in formal and informal assessments, yet relatively good hearing sensitivity for pure tones bilaterally. Distortion product otoacoustic emissions showed only minimal deficits in each ear. The auditory brain stem response was abnormal bilaterally, indicating neural and/or central involvement. CONCLUSION:Dimethylmercury poisoning, in this case, resulted in compromise of the auditory neural system with little effect on the sensory (cochlea) mechanism.