The Disconnected Ear: Phenomenological Effects of a Large Acoustic Tumor

Objective To document the existence of a peripheral auditory disconnection syndrome in a 23-yr-old male with a large tumor of the right cerebellopontine angle using contemporary behavioral, electroacoustic, and electrophysiologic auditory tests. Design Single subject with repeated measures. Results In spite of a profound hearing loss in an ear with a large cerebellopontine angle tumor determined by behavioral audiometry, distortion product otoacoustic emissions, surface recorded brain stem auditory evoked potentials, and Tran tympanic Electrocochleography (click evoked compound action potentials and tone evoked cochlear microphonics) demonstrated that the cochlea was intact and functional over a broad bandwidth and intensity range. Conclusions A peripheral auditory disconnection syndrome is demonstrated in a 23-yr-old male with a large tumor of the cerebellopontine angle. In this instance, the tumor effectively dederentated the peripheral from central auditory nervous system, resulting in profound hearing loss of presumed neural origin. It is suggested that other pathologic conditions/mechanisms could produce similar findings.