Auditory tests in 14 patients(16 ears)with acoustic neuroma / 中国耳鼻咽喉头颈外科

ABSTRACT

Objective:To investigate the relationship between hearing loss and acoustic neuroma(AN),the tests of pure tone audiometry,acoustic emissions impedance audiometry,audiometry brainstem response(ABR)and evoked otoacoustic emissions(EOAE)wee measured in 14 patients (16 ears)from March 1999 to December 2000.Methods:Fourteen patients (16 ears)with acoustic neuroma (8 males and 6 females,ranging in age from 21 to 72 years old)were diagnosed by CT or MRI scaning,and final confirmed by surgery and pathology.In the auditory tests ,efferent suppression test was curried out only in 4 ears with recordable emissions,promontory stimulation test (PST)was examined only in 5 ears with severe or profound deafness (hearing loss≥80dB SPL)who have no both measurable ABR and recordable EOAE.Results:It was found that 2 ears (12.5%,2/16)of the AN ears showed neural impairment,6 ears (37.5%,6/16)were cochlear impairment and 8 ears (50.0%,8/16)were cochlear-retrocochlear impairment.All of 4 tumors ears with EOAE emission have a disorders of efferent function.Conclusion:EOAE test had significant value for evaluation of the status of cochlear function (at the level of outer hair cells)in AN patients.The retrocochlear auditory nerve function of AN patients were evaluated by the tests of ABR combined PST which showed significant value.Results showed that the hearing impairment of AN have different levels of the peripheral auditory system according to auditory tests,including cochlear,eighth cranial nerve and efferent nerve level at the same or independently.