BACKGROUND: Although being established as a standard procedure in intra-operative monitoring in @entity5513 surgery, auditory brainstem responses (ABR) represent a far-field technique bearing some technical limitations. This prospective study was designed to evaluate electrocochleography (ECochG) as a supplementary tool for hearing preservation. METHOD: 84 @entity1 with unilateral intra-/extrameatal @entity5513 (extrameatal diameter: 5-55 mm) preserving serviceable hearing, were operated on using a combined (neuro-/otosurgical) suboccipital approach. ECochG was recorded simultaneously to ABR following transtympanic insertion of a steel needle electrode into the promontory under otoscopic view. FINDINGS: Serviceable hearing (Class 1-3 according to Gardner/Robertson) was preserved in 43 out of 84 @entity1 (51.2%), of whom 40 showed both ECochG and ABR being preserved. All 24 @entity1 with loss of both modalities became deaf. Hearing preservation was observed in 4 out of 12 @entity1 with preserved ECochG but loss of ABR (waves III-V). The reverse was observed in 2 cases with @entity86 . While both ECochG and ABR amplitudes were significantly correlated with pre- and postoperative hearing, latencies of ECochG summating (SP) and action potential (AP) proved to be more reliable indicators for preserved hearing than ABR (peak I/III/V) latencies. The predictive value of baseline ABR amplitudes for postoperative hearing, however, was superior to ECochG parameters. Only in large @entity808 (extrameatal diameter: >2 cm) @entity5 size was found to be a significant predictor for the preservation of hearing. Apart from three cases with @entity86 and one further case presenting with local @entity548 within the external acoustic meatus, no side effects were observed. CONCLUSIONS: In combination with ABR monitoring, ECochG proved to be a useful supplementary tool for hearing preservation in @entity5513 surgery. It is particularly helpful during electrocautery and drilling, since no averaging is required. Special applications are: (1) small @entity5 with good serviceable hearing; (2) and/or a large intrameatal portion; (3) cases with lost or endangered contralateral hearing (e.g. bilateral @entity5513 ), when the preservation of poor or even non-functional hearing is desirable.

Combined intra-operative monitoring of hearing by means of auditory brainstem responses (ABR) and transtympanic electrocochleography (ECochG) during surgery of intra- and extrameatal XXXX .

@entity1 :: ('9606', 'Species') :: ['patients'] @entity808 :: ('MESH:D009442', 'Disease') :: ['neurinomas'] @entity5513 :: ('MESH:D009464', 'Disease') :: ['acoustic neurinoma', 'acoustic neurinomas'] @entity548 :: ('MESH:D006470', 'Disease') :: ['bleeding'] @entity5 :: ('MESH:D009369', 'Disease') :: ['tumour', 'tumours'] @entity86 :: ('MESH:D019106', 'Disease') :: ['postoperative otoliquorrhea', 'postoperative deafness']
@entity5513 :: (MESH:D009464,Disease) :: ['acoustic neurinomas']
