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Skull base surgery. 1994 January; 4(1): 1–9.
PMCID: PMC1656458

Changes in Directly Recorded Cochlear Nerve Compound Action Potentials During Acoustic Tumor Surgery

Abstract

Damage to labyrinthine, neural, and vascular structures may possibly account for failure to achieve hearing preservation after removal of small acoustic neuromas. The pathogenesis of auditory impairment is, however, sometimes unclear. Intraoperative monitoring of auditory evoked potentials enables us to study possible correlations between surgical maneuvers and the function of auditory structures and pathways. To this end, simultaneous recording of brainstern auditory evoked potentials and direct cochlear nerve action potentials (CNAPs) was utilized in 14 patients with small (12 to 18 mm) unilateral acoustic neuromas. The latency of the first negative component (N1) of the CNAPs proved extremely sensitive in detecting intraoperative auditory damage and was a good predictive index of postoperative auditory outcome. Evaluation of temporal and morphologic CNAP patterns allowed identification of coagulation close to the cochlear nerve, drilling of the internal auditory canal, and removal of the intrameatal portion of the tumor, the most critical steps in hearing preservation. The mechanisms of damage are analyzed and discussed.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.
  • Abramson M, Stein BM, Pedley TA, Emerson RG, Wazen JJ. Intraoperative BAER monitoring and hearing preservation in the treatment of acoustic neuromas. Laryngoscope. 1985 Nov;95(11):1318–1322. [PubMed]
  • Shelton C, Hitselberger WE, House WF, Brackmann DE. Hearing preservation after acoustic tumor removal: long-term results. Laryngoscope. 1990 Feb;100(2 Pt 1):115–119. [PubMed]
  • Jannetta PJ, Møller AR, Møller MB. Technique of hearing preservation in small acoustic neuromas. Ann Surg. 1984 Oct;200(4):513–523. [PubMed]
  • Raudzens PA, Shetter AG. Intraoperative monitoring of brain-stem auditory evoked potentials. J Neurosurg. 1982 Sep;57(3):341–348. [PubMed]
  • Grundy BL, Jannetta PJ, Procopio PT, Lina A, Boston JR, Doyle E. Intraoperative monitoring of brain-stem auditory evoked potentials. J Neurosurg. 1982 Nov;57(5):674–681. [PubMed]
  • Møller AR, Jannetta PJ. Compound action potentials recorded intracranially from the auditory nerve in man. Exp Neurol. 1981 Dec;74(3):862–874. [PubMed]
  • Silverstein H, McDaniel AB, Norrell H. Hearing preservation after acoustic neuroma surgery using intraoperative direct eighth cranial nerve monitoring. Am J Otol. 1985 Nov;Suppl:99–106. [PubMed]
  • Ojemann RG, Levine RA, Montgomery WM, McGaffigan P. Use of intraoperative auditory evoked potentials to preserve hearing in unilateral acoustic neuroma removal. J Neurosurg. 1984 Nov;61(5):938–948. [PubMed]
  • Schramm J, Mokrusch T, Fahlbusch R, Hochstetter A. Detailed analysis of intraoperative changes monitoring brain stem acoustic evoked potentials. Neurosurgery. 1988 Apr;22(4):694–702. [PubMed]
  • Møller AR, Jannetta PJ. Monitoring auditory nerve potentials during operations in the cerebellopontine angle. Otolaryngol Head Neck Surg. 1984 Aug;92(4):434–439. [PubMed]
  • Kveton JF, Tarlov EC, Drumheller G, Katcher P, Abbott C. Cochlear nerve conduction block: an explanation for spontaneous hearing return after acoustic tumor surgery. Otolaryngol Head Neck Surg. 1989 Jun;100(6):594–601. [PubMed]
  • Tatagiba M, Samii M, Matthies C, el Azm M, Schönmayr R. The significance for postoperative hearing of preserving the labyrinth in acoustic neurinoma surgery. J Neurosurg. 1992 Nov;77(5):677–684. [PubMed]
  • Sekiya T, Møller AR. Avulsion rupture of the internal auditory artery during operations in the cerebellopontine angle: a study in monkeys. Neurosurgery. 1987 Nov;21(5):631–637. [PubMed]

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