Detailed insight in intraoperative eABR measurements to assist auditory brainstem implantation in a patient with neurofibromatosis type 2


Auditory brainstem implant (ABI) is used to provide auditory sensations in patients with neurofibromatosis type 2 who lost their hearing due to a surgical removal of the tumor. ABI surgery, implant activation and follow-up sessions present unique challenges including the exact placement of the electrode pad in the lateral recess of the IVth ventricle, identification of electrodes that trigger non-auditory sensation and their deactivation which lowers the number of electrodes responsible for hearing, changes of T- and C-levels across follow-up sessions. We present a complete procedure using an example case starting from the surgical part with the detailed description of intraoperative eABR measurement as a guidance for pad placement to the ABI activation and first fitting sessions with auditory sensation assessment. Since the first ABI electrode pad position presented non-satisfactory intraoperative eABR results it was decided to move the pad slightly which resulted in better eABR (more electrodes with auditory responses). The discussed patient demonstrated great auditory and speech perception results after the first ABI fitting (which included three sessions over 2 consecutive days). Repositioning of the ABI electrode pad during the surgery was carried out taking into account the intraoperative eABR results and this led to an overall positive outcome for the patient. The placement of ABI electrode pad is crucial for later auditory results. This study provides detailed insight in this very specialized procedure that is not performed in every clinic and adds to the knowledge of intraoperative navigation using eABR measurements during ABI surgery.

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  1. 1.

    Waring MD (1995) Intraoperative electrophysiologic monitoring to assist placement of auditory brain stem implant. Ann Otol Rhinol Laryngol Suppl 166:33–36

    CAS  Google Scholar 

  2. 2.

    Waring MD (1996) Properties of auditory brainstem responses evoked by intra-operative electrical stimulation of the cochlear nucleus in human subjects. Electroencephalogr Clin Neurophysiol 100(6):538–548

    CAS  Article  Google Scholar 

  3. 3.

    Nevison B, Laszig R, Sollmann WP, Lenarz T, Sterkers O, Ramsden R, Fraysse B, Manrique M, Rask-Andersen H, Garcia-Ibanez E, Colletti V, von Wallenberg E (2002) Results from a European clinical investigation of the nucleus multichannel auditory brainstem implant. Ear Hear 23(3):170–183

    Article  Google Scholar 

  4. 4.

    Nevison B (2006) A guide to the positioning of brainstem implants using intraoperative electrical auditory brainstem responses. Adv Otorhinolaryngol 64:154–166.

    Article  Google Scholar 

  5. 5.

    O’Driscoll M, El-Deredy W, Ramsden RT (2011) Brain stem responses evoked by stimulation of the mature cochlear nucleus with an auditory brain stem implant. Ear Hear 32(3):286–299.

    Article  Google Scholar 

  6. 6.

    Herrmann BS, Brown MC, Eddington DK, Hancock KE, Lee DJ (2015) Auditory brainstem implant: electrophysiologic responses and subject perception. Ear Hear 36(3):368–376.

    Article  Google Scholar 

  7. 7.

    Puram SV, Herrmann B, Barker FG 2nd, Lee DJ (2015) Retrosigmoid craniotomy for auditory brainstem implantation in adult patients with neurofibromatosis type 2. J Neurol Surg B Skull Base 76(6):440–450.

    Article  Google Scholar 

  8. 8.

    Barber SR, Kozin ED, Remenschneider AK, Puram SV, Smith M, Herrmann BS, Cunnane ME, Brown MC, Lee DJ (2017) Auditory brainstem implant array position varies widely among adult and pediatric patients and is associated with perception. Ear Hear 38(6):e343–e351.

    Article  Google Scholar 

  9. 9.

    Colletti V, Shannon RV, Carner M, Veronese S, Colletti L (2010) Complications in auditory brainstem implant surgery in adults and children. Otol Neurotol 31(4):558–564.

    Article  Google Scholar 

  10. 10.

    Behr R, Colletti V, Matthies C, Morita A, Nakatomi H, Dominique L, Darrouzet V, Brill S, Shehata-Dieler W, Lorens A, Skarzynski H (2014) New outcomes with auditory brainstem implants in NF2 patients. Otol Neurotol 35(10):1844–1851.

    Article  Google Scholar 

  11. 11.

    Chatterjee M (1999) Effects of stimulation mode on threshold and loudness growth in multielectrode cochlear implants. J Acoust Soc Am 105(2 Pt 1):850–860

    CAS  Article  Google Scholar 

  12. 12.

    Galvin JJ 3rd, Fu QJ (2009) Influence of stimulation rate and loudness growth on modulation detection and intensity discrimination in cochlear implant users. Hear Res 250(1–2):46–54.

    Article  Google Scholar 

  13. 13.

    Sanna M, Di Lella F, Guida M, Merkus P (2012) Auditory brainstem implants in NF2 patients: results and review of the literature. Otol Neurotol 33(2):154–164.

    Article  Google Scholar 

  14. 14.

    Deep NL, Choudhury B, Roland JT Jr (2019) Auditory brainstem implantation: an overview. J Neurol Surg B Skull Base 80(2):203–208.

    Article  Google Scholar 

  15. 15.

    Wong K, Kozin ED, Kanumuri VV, Vachicouras N, Miller J, Lacour S, Brown MC, Lee DJ (2019) Auditory brainstem implants: recent progress and future perspectives. Front Neurosci 13:10.

    Article  Google Scholar 

  16. 16.

    Anwar A, Singleton A, Fang Y, Wang B, Shapiro W, Roland JT Jr, Waltzman SB (2017) The value of intraoperative EABRs in auditory brainstem implantation. Int J Pediatr Otorhinolaryngol 101:158–163.

    Article  Google Scholar 

  17. 17.

    Moore JK (1987) The human auditory brain stem as a generator of auditory evoked potentials. Hear Res 29(1):33–43

    CAS  Article  Google Scholar 

  18. 18.

    Waring MD (1995) Auditory brain-stem responses evoked by electrical stimulation of the cochlear nucleus in human subjects. Electroencephalogr Clin Neurophysiol 96(4):338–347

    CAS  Article  Google Scholar 

  19. 19.

    Waring MD (1998) Refractory properties of auditory brain-stem responses evoked by electrical stimulation of human cochlear nucleus: evidence of neural generators. Electroencephalogr Clin Neurophysiol 108(4):331–344

    CAS  Article  Google Scholar 

  20. 20.

    Frohne C, Matthies C, Lesinski-Schiedat A, Battmer RD, Samii M, Lenarz T (2000) Extensive monitoring during auditory brainstem implant surgery. J Laryngol Otol Suppl 27:11–14

    Google Scholar 

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We would like to thank Tomáš Tichý from Cochlear Company for his assistance with intraoperative measurements and ABI activation sessions.

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Correspondence to Magdalena Lachowska.

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Research involving human participants

All procedures performed in this study involving human participant were in accordance with the ethical standards of the institutional research committee (the local Institutional Ethics Committee Review Board, reference number AKBE/175/2018) and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards.

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One patient participated in this study—the patient has given full written and informed consent, both for the participation and for the publication of the report.

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Lachowska, M., Pastuszka, A., Mikołajewska, L. et al. Detailed insight in intraoperative eABR measurements to assist auditory brainstem implantation in a patient with neurofibromatosis type 2. Acta Neurol Belg 120, 1371–1378 (2020).

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  • Hearing loss
  • Evoked potentials
  • Neurofibromatosis
  • Cochlear nerve
  • Cochlear nucleus
  • Auditory brainstem implant