Cochlear implantation in chronic demyelinating inflammatory polyneuropathy^†

† This work was presented as a poster presentation at the 14th International Conference on Cochlear Implants, Toronto, Quebec, Canada, May 12–14, 2016.

Abstract

Objective: To describe a case of chronic inflammatory demyelinating polyneuropathy (CDIP) with bilateral sudden sensorineural hearing loss who subsequently benefited from unilateral cochlear implantation.

Methods: case history review and review of the literature for the terms CDIP, hearing loss, cochleovestibular dysfunction, and cochlear implantation.

Results: A 49-year-old woman presented with bilateral rapidly progressive sensorineural hearing loss (SNHL) 1 month after an upper respiratory tract infection. Hearing loss was not responsive to high-dose steroids and there were no other laboratory abnormalities or physical findings. Within 1 month, she developed ascending motor palsy, requiring long-term ventilator support. This neurologic condition was diagnosed as CDIP and she was successfully treated with plasmapheresis and intravenous immunoglobulin. Her hearing never recovered. At the time of cochlear implant, she had no response at the limits of the audiometer and obtained 0% on AzBio testing. No ABR could be recorded preoperatively. She underwent uneventful cochlear implantation with a perimodilar electrode. One year after activation, she had a PTA of 20 dB and 40% on AzBio sentence testing. Her eABR demonstrated a neuropathy pattern. Only two other cases of CDIP associated with dysfunction of the eighth nerve have been described, and neither had documented profound hearing loss.

Conclusions: Severe SNHL associated with CDIP is rare. Although this patient has good access to sound, speech discrimination is poor at 1-year post implantation. This outcome may be due to incomplete recovery of myelination of the eighth nerve. Other possibilities include loss of peripheral nerve fibers due to the initial viral upper respiratory infection, which may lead to less neural substrate to stimulate.

Keywords:

• Chronic inflammatory demyelinating polyneuropathy
• Cochlear implant
• Hearing loss
• Electrophysiology
• eABR
• Auditory neuropathy

Acknowledgements

The authors are grateful to Christine Etler, AuD CCC of the University of Iowa; Megan Narron, AuD and Peter Arkis, AuD both of Cochlear Americas, without whose help this work would not have been possible.

Disclaimer statements

Contributors None.

Funding None.

Conflict of interest None.

Ethics approval None.

ORCID

Sarah E. Mowry http://orcid.org/0000-0003-2366-3205

Notes

† This work was presented as a poster presentation at the 14th International Conference on Cochlear Implants, Toronto, Quebec, Canada, May 12–14, 2016.