Charcot-Marie-Tooth Disease With Long-Term Follow-Up on Auditory Neuropathy-After Cochlear Implantation Or Hearing Aid Use

Brazilian Society of Otology task force - cochlear implant ‒ recommendations based on strength of evidence

OBJECTIVE

To make evidence-based recommendations for the indications and complications of Cochlear Implant (CI) surgery in adults and children.

METHODS

Task force members were educated on knowledge synthesis methods, including electronic database search, review and selection of relevant citations, and critical appraisal of selected studies. Articles written in English or Portuguese on cochlear implantation were eligible for inclusion. The American College of Physicians' guideline grading system and the American Thyroid Association's guideline criteria were used for critical appraisal of evidence and recommendations for therapeutic interventions.

RESULTS

The topics were divided into 2 parts: (1) Evaluation of candidate patients and indications for CI surgery; (2) CI surgery - techniques and complications.

CONCLUSIONS

CI is a safe device for auditory rehabilitation of patients with severe-to-profound hearing loss. In recent years, indications for unilateral hearing loss and vestibular schwannoma have been expanded, with encouraging results. However, for a successful surgery, commitment of family members and patients in the hearing rehabilitation process is essential.

Charcot-Marie-Tooth Disease and Hearing Loss: A Systematic Review With Meta-Analysis

OBJECTIVE

To characterize the pattern of hearing loss in Charcot-Marie-Tooth (CMT) disease to help guide clinical management.

DATABASES REVIEWED

CINAHL, PubMed, and Scopus.

METHODS

Two independent investigators selected studies on CMT patients with pure-tone average (PTA) and auditory brainstem response (ABR) data. Case reports, case series <5 patients, and data that overlapped with another study were excluded. Investigators performed data extraction, quality rating, and risk-of-bias assessment using the Newcastle-Ottawa Scale. Meta-analysis of mean difference using fixed/random effects models was used. Also, data were analyzed using a weighted one-way analysis of variance, with post-hoc Tukey's test for comparison.

RESULTS

Ultimately, 6 prospective studies (N = 197) were included. The most common demyelinating subtype (CMT1A) had significantly prolonged ABR latency values across wave III (0.20 ms, 95% confidence interval [CI]: 0.05-0.35), wave V (0.20 ms, 95% CI: 0.01-0.39), waves I-III (0.20 ms, 95% CI: 0.01-0.39), and waves I-V (0.20 ms, 95% CI: 0.01-0.39) when compared to matched controls. The autosomal recessive demyelinating subtype (CMT4C) had significantly worse PTA when compared to the most common subtype (CMT1A) (Δ 28.93 dB, 95% CI 18.34-39.52) and nondemyelinating subtype (CMT2A) (Δ 28.3 dB, 95% CI: 15.98-40.62).

CONCLUSIONS

Patients with CMT can present with a variety of phenotypes depending on the causative mutation. The ABR interpeak latency values for the most common demyelinating form of CMT are delayed when compared to matched controls. Most subtypes have normal hearing thresholds, apart from CMT4C, which presents with mild hearing loss on average.

Cochlear implantation in patients with Charcot-Marie-Tooth disease: two cases with a review of the literature

PURPOSE

To report two cases of bilateral cochlear implantation (CI) in Charcot-Marie-Tooth disease (CMT) patients with novel mutations. Furthermore, we conducted a detailed literature review on the profile and outcomes of CI in this uncommon clinical circumstance.

CASE PRESENTATION

Case 1 involved a 25-year-old woman who was referred for sudden hearing loss (HL) in her left ear and had a 7-year history of HL in her right ear. She was diagnosed with CMT type 1 with a thymidine phosphorylase gene mutation. CI was performed on her left side because her hearing gradually worsened to deafness in both ears. At 3 months post-operation, her speech discrimination score without lip-reading improved from 0 to 100%. She underwent a second CI on her right ear 6 months after her first CI. Two years from her first operation, the speech discrimination score was 100%. Case 2 received her first CI on her right ear at the age of nine for her bilateral HL. She was diagnosed with CMT type 2 with a Twinkle mitochondrial DNA helicase gene mutation. Preoperatively, the speech discrimination score in both ear-aided conditions was 70%. At the 7-year post-operation follow-up, the speech discrimination score was 76%. A second CI was performed due to decreasing hearing ability in her left ear. The speech discrimination score showed 100% at 7 months after the second CI.

CONCLUSIONS

CI is an effective hearing rehabilitation option for CMT patients with severe-to-profound SNHL. Neuro-otologists should consider CI as a treatment option, even though hearing loss in CMT is associated with auditory neuropathy spectrum disease (ANSD).

Cochlear Implantation in Charcot-Marie-Tooth Patients: Speech Perception and Quality of Life

OBJECTIVES

There is a limited understanding of the impact of cochlear implantation (CI) in patients with Charcot-Marie-Tooth disease (CMT), given the scarcity of reported cases. We aim to evaluate the audiological outcomes and quality of life (QoL) after CI in CMT.

METHODS

Multi-institutional, university-affiliated, tertiary-referral centers, retrospective chart review.Our cohort includes 5 patients with CMT. Patients' charts were reviewed for demographic characteristics, operation notes, and pre- and post-implantation audiology evaluation. Patients completed the Cochlear Implant Quality of Life-10 (CIQOL-10) Global questionnaire.

RESULTS

Pre-implantation, the mean pure tone average was 84.1 ± 7.2 dB, and the mean word recognition score was 2.4% in the implanted ear. AzBio sentence test was performed in quiet, revealing a mean of 4 ± 1.4% in the implanted ear. Post-implantation, PTA results were all within the mild hearing loss range (mean 33.0 ± 5.9 dB). Post-CI, AZ-Bio test results were 5%, 65%, and 74% (for 3 patients), and HINT scores were 55% and 58% (for 2 patients). The mean score of the CIQOL-10 questionnaire was 42.7 ± 10.47 (range 1-100). Patients were most satisfied with their ability to listen to the television or radio, have conversations in a quiet environment, and feel comfortable being themselves.

CONCLUSION

To the best of our knowledge, this is the most extensive series of CI in CMT-associated sensorineural hearing loss and auditory neuropathy. Our cohort suggests that CI is a safe and reliable method for hearing rehabilitation that can achieve good speech performance and improve QoL in CMT patients.