The audiologic profile of patients with Charcot-Marie Tooth neuropathy can be characterised by both cochlear and neural deficits.

Objective

The primary goal of this study was to characterise the cochlear and neural components of hearing loss in a large cohort of people with Charcot-Marie Tooth neuropathy who reported hearing difficulties.

Design

A full complement of audiologic measures including behavioral, physiologic and subjective assessments were administered.Study sample: Seventy-nine participants completed the study. Forty-four people had CMT1, 27 had CMT2 and four had CMT-INT.

Results

Pure tone average was related to age and the absence of high-frequency DPOAE energy, suggesting a strong cochlear component. Acoustic reflexes were often elevated or absent and many participants exhibited abnormal ABR waveforms, suggesting additional neural hearing loss components. Participants with an abnormal or absent ABR wave V exhibited poorer speech perception abilities. There was an association between a prolonged ABR wave I latency and an abnormal or absent ABR wave V with a higher Charcot-Marie Tooth Neuropathy Score (indicating greater disability).

Conclusions

The hearing abilities of people with CMT are highly variable. While there were strong neural hearing loss components, speech perception abilities were not disproportionately affected in most participants. Therefore, a hearing aid trial is recommended. ABR responses may be a useful tool for monitoring the progression of CMT over time.