Hidden hearing loss in patients with Charcot-Marie-Tooth disease type 1A

Ji Eun Choi,Jin Myoung Seok,Sung Hwa Hong,Kyung Myun Lee,Il Joon Moon,Yoon Sang Ji,Byung-Ok Choi,Jungmin Ahn

doi:10.1038/s41598-018-28501-y

Abstract

The aim of this study was to investigate hidden hearing loss in patients with Charcot-Marie-Tooth disease type 1 A (CMT1A), a common inherited demyelinating neuropathy. By using pure-tone audiometry, 43 patients with CMT1A and 60 healthy controls with normal sound detection abilities were enrolled. Speech perception in quiet and noisy backgrounds, spectral ripple discrimination (SRD), and temporal modulation detection (TMD) were measured. Although CMT1A patients and healthy controls had similar pure-tone thresholds and speech perception scores in a quiet background, CMT1A patients had significantly (p < 0.05) decreased speech perception ability in a noisy background compared to controls. CMT1A patients showed significantly decreased temporal and spectral resolution (both p < 0.05). Also, auditory temporal processing of CMT1A patients was correlated with speech perception in a noisy background (r = 0.447, p < 0.01) and median motor conduction velocity (r = 0.335, p < 0.05). Therefore, we assumed that demyelination of auditory nerve in CMT1A causes defective cochlear neurotransmission, which reduces temporal resolution and speech perception in a noisy background. Because the temporal resolution test was well correlated with the degree of demyelination in auditory and peripheral motor nerves, temporal resolution testing could be performed as an additional marker for CMT1A.

Highlights

Charcot-Marie-Tooth (CMT) disease, the most common hereditary peripheral neuropathy, affects 1 in 2500 people[1]
No Charcot-Marie-Tooth disease type 1 A (CMT1A) patients had prolonged click auditory brainstem response (ABR) latencies compared to normative data[8]
This study evaluated hidden hearing loss of CMT1A patients and found that they had significantly reduced speech perception in a noisy background compared to controls (Fig. 1)

Summary

Introduction

Charcot-Marie-Tooth (CMT) disease, the most common hereditary peripheral neuropathy, affects 1 in 2500 people[1]. CMT1A is a demyelinating peripheral neuropathy characterized by distal muscle weakness, sensory loss, areflexia, and slow motor and sensory nerve conduction velocities[2,3,4]. CMT1A patients could have normal audiograms even though they have difficulty hearing in their daily lives. Hidden hearing loss is recently described as auditory neuropathy believed to contribute to speech discrimination and intelligibility deficits in people with normal audiograms[6,7]. The relationship between auditory deficit and disease progression of CMT1A remains elusive. The objective of this study was to evaluate hidden hearing loss and determine diagnostic values of new auditory tests by comparing auditory measures and disease progression in CMT1A patients

Objectives

Methods

Results

Conclusion