Steroid-dependent sensorineural hearing loss in a patient with Charcot-Marie-Tooth disease showing auditory neuropathy

Charcot-Marie-Tooth disease (CMT) is the most common form of hereditary sensorimotor neuropathy and sometimes involves disorders of the peripheral auditory system. We present a case of steroid-dependent auditory neuropathy associated with CMT, in which the patient experienced 3 episodes of acute exacerbation of hearing loss and successful rescue of hearing by prednisolone. An 8-year-old boy was referred to the otolaryngology department at the University Hospital. He had been diagnosed with CMT type 1 (demyelinating type) at the Child Neurology Department and was suffering from mild hearing loss due to auditory neuropathy. An audiological diagnosis of auditory neuropathy was confirmed by auditory brainstem response and distortion-product otoacoustic emissions. At 9 years and 0 months old, 9 years and 2 months old, and 10 years and 0 months old, he had experienced acute exacerbations of hearing loss, each of which was successfully rescued by intravenous or oral prednisolone within 2 weeks. Steroid-responsive cases of CMT have been reported, but this is the first case report of steroid-responsive sensorineural hearing loss in CMT. The present case may have implications for the mechanisms of action of glucocorticoids in the treatment of sensorineural hearing loss.