Objective: The metabolic disorder Pompe disease mainly affects the skeletal muscle in adults. The hearing impairment due to stapedius muscle involvement in adult patients is not known.
Design: The frequency, severity, and type of hearing impairment was characterized prospectively using pure-tone audiometry, tympanometry, stapedial reflexes, otoacoustic emissions, and brainstem-evoked response audiometry in adult patients on enzyme replacement therapy for genetically confirmed Pompe disease.
Study sample: 11 adult patients (median age: 47 years, range: 22-71).
Results: Four patients complained about subjective hearing disturbances. Using World Health Organization definition of hearing impairment, abnormal hearing thresholds resulting in mild hearing loss were found in 36% of patients. Compared to normative data (ISO 7029), the hearing threshold was below the median in all but three ears. Stapedial reflexes could not be elicited ipsilateral in 18% and contralateral in 36%. Auditory brainstem responses showed no retrocochlear pathology.
Conclusions: The prevalence of hearing loss slightly exceeded the normative data of the general population. Consistent with previous studies the hearing impairment was usually mild. The percentage of pathological stapedial reflexes exceeded that of matched control subjects and suggests a selective involvement of the stapedius muscle, potentially as a sequela of Pompe disease.