Development of progressive hearing loss and tinnitus in a patient with myasthenia gravis: an overlooked comorbidity?. (2nd October 2017)

• Record Type: Journal Article
• Authors: Ralli, Massimo; di Stadio, Arianna; Greco, Antonio; Altissimi, Giancarlo; Mazzei, Filippo; Turchetta, Rosaria; de Vincentiis, Marco; Cianfrone, Giancarlo
• Is Part Of: Hearing, balance and communication. Volume 15:Number 4(2017:Dec.)
• Page Start: 260
• Page End: 266
• Publication Date: 2017-10-02
• Subjects: Myasthenia gravis -- hearing loss -- tinnitus -- otoacustic emissions; Audiology -- Periodicals; Hearing disorders -- Periodicals; 612.85
• DOI: 10.1080/21695717.2017.1380968
• Languages: English
• ISSNs: 2169-5717

Abstract

Abstract: Purpose: There is evidence of progressive antibody-mediated loss of acetylcholine receptors on outer hair cells in the inner ear that underlies hearing dysfunction in myasthenia gravis patients. In this paper, we present the case of a 35-year-old patient with adult-onset myasthenia gravis and thymoma who experienced progressive hearing loss and bilateral high-pitched tone tinnitus worsening over time. Materials and methods: Patient underwent pure tone audiometry, acoustic immittance test, decay test, transient-evoked and distortion product otoacustic emissions with and without contralateral acoustic stimulation, somatosensory tinnitus screening maneuvers and self-assessment questionnaires for tinnitus, hearing loss and hyperacusis, in addition to anamnestic interview and complete ENT visit. Questionnaires for psychiatric comorbidities (SCL90R – Symptom Checklist 90 Revisited) were also administered to the patient. The patient was studied in baseline conditions and 1 h after administration of the acetylcholinesterase inhibitor pyridostigmine bromide, a drug that has been reported to have a temporary effect on outer hair cell electromotility in myasthenia gravis patients. Results: Pure-tone audiometry showed a progressive hearing loss for high frequencies. Consistently, transient-evoked and distortion product otoacoustic emission amplitudes were significantly reduced for mid and, especially, high frequencies; after drug administration, a significant otoacoustic emission amplitude increase was recorded. Conclusions: Our findings documented a chronic dysfunction of outer hair cells consistent with acetylcholine receptor loss; these alterations could represent a basis for development of hearing loss and tinnitus.