Conclusion: Like NAC ameliorates hearing loss from acoustic trauma in the inner ear, NAC may also rescue hearing loss from sudden deafness confined to the inner ear.
Objective: This study assesses the effect of N-acetyl-L-cysteine (NAC) as a single therapy for sudden deafness.
Methods: Thirty-five sudden deafness patients with neither systemic disorders nor central signs in electronystagmography were treated with NAC alone and assigned to Group A. For comparison, another 35 sudden deafness patients treated by corticosteroids and plasma expander were assigned to Group B. There were no significant differences between the two groups in terms of age, sex, laterality, and pre-treatment mean hearing level. All patients underwent an inner ear test battery comprising audiometry, and ocular vestibular-evoked myogenic potential (oVEMP), cervical VEMP (cVEMP), and caloric tests.
Results: Groups A and B did not significantly differ in the pre-treatment mean hearing level, and percentages of abnormal oVEMP, cVEMP, and caloric tests, indicating that the involvement severity of sudden deafness between the two groups was similar. However, Group A (43 ± 27 dB) showed significantly greater mean hearing gain than Group B (21 ± 28 dB), and Group A (91%) revealed better improved rate of hearing than Group B (57%).
Keywords: Antioxidant; N-acetyl-L-cysteine (NAC); cervical vestibular-evoked myogenic potential; ocular vestibular-evoked myogenic potential; sudden deafness.