Objective: To determine whether treatment with Mg2+ improves the outcome of idiopathic sudden hearing loss and to investigate which variables influence its prognosis.
Study Design: Prospective randomized study.
Setting: Department of Otolaryngology-Head and Neck Surgery, Rambam Medical Center, Haifa, Israel.
Patients: The study group included 133 patients. Sixty patients were treated with carbogen inhalation, and 73 were treated with a combination of carbogen inhalation and intravenous MgSO4.
Results: The mean improvement rate was 66.4% in the Mg2+ group and 49.9% in the carbogen group (p < 0.01). Recovery was achieved in 35 patients (48%) in the Mg2+ group and only in 19 patients (31.6%) in the carbogen group (p < 0.01). Significant improvement was seen in 20 patients (27.4%) in the Mg2+ group and in 14 patients (23.3%) in the carbogen group. Partial improvement was seen in eight patients (10.9%) in the Mg2+ group and in 12 patients (20%) in the carbogen group. No improvement was achieved in 10 patients (13.6%) in the Mg2+ group and in 15 patients (25%) in the carbogen group. Patients with vestibular symptoms had a poorer hearing outcome compared to those without vertigo (p < 0.04). Patients who commenced the treatment 8 days or more after onset had poorer recovery as compared with those who started treatment earlier (p < 0.03), regardless of the treatment regimen. Age, sex, and tinnitus had no significant impact on hearing recovery.
Conclusion: We found that Mg2+ improved hearing recovery in cases of idiopathic sudden hearing loss. Vertigo and treatment delay beyond 8 days were poor prognostic factors for recovery.