Prospective Short-Term Observation for Spontaneous Recovery of Sudden Sensorineural Hearing Loss

OBJECTIVE: To determine the rate of spontaneous recovery in sudden sensorineural hearing loss (SSNHL) within 1 week of onset and evaluate the effect of corticosteroid treatment in patients without early recovery. STUDY DESIGN: Prospective, non-randomized comparative study. SETTING: Tertiary academic medical center. PATIENTS: Patients with SSNHL who presented within 3 days of onset between September 2023 and December 2024. INTERVENTION: Patients were observed for 1 week from the onset, followed by corticosteroid therapy only in insufficient early recovery group. MAIN OUTCOME MEASURES: Pure-tone average (PTA), word recognition score (WRS), and hearing gain. RESULTS: Among 41 patients who completed the 3-month follow-up, 13 (31.7%) showed complete or partial recovery after 1 week and were classified into the observation group. The remaining 28 patients (68.3%) received corticosteroid therapy. At the end of the observation, the observation group showed significantly better PTA (17.7±8.0 dB), WRS (94.2±3.5%), and hearing gain (36.4±12.3 dB) than the treatment group (P<0.001). Frequency-specific analysis demonstrated significant spontaneous recovery across all measured frequencies (250 to 8000 Hz, P<0.05). Logistic regression identified initial PTA as the only significant predictor of spontaneous recovery, with a cutoff value of 71 dB (AUC=0.934). In the treatment group, PTA improved significantly from the end of observation to 3 months (mean change: 33.8±23.9 dB, P<0.001). CONCLUSIONS: Approximately one-third of patients with SSNHL recovered spontaneously within 1 week. Initial PTA was the strongest predictor of spontaneous recovery, with a threshold of 71 dB. For patients with limited early recovery, corticosteroid therapy resulted in meaningful hearing improvement.