Simultaneous and sequential bilateral sudden sensorineural hearing loss: are they different from unilateral sudden sensorineural hearing loss?

Abstract

Aim: To compare bilateral (BSSHL) with unilateral (USSHL) sudden sensorineural hearing loss.

Methods and subjects: Two hundred and thirty-two patients with USSHL, 11 with simultaneous BSSHL and 7 with sequential BSSHL, who were older than 15 years had onset of hearing loss <30 days, no head injuries or history of acoustic trauma. All patients received the same treatment (prednisolone).

Results: Hearing loss was more severe in simultaneous BSSHL in comparison to sequential BSSHL (p = 0.01) or USSHL (p = 0.03). Autoimmune diseases were far more common in simultaneous BSSHL (36% of patients) than USSHL. Positive antinuclear antibody was found in half of BSSHL patients and in only 8% of unilateral cases (p = 0.01). The frequency of hearing improvement was much lower in simultaneous BSSHL than in USSHL (p = 0.001). Complete or partial improvement was noted in 74% of unilateral cases versus 27% in simultaneous bilateral cases. Patients with sequential BSSHL improved in a similar way to unilateral cases.

Conclusions: Simultaneous BSSHL, sequential BSSHL and USSHL may have a completely different profile and should not be managed as one disease. Hearing loss, underlying autoimmune diseases, antinuclear antibodies, and improvement/recovery of hearing loss vary in a degree that implies different pathophysiology and prognosis.