Diagnosis and management of acute sensorineural hearing loss: a Japanese perspective
Reviewed by Praneta Kulloo

In this paper, the authors set out the clinical guidelines to standardise diagnosis and treatment of acute sensorineural hearing loss in Japan. They categorised acute sensorineural hearing loss into five disorders: idiopathic sudden sensorineural hearing loss (iSSNHL), acute low-tone sensorineural hearing loss (ALHL), perilymphatic fistula (PLF), mumps-associated hearing loss and acoustic trauma. iSSNHL was defined as hearing loss of 30dB or more at three contiguous frequencies within 72 hours. ALHL was excluded from this group. Despite standard treatment of iSSNHL, one third of patients fully recover, one third achieve partial recovery and one third see no change. Systemic corticosteroids are recommended for treatment of iSSNHL. Intratympanic steroids are used as initial or salvage treatment. There are some low-quality studies that suggest hyperbaric oxygen therapy as an option. Prostaglandin E1 has been suggested as complementary therapy to steroids in severe-to-profound cases but the evidence is controversial. ALHL is sudden hearing loss limited to low frequency. Involvement of endolymphatic hydrops is a potential underlying pathology and recurrence may suggest Ménière’s disease. Treatment of ALHL focuses on addressing the presumed endolymphatic hydrops. In addition to corticosteroids as in iSSNHL, osmotic diuretics are administered but there is no clear evidence for efficacy of diuretics. PLF is diagnosed based on clinical symptoms and detection of perilymph specific protein. Acutely, patients are advised to rest for one week to allow for potential spontaneous recovery. If symptoms persist or worsen, surgical intervention to close the fistula is indicated. Mumps-associated hearing loss typically affects young children. Prognosis is generally poor. Treatments are like iSSNHL although there is no high-level evidence. Cochlear implants are effective for bilateral severe-to-profound SNHL. Acoustic trauma is often caused by loud sounds. Early treatment with corticosteroids is generally recommended. Prevention using ear protection is emphasised.

Clinical practice guidelines for the diagnosis and management of acute sensorineural hearing loss.
Kitoh R, Shin-ya Nishio S, Sato H, et al.
AURIS NASUS LARYNX
2024;51(4):811–21.