Management Approach for Asymmetric Hearing Loss
Diagnostic Evaluation
- The American Academy of Otolaryngology-Head and Neck Surgery recommends that patients with asymmetric hearing loss undergo comprehensive audiometric evaluation followed by MRI of the internal auditory canal to rule out retrocochlear pathology, particularly vestibular schwannoma 1, 2
- A comprehensive audiogram including pure tone thresholds, speech audiometry, tympanometry, and acoustic reflex testing should be obtained to differentiate the type and severity of hearing loss 1
- Asymmetric hearing loss is defined as a difference in pure tone average (500, 1000, and 2000 Hz) between ears of >15 dB, or a difference in word recognition scores >15% between ears 3
Imaging Studies
- MRI of the internal auditory canal and posterior fossa should be performed in patients with asymmetric sensorineural hearing loss to rule out retrocochlear pathology 5, 6
- Non-contrast MRI has been proposed as a cost-effective means to evaluate for vestibular schwannoma 6
Management Based on Etiology
- For sudden sensorineural hearing loss (occurring within 72 hours), oral steroids should be offered as soon as possible, and intratympanic steroid therapy should be offered for treatment failures or patients presenting between 2-6 weeks after onset 4
- Patients with conductive hearing loss should be referred to an otolaryngologist for evaluation and potential surgical intervention 4
Rehabilitation Options
- Hearing aids are appropriate for patients with serviceable hearing (typically word recognition scores >50%) 8
- Contralateral routing of sound (CROS) devices may be beneficial for profound unilateral hearing loss, and cochlear implantation may be considered for profound unilateral hearing loss in appropriate candidates 6
Follow-up and Monitoring
- Patients with asymmetric hearing loss should have audiometric follow-up to monitor stability or progression, with assessments at least every 3 years in patients with known hearing loss 7, 9