From the Guidelines
The initial workup for a patient presenting with unilateral hearing loss should begin with a comprehensive history and physical examination, focusing on onset, duration, associated symptoms, and risk factors, followed by a prompt and comprehensive audiologic examination, as recommended by the American Academy of Otolaryngology and Head and Neck Surgery Foundation guidelines 1.
Initial Evaluation
A detailed otoscopic examination is essential to visualize the ear canal and tympanic membrane, and to check for cerumen impaction, which is a frequent reversible cause of hearing loss, especially in older patients 1.
- Audiometric testing, including pure tone audiometry, speech audiometry, and tympanometry, should be performed to characterize the type (conductive, sensorineural, or mixed) and severity of hearing loss.
- Weber and Rinne tuning fork tests can provide immediate information about the nature of hearing loss at the bedside.
Further Testing
Laboratory tests may include complete blood count, erythrocyte sedimentation rate, and specific serologies if infection or autoimmune causes are suspected.
- Imaging studies are crucial, with MRI being the gold standard to rule out acoustic neuroma or other retrocochlear pathologies, while CT scans are better for evaluating bony abnormalities, as recommended by the ACR Appropriateness Criteria 1.
- For sudden-onset unilateral hearing loss, prompt treatment with oral corticosteroids (typically prednisone 1 mg/kg/day for 7-14 days with a taper) should be initiated, ideally within 2-4 weeks of symptom onset for optimal recovery chances.
Specialized Evaluation and Management
Referral to an otolaryngologist is recommended for specialized evaluation and management, particularly if the hearing loss is progressive, associated with vestibular symptoms, or if initial treatments are ineffective, as suggested by the American Academy of Otolaryngology and Head and Neck Surgery Foundation guidelines 1.
- A comprehensive audiologic examination is essential in patients with unilateral persistent tinnitus or hearing problems, as recommended by the American Academy of Otolaryngology and Head and Neck Surgery Foundation guidelines 1.
From the Research
Initial Workup for Unilateral Hearing Loss
The initial workup for a patient presenting with unilateral hearing loss involves several steps:
- In-office hearing tests such as the whispered voice test or audiometry to confirm the presence of hearing loss 2
- Examination for cerumen impaction, exostoses, and other abnormalities of the external canal and tympanic membrane, in addition to a neurologic examination 2
- Pure-tone audiometry to determine the type and degree of hearing loss, which can be used for screening or comprehensive testing when combined with tympanometry, speech-reception thresholds, and word-recognition testing 3
Further Evaluation
If the patient is found to have unilateral or asymmetrical sensorineural hearing loss, further evaluation is warranted:
- Audiograms that show a unilateral or asymmetrical sensorineural hearing loss can be signs of retrocochlear pathology and warrant additional evaluation by an audiologist and otolaryngologist as well as imaging studies 3
- Computed tomography or magnetic resonance imaging is indicated in patients with asymmetrical hearing loss or sudden sensorineural hearing loss, and when ossicular chain damage is suspected 2
- Magnetic resonance imaging (MRI) is proposed as the only investigation to be performed in case of an unilateral sensorineural hearing loss, due to its ability to detect small tumors and its cost-effectiveness compared to brainstem evoked response auditory (BERA) 4
Special Considerations
Certain conditions require prompt referral to an otolaryngologist:
- Sudden sensorineural hearing loss (loss of 30 dB or more within 72 hours) requires prompt otolaryngology referral 2
- If an acoustic neuroma is suspected, a detailed patient history and a thorough otologic and neurotologic physical examination should be carried out, followed by a pure tone audiogram, speech reception threshold, speech discrimination testing, and acoustic reflex testing, and if necessary, a Gd-MRI scan 5