Guidelines Summary
AAO-HNSF guidelines
The American Academy of Otolaryngology–Head and Neck Surgery Foundation (AAO-HNSF) issued clinical practice guidelines for sudden hearing loss on August 1, 2019. [29]
Presentation
Sensorineural hearing loss (SNHL) should be differentiated from conductive hearing loss (CHL) in patients who present with sudden hearing loss (SHL).
Patients with suspected sudden sensorineural hearing loss (SSNHL) should undergo history and physical examination for bilateral SHL, recurrent SHL, and/or focal neurologic findings.
Workup
Patients with presumptive SSNHL should not undergo routine head CT scanning during the initial evaluation.
Audiometry should be performed as soon as possible to confirm a diagnosis of SSNHL, within 14 days of symptom onset.
Routine laboratory tests should not be performed in the workup of SSNHL.
Patients with SSNHL should undergo MRI or auditory brainstem response (ABR) to evaluate for retrocochlear pathology.
Patient education
Patients with SSNHL should be educated regarding the condition’s natural history and the potential benefits and risks of treatment.
Treatment
Corticosteroids may be offered to patients with SSNHL as initial therapy within 2 weeks of onset.
Hyperbaric oxygen therapy (HBOT), in combination with steroid therapy, may be offered to patients with SSNHL within 2 weeks of onset.
HBOT, in combination with steroid therapy, may be offered as salvage therapy to patients with SSNHL within 1 month of onset.
Patients with an incomplete recovery from SSNHL should be offered intratympanic steroid therapy 2-6 weeks after symptom onset.
Antiviral therapy, thrombolytic therapy, vasodilator therapy, and vasoactive substances should not be routinely prescribed to patients with SSNHL.
Outcome assessment
At the conclusion of treatment and then 6 months thereafter, follow-up audiometric evaluation should be performed in patients with SSNHL.
Rehabilitation
Patients with SSNHL who have residual hearing loss and/or tinnitus should be educated about the potential benefits of audiologic rehabilitation and other supportive measures.
ACMG guidelines
The 2014 American College of Medical Genetics and Genomics (ACMG) guidelines for clinical evaluation and etiologic diagnosis of hearing loss are summarized below. Medical histories may be helpful in differentiating between acquired versus inherited causes of hearing loss. According to the ACMG, histories aimed at assessing hearing loss should include the following [30] :
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Prenatal history of maternal infections (eg, cytomegalovirus, rubella, syphilis) or drug exposures (eg, thalidomide, retinoic acid)
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Neonatal history, including premature birth, low birth weight, birth hypoxia, hyperbilirubinemia, sepsis, and exposure to ototoxic medications
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Postnatal history, including viral illnesses, bacterial meningitis, head trauma, noise exposure, and exposure to ototoxic medications
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Audiometric assessment of the hearing loss; age of onset; progressive, nonprogressive, or fluctuating nature of the hearing loss; laterality, symmetry, severity, and configuration of the hearing loss; and the presence or absence of vestibular dysfunction or auditory neuropathy
The family medical history should concentrate on the following [30] :
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First- and second-degree relatives with hearing loss or with features commonly associated with hearing loss (such as pigmentary, branchial, or renal anomalies) or sudden cardiac death
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A pattern of inheritance
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Ethnicity and country of origin
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A common origin from ethnically or geographically isolated areas
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Consanguinity
The physical examination should focus on the following [30] :
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Unusual facial appearance, with attention to asymmetry
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Pigmentary anomalies
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Neck, skin, facial, or ear anomalies
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Neurologic abnormalities
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Balance disturbances
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Skeletal abnormalities
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Other unusual physical findings
For individuals with physical findings and histories that do not suggest a known syndrome or environmental cause of hearing loss, a tiered diagnostic approach is needed that includes the following [30] :
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Genetic counseling and, after informed consent, genetic testing
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Single-gene testing in cases in which a specific etiology is suspected from the history and physical findings
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In the absence of any specific clinical indications and for apparent autosomal recessive inheritance, testing for DFNB1-related hearing loss (due to mutations in GJB2 and adjacent deletions in GJB6)
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If initial genetic testing is negative, consider genetic testing using gene panel tests and next-generation sequencing (NGS) technologies; however, the clinician must be aware of the genes included in the test (panel) and the performance characteristics of the platform chosen, including coverage, analytic sensitivity, and what types of mutations will be detected
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Test results should be communicated through genetic counseling regardless of whether they are positive, negative, or inconclusive
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If genetic testing reveals mutation(s) in a hearing loss–related gene, mutation-specific genetic counseling should be provided, followed by medical evaluations and referral to a multidisciplinary care center, when available
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Consider temporal bone imaging by CT scanning or MRI, particularly if the diagnosis remains unclear, if cochlear implantation is being considered, if auditory neuropathy is noted, in cases of progressive hearing loss, or if other clinical concerns exist
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If genetic testing fails to identify an etiology for a patient's hearing loss, the possibility of a genetic or acquired etiology remains and further genetic testing may be pursued in a research setting; periodic follow-up care every 3 years with a geneticist may be appropriate to identify syndromic forms of hearing loss that may appear as individuals age and to discuss new genetic tests that may have become available
