Sudden Hearing Loss

Publication Date: August 1, 2019

Key Points

Key Points

  • Sudden hearing loss (SHL) is a frightening symptom that often prompts an urgent or emergent visit to a clinician. This guideline update focuses on sudden sensorineural hearing loss (SSNHL), the majority of which is idiopathic and which, if not recognized and managed promptly, may result in persistent hearing loss and tinnitus and reduced patient quality of life (QOL). SSNHL affects 5–27 per 100,000 people annually, with about 66,000 new cases per year in the United States.
  • SHL is defined as a rapid-onset subjective sensation of hearing impairment in one or both ears. The hearing loss in SHL may be conductive (CHL), sensorineural (SNHL), or mixed (MHL), defined as both CHL and SNHL occurring in the same ear. CHL and the conductive component of MHL may be due to an abnormality in the ear canal, tympanic membrane (‘ear drum’), or middle ear.
    • Physical examination will help determine if there is obstructing cerumen or a foreign body in the ear canal, if there is a perforation of the tympanic membrane, or if there is fluid in the middle ear.
    • Tuning fork testing will enable the initial treating clinician to distinguish CHL from SNHL, so that the SSNHL evaluation and management (E&M) pathway can be triggered appropriately.
  • SSNHL is a subset of SHL that is: a) sensorineural in nature, b) occurs within a 72-hour window, and c) meets certain audiometric criteria.
    • SNHL is sometimes referred to colloquially as ‘nerve hearing loss’ and indicates abnormal functioning of the cochlea, auditory nerve, or higher aspects of central auditory perception or processing.
    • The most frequently used audiometric criterion for SSNHL is a decrease in hearing of greater than or equal to 30 decibels affecting at least 3 consecutive frequencies. Because premorbid audiometry is generally unavailable, hearing loss is often defined in relation to the opposite ear’s thresholds.
    • The CPG update group acknowledges that in both clinical practice and in research studies, less stringent criteria for SSNHL are employed.
    • SSNHL is often but not always accompanied by tinnitus and/or vertigo. The tinnitus may persist and may be disturbing to the patient.
  • Idiopathic sudden sensorineural hearing loss (ISSNHL) is defined as SSNHL with no identifiable cause despite adequate investigation. This is the situation in 90% of patients with SSNHL and is the primary focus of this CPG update. The use of SSNHL in this document refers to ISSNHL, after the appropriate workup has been done as denoted in KAS 1 and KAS 2.

Table 1. Definitions of Common Terminology

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Sudden Hearing Loss (SHL) A rapid-onset subjective sensation of hearing impairment in one or both ears.
Sensorineural Hearing Loss (SNHL) Hearing loss resulting from abnormal function of the cochlea, auditory nerve, or higher aspects of central auditory perception or processing.
Conductive Hearing Loss (CHL) Hearing loss resulting from a problem conducting sound waves anywhere along the route through the outer ear, tympanic membrane, or middle ear.
Mixed Hearing Loss (MHL) Hearing loss resulting from both SNHL and CHL occurring in the same ear.
Sudden Sensorineural Hearing Loss (SSNHL) A subset of SHL that is a) sensorineural in nature, b) occurs within a 72-hour window, and c) consists of a decrease in hearing of greater than or equal to 30 decibels affecting at least 3 consecutive frequencies.
Idiopathic Sudden Sensorineural Hearing Loss (ISSNHL) SSNHL with no identifiable cause despite adequate investigation.
Salvage Therapy Any therapy offered after 2 weeks from symptom onset (even if initial therapy was observation).

Summary of Key Action Statements (KAS)

Exclusion of CHL

Clinicians should distinguish SNHL from CHL when a patient first presents with sudden hearing loss. (S)
6889

Modifying factors

Clinicians should assess patients with presumptive SSNHL through history and physical examination for bilateral sudden hearing loss, recurrent episodes of sudden hearing loss, and/or focal neurologic findings. (R)
6889

Computed tomography (CT)

Clinicians should NOT order routine CT of the head in the initial evaluation of a patient with presumptive SSNHL. (S)
6889

Audiometric confirmation of SSNHL

In patients with sudden hearing loss clinicians should obtain, or refer to a clinician who can obtain, audiometry as soon as possible (within 14 days of symptom onset) to confirm the diagnosis of SSNHL. (R)
6889

Laboratory testing

Clinicians should NOT obtain routine laboratory tests in patients with SSNHL. (S)
6889

Retrocochlear pathology

Clinicians should evaluate patients with SSNHL for retrocochlear pathology by obtaining an MRI or Auditory Brainstem Response (ABR). (R)
6889

Patient education

Clinicians should educate patients with SSNHL about the natural history of the condition, the benefits and risks of medical interventions, and the limitations of existing evidence regarding efficacy. (S)
6889

Initial corticosteroids

Clinicians may offer corticosteroids as initial therapy to patients with SSNHL within 2 weeks of symptom onset. (O)
6889

Initial therapy with hyperbaric oxygen therapy (HBOT)

Clinicians may offer, or refer to a clinician who can offer, HBOT combined with steroid therapy within two weeks of onset of SSNHL. (O)
6889

Salvage therapy with HBOT

Clinicians may offer, or refer to a clinician who can offer, HBOT combined with steroid therapy as salvage within one month of onset of SSNHL. (O)
6889

Intratympanic steroids for salvage therapy

Clinicians should offer, or refer to a clinician who can offer, intratympanic (IT) steroid therapy when patients have incomplete recovery from SSNHL 2–6 weeks after onset of symptoms. (R)
6889

Other pharmacologic therapy

Clinicians should NOT routinely prescribe antivirals, thrombolytics, vasodilators, or vasoactive substances to patients with SSNHL. (S)
6889

Outcomes assessment

Clinicians should obtain follow-up audiometric evaluation for patients with SSNHL at the conclusion of treatment and within six months of completion of treatment. (R)
6889

Rehabilitation

Clinicians should counsel patients with SSNHL who have residual hearing loss and/or tinnitus about the possible benefits of audiological rehabilitation and other supportive measures. (R)
6889

Diagnosis

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Treatment

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Patient Information

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