• Hear the family!
• Hear, "I do"
• Hear your friends!
• Hear the smoke alarm!
• Hear the laughter
• Hear the birds sing!
• Hear the television!
• Hear nature!
• Hear your grandchildren on the phone!
• Hear your best friend!
• Hear the music and the crackling fire!
• Hear the piano!
• Hear the song!
• Hear the orchestra!
• Hear, the happiness
• Hear the play by play!

Sudden hearing loss (SHL) is a frightening symptom that often leads to an urgent visit to a physician or emergency room.  Because this is such a common symptom, both patients and physicians are not sufficiently frightened or worried by it.  Thus, evaluation and treatment are often delayed. New onset of ear blockage or fullness can be a symptom of potentially serious conditions and requires prompt evaluation.  Wax impaction, ear infection or the presence of a foreign object in the ear needs to be ruled out as a cause of hearing loss first. In the absence of abnormal ear canal or ear drum appearance, a SHL should be suspected.

Sudden sensorineural hearing loss (SNHL) affects 5 to 20 people in 100,000. The primary symptom of SHL is a full or blocked ear.  "Sudden" is defined as quick onset (occurring over a 72-hour period) of a sensation of hearing loss in one or both ears.  Dizziness can be present in 30% to 40% of cases of SSNHL. Sometimes roaring or ringing (tinnitus) is also present in the affected ear(s).  Sensorineural hearing loss indicates an abnormality of the cochlea, auditory nerve, or more central parts of auditory areas in the brain.

A cause for SSNHL is identified in only 10% to 15% of patients at the time of presentation.  Emergency intervention may be needed for rare, life-threatening conditions of which SSNHL is a part.  Causes of SSNHL must be identified and addressed during the course of management; the most pressing of these are vestibular schwannoma (acoustic neuroma), stroke, and malignancy.  In some cases, the cause may not be identified immediately and only after long- term follow-up evaluations.

Idiopathic sudden sensorineural hearing loss (ISSNHL) is defined as SSNHL with no identifiable cause despite adequate investigation.  Up to 90% of SSNHL, however, is idiopathic at the start and may be attributed to vascular, viral, or multiple causes.

A maximum of 32% to 65% of cases of SSNHL may recover on their own. Approximately one-third to two-thirds of patients with ISSNHL may recover some percentage of their hearing within 2 weeks.  Those who recover half of their hearing in the first 2 weeks have a better prognosis.  Patients with minimal change within the first 2 weeks are unlikely to show significant recovery.  Prognosis for recovery is dependent on a number of factors, including patient age, presence of vertigo at onset, degree of hearing loss, audiometric configuration, and time between onset of hearing loss and treatment.  Early recognition of ISSNHL is important.  Although there is a lack of evidence-based research, it is generally accepted that early intervention may increase recovery.  Treatment options vary and include medications, surgery, and observation alone.  The effectiveness of these treatments, however, is not known, considering that the cause is also commonly not known.

Prompt recognition and management of SSNHL may improve hearing recovery and patient quality of life.   Sudden hearing loss can be frightening and may result in embarrassment, frustration, anxiety, insecurity, loneliness, depression, and social isolation.  Individual or group counselling can be helpful in supporting patients with ISSNHL.  A “team approach” to the overall management of these patients is encouraged.

The Audiologist
The audiologist is the most qualified professional to provide accurate audiometric evaluations. Initial (identification) audiometry and follow-up testing are essential for proper management of patients with sudden hearing loss. Audiologic assessment and rehabilitation needs to be addressed as soon as the hearing loss is identified.

The audiologist will:

(1) work with your physician (and sometimes the emergency physician) to determine the origin and severity of the hearing loss for adequate treatment options;

(2) provide diagnostic behavioural hearing testing and/or Auditory Brainstem Response (ABR) testing to distinguish sensorineural hearing loss from conductive hearing loss in a patient presenting with SHL;

(3) counsel patients with incomplete recovery of hearing about the possible benefits of amplification and hearing-assistive technology and other supportive measures; and

(4) obtain follow-up audiometric evaluation within 6 months of diagnosis for patients with ISSNHL.

Audiometric Follow-up
Repeated hearing tests looking for progression can be used as an indicator of patients with higher likelihoods of a lesion or pathology.  Serial audiometry will not identify a cause directly and is not as effective as either MRI or ABR.  Growth of a lesion is possible without immediate progression of hearing loss.  However, given the nature of the vast majority of lesions and the relatively low incidence of pathology in patients with SHL, it is an option.  With shared decision making, serial audiometric follow-up may be appropriate for older patients in whom aggressive treatment is less likely, patients unable to tolerate an MRI, or patients with other concerns leading them to select a less definitive evaluation strategy with the understanding that it could lead to a delay in diagnosis.  A progressive loss of hearing of greater than 10 dB (HL) in 2 or more frequencies or a drop in word recognition scores of greater than 10% should trigger an evaluation with an ABR or MRI.

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Source:
Clinical Practice Guideline : Sudden Hearing Loss
Robert J. Stachler, Sujana S. Chandrasekhar, Sanford M. Archer, Richard M. Rosenfeld, Seth R. Schwartz, David M. Barrs, Steven R. Brown, Terry D. Fife, Peg Ford, Theodore G. Ganiats, Deena B. Hollingsworth, Christopher A. Lewandowski, Joseph J. Montano, James E. Saunders, Debara L. Tucci, Michael Valente, Barbara E. Warren, Kathleen L. Yaremchuk and Peter J. Robertson Otolaryngology -- Head and Neck Surgery 2012 146: S1 DOI: 10.1177/0194599812436449

The online version of this article can be found at:  http://oto.sagepub.com/content/146/3_suppl/S1