Sudden Hearing Loss
Sudden sensorineural hearing loss is defined by a sudden loss of hearing within a 72 hour period, resulting in greater than a 30 dB drop in hearing for at least three consecutive test frequencies. Sudden hearing loss is a rare condition that affects between five-20 people per 100,000 annually according to the American Academy of Otolaryngology.
Sudden Hearing Loss Symptoms
Sudden hearing loss most typically occurs in one ear and varies in severity from patient to patient. For some, the onset of the sudden hearing loss is reported to have been noticed instantaneously, often in the morning. Others report the onset of hearing loss occurred over a period of hours or often days.
Tinnitus (ringing in the ears) typically accompanies sudden hearing loss. Vertigo (dizziness) has also been reported to be present in roughly 40% of sudden hearing loss cases.
Sudden Hearing Loss Causes
Although the exact cause of sudden hearing loss is unknown for most people, there are many potential causes of sudden hearing loss, including: viral infections, neurologic issues, metabolic and immunologic disease, toxicity, trauma to the inner ear, circulatory problems of the inner ear such as meniere’s disease, idiopathic (unknown) and others.
Sudden Hearing Loss Diagnosis and Treatment
People who experience a sudden loss of hearing should seek medical attention immediately from a qualified health professional.
The diagnosis of sudden hearing loss begins with having a full hearing evaluation to assess the amount of hearing loss that has occurred. Based on the audiogram and a full evaluation by a physician, the sudden hearing loss is diagnosed.
The physician may suspect possible causes based on case history and the physical evaluation. Blood work and imaging tests are also often recommended to rule out possible medical causes.
Treatment for sudden hearing loss has been controversial and inconsistent among physicians due to the fact the cause of the sudden hearing loss is often unknown. According to research presented at the American Academy of Otolaryngology – Head & Neck Surgery Foundation meeting in 2008, there are no official guidelines or position statements regarding the evaluation and treatment of sudden sensorineural hearing loss (Friedland and Shemirani, 2008).
Currently the most common forms of treatment include oral-steroids and anti-viral medication prescribed typically by either a family physician or an otolaryngologist (ENT).
Between 32%–65% of patients who experience sudden sensorineural hearing loss will recover. Recovery is more likely to occur if the time between onset of symptoms and treatment is a short interval, vertigo is absent, a mild to moderate hearing loss, a mid-frequency/upsloping audiometric pattern, and the patient's age is of 15–40 years old. "Because the chance of recovery is greater if the hearing loss is treated early—and because a significant percentage of patients do not recover their hearing—evaluation of treatment options is critical" (Montano, J., Diercks, G., & Selsnick, S.,2008).
Friedlan, D & Shemirani, N. (2008, September). Practical Guidelines for Sudden Sensorineural Hearing Loss. Paper presented at the meeting of the American Academy of Otolaryngology Head & Neck Surgery Foundation (AAO-HNSF) Annual Meeting, Chicago, IL.
Montano, J., Diercks, G., & Selsnick, S. (2008, Nov. 4). Sudden sensorineural hearing loss: Otolaryngologic and audiologic options. The ASHA Leader, 13(15), 14-17.