Sudden Sensorineural Hearing Loss (SSHL), or sudden deafness, is a rapid loss of hearing. SSHL can happen to a person all at once or over a period of up to 3 days. It should be considered a medical emergency. A person who experiences SSHL should visit a doctor immediately. Approximately 4,000 new cases of SSHL occur each year in the United States. It can occur at any age but most commonly affects people between the ages of 30 and 60.
A doctor can determine whether a person has experienced SSHL by conducting a normal hearing test. If a loss of at least 30 decibels in three connected frequencies is discovered, it is diagnosed as SSHL. The problem is unilateral ( affecting only one ear) in 9 out of 10 people who experience SSHL. Many people notice it when they wake up in the morning. Others first notice it when they try to use the deafened ear, such as when they make a phone call. Still others notice a loud, alarming "pop" just before their hearing disappears. People with SSHL often experience dizziness, ear fullness, or a ringing in their ears (tinnitus. Any or all of these symptoms may occur together. The presence of vertigo is thought to be a poor prognostic factor.
Some patients recover completely without medical intervention, and this is called a spontaneous recovery.
Sudden Sensorineural Hearing Loss (SSHL), or sudden deafness, is a rapid loss of hearing. SSHL can happen to a person all at once or over a period of up to 3 days. It should be considered a medical emergency. A person who experiences SSHL should visit a doctor immediately.
Causes and Diagnosis
Though there are more than 100 possible causes of sudden deafness, it is rare for a specific cause to be precisely identified. Only 10 to 15 percent of patients with SSHL are found to have a cause for their loss. The remaining are called idiopathic, where no cause can be found. Normally, diagnosis is based on the patient's medical history. Possible causes include the following:
The evaluation begins with a careful health history and physical examination. A complete diagnostic audiometric evaluation is also performed to evaluate the type and severity of the loss. Patients who lose hearing suddenly require an MRI scan with gadolinium injection as studies show that 4-10% of these patients will have an acoustic neuroma tumor (link). Lab work is also performed to exclude metabolic causes. Angiography, balance testing and other electrophysiologic tests are sometimes indicated.
People who experience SSHL should see a physician immediately. Doctors believe that early treatment increases the chances for recovery. Several treatments are used for SSHL, but researchers are not yet certain which is the best for any one cause. The most common therapy for SSHL, especially in cases with an unknown cause, is treatment with steroids. Steroids are used to treat many different disorders and usually work to reduce inflammation, decrease swelling, and help the body fight illness. Another common method that may help some patients is a diet low in salt. Researchers believe that this method aids people with SSHL who also have Ménière's disease, a hearing and balance disorder. A water pill is also frequently prescribed to reduce possible swelling in the inner ear.
Intratympanic steroid injection can also be considered if the hearing is very poor. This involves injecting steroid through the ear drum and into the middle ear where it is absorbed through the round window and in to the cochlea. Animal research has shown this treatment can increase the concentration of steroids into the cochlea higher than can oral steroids alone.
If hearing does not completely recover, and the ear is aidable (has good word recognition) then a hearing aid can be considered if the patient feels impaired by their hearing loss. If the ear has such poor word recognition that a hearing aid is not successfully worn (unaidable), then a bone anchored hearing aid insertion can be considered.