Sudden Hearing Loss (SHL) is an alarming medical emergency that is often a medical mystery. It’s devastating to patients and demoralizing for physicians.
For decades ENT specialists and researchers have tried to untangle the problem of sudden sensorineural hearing loss (Sudden SNHL) with limited success.
The cause of sudden hearing loss is frequently unknown and the treatment often does not work. The incidence of such a loss has been estimated to be about 4,000 new cases per year in the United States, mainly between people 50 and 60 years of age. (1-2-3)
Consider the situation of Maria, a 54 year old female in good health until she woke up one morning and experienced a sudden loss of hearing. After two days she visited her ENT specialist who asked her:
“Is just one ear involved?” Yes, the right ear.
“Have you been sick or anyone in the family been sick? Cold, fever…?” No.
“Have you experienced any physical or emotional trauma?” No
“Do you take any medications? Have you had any ear surgery?” No. No.
“Do you have any other symptoms besides hearing loss?” — Just some ringing in my ear and my ear feels full.
And the questions continued until Maria finally interrupted, “I feel well except for the fact that I cannot hear out of my right ear. No pain, no ear drainage, no fever, no dizziness. Can you tell me what caused the loss of my hearing and whether I can get my hearing back?”
He said, “Sound goes through the ear canal causing the eardrum to vibrate. It crosses the middle ear and enters the inner ear. Most likely, a virus damaged the delicate structures of your inner ear. One can’t be certain of how this happened and we need to rule out other causes of your hearing loss.”
What causes sudden hearing loss?
- Unknown
- Physical: Head trauma, temporal bone fracture, ototoxicity (medicines that poisoned the ear)
- Infection: Viral or Bacterial – e.g. Mumps, HIV, Shingles, Lyme Disease, Syphilis
- Tumors: Acoustic neuroma – tumor attacks the hearing nerve
- Neurologic: Multiple Sclerosis
- Vascular: Blockage of the vessels feeding the inner ear, Stroke, Sickle Cell Anemia
- Metabolic: Diabetes, Hypothyroidism
- Autoimmune:
The above highlights the causes of sudden hearing loss. In spite of a thorough evaluation by your physician, 85-90% of the time the underlying cause of SHL is unknown or uncertain. One of the first steps in evaluating this problem is to perform a hearing test.
On Maria’s first visit in the office, she underwent a routine hearing test to diagnose the nature and extent of the hearing ‘nerve’ loss. If it’s a moderate hearing loss, there’s a better likelihood of reversing the problem in contrast to a very severe loss.
Although rarely encountered, a tumor called acoustic neuroma is of major concern. Sudden hearing loss is the first symptom told to doctors in about one out of ten patients with an acoustic neuroma. To help rule out this tumor, the physician advised Maria to undergo an image study called a MRI. Her doctor discussed with Maria key points or takeaways about her problem:
Takeaways: ‘Sudden’ Hearing Loss
- Most of the time the cause is unknown
- Viruses are thought to cause the majority of these cases
- It can be the first sign of a serious underlying problem
- Spontaneous recovery of hearing has been reported
- Corticosteroids are the medications most commonly used to treat the problem
He continued the discussion with her: “The earlier the diagnosis, the earlier the treatment is initiated, the better are the chances of restoring a patient’s hearing. The prospect of bringing back one’s hearing drops precipitously if a patient delays by two or more weeks in seeking medical attention. A profound loss of hearing and/or vertigo reduces the likelihood of improving one’s hearing.”
‘More’ Takeaways — He concluded his conversation with Maria by noting:
- A known cause of Sudden SNHL has been reported in only 10-15% of the cases
- Prognosis for recovery is based on several factors as noted above
- You and other patients may experience incomplete or no recovery of hearing
- Audiologists should be included in a team approach in treating SHL
- Patients can benefit from counseling regarding amplification and supportive measures
- Follow-up appointments is advised to monitor one’s hearing status
Maria’s MRI was negative for any evidence of a tumor. She was treated with corticosteroids and her hearing was restored to almost where it was before the emergency. She was asked to make a follow-up appointment in the months ahead to evaluate her hearing status.
The challenge for physicians is that the cause of Sudden SNHL is often elusive and treatment is not ideal. Unquestionably, if you experience this problem, the sooner you get it diagnosed and treated the better the likelihood of reversing you hearing loss.
References:
- Sensorineural hearing loss indicates an abnormality of the inner ear or hearing nerve
- Sudden Sensorineural hearing loss (SSNHL) is a hearing loss that develops in less than three days
- Robert J., Stacher, MD et al; Sudden Hearing Loss; Clinical Practical Guideline; January 3, 2012
This article is intended solely as a learning experience. Please consult your physician for diagnostic and treatment options.