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AUDIOLOGY SERVICES
• Hearing Conservation & Accessories
• Tinnitus
• Earwax
• Sudden Hearing Loss
Other Related Links
• Hearing Impairment Calculator
• Dizziness and Balance Website
Videos On ENT Topics
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Sudden Hearing Loss Last Modified 6/16/2009 • |
If you like this article, please comment below!
Introduction
This webpage describes an alarming situation where your hearing suddenly decreases inexplicably. One day your hearing fine, and the next, it suddenly has gotten worse... and doesn't seem to be getting better.
This situation is known as Sudden Sensorineural Hearing Loss and is considered an EMERGENCY for which you should see an ENT as soon as possible!!!
Why?
Because there is a window of opportunity where treatment can be administered which increases the chance that your hearing can be restored back to normal. Beyond that window of opportunity, NOTHING can be done other than time and hope. This time period of ideal treatment is within 14 days of hearing loss. After about 30 days, treatment has not been found to significantly improve hearing.
Why?
It is not precisely known why this occurs, but there are several theories. The most common theory is a herpes viral infection of the hearing nerve (cranial nerve number 8). This situation is akin to the loss of smell when the smell nerve is infected during a cold or Bell's Palsy leading to facial paralysis.
When a nerve becomes infected, it tends to swell. Unfortunately, the hearing nerve goes through a bony canal called the Internal Auditory Canal (arrow in picture) which is a passageway for the nerve to go through the skull to get to the ear. This bony passage does not enlarge to accomodate the nerve as it swells leading to the nerve becoming "strangulated" and therefore becoming non-functional leading to hearing loss.
 Arrow pointing to the hole where the hearing nerve passes thru to get to the ear. |
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To use an analogy, if your foot is the nerve and your shoe is the bony canal, imagine what would happen to your foot if it starts to swell, but you keep wearing the same size shoe. Ouch!
In this swollen and entrapped state, the nerve only has so much time before it potentially starts to die. As such, the only medication found to be helpful is steroids... lots of it and at high doses. Just as steroids decreases swelling of an inflamed arthritic knee, it seems to decrease sweling of the hearing nerve allowing it to recover more quickly before permanent damage settles in.
That's why the window of opportunity. The nerve only has so much time of being strangulated inside its bony canal before it starts to die. Treatment High doses of prednisone is the treatment of choice, typically tapered over a 3 week course (start at 20mg 3X per day for 5 days than taper the dose slowly every 3 days). Depending on timing, intra-tympanic steroid injection is also offered (dexamethasone 24mg/cc). Intra-typmpanic steroid injection is performed by inserting a needle through the eardrum and injecting about 1.5cc of highly concentrated steroids directly into the ear. The patient is than instructed to keep the affected ear up for 30 minutes without swallowing, yawning, or popping the ear. After injection, the patient is allowed to immediately resume normal activities. Anti-viral antibiotics such as valtrex (valacyclovir) or acyclovir has NOT been shown to be helpful and is no longer recommended. SO, to summarize, the following treatment course is expected ideally: |
- Visit #1 (ideally within 5-10 days of hearing loss)
- Audiogram to document the hearing loss
- Examination of the ear to ensure no other pathology that may cause hearing loss (ie, earwax, fluid in the middle ear, eustachian tube dysfunction)
- Prescription of prednisone burst and taper
- Option given to patient for Intra-Tympanic Steroid Injection (only option if patient is diabetic)
- Visit #2 (2-3 weeks later)
- Repeat audiogram to see if there is any improvement. If no or minimal improvement, recommend Intra-Tympanic Steroid Injection to be done ASAP.
- If hearing almost back to normal, no further intervention recommended.
- Visit #3 (2-3 weeks later)
- Repeat audiogram. If significant improvement, no further intervention recommended.
- If still no or minimal improvement, recommend MRI scan of the head. Why? To make sure there is no tumor that is causing the hearing loss.
- Visit #4 (after MRI)
- Review of MRI results. Only in less than 10% of cases does it actually show anything abnormal
- At this point, assuming normal MRI, no further intervention can be performed.
- Return visit in 3-6 months is recommended.
- If no hearing improvement after 1 year, the hearing loss is considered permanent.
If you have suffered a sudden hearing loss, call for an appointment ASAP!!!
Any information provided on this Web site should not be considered medical advice or a substitute for a consultation with a physician. If you have a medical problem, contact your local physician for diagnosis and treatment. Advertisements present are clearly labelled and in no way support the website or influence the contents.
