Sudden Sensorineural Hearing Loss (SSNHL) is a rapid onset of hearing loss, which can be quite frightening. This is caused by a problem in the hearing nerve.
The usual scenario is waking up to realize that one cannot hear things they could the day before, such as putting the phone up to the ear. This condition often comes with ringing in the ear (tinnitus) and sometimes dizziness (vertigo).
What makes this condition urgent is that prompt treatment can affect the outcome and the chance of hearing recovery.
Therefore, anyone experiencing sudden hearing loss should see a doctor, preferably an ENT, as soon as possible.
Here’s what an ENT doctor will do:
1. Take a thorough history and physical examination:
Your ENT doctor will assess if the hearing loss is a nerve problem (SSNHL) or a blockage of sound in getting to the nerve (conductive hearing loss). They will review your medical history, medications, and recent symptoms related to the hearing loss. They will then examine your ear to check for blockages like wax or other issues such as fluid behind the eardrum or a hole in the eardrum. Tuning fork tests may also be done to assess how well sound is perceived through air and bone (skull), helping to categorize the hearing loss into conductive (obstructive) or sensorineural (nerve problem) or both.
2. Conduct a hearing test (audiogram):
An audiogram measures how well you hear and identifies problems with the hearing nerve or sound transmission. This test provides precise measurements of hearing loss in decibels and matching frequencies. It helps the ENT doctor determine the appropriate treatment approach based on the degree of hearing loss.
3. Treatment
Since the immediate cause of SSNHL is often unknown, timely treatment is crucial initially.
Glucocorticosteroids are the main treatment for SSNHL. Studies have shown that high-dose steroids do not improve hearing more than lower doses but may increase side effects. Therefore, the preferred treatment is prednisone 60mg/day for 5 days followed by a taper. This treatment has the best chance of success if given within the first 2 weeks of onset.
Intratympanic Steroids: Injecting steroids directly into the middle ear can help increase their concentration in the affected area without significant systemic side effects. This approach is beneficial for individuals who cannot tolerate oral steroids or in cases of profound hearing loss where oral steroids are ineffective. The procedure can be performed in the clinic and is generally well tolerated.
4. Work Up:
MRI of the internal auditory canal (IAC) is the only imaging test with value in SSNHL cases, mainly to exclude rare conditions like acoustic neuroma or vestibular schwannoma. Other imaging tests like CT scans are not helpful, and blood work does not provide useful information in the initial evaluation.
What Causes SSNHL?
Most causes will fall into the broad categories of autoimmune, infectious (viral) and hypercoagulative states. But exact reasons as to why are largely unknown.
Hearing Recovery:
Around 30-50% of people with SSNHL may recover some hearing without treatment, while prompt steroid treatment may increase the recovery rate to 60-70%. However, it’s difficult to predict who will recover without treatment. Some factors like the severity of hearing loss and absence of comorbidities (other medical problems) may indicate a better prognosis. If hearing loss persists after 6 months, hearing aids like BAHA or cross hearing aids may be recommended.
Counseling:
Patients with profound one-sided SSNHL require counseling on sound localization and safety. Sound localization requires being able to hear well from both ears. A person with a loss of hearing in one-side will not be able to tell where a sound is coming from. This can be hazardous situations like crossing busy streets. So situations like these will require more care and assistance to maintain their safety.
Follow Up:
Since the cause of SSNHL may remain unknown for months (possibly even never), it is important that patients have regular appointments with an audiologist to monitor hearing tests, and with their primary physician to address any systemic issues and maintain overall health.
