20-11-24
Acute hearing loss or sudden deafness is a rapid decrease in hearing. It is usually significant, and can even lead to complete deafness. This hearing loss can occur either immediately or with progressive deterioration over a period of up to three days. It usually affects one ear. It is considered an emergency and the patient should seek for medical advice as soon as possible.
The average age of patients is 50 years, but the condition may affect younger or older people. Both sexes are affected in equal proportion. Most often, patients complain of a feeling of fullness in one ear (aural fullness), and less often of hearing loss and/or tinnitus. Half of patients, in addition to hearing loss, also experience vertigo or unsteadiness.
The research showed that patients who also suffer from symptoms of vertigo usually have a worse prognosis in terms of restoring their hearing compared to patients who suffer only from hearing loss. Studies also showed that the greater the nerve damage, the more difficult it is to fully restore it. If the beginning of treatment is delayed for a period of more than 4 weeks, then the chances of improvement are minimal. On the contrary, an early start may guarantee an improvement rate of up to 80%, while in some of patients the restoration of hearing may even be complete.
The vast majority of cases of acute hearing loss are idiopathic, that is, of unknown etiology. Of course, over 50 different causes of sudden deafness have been reported, from simple causes, such as impacted ear wax to neurological diseases. The most popular theories are viral infection, circulatory system disorder and autoimmune causes. However, in all cases, important diseases must always be ruled out, such as 'retrocochlear' lesions (acoustic neuroma, i.e. a tumor of the auditory nerve), meningioma, cholesterol granuloma or multiple sclerosis.
The diagnosis is made with an audiogram, where it appears that the hearing loss is unilateral (affecting one ear) and sensorineural, i.e. it concerns the auditory nerve. All patients should undergo further imaging studies (magnetic resonance imaging with contrast) in order to rule out any tumors of the auditory nerve, infarctions or neurological diseases. CT scan or auditory brainstem response are used when patients cannot undergo an MRI, but they are fewer sensitive tests for diagnosis. Although imaging is very important, it can be done at a later date and should not be the reason for delaying the start of treatment.
The main issue with acute hearing loss is delayed diagnosis. Usually, patients visit their physician after 3 or more weeks, thinking that the blockage they feel in their ear is due to a simple cold or impacted ear wax. The usual medical treatment for sudden deafness is oral cortisone with gradual tapering. The dosage depends on the experience of the treating physician and the severity of the hearing loss. Significant progress in treatment has recently been made with the use of intratympanic dexamethazone injections into the affected ear, i.e. the administration of a cortisone solution through the tympanic membrane into the tympanic cavity. This method is simple, performed in the doctor's office, is relatively painless and without complications. It has been shown to significantly increase the success rate of treatment, especially when combined with the administration of cortisone by mouth. Also, intratympanic cortisone injection is indicated for the treatment of those patients who cannot take oral cortisone due to various diseases (diabetes mellitus, osteoporosis, history of gastrointestinal bleeding, etc.). Usually, the response to treatment is quick, but it is not excluded that it may occur later, after 2 or even 3 weeks. Of course, the faster the response to treatment, the better the prognosis. In addition to administration of cortisone, other treatments for sudden deafness have been proposed. These include antiviral and vasodilator drugs or the use of hyperbaric oxygen. However, none of the above treatments have been shown to be more effective than cortisone.
After completing treatment, patients should continue to undergo audiological monitoring for 1 year. Initially during the 2nd month, after the 6th and finally at the 12th month. Monitoring not only helps to record the progression of sudden deafness, but also to detect any recurrence of the disease or even the onset of hearing loss in the other healthy ear.
Patients with unilateral hearing loss are given the following advice:
- Avoid exposure to very loud sounds, in order to avoid auditory trauma to the healthy ear.
- Immediately visit an otolaryngologist in case of suspected hearing loss in the healthy ear as well.
- Avoid diving and avoid traveling by plane when they are congested.