Sudden deafness – Early Treatment

In our last article, I wrote about sudden hearing loss, its causes and why it happens. This catastrophic condition is regarded as one of the few ear emergencies where early treatment within the first two weeks has been shown to significantly improve the outcome and potential recovery of the hearing loss.

Often the cause of the hearing loss is not obvious. The hearing suddenly drops and may be associated with a ringing noise in the ear and /or disequilibrium. This depends on whether the effect is limited to the hearing organ only or also affect our balance organ function too as they share the same inner ear fluids. The screening battery tests may not show any obvious diagnosis but treatment for this condition should not be delayed. The current medical thinking is that there is an insult to the inner ear which could be a blocked micro-vessel that starves the cochlear of its blood supply and oxygen or perhaps it is an inflammation of the cochlea by possibly a virus. In either cases, the ear often looks normal and imaging is usually unremarkable. The dilemma that physicians face is do we wait for the condition to declare itself to get the right diagnosis, or do we act with a “shotgun” treatment of different drugs to prevent further ear damage and set the course for early recovery? The answer is we should act “blindly”. We have to remember that we are unable to cut out the inner ear for test sampling as doing so is a major operation and the operation would certainly kill the ear and its hearing.

What constitutes this shotgun rescue treatment? It is thought that perhaps a virus might be the cause so a week’s course of high dose antiviral medication is given. Inflammation from a viral attack, diabetes mellitus event or deoxygenation of the nerves, is treated with a two week course of high dose steroids which is frontloaded at a high dose, slowly tailoring downwards over two weeks to maintain a treatment effect without causing a sudden steroid withdrawal that could affect the body. This steroid treatment has been studied extensively and research has shown that if it is given timely with in two-week golden window from the first reported ate of the sudden hearting loss symptoms, it is statistically beneficial in improving partially or totally the loss hearing. It is this research that effects sudden hearing loss as an emergency, to be recognized early and confirmed so that treatment can be provided. Such a large dose of oral steroids can cause complications. One of them is stomach ulcers so this course is accompanied with a two-week course of proton pump inhibitors that reduces gastric acid production.

Some patients are unable to take such high dose steroids e.g. diabetics, patients with viral hepatitis or known gastric ulcer disease. With these patients, research has shown that liquid steroids can be injected into the middle ear cavity every 2-3 days for 2 weeks to permit the steroid drug to diffuse directly into the inner ear where there is “supposed” to be inflammation and failing nerve function.  This prevents the steroid drug to be in the blood system where it can exert its side effects on the rest of the body organs even though its target is only the ear. Attractive as this may sound, it is more invasive and less economical for the patient, as every two days, the eardrum needs to be pierce by a needle to deliver the drugs on site. The decision is a risk-benefit exercise to be discussed with the patient.

Another reason maybe that the blood vessels are blocked and insufficient blood and oxygen are getting to the delicate hearing cells. Vasodilators are prescribed to dilate the small blood vessels to the brain thereby improving brain blood flow. With any nerve insult, it takes time and ingredients for a nerve to recover so high-dose Vitamin B Complex, the building blocks of nerve function, is also prescribed.

Any improvement in the ear’s hearing would usually be known within the first 6 weeks. Thereafter recovery rates diminish. An MRI scan is naturally important diagnostically to exclude a brain/ nerfve tumour. If seen, treatment may include simply observing with annual MRI scanning (as acoustic neuroma can grow so slowly that no treatment may ever be required), or radiotherapy or neurosurgery to remove a tumor. Again the choice of treatment is an exercise of risk versus benefit for such major operations. If diabetes mellitus is diagnosed, then anti-diabetic medication would be required.

One would think that diagnosing a condition and providing a “shotgun” or highly specific targeted treatment for a known diagnosis will solve and rescue the hearing. In this regard, you would be wrong! In spite of the best efforts and timely care, some patients will continue to have hearing loss on one side. For these patients, the treatment is symptomatic. That is to say that if they are socially and professionally bothered by their one sided hearing loss, normal hearing aids or a surgically implanted hearing system for single sided deafness may help. If the ear generates a disturbing ringing ie tinnitus, medical treatment with tinnitus retraining therapy (TRT) may help.

So losing one’s hearing suddenly should be taken seriously. Early medical attention to confirm single sided sudden deafness and the provision of early treatment within two weeks of the episode, may just arrest and improve the deafness.

The Chinese version of this article was published in Hong Kong Economic Journal on 18 Jul 2016 and 1 Aug 2016