What is an Intratympanic steroid injection?
An intratympanic steroid injection is an operation in which a small amount of steroid is injected directly into the middle ear. It is used in patients suffering with severe vertigo, such as caused by Meniere’s disease or a sudden vestibular failure which has not responded to vestibular sedative medications or rehabilitation exercises.
Why might I need an intratympanic steroid injection?
The commonest reasons for having an intratympanic steroid injection are below:
Menière’s disease is a condition of the inner ear which results in episodes of severe vertigo that can last up to several hours at a time. They are usually associated with an increase in tinnitus and hearing loss in the affected ear, as well as nausea and vomiting on occasions. The hearing and tinnitus usually recover once the vertigo has settled, but the hearing may gradually deteriorate with time. It is thought to be due to an increase in the pressure or fluid within the inner ear known as endolymphatic hydrops. Treatment of Menière’s disease can involve medications and, on occasions, surgery if the medicines prove ineffective.
Sudden vestibular failure
On occasions, a patient may suffer with a sudden loss of hearing which may be associated with sudden vertigo. This can last for many days. The cause is not known although many specialists believe that it is due to an autoimmune condition, which means that there is a problem with the patient’s immune system which attacks part of his or her own inner ear. This causes inflammation and damage of the delicate inner ear structures. As a result, steroid injections became popular owing to the ability of steroid medications to reduce inflammation and congestion.
What is involved in an intratympanic steroid injection?
Your specialist will have taken a detailed history and carried out a thorough examination, and on the basis of this will have decided that you are likely to benefit from an intratympanic steroid injection. The assessment will have included a full hearing test. This is important as it gives your specialist a clue as to which ear is affected, and indicates the amount of useful hearing left.
The procedure itself is straightforward and can be carried out either under local or general anaesthetic. Even if it is done under a LA, your surgeon may want to perform the procedure in the operating room. The ear is numbed with a combination of local anaesthetic creams placed into the ear canal, and LA injections. The steroid medication is then gently injected into the middle ear through a fine needle. This can cause a feeling of fullness within the ear and a reduction of hearing whilst the ear fills with the steroid medication, but this is usually short-lived. Once the procedure is over, the operating table is usually tilted in a head-down position as this encourages the steroid medication to remain within the middle ear and not to leak out too soon.
What to expect after an intratympanic steroid injection
You will be taken back to the recovery area and subsequently the ward where basic observations will be taken. You will be allowed to eat and drink something, and when you are feeling better you can go home. It is not unusual to experience feelings of ear fullness, tinnitus or even dizziness after the procedure, although these should settle quickly. It is not particularly painful.
How many injections might I need?
It is quite common for several injections to be required. This is because the effect of steroids is cumulative, in other words their maximum benefit is seen after multiple treatments. Usually a course of three to four injections is administered, separated a month apart, although this may vary according to your own particular condition.
Can anything go wrong following an intratympanic steroid injection?
The procedure is generally extremely safe. Steroids do not have any significant side effects when used in such small doses to a specific local area. One possible risk is of a perforation of the ear drum after repeated injections, although this is not usually a major problem as the hole is usually tiny and easily repaired. Likewise, some scarring of the eardrum may occur but this rarely causes any symptoms. It is possible that the vertigo may not get any better. There is a very remote chance that it could get worse if the steroid is injected into the wrong part of the ear, although this is highly unlikely to happen.
In some instances, your specialist may recommend that you undergo an injection of gentamicin into the middle ear instead of a steroid. Gentamicin is an antibiotic which is known to have mildly toxic effects on both the balance and hearing parts of the ear, although its toxic effects on the vestibular system are very much more potent than on the hearing. Despite this, there is an increased chance of a hearing loss occurring with intratympanic gentamicin injections. For this reason, they are usually reserved for patients with a pre-existing severe hearing loss at the time the vertigo is diagnosed.