Ear injection to stop that dizzy feeling
STEROID jabs in the ear could help reduce severe dizziness, but without the side- effects of existing treatments. The jabs, tested over two years by scientists at Imperial College London, cut the number of dizzy spells by about 90 per cent.
Most of us experience occasional dizzy spells. These can be due to anything from ear infections, migraines or anxiety to hypotension — low blood pressure that can make you feel dizzy, especially when you stand up. For some, it can be a chronic condition.
About 30,000 people in the UK have Meniere’s disease, that causes severe and repeated dizziness lasting up to 24 hours, often accompanied by nausea and vomiting.
Current treatment involves injecting a potent antibiotic drug, called gentamicin, into the eardrum. Although it reduces attacks of dizziness by 90 per cent, it causes permanent hearing loss in one in five patients because the drug destroys delicate hair cells deep inside the ear.
Dizziness is typically caused by a problem in the inner ear, which is crucial to our sense of balance. The inner ear contains a complex set of tubes ( the labyrinth) that carry a fluid (endolymph). The movement of this fluid is detected by hair cells and the information is relayed to the brain, telling it that the body is moving. Changes in pressure in this fluid can trigger dizziness.
This may be the result of an inner ear infection, for example — it causes inflammation in the labyrinth, which increases fluid pressure and disrupts the balance signals sent to the brain.
With Meniere’s disease the theory is that an imbalance of salt in the body leads to a build- up of salt- rich fluid in the inner ear and raises pressure.
As pressure inside the labyrinth rises, some of the tubes eventually rupture, causing the sudden onset of vertigo and dizziness as the balance mechanism is disrupted.
These tubes slowly repair themselves — which is why dizziness is prolonged — but repeat episodes can leave scarring, which can trigger hearing loss.
Patients are sometimes advised to reduce dietary salt to see if it wards off attacks.
However, if the dizzy spells don’t resolve, a single injection of gentamicin is given in the affected ear (which is determined with a caloric test — where nerves in the ear are monitored after putting warm, then cool water in the ear canal).
While gentamicin is known to destroy the hair cells that control dizziness, it can also destroy hearing cells, which means some patients are left permanently deaf in the affected ear.
Researchers at Imperial College London wanted to see if a steroid, called methylprednisolone, could be as effective without harming hearing after previous small- scale studies indicated it could help.
In a study, they gave 60 patients who suffered an average of one severe dizzy attack a week either a gentamicin or steroid jab, followed by another two weeks later.
Symptoms were monitored over two years and the results, published recently in The Lancet, showed both treatments reduced the frequency of dizzy spells by 90 per cent.
But hearing tests showed patients given steroid injections were able to hear speech more clearly than those given gentamicin because they had not suffered damage to cells deep inside the ear.
Researchers have called for patients with Meniere’s to be given steroid injections before trying gentamicin.
It’s not known how steroid jabs work, but one theory is they reduce inflammation caused by repeated ruptures, easing pressure deep inside the ear.
To n y Narula, president of ENT (ear, nose and throat) UK, says the steroid therapy is a major breakthrough.
‘ This is fantastic news for patients,’ he says. ‘ Gentamicin works, but unfortunately can also destroy cells in the inner ear at the same time. It is particularly damaging to the balance organ, and the more you put in, the more hearing damage the patient gets.
‘We don’t know exactly how steroids work, but they appear much safer.’