A sound of hope for tinnitus victims
by ROBER DOBSON, Daily Mail
The sonic brain reprogramming treatment, based on sound vibrations that pass through a bone behind the ear, helped eight out of ten of the patients who had twice-weekly sessions of the therapy.
Its inventors, who are planning larger trials, say the technology could be a real breakthrough for the one in ten people who suffer with the debilitating condition at some time.
Tinnitus is the sensation of a sound in the ear, usually a hissing, whooshing or ringing noise.
Once, it was thought tinnitus was caused by a physical problem, but one new theory is that in some people it's the result of the brain turning up its sensitivity, while in others it's a consequence of a change or loss in hearing.
Although it can be triggered by underlying problems, including earwax, respiratory and ear infections, exposure to loud noise, and high blood pressure, the cause is often unknown.
In some cases it is linked to ageing and deteriorating hearing, but it can occur where there is no hearing loss.
'A third of people I see have some hearing loss and tinnitus is strongly associated with that. In another third of cases, the tinnitus appears to have started at a time of great stress, bereavement, redundancy, mugging, or some other kind of a big life event.
'In another third we don't know,' says David Baguley, head of audiology at Addenbrookes Hospital in Cambridge.
One theory to explain some cases of tinnitus is that we all have these sounds in our ears, but that we are conditioned to them, in much the same way that people who live next to a road become oblivious to traffic noise. The problem in some cases of tinnitus can be not so much the noise itself, as our body's reaction to it.
'Biochemical research suggests the inner ear changes during stress so it is not possible to look at hearing in isolation. If you are lying in bed at night and you hear a creak on the stairs, you have an immediate response in your muscles, breathing, alertness and so on.
'All that begins 12-thousandth of a second after the start of the creak,' says Mr Baguley. The first sound of tinnitus can have the same kind of effect. The more the patient worries about and concentrates on the sound, the greater and more persistent it becomes.
The goal of therapy is to get the brain to ignore it. Masking with noise has been used, but in most cases the relief is shortterm, usually only while the masking noise is present. Long-term habituation or retraining therapy also helps many people, but its effects can take time to kick-in, sometimes a year or two.
The idea behind the new therapy, which is expected to go on trial in the UK at the end of the year, is that when people lose the ability to hear very high frequencies, the nerve cells in the brain that processed those sounds start to respond to a lower frequency instead.
At the same time, they also begin to react when there is no sound, causing the phantom ringing of tinnitus. Researchers say this loss of high-frequency sound is one of the causes of tinnitus in some people.
The Ultraquiet therapy developed by researchers in New York and Virginia University works by reprogramming the nerve cells to get them working properly by exposing them to high-frequency vibrations.
In the therapy, the processed sound is conducted down the bone rather than through the ear. In that way, the highfrequency sound by-passes the middle ear and restores highfrequency signals to the cochlea which are then processed by the brain.
The Ultraquiet equipment includes a music player and amplifier and a headpiece. The headpiece has an aluminum ceramic transducer, a tiny disc that is held against the mastoid bone behind the patient's ear.
The disc turns the music sound from the amplifier into vibrations which are sent through the skin and into the bone of the skull. The vibrations stimulate the nerve cells, which respond as if they were hearing high-pitched sounds coming from the ear itself.
Although the vibrations are delivered only to one side of the head, the brain 'hears' them as if they were coming from both sides.
During the preliminary trial, patients aged 35 to 72 with severe disabling tinnitus had two half-hour sessions for four weeks. All the patients, men and women, had mild to moderate highfrequency hearing loss.
Patients who completed the study said they had improvements in their symptoms during the course of treatment. The duration of the improvement- - known as residual inhibition - varied up to several weeks. That, say the researchers, is much longer than the relief provided by conventional forms of masking which last for only a few second or minutes.
Symptoms in the patients returned after two weeks, but repeated treatments can keep the nerve cells in the brain behaving properly.
Pennie Kidd, 59, from Kent, who developed tinnitus about five years ago, had tried a number of different treatments.
'I don't know what the trigger was. I had no loss of hearing that could have caused it, it was suddenly just there one day and has stayed,' she says.
'I did try a number of things. Counselling was helpful, and then I had a noise generator, a device a little bit like a hearing aid that makes a sound that you concentrate on rather than thinking about the tinnitus. That gave me some sense of control.
'I have tinnitus in my head. I wouldn't describe it as being in one ear or the other. Mine is a high-pitched whistling noise. It is continuous, but it also seems to fluctuate, getting worse when you are tired and lessening when you are distracted.
'The problem with getting stressed about your tinnitus is that you dwell on it and it gets magnified.
'Your brain will learn to accommodate the tinnitus. The initial reaction can be very profound and distressing, so the news of these new trials is very welcome, indeed.'
Fuente: British Tinnitus Association, tel. 0800 0180527.
daylymail
No hay comentarios:
Publicar un comentario