Thursday, March 03, 2011


Hundreds of thousands of Britons suffering from tinnitus which causes incessant ringing in the ears and could be cured by "retuning" part of the brain, scientists have discovered

The condition, which affects one in 10 of the elderly, is caused when the brain overreacts to hearing damage and produces constant "phantom" sounds.

At present there is no cure but scientists believe it could be eliminated by tricking the brain into switching off the imaginary ringing.

By electrically stimulating the vagus nerve – a large nerve running from the head and neck to the abdomen – at the same time as playing sounds tuned to specific frequencies, they banished tinnitus – at least in rats.

When the vagus nerve is stimulated it releases chemicals that open the brain circuitry to being rewired.

Playing the sounds at the same time permanently undoes the original damage caused by the hearing loss.

While some people are only mildly affected tinnitus, others – around 600,000 in this country – find the noises highly distressing.

Dr Michael Kilgard, from the University of Texas, who led the study in Nature, said: When we paired tones with brief pulses of vagus nerve stimulation, we eliminated the physiological and behavioural symptoms of tinnitus in noise-exposed rats.

The key is that, unlike previous treatments, we're not masking tinnitus, we're not hiding the tinnitus.

We are returning the brain from a state where it generates tinnitus to a state that does not generate tinnitus.

We are eliminating the source of the tinnitus.

Preparations are now under way for a pilot trial due to be launched in Europe early this year.

Patients will undergo vagus nerve stimulation (VNS) paired with sounds at daily treatment sessions over several weeks.

The stimulation will be delivered by a wireless electrode surgically attached to the left vagus nerve.

The device was developed by MicroTransponder, a US biotech firm affiliated to the University of Texas that has been involved in the research.

Treated rats showed responses that indicated the ringing in their ears had stopped.

Animals that did not receive the therapy continued to display signs of tinnitus.

Vegas nerve stimulation is already used to treat patients with epilepsy and depression.

Another study published in the journal Neuron suggests the brain's "limbic system" – a series of structures that process emotions and reward responses – plays a role in tinnitus.

Brain scans carried out on volunteers with tinnitus showed hyperactivity in the nucleus accumbens, central part of the brain.

Like many reports it sounds fine however it is early days yet

Who knows what side effects there might be

Better wait a while yet

No comments: