Mind unlocks tinnitus secret

Tinnitus is a distressing and incurable condition

Some cases of tinnitus - a persistent ringing in the ears - could be felt because of a breakdown in the controls linking hearing to the other senses.

It is estimated that 1% of the population hear the buzzing or ringing to such an extent that it has disabling consequences on their normal lives.

However, while many cases are obviously caused by physical injury to the ear, some, say scientists, could have their roots in a failure of a normal mental mechanism which would switch them off.

The latest study, published in the journal Neurology, examined eight patients with a variant of tinnitus called "gaze-evoked tinnitus".

In this condition, the ringing changes pitch or volume depending on the way the patient moves his field of vision to left and right, or up and down.

When the brains of these eight were scanned, it was found that there was a clear "imbalance" between parts of the brain linked to the auditory and visual stimuli.

Cause of tinnitus?

Professor Alan Lockwood, who led the study, said: "This is the first research to show that a failure of the complicated way our brain systems talk to each other contributes to the cause of tinnitus.

"It is not the simple problem we hoped for. It remains to be seen what other parts of the brain are involved in the cause of tinnitus."

Some cases of tinnitus appear to arise entirely within the central nervous system, rather than in the cochlea of the ear, but UK expert Dr Ross Coles, a scientist at the MRC Institute of Hearing Research in Nottingham says that most have a physical root.

"While this may explain some of these cases, in so many the tinnitus is initiated by something wrong in the ear."

He said that what was important within the brain were the reactions that tinnitus provoked - feelings of fear, anxiety or irritation, which could become overwhelming for sufferers.

He said: "We use a variety of relaxation techniques and counselling to try to reduce these."