People with tinnitus could be suffering from a similar brain distortion to that of amputees who experience phantom limb pain. For 5% of the population, the condition characterised by ringing in the ears, is chronic and debilitating. Researchers have launched a full-scale trial of a promising study suggesting that differentiating between computer-generated tones could help relieve the problem.
Unlike people without the condition, those with tinnitus have a disproportionately large region of their brain which corresponds to the frequencies of the rogue sounds. A distortion also occurs in patients with phantom limb pain who have a shrunken area of that part of the brain which represents the amputated arm or leg.
Researchers successfully treated amputees by asking them to identify the position and frequency of non-painful electric shocks applied to their amputated stumps. The corresponding brain areas were stimulated by the treatment, which led to growth of these areas and resulted in a 70% reported drop in patients' pain.
After training for two hours a day over four weeks the tinnitus sufferers reported a 35% reduction in the noises, while a control group prompted with unrelated tones showed no improvement. The team says that four weeks may not be enough to make a permanent difference but suggest that the longer the training programme the more patients will benefit.