London: Scientists have shown for the first time that 'tuning-in' the brain to a particular frequency can alleviate chronic pain, paving way for a simple and safe therapy to treat the condition.
Chronic pain - which lasts for more than six months - is a real problem for many people, with 20-50 per cent of the general population estimated to suffer from it.
Chronic pain is often a mixture of recurrent acute pains and chronic persistent pain. Unfortunately there are very few treatments available that are completely safe, particularly in the elderly.
Nerve cells on the surface of the brain are co-ordinated with each other at a particular frequency depending on the state of the brain. Alpha waves which are tuned at 9-12 cycles per second have been recently associated with enabling parts of the brain concerned with higher control to influence other parts of the brain.
Researchers at The University of Manchester in UK found that alpha waves from the front of the brain, the forebrain, are associated with placebo analgesia and may be influencing how other parts of the brain process pain.
"This led to the idea that if we can 'tune' the brain to express more alpha waves, we may reduce pain experienced by people with certain conditions," researchers said. They found that this can be done by providing volunteers with goggles that flash light in the alpha range or by sound stimulation in both ears phased to provide the same stimulus frequency.
Both visual and auditory stimulation significantly reduced the intensity of pain induced by laser-heat repeatedly shone on the back of the arm.
"This is very exciting because it provides a potentially new, simple and safe therapy that can now be trialled in patients," said Anthony Jones, director of the Manchester Pain Consortium which is focussed on improving the understanding and treatment of chronic pain.
Further studies are required to test the effectiveness in patients with different pain conditions but the simplicity and low cost of the technology should facilitate such clinical studies.
"It is interesting that similar results were obtained with visual and auditory stimulation, which will provide some flexibility when taking this technology into patient studies," said Chris Brown, from The University of Liverpool "For instance this might be particularly useful for patients having difficulty sleeping because of recurrent pain at night," said Brown, who was at University of Manchester at the time of the study.