The Health Editor of The Independent has written a baffling article where he seems to confuse transcranial magnetic stimulation, a technique used in cognitive neuroscience to induce current in the brain through the use of large electromagnets, and dodgy ‘magnet therapy’ which involves wearing magnetic pendants that are advertised as curing various ailments.
Transcranial magnetic stimulation or TMS is a technique that takes advantage of the fact that if you move a magnetic field over a conductor, a current is generated.
Your brain, of course, is a conductor of electricity and TMS allows researchers or clinicians to electrically stimulate parts of the brain by applying a magnetic field from outside the skull.
But to generate enough electricity to actually cause neurons to discharge you need very large electromagnets. Typical TMS magnets generate pulses of about 1 telsa (30,000 times greater the the Earth’s magnetic field) for less than a hundred milliseconds.
In fact, this requires so much energy that if you use a TMS machine plugged into standard domestic power supply, the lights dim when you trigger a pulse.
Depending on the arrangement of pulses, TMS can be used to temporarily increase or decrease the activity in parts of the brain near the surface of the skull and there is now an increasing interest in using this to treat psychiatric or neurological disorders.
This new study used the technique to ‘tune down’ the activity of an area of the frontal lobe called the left dorsolateral prefrontal cortex (DLPFC) in patients with Alzheimer’s disease, finding that it improved the understanding of sentences when given over four weeks.
The trial only included 10 patients, 5 in each group but it is an interesting but preliminary pilot study.
Magnet therapy, on the other hand, is a practice from alternative medicine that claims that wearing a magnetic bracelet or drinking ‘magnetised water’ can relieve arthritis or cure minor ailments.
Curious then, that the article in The Independent, despite noting that there is no evidence for ‘magnet therapy’, suggest that results from this new TMS study “are likely to be seized on as further evidence of magnetism’s healing powers”.
Needless to say, some of the people commenting on the article are less than impressed with the piece.