Weak magnetic field applied to head increases pain threshold

A weak magnetic field applied to their heads makes healthy subjects less sensitive to heat pain. ‘We are developing a whole new method of pain management’, says Dr Ruud Kortekaas from the Department of Neuroscience in the UMCG. The researchers published their findings in the leading journal PLoS ONE of 19 April 2013.

‘The weak magnetic field was generated by small coils that are fixed to a cap’, says Kortekaas. The subjects wore the cap on their heads for half an hour, but did not know whether the coils were on or off. Kortekaas explains the design of the study: ‘During the experiment one of the subject’s hands was gradually heated using a special device. If the subjects felt pain they could turn it off using an escape button in their other hand.’ This allowed the researchers to determine that the weak magnetic fields cause the pain threshold to increase.

Application

It is not always possible to treat pain with existing pain medication, and some painkillers have unpleasant side effects. ‘We can see possible applications with pain caused by tissue damage and if painkillers cause too many side effects’, Kortekaas explains. ‘Some people experience pain due to nerve damage. This kind of pain does not respond well to drugs, so we want to investigate whether the method using weak magnetic fields could help such people.’ The researchers are now working with a Groningen company to develop the method further. They are also working with technicians and students from the University of Groningen to improve the technology.

Feel

The subjects could not feel whether the coils in the cap were on or off. ‘We asked the subjects whether they thought that they had been treated with the magnetic field or the placebo, but they were right as many times as they were wrong’, says Kortekaas. The test subjects also said that they did not experience any side effects. The researchers are currently carrying out tests with patients with pain, and conducting follow-on studies to find out how long the pain relief lasts.

Link to article in PLoS ONE: http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0061926

More information on research into weak Transcranial Magnetic Stimulation (microTMS) can be found at: http://www.magnetisme.nu/