Tiny electric currents may help ease pain

A researcher at St Luke's Hospital is studying the use of pulsed magnetic fields as a non-pharmaceutical way to reduce pain and accelerate healing. Deborah Culhane reports:

ELECTRICITY might become an important "drug" of choice in the treatment of arthritis and pain caused by cancer. Early research suggests that it can help alleviate pain and possibly promote healing and a Dublin researcher is trying to measure its benefits.

Dr Denis Bailey, a radiotherapist at St Luke's Hospital, Dublin, hopes to begin a medical trial soon involving 50 patients. He will test the effects of a device which creates tiny but harmless extremely low frequency (ELF) electric currents inside the body.

"They are tiny currents but they are still bioactive," Dr.Bailey explained. As a radiotherapist he treats cancer patients using ionising electromagnetic radiation. His new treatment also involves radiation, but in this case it is non-ionising and works at very low energy intensities.

The device is a simple electric coil about the size of a dinner plate through which pulses of electric current are passed. One or two coils are placed adjacent to an arthritic joint or site of a cancer lesion.

The current creates a short-lived magnetic field which can reach into the tissues. This field in turn induces very small electric currents in the cells. The treatment is both painless and harmless, but there does seem to be some therapeutic benefit to it, Dr Bailey said.

Earlier international research indicated several benefits from this treatment both in pain relief and faster knitting of broken bones.

"The great thing about this treatment is that there are no side effects, something which is unprecedented in medical therapy to date," he said.

Italy was the first country to successfully use this treatment. A group of 3,000 patients suffering from rheumatoid afid osteo-arthritis and sports injuries were treated and then monitored during an 11 year follow up. While the normal rate of improvement with patients exposed to a placebo (dummy) device is 15-30%, about 80% of patients who received active treatment indicated an improvement in their condition.

The device has other medical applications, Dr Bailey said. "In the St Mary's Orthopaedic Hospital Cappagh, Dublin, [it] was successfully used to heal non-uniting fractures."

Non-healing fractures can sometimes necessitate amputation. A clinical trial with 26 such patients showed 23 of them ultimately healed after the treatment. The key to the biological effect seemed to be the time rate of change of the pulse. Dr Bailey is using the device at rates that vary between five and 15 pulses per second. Research elsewhere had suggested that no benefits were present above 20 pulses per second or below five.

The magnetic field generated by the coils is very low, just 0.1 of a milli-Tesla. It is not clear what portion of the pulse cycle is important for the biological effect, whether it is the rate of rise of the magnetic field and the resultant ELF currents or the duration of the pulse.

Prob lems in fine-tuning the best amplitude and frequency for the system must be overcome, Dr Bailey said. "People have been very coy about giving details of the pulses, used in the experiments to date - probably for commercial reasons. Unfortunately this has held up international progress on how the therapy can be used as a medical tool," he said. "I plan to reveal all relevant data on, pulse ELF in my research," he added.

Help with studying the significance of pulse, parameters will come from Prof David Rodger, professor of electrical engineering at the University of Bath. He will use computer models to help explain the electrical affects inside the cell.

The potential of ELF magneto therapy is huge for patients with arthritis or who have problems tolerating their medication. Dr Bailey believes. "The problem is in convincing others. People are not inclined to take it seriously because the energy levels are so low but the facts are the treatment produces beneficial clinical effects and is side-effect free."

In a preliminary trial Dr Bailey treated 15 arthritis patients at St Luke's with his newly designed equipment. "None of the patients were the worse off for the treatment," he said. "At least two patients who received more than one treatment showed a dramatic improvement in their condition."

Additional reporting by Dick Ahlstrom