What "pulsing electromagnetic field generators are and do: Pulsing electromagnetic field (PEMF) generators of the type used for prevention of migraine headaches provide high frequency electromagnetic energy fields so powerful they can light a 40 Watt bulb, but pulse so quickly they do not heat the body very much. These devices are not similar to magnets or battery powered stimulators which are far less powerful and work on very different principles.

The machines have been in use for over thirty years and are normally used to decrease swelling (usually for sprained ankles), speed wound healing, and to heal broken bones which will not knit on their own. The US Food and Drug Administration (FDA) has given them marketing labels for these purposes. They have been shown to be safe and without any known negative side effects.

Diapulse generators (Diapulse INC. of New York) produce pulsed high-frequency, high peak power electromagnetic energy at a frequency of 27.12 MHZ in 65 microsecond bursts occurring in 600 pulse per second sequences at 975 peak watts.

A typical pulsing electromagnetic field generator:

How the treatment may work: When PEMFs are used to prevent migraine headaches, the device is pointed at the inner thighs. We think that the device works because it increases blood flow to the legs. This causes a known reflex which decreases blood flow in the brain's "central cerebral" arteries. Most people with simple migraine headaches have too much blood flow in these cerebral arteries. When the amount of blood flow is reduced to normal, migraines do not occur as often. Thus, the device probably works by decreasing blood flow in these brain arteries.

How well the treatment works: To date, four research studies have been conducted with the Diapulse device (several double-blind, placebo controlled) in about 80 patients. Over three quarters of the patients showed great decreases in the number of headaches per month. Many also reported decreased intensity and duration of those headaches which did come on.
It does not work for headaches which started due to an accident or for tension or cluster headaches.
One follow-up study showed that the treatment's effects are likely to last for about six months. A fifth study showed that an apparently similar device did not work as well as the Diapulse generator we use.
It is important to know that approximately one out of nine people received no benefit from the treatment even though their headaches seemed to be the same as those of the people who did get better.

The treatment procedure: Each of the patient's inner thighs are exposed to PEMFs for one half hour (a total of one hour of exposure), five days per week for three weeks. The field goes through clothing so patients can wear pants and sit or lie down. The treatment does not work well if patients do not come every day for three weeks. This treatment is provided at a clinic in Tacoma Washington.

Likely results of the treatment: The treatment is mainly preventative and takes two to three weeks to begin working. Patients should not expect decreased headaches for the first few weeks nor should they expect the treatment to stop a headache in progress. They can not feel anything while the treatment is in progress and there are no known negative side effects. Patients may feel slight tingling in their legs the first night.
Patients have an 85% to 90% chance of experiencing far less headaches and / or that those they do get will be less painful and much shorter for about six months. Patients should expect to need a several day "tune-up" after six months.

To take this treatment: Patients must (1) have migraine headaches not started by an accident (the treatment doesn't work for other types of headaches or migraines with traumatic onset) and (2) agree to (a) come to our clinic in Tacoma Washington for five days per week for three consecutive weeks (unless you have an emergency) and (b) keep a log of headaches starting as long before beginning treatment as is practical and for at least six months after treatment ends.

Insurance and the FDA: There is not yet enough experience using PEMF devices to prevent migraines for the FDA to add this application to their marketing "labels". Therefore, a PEMF device can be used to treat headaches only if (1) a health care provider prescribes the use of a PEMF device for the patient's headaches or (2) the patient enters an approved research study. Marketing labels do not affect how health care providers choose to use a drug or device so they frequently prescribe them for conditions not covered by FDA labels. An example would be a physician recommending using aspirin regularly to prevent heart problems. It is not likely that insurance will cover the treatment because it is very new and the FDA has not extended the device's label to include migraines.

People with migraines who want treatment in the Tacoma Washington area can contact Dr. Sherman at rsherman@nwinet.com.

Studies on Migraines using Diapulse PEMF: The inner thighs are exposed for one hour per day for ten to 15 days. This is done to increase blood flow to the legs in order to take advantage of a reflex in which increased blood flow to the arms and legs causes a decrease in blood flow to the central cerebral arteries. These arteries may have too much blood flow in people with migraines. If the blood flow is decreased to normal, migraines may not occur.
The following types of studies have been conducted:
1. Open (the test to see if there is any merit to the idea): 23 subjects
2. Placebo Controlled / double blind (the gold standard): 42 subjects
3. Follow-up: Results last at least 6 months.
4. Comparative study (two types of PEMF generators compared for effectiveness)

Four studies have now been completed with over sixty-five people. These studies demonstrated that over 90% of people who are treated with Diapulse generated PEMFs have significantly fewer headaches and that those headaches which do come are frequently less intense and of shorter duration. Two of the studies were placebo controlled so half the patients were exposed to a machine that didn't produce PEMFs but appeared to be working. No one knew who was exposed to the real machine and who had the placebo until the study was over. Most of the people who were exposed to actual PEMFs got better while far less of those getting the placebo did. The treatment results last for about six months. Improvements return with a brief "tune-up". PEMFs produced by the Diapulse generator worked far better than those of the other device tried.

Publications in a peer reviewed journal (peer review is the crucial test as other clinicians expert in the area must agree that the study has scientific and clinical merit. Publication in such as journal does not indicate support of the treatment by the journal or that the treatment actually is as good as claimed by the authors.)

The open study:
Sherman R, Robson L, Marden L: Explorations of pulsing electromagnetic fields in the treatment of migraine headaches. Headache, 38: 208-213, 1998.

The double blind study (gold standard):
Sherman R, Acosta N, Robson L: Treatment of migraine headaches with pulsing electromagnetic fields: A double blind, placebo controlled study. Headache 39: 567 - 575, 1999.

Work supported by both the US Army and the National Headache Foundation.

Is the treatment still experimental? The technique has been demonstrated to work for a moderate size group of patients. However, the technique has to be tested on approximately 500 patients in a clinical setting for the treatment to be accepted as being effective by the general medical community, the FDA, and insurance companies. It is also important for other clinical research teams to replicate the work of the original team. Both of these efforts are in progress at a private clinic in Tacoma Washington which charges a fee for the treatment.

Richard A. Sherman, MS, PhD; Director, Behavioral Medicine Research and Training Foundation
and
Consultant for Surgical Research; Orthopedic Surgery; Madigan Army Medical Center

Nancy Acosta, BS; Research Associate, Orthopedic Surgery, Madigan Army Medical Center
Linda Robson, BA; former Research Associate, Orthopedic Surgery, Madigan Army Medical Center