A hand-held device that delivers magnetic pulses to the head could be a promising new way to treat the crushing pain of migraine headaches, new research suggests.

According to research in The Lancet Neurology, the device offers effective pain relief for up to 48 hours in some patients who get migraines with aura. What's more, the treatment is non-invasive and has no side effects.

People who get migraines with aura often experience visual symptoms, such as spots of light or zigzag lines, just before an intense headache begins.

While there are medications available that help prevent migraines, most sufferers find that over-the-counter pain relievers aren't effective once a migraine begins.

Now, researchers from the Albert Einstein College of Medicine in New York have tested an experimental treatment option, called single-pulse transcranial magnetic stimulation, or sTMS.

An sTMS device sends out a magnetic pulse that, when held against a person's head, creates an electric current among the nerves cells of the brain. It's thought that the magnetic pulses interrupt the migraine's "electrical storm" in the aura phase, before it triggers pain.

Previous studies have noted the effectiveness of sTMS, but they used large and expensive devices not suitable for use outside a clinic. The researchers in this study wanted to test the effectiveness of a handheld device.

So they assigned 102 patients to use the STMS device, while another 99 got a "sham" device that made the same sounds and vibrations as a real device but that didn't actually send out magnetic pulses. (The researchers found that 80 per cent of patients in both groups thought they received active sTMS.)

The patients were told to take the devices home and watch for the signs of aura and then use the device to treat up to three migraine attacks over three months. They were also asked to record pain and symptoms before and at regular intervals after treatment.

They found that sTMS was significantly more effective than the sham device. More patients were pain-free two hours later, as well as 24 and 48 hours later.

Of the 164 patients who treated at least one attack, 39 per cent in the sTMS group were pain free two hours after treatment, compared with 22 per cent in the sham group -- a therapeutic gain of 17 per cent.

Patients using the real sTMS were also more likely to be free of headache recurrence, and did not require "rescue" medication, compared with sham stimulation.

Importantly, sTMS users didn't report any device-related side effects events and rated it an average 8 out of 10 for user-friendliness.

The authors say that while doctors continue to try to understand the exact mechanisms of migraine, "administration of sTMS in people with migraine with aura decreases progression of the attack in some individuals…and could be a promising acute treatment."

They conclude by noting that more research is needed to examine the best dose of sTMS, and to establish the optimum timing of treatment, as well as its cost-effectiveness.

About 10 to 20 per cent of people suffer migraines; of them, about a third also experience aura. Women are up to four times more likely than men to get migraines, though no one is quite sure why.