British experts said the findings were interesting but warned that many more tests needed doing before the device could be approved officially.
Migraine sufferers often describe seeing zigzagging lines and flashing lights, as well as losing their vision, weakness, tingling or confusion and these neural disturbances or 'auras' are a signal of the onset of migraine headaches.
The electronic device, called TMS, delivers a strong electric current through a metal coil, which creates an intense magnetic field for about one millisecond and the idea is that the electrical charge interrupts the aura phase of the migraine before it causes the condition.
In 23 patients who were tested with the TMS device, 69% had either no or mild pain two hours after treatment compared with 48% of the placebo group and 42% of the TMS-treated patients graded their lack of symptoms as very good or excellent compared to 26% for placebo.
Head researcher Dr Yousef Mohammad, who is a neurologist at Ohio State University Medical Centre, said: "Perhaps the most significant effect of using the TMS device was on the two-hour symptom assessment, with 84% of the episodes in patients using the TMS occurring without noise sensitivity.
"Work functioning also improved, and there were no side effects reported," he said.
The research team are planning to do a lot more studies on far more patients.
