HOW IT WORKS

Here's how St. Jude Medical's Eon Mini works:

•The tiny pacemaker is implanted either near the hip (above) or in the chest area.

•Small wires, or leads, with electrodes run from the device, just beneath the skin, to the base of the skull.

•There they deliver a programmable pulse of energy to the occipital nerve (above, inset) to alleviate pain.

A BIG HEADACHE

The American Headache Society estimates that 36 million Americans suffer from migraine.

The World Health Organization gives migraine a rank of 7 on a scale of 1-7 in terms of health impact.