The system delivers mild electrical pulses from an implanted device to leads placed under the skin at the back of the head, stimulating the occipital nerves.

The study followed 157 participants who, on average, suffered from headache 26 days per month.

Participants were implanted with the St Jude Medical Genesis neurostimulator and randomly assigned to an active or control group for 12 weeks.

The active group received stimulation immediately upon implant, while patients in the control group did not receive stimulation until after the first 12 weeks.

The study showed improvement across multiple measures including a reduction in the number of headache days per month and improvement in quality of life.

It was not however observed in the primary endpoint as established by the US Food and Drug Administration.

This was defined as a significant difference between active and placebo groups who reported a 50% reduction in pain as measured on a visual analog scale and a minimum 10% point difference between the 95% confidence intervals comparing the active and placebo groups.

A statistically significant difference between the active and placebo groups was observed at the 40% reduction in pain level.

Principal investigator of the study, Jefferson Headache Center director and the American Headache Society past president Stephen Silberstein said achieving a reduction in the number of days and a significant improvement in the quality of life may be even more important than pain reduction alone and this research demonstrates that peripheral nerve stimulation can ease the suffering of chronic migraine patients.

St Jude Medical has filed for CE Mark approval of the Genesis neurostimulation system and expects to begin a limited launch in Europe later this year.