Medtronic Begins Study of Occipital Nerve Stimulation for Chronic, Refractory Migraine Headaches

Implanted Device Delivers Electrical Impulses to Occipital Nerves

MINNEAPOLIS, Sept. 28, 2004 – Medtronic, Inc. (NYSE: MDT), today announced the first patient implant in a preliminary study to evaluate if an implanted device might help some of the thousands of Americans who suffer the agony of chronic migraine headaches that have not responded to other treatments.

Called Occipital Nerve Stimulation for the Treatment of Intractable Migraine, or ONSTIM, the study involves a Medtronic Synergy® neurostimulation device, which was implanted in a 47-year old female who has suffered from chronic headache for 8 years. The neurostimulator delivers electrical impulses via insulated lead wires tunneled under the skin near the occipital nerves at the base of the head.

According to Joel Saper, M.D., the ONSTIM study’s principal investigator, and the founder and director of the Michigan Head Pain and Neurological Institute in Ann Arbor, Mich., “It is time to take a hard look at stimulation for chronic migraines. If stimulation proves to be as effective as we hope, it could help the large numbers of people who have failed to respond to currently available treatments.”

The implant launched a prospective, randomized, blinded feasibility study, which will enroll participants at seven medical centers in the U.S. and one medical center in Europe. Medtronic received approval from the U.S. Food and Drug Administration (FDA) to conduct the study. Candidates for the study are adults who have had chronic migraines which have persisted at least 15 days per month over three months and have been refractory to other treatments. Study patients first will receive stimulation from an external device to determine patient response. If adequate response is achieved, the Medtronic Synergy™ or Synergy Versitrel™ neurostimulator system will be implanted.

The National Headache Foundation ( estimates that 28 million Americans – 70 percent of whom are women -- suffer migraine headaches and that sufferers lose about 157 million workdays each year. Many migraine sufferers progress to a chronic condition, experiencing headaches more than 15 days per month. The majority of chronic migraine sufferers can be helped with medical measures that prevent attacks or treat them when they occur. However, Medtronic estimates that approximately 40,000 people in the U.S. do not respond to existing treatments, and many may be candidates for an alternative therapy.

“Occipital nerve stimulation may be a reasonable alternative to more invasive surgical procedures for treating chronic migraine. This study is an important step forward in helping patients, many of whom have suffered in pain for years,” said Richard L. Weiner, M.D., of Dallas Neurosurgical Associations in Dallas, Texas, who pioneered the procedure.

The first implant in this study was performed by Lesco Rogers, M.D., a colleague of Dr. Saper at Michigan Head Pain and Neurological Institute. “The study will also give us important information on the technique and use of the device in these patients. A new therapeutic approach would be welcomed for this unmet medical need,” said Rogers.

Neurostimulation already has won wide medical acceptance for the management of symptoms of advanced Parkinson’s disease along with such pain conditions as chronic back and leg pain and Complex Regional Pain Syndrome (CRPS).

Medtronic, Inc., headquartered in Minneapolis, is the world’s leading medical technology company, providing lifelong solutions for people with chronic disease. Its Internet address is Patients can obtain more information about neurostimulation at ( or by calling 1-800-510-6735.

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Any statements made about the company’s anticipated financial results and regulatory approvals are forward-looking statements subject to risks and uncertainties such as those described in Medtronic’s Annual Report on Form 10-K for the year ended April 30, 2004. Actual results may differ materially from anticipated results.


Chris King, Investor Relations, 763-505-2695

Kathleen Janasz, Public Relations, 763-505-2634

Kyra Schmitt, Public Relations, 763-505-0237