According Device Makers Vie in Pain Treatment Market, a recent Reuters article, "Medical device makers are battling in the fast-growing market for implantable systems that manage debilitating pain in patients for whom medical alternatives, such as drugs or spine surgery, have failed." These implantable systems include nerve stimulators for headache treatment.
The short article provides a good snapshot of the market and discusses the three major players, Medtronic, Boston Scientific (which is produced under the company name of Advanced Bionics), and Advanced Neuromodulation Systems. If you’re considering nerve stimulation and are curious about the devices and companies that make them, it’s good background information.
See Nerve Stimulation Devices: Leads & Batteries for a little about my experience with a Medtronic occipital nerve stimulator. I’ll post more information on the devices and companies mentioned in the article as soon as I round it up.