“It is a minimally invasive procedure. The patient can be given multiple channels to use for nerve stimulation. One channel might be a low and continuous stimulation, another might be for serious headache, and another might be for mild headache. Finding the best settings is a bit of trial and error,” Dr. Huh said.
The implanted neurostimulator is about the size of a stopwatch, and gives off mild electrical pulses to stimulate peripheral nerves that may be causing headache.2
“We assume that PNS works similarly to spinal nerve stimulation for pain, but nobody knows the exact mechanism. The simplest way to think of it is a nerve roadblock. By stimulating the nerve, we block pain transmission,” Dr. Huh explained.
Although the device may need to be removed or replaced if there are complications, Dr. Huh expressed the belief that such complications are much less likely in the hands of experienced operators. Only 3 patients in the study required PNS explantation due to infection, Dr. Huh noted.
“It is still a big deal [to have a PNS device implanted],” Dr. Estemalik pointed out, adding, “Patients can’t go through a metal detector or have an MRI. You need to explore all other options first. PNS is not a frontline treatment.”
Waiting In the Wings For FDA Approval
Both Drs. Huh and Estemalik agree that the FDA will require better results and lower complication rates from a larger randomized, controlled trial before approving PNS.
“For now, patients will have to pay out-of-pocket for this treatment unless they are part of a clinical trial,” Dr. Huh said.
Another option may be a portable, battery-powered transcutaneous electrical nerve stimulation (TENS) device (Cefaly, STX-Med), approved by the FDA in March, 2014 for the treatment of migraines. Worn as a headband, the device is also approved as an alternative to migraine prevention medication.3
So why would someone opt for an implantable device if they could wear a removable device around their head?
“That’s a good question,” said Dr. Estemalik. “I think the TENS device would be one of those things that you try first.”
Still, as Dr. Huh notes, PNS has the advantage of working for many types of chronic headache, not just migraine.
“[PNS] should be reserved for people who have tried everything else. In that case, an implanted PNS might be worth a try. Primary care providers should refer patients with intractable headaches to a neurologist or headache clinic that has experience with all types of headache treatment, including PNS,” advised Dr. Huh.
The findings previously were presented at the annual meeting of the American Society of Anesthesiologists, Oct. 2013, in San Francisco, CA.
The study was not funded by external sources. Dr. Huh reports being a consultant for St. Jude Medical in Plano, TX.
1. Lee PB, Horazeck C, Nahm FS, Huh BK. Peripheral Nerve Stimulation for the Treatment of Chronic Intractable Headaches: Long-term Efficacy and Safety Study. Pain Physician. 2015 Sep-Oct;18(5):505-16.
2. American Society of Anesthesiologists, Peripheral Nerve Stimulation: Promising Long-Term Treatment for Chronic Headache Sufferers, http://www.prnewswire.com/news-releases/peripheral-nerve-stimulation-promising-long-term-treatment-for-chronic-headache-sufferers-227665301.html
3. FDA, FDA News release, http://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm388765.htm