BACKGROUND: I recently read a paper in Neurology reporting the results of a pilot study testing the Nerivio Migra device (go here for PubMed abstract). I had heard people refer to it as a “migraine patch”. In truth, it is more of an arm band. This is a new and very interesting technology that takes advantage of something called the conditioned pain modulation effect to stop patients from feeling the pain of their migraine. This is a phenomenon where “pain is used to inhibit another pain”. Except, since none of us need more pain in our lives, it is really a non-painful electrical stimulus applied to the arm that is just enough to cause pain inhibition. For anyone who wants to undergo the process of learning the details of how this works neurologically go here: Diffuse Noxious Inhibitory Controls (DNIC). The idea of DNIC can get very complicated. But it boils down to something Hippocrates noticed before any of us were even eggs: “If a patient be subject to two pains arising in different parts of the body simultaneously, the stronger blunts the other.” In other words, put this stimulator on your arm early enough in the migraine process and, hopefully, you can blunt the pain felt by your migraine.
METHODS: This study enrolled 86 patients with episodic migraine who had 2-8 attacks per month and were not taking preventive medication. The device was used for 20 migraine attacks. Chronic migraineurs were excluded from this early study. The stimulator was used for 20 minutes and controlled by the patient’s smartphone. The stimulator was programmed with 3 modes. The study was a double blinded, randomized, sham-controlled trial (patients were placed in groups without either the patients or the study personnel knowing their group identity). A sham group was included so they could have results from a group who did not actually receive treatment, but still experienced the emotional and mental effects of believing that perhaps they had been treated.
RESULTS: The device transformed patients’ experience of pain from severe or moderate to mild or no pain 58% of the time. 30% of the time patients reported that the device helped them achieve “no pain”.
LIMITATIONS: The design of this study was sound. I have emailed the team for one clarification on their statistical design. However, I feel fairly safe in saying the original study design was carried out with little room for bias, or at least bias large enough to negate their results. Two things about this study stood out as possible sources of bias. The first is that the patients in the sham group became aware that their device was not delivering treatment and stopped using it; thus the blinding was ineffective. Second, the study was funded by Theranica, the company that makes the device. I believe there are inherent challenges when blinding the sham group in an electrical stimulation trial. Also, a study carried out this early on is normally funded by the company.
MY TWO CENTS: What impressed me most in this study were the results achieved by this device in migraine patients. In this particular study, the device was equally as effective as triptans. This was merely a pilot trial and the device is currently undergoing testing in a multi-center trial. It is important to note that it is still investigational at this time. But I feel the preliminary results are really promising. I am optimistic!
This paper gets a thumbs up from #themigraineexpert!