The therapeutic use of transcranial magnetic stimulation (TMS) for migraine headache is quite new, but the therapy has been tested for many medical conditions over recent years.
The industry-funded study referenced in this news release suggests twice-a-day, self-administered “pulses” with a portable home device (manufactured by the study funder, eNeura), may have reduced the frequency of headaches in a small cohort of predominantly Caucasian women with episodic migraines.
The news release does well in establishing the need for non-pharmacologic alternatives in treating this disabling condition, but falls short in explaining a host of limitations in the study that render the beneficial results highly questionable.
It also neglects to let readers know the study is funded by a manufacturer of the device used in the study, and that many of the authors have financial ties to this company.
Migraines affect roughly 1 out of 7 Americans and the Centers for Disease Control and Prevention (CDC) estimates that prevalence is still increasing. It’s the 6th most disabling illness in the world, with healthcare and loss productivity costs in the U.S. alone estimated to be almost $40 billion annually.
There is no cure. Both preventing attacks, and treating them once they’ve started, is notoriously difficult and often involves a great deal of trial-and-error with a variety of drugs that usually have substantial side effects.
A non-pharmacologic treatment — if rigorously proven to be effective in both prevention and treatment — would be life-changing for patients, a gold mine for those who manufacture it, and have a major impact on health care costs.
This places a premium on reporting cautiously and thoroughly about any such “non-invasive” intervention for migraines. Studies such as this one — which lack a placebo control and rely upon self-reporting of pain — should be especially scrutinized.
Cost is not mentioned.
According to the American Psychological Association:
A typical course of TMS therapy for depression involves 20 to 30 sessions, generally given in three to five treatments per week for four to six weeks. The full course of therapy with the pricey machines can cost $6,000 to $12,000.
This is consistent with other sources estimating the cost-per-session as approximately $400-500. Some (but not all) insurance plans cover TMS. Many insurance companies will require written justification from a physician for using TMS.
It’s unclear whether patients would need to buy or rent the machine, and at what cost.
The news release states that twice daily, self-administered TMS reduced the frequency of headache days by nearly three days per month. Also, just under half the patients had at least 50% or less migraine attacks per month with treatment.
The release reports that patients had nine migraine days per month at baseline and this was reduced by 2.75 days with TMS treatment. This earns a satisfactory for describing the benefit in numerical terms. However, quantifying the improvement at followup would have been more helpful for readers wanting to assess TMS as a treatment option.
The release would have been improved had it included what the baseline severity and frequency of the 95 volunteers headaches were, and that claims of benefits were self reported. Furthermore, there was incomplete information regarding the concomitant use of pain medications during the 3-month study period.
The news release establishes in the first paragraph that TMS is “easy-to-use…noninvasive…safe,” but does not mention any side effects. These include worsening headaches, transient mood disturbances, and very rarely seizures. Importantly, given how new this treatment is, studies on potential long-term side effects are lacking at this time.
The procedure cannot be used in people who have metal in their head such as stents, aneurysm clips, metallic ear/eye devices, and bullet fragments.
This open label observational study has several important limitations that are not brought up in the brief news release.
First, there is no placebo (or sham device) with which to compare the results. Therefore, how much of a placebo effect occurred is unknown.
Second, beneficial outcomes relied upon self-assessment of pain. Such subjective reports are difficult to reproduce.
Third, there was missing information regarding patients’ overuse or underuse of pain medications during the 3-month study. How much pain medication was or was not used by subjects could alter the frequency and intensity of their headaches.
Fourth, the small sample group consisted mostly of Caucasian women, which may not generalize to the general population. The dropout rate reported in figure 2 of the paper also suggest a validity problem due to lack of information on why patients dropped out during the trial. Note that a number of patient volunteers didn’t have enough headaches to qualify for the end points (the outcomes that can be measured objectively to determine whether the intervention was beneficial). Thus, the treatment couldn’t really help them.
Finally, most of the subjects in this study had episodic migraines. Because response to the treatment was not subdivided by headache type, it’s unclear from the results if TMS is more or less beneficial depending on what type of migraine a patient has.
No disease mongering.
The news release clearly establishes that migraine headaches are the “sixth leading cause of disability, according to the World Health Organization.”
This is a major weakness of the news release.
Not only is the funding for the study not mentioned (the study was supported by eNeura Inc.) but it’s also not mentioned that 5 of 13 authors have financial conflicts of interest with this manufacturer of portable TMS devices.
Furthermore, one of the lead authors is chairman of eNeura’s medical advisory board.
The lead author is quoted as saying:
For certain patients, treatment options for migraines, such as oral medications, are not effective, well-tolerated, or preferred.
Some context would have been helpful here. It would help readers to know that the treatment of migraines is usually dictated by which of the several types of migraine the patient has (ie. episodic, chronic, environmentally triggered, and with or without an aura), and whether the goal is preventing an attack or treating an ongoing attack.
TMS is a relative newcomer to a vast menu of treatment options for migraine.
It would have been helpful to state that there a large number of different treatments available for migraines including over-the-counter and prescription medications. Some are FDA approved and some are not. They include treatments for both acute symptoms of a migraine as well as preventing migraines from happening. There are also non-medication based treatments such as laying down in a darkened room and relaxation techniques. The use of preventive therapies for migraines is considered when the frequency is enough that focusing on the acute episode alone is not enough. This is something that patients decide, but is often considered if there are more than one attack per week. As noted, this study shows benefit, but it was not blinded and it doesn’t compare itself to other available treatments.
It’s mentioned that the subjects in this study self-administered “pulses” each morning and evening, but readers are left wondering if this is done at a medical center or at home. If the former, do most hospitals and clinics have TMS machines? If done at home, how and where does one get a machine? Unclear.
The last line of the news release is an important inclusion since it clarifies that this is a treatment used for acute treatment that is being extended to prevention:
The U.S. Food and Drug Administration had already approved the sTMS device for the acute treatment of migraine with aura. The FDA has approved it to prevent migraine as well.
It may have been helpful to let readers know this approval came just last fall.
The release doesn’t rely on unjustifiable language.