This news release speaks to the results of a small open-label study examining the effectiveness of repetitive transcranial magnetic stimulation (rTMS) in patients who have suffered a stroke. The 18 patients studied all had chronic pain as a consequence of their stroke and did not obtain adequate relief from more traditional approaches. The release includes useful background about the burden of post-stroke pain and the history of research into rTMS as a treatment option. But the study’s small size and lack of control group are key limitations that should have been commented on, but weren’t. We also think that since the device is commercially available and is in widespread use for depression, cost should have mentioned as well as a few words about other treatment options.
There are limited effective treatment options for patients with post-stroke pain. This research provides very preliminary evidence that rTMS may also be an option. It is believed that the stimulation aids in plasticity, the ability of the brain to gradually form new neural connections to take on functions previously performed by damaged areas.
The FDA approved the use of rTMS for chronic depression several years ago, so it should have been easy to approximate the costs of a 12-week course of therapy. The usual cost of the use of rTMS for depression is $6,000 to $10,000 for 4 sessions per week for 5 weeks. So, continuing with treatment weekly for an ongoing basis (the approach advocated here) would appear to be relatively costly.
Benefits are described like this: Of the 18 patients, “11 patients achieved satisfactory-to-excellent pain relief. Pain relief was sustained in six patients who continued treatment for one year. All patients received repetitive transcranial magnetic stimulation (rTMS) to their primary motor cortex once a week for at least 12 weeks.”
It also describes what “satisfactory relief” was (a 40 – 69 percent reduction in pain scores) which happened with 6 patients, and “excellent relief,” which is pain reduction of 70 percent or more (5 patients). Finally, it said that “Overall, 8 patients who had severe stroke-caused dysesthesias, such as uncomfortable numbness or prickling, experienced less relief than patients without severe dysesthesias, suggesting possible neural circuit damage was inhibiting response to treatment.”
Although it arguably would have been most helpful to include the actual reduction in pain scores rather than the relative percentage decrease, we think the relative number plus the qualifying description (“satisfactory,” “excellent,” etc) are enough for a Satisfactory grade here.
Quoting from the release: “None of the 18 patients reported any serious side effects from weekly sessions of 10 trains of 10-second 5Hz rTMS, at 90 percent of the active motor threshold. Two patients reported transient, slight scalp discomfort after rTMS.”
There were a small number of patients in this open-label study. The fact that there was no control group means that the results should be viewed very cautiously, as the authors of the study pointed out in the original paper: “Our results were, however, based on an open-label study with a limited number of patients, and could have been influenced by placebo effects. Further studies will be needed before any robust conclusions can be drawn.” There is no such restraining language in the news release. Much has been written about the potential for rTMS to induce placebo effects in open label studies, and that so-called “sham” therapies used in control groups may not be adequate because patients can tell the difference between real and sham treatment. It was important to acknowledge some of this context.
No obvious mongering here. Post-stroke pain is serious.
The news release did not report the funding source, which is reported in the study as coming from a Japanese government grant. That would have been helpful information to include, as it bolsters the credibility of the research.
Although a similar but more invasive therapy (electrical motor cortex stimulation) was noted in passing, we think that some additional comments should have been included about alternative treatments, Stroke.org list a host of therapies for post-stroke pain including physical therapy, NSAIDs, narcotics, and antiepilesy drugs.
rTMS is commercially available and in widespread use in the US for the treatment of resistant depression. However, the release does not establish that fact, and few patients/consumers would be aware of it. A brief statement about the availability of the device and insurance coverage (none at the moment) would have been helpful for the average reader.
The role of rTMS in the management of chronic post stroke pain has been evolving for the past several years with a number of clinical trials suggesting efficacy. The news release notes that “there has still been controversy about the efficacy of rTMS in post-stroke pain,” and that this study is intended to help clarify the role of rTMS in these patients and establish optimal dosing.
There wasn’t any evidence of ‘over-the-top’ exaggeration of the findings of this study.