A trial of chiropractic spinal manipulative therapy (CSMT) to treat migraine successfully blinded its patients to the trial intervention.
A trial of chiropractic spinal manipulative therapy (CSMT) to treat migraine was able to successfully blind its patients to the trial intervention compared with a sham chiropractic intervention, but any effect of CSMT observed in the study was likely due to a placebo response, researchers concluded.
“The blinding was strongly sustained throughout the randomized controlled trial, adverse events were few and mild, and the effect in the CSMT and placebo group was probably a placebo response,” wrote Aleksander Chaibi, of the head and neck research group at Akershus University Hospital, Norway, and colleagues in European Journal of Neurology. “Because some migraineurs do not tolerate medication because of adverse events or co-morbid disorders, CSMT might be considered in situations where other therapeutic options are ineffective or poorly tolerated.”
Previous research has suggested that spinal manipulation may stimulate the neural inhibitory system, but trials of this therapy are difficult and cannot be double-blinded because the interventional therapist cannot be blinded. With this study, Chaibi and colleagues sought to determine if they could conduct a single-blinded, randomized controlled trial of manual therapy with a methodological standard similar to that of pharmacological trials.
The trial included 104 patients with at least one migraine attack per month. Patients were randomly assigned to active treatment with CSMT, a placebo treatment with a sham push maneuver of the lateral edge of the scapula and/or gluteal region, or control with usual pharmacological management. There was a one-month run-in period, followed by 3 months of the intervention, with follow-up at 3, 6, and 12 months. The primary endpoint was the number of migraine days per month.
After 12 treatment sessions, 80% of participants believed they had received the CSMT intervention.
“The importance of our successful blinding is emphasized by the fact that all previous manual-therapy randomized controlled trials on headache lack placebo,” the researchers wrote. “Thus, we believe that our results discussed below are valid at the same level as a pharmacological randomized controlled trial.”
Patients assigned to all three groups had significant reductions in migraine days from baseline to post treatment (P<0.001). The effect continued at 3, 6, and 12 months follow-up for patients assigned to the intervention and the sham procedure; however, patients in the control group reverted to baseline levels of migraine days.
In addition, patients assigned to CSMT had reductions from baseline to post treatment in migraine duration (P=0.003), intensity (P=0.002), and headache index (P<0.001), as did patients assigned to the sham procedure. These effects continued at all three follow-up time points. However, at 12 months follow-up patients assigned to CSMT had significant reductions in the consumption of paracetamol compared with placebo (P=0.04) and the control groups (P=0.03).
Overall, adverse events were few, mild, and transient.
Chaibi A, et al. Chiropractic spinal manipulative therapy for migraine: a three-armed, single-blinded, placebo, randomized controlled trial. Eur J Neurol. 2017;24:143-153.