Associate Professor, Global Health, School of Medicine, Trinity College, Dublin

Dr. Merry reports no financial relationships relevant to this field of study.

SYNOPSIS: Chiropractic spinal manipulation offers no benefit over placebo for migraineurs.

SOURCE: Chaibi A, Benth JŠ, Tuchin PJ, Russell MB. Chiropractic spinal manipulative therapy for migraine: A three-armed, single-blinded, placebo, randomized controlled trial. Eur J Neurol 2017;24:143-153.

Manual therapy sometimes is used as migraine prophylaxis in migraineurs who fail pharmacological therapy and also in migraineurs who wish to avoid drug treatment.¹ The rationale for the role of spinal manipulative therapy in migraine is based on research that suggests spinal manipulation may activate neural inhibitory systems at different spinal cord levels.²

The field of manual therapy research has been limited by a lack of an acceptable sham procedure to act as a placebo control. Researchers in Norway developed a nontherapeutic chiropractic manipulative therapy involving manipulation in a nonintentional, nondirectional line of the lateral edge of the scapula and/or gluteal region. The aim of this study was twofold: 1) to conduct a prospective three-arm placebo-controlled study for migraineurs and 2) to assess the efficacy of chiropractic spinal manipulation vs. sham manipulation (placebo) vs. standard of care for migraine prevention.

The eligibility criteria for entry into the study included age between 18 and 70 years and at least one migraine headache per month. Exclusion criteria were any contraindication to spinal manipulative therapy, spinal radiculopathy, pregnancy, depression, or chiropractic spinal manipulation in the previous year. Study participants were allowed to continue and change acute migraine medication at any time during the study.

A total of 104 migraineurs were randomized into three groups: chiropractic spinal manipulative therapy, sham manipulative therapy (placebo), or control (who continued with their usual standard of care). Both the treatment and placebo groups underwent structural and motions assessments prior to and after each intervention. Each intervention lasted for 15 minutes. The chiropractic treatment arm of the study received a specific contact, low-amplitude, short-lever spinal with no adjustment recoil directed to the spinal biomechanical dysfunction (Gonstead method). The sham manipulation was conducted outside of the spinal column without soft tissue pre-tension and with adequate joint slack. The sham manipulation involved low-velocity, non-intentional maneuvers in the direction of the lateral edge of the scapula and/or the gluteal region.

The primary endpoint was the number of migraine days per month. A migraine day was defined as a day with a migraine or probable migraine. The secondary endpoints were migraine duration, intensity, headache index, and medicine consumption. The headache index was defined as mean migraine days per month × mean migraine duration mean intensity (0-10 scale). Medicine consumption was defined as mean doses of paracetamol, ergotamine, paracetamol plus codeine, nonsteroidal anti-inflammatories, or morphinomimetics.

The study took place over 17 months: one month baseline, three months of treatment, and follow-up three, six, and 12 months post-treatment. The study results of the study are summarized in Tables 1 and 2. Migraine days were reduced significantly in all three groups from baseline (P = 0.001). Data from the three, six, and 12 months of follow-up showed that the control group returned to baseline but the migraine improvement continued in both the treatment and placebo groups.

A statistically significant reduction from baseline to post-treatment in migraine duration, intensity, and headache index was noted in all three groups and its effect continued throughout the follow-up period. Change in paracetamol consumption was significantly lower in the chiropractic manipulation arm compared to the placebo (P = 0.04) or control (P = 0.03) arms at 12 months of follow-up. No severe or serious adverse events were reported throughout the study. Side effects were reported more commonly in the chiropractic manipulation arm compared to the placebo arm (P < 0.001), with local tenderness the most commonly reported side effect.

The results showed that 80% of the study participants believed they had received the chiropractic spinal manipulation, regardless of the group allocation. The authors concluded that it is possible to conduct a manual randomized, controlled trial with a placebo arm and that the observed effect of the chiropractic manipulation is likely the result of a placebo effect.

COMMENTARY

A key strength of the study is that all patients were seen by a neurologist and had a definite diagnosis of migraine. This compares to other migraine studies that recruited people with migraine from advertisements. On the downside, this theoretically limits the applicability of the results to a tertiary referral population.

An Australian randomized, controlled trial in 129 people over six months showed significant improvements in migraine with chiropractic spinal manipulation. Since more than 80% of study participants reported stress as a major factor in their migraines, the authors hypothesized that alleviation of stress was the key mechanism of action at play in this study.³

In a study of 218 patients with migraine, researchers compared spinal manipulation, amitriptyline, and spinal manipulation plus amitriptyline for eight weeks. Spinal manipulation was as effective as amitriptyline, and there was no advantage noted for the combination of spinal manipulation plus amitriptyline.⁴

Even though these authors failed to show any benefit of chiropractic manipulative therapy over placebo for migraine, this is a landmark study in many ways. Lack of quality research data always has been a key challenge for integrative health practitioners. The failure of many integrative health modalities to fit neatly into the randomized, controlled trial “box” has been the rate-limiting step for integrative health researchers. Essentially, integrative health researchers have two options: 1) convince the scientific community of the validity of research other than the randomized, controlled trial, or 2) find a way to conform to the randomized, controlled trial. These researchers have done the latter, which is the path of least resistance but marks a major milestone in integrative health research methodology.

REFERENCES

1. Diener HC, Charles A, Goadsby PJ, Holle D. New therapeutic approaches for the prevention and treatment of migraine. Lancet Neurol 2015;14:1010-1022.
2. Boal RW, Gillette RG. Central neuronal plasticity, low back pain and spinal manipulative therapy. J Manipulative Physiol Ther 2004; 27: 314-326.
3. Tuchin PJ, Pollard H, Bonello R. A randomized controlled trial of chiropractic spinal manipulative therapy for migraine. J Manipulative Physiol Ther 2000;23:91-95.
4. Nelson CF, Bronfort G, Evans R, et al. The efficacy of spinal manipulation, amitriptyline and the combination of both therapies for the prophylaxis of migraine headache. J Manipulative Physiol Ther 1998;21:511-519.