THE BACK PAGE RESEARCH REVIEW Migraine pain & SMT REVIEWED BY SHAWN THISTLE STUDY TITLE: The Impact of Spinal Manipulation on Migraine Pain and Disability: A Systematic Review and Meta-Analysis AUTHORS: Rist PM, Hernandez A, Bernstein C et al. PUBLICATION INFORMATION: Headache 2019; 59(4): 532-542. doi: 10.1111/head.13501. A pproximately 38 million adults in the United States are reported to suffer from migraine headaches, of which 91% experience migraine-associated disabil-ity. Pharmacological treatments repre-sent the first-line treatment for many migraine sufferers; however, approxi-mately 40% of patients with episodic migraine symptoms have unmet treat-ment needs. One-third of this group report dissatisfaction with current treatment and half report headache-as-sociated disability. As such, alternative treatments to the traditional pharma-cological approach are warranted. Literature search results and study characteristics Six studies were identified as eligible from database searches, three of which had been included in previous system-atic reviews. A total of 677 patients were randomized in these studies, with an average age of 39.3 years. 75% of par-ticipants were female. Intervention and Control Group Char-acteristics: All studies used a paral-lel-arm design, with participants as-signed to the intervention group (spinal manipulative therapy delivered by a chiropractor, osteopathic physician or physiotherapist) or a control group. Pertinent results Treatment duration lasted from 2 to 6 months. Control groups included sham therapy, cervical mobilization, detuned interferential therapy or a combination of SMT and amitripty-line. Outcomes: Outcomes included mi-graine diaries, questionnaires, mi-graine days per month or migraine frequency, migraine intensity/pain and migraine disability. Adverse Effects: Two studies reported adverse effects. One reported adverse effects via headache diaries – with none actually reported in this study. The second study reported adverse events after each intervention session. In this study, few events were reported and none were considered serious. A third study reported neck pain preva-lence among those receiving SMT but not control participants. Risk of Bias Assessment: Three stud-ies were deemed to be low risk of bias for random sequence generation. Given the nature of the intervention, blinding of intervention group partic-ipants was not possible. Two studies provided sufficient information to show low attrition rates. Outcome measures were mentioned in all stud-ies but only three identified a primary outcome. Participant compliance was not sufficiently addressed in five of six studies. Results Effects of SMT on Migraine Days/Fre-quency: SMT had a significant positive impact on the number of migraine days vs. controls. Heterogeneity was high across all 6 studies (I2 ratio = 93.80%). Exclusion of one study by Cerritelli et al. deemed to be the main driver of the heterogeneity improved homogeneityand revealed improved positive effect on migraine days. Note – the Ceretelli et al. study included only those with chronic migraine and showed effect sizes that were signifi-cantly higher than the other studies – this was the reason the authors ran a separate analysis without it, as it was considered to be an outlier. Effects of SMT on Migraine Pain/In-tensity: Analysis excluding the Cerritelli study observed that SMT reduced migraine pain with a small effect size. effect size was similar when limited to studies with an active treatment con-trol group and to passive controls Effects of SMT on Migraine Disability: Four of the six included studies exam-ined migraine disability. Excluding the Cerritelli study, a small effect size was observed. Application, conclusions DR. SHAWN THISTLE is a practising chiropractor, educator, international speaker, knowledge-transfer leader, evidence-based health care advocate, entrepreneur and medicolegal consultant. He founded RRS Education in 2006 and currently acts as the company’s CEO. RRS Education helps chiropractors and other manual medicine clinicians around the world integrate research into patient care via weekly research reviews, online courses and seminars. rrseducation.com 26 Canadian Chiropractor June 2019 Overall, the results of this review sug-gest that SMT may reduce migraine days and pain/intensity. However, variations in study quality limit the ability to firmly make these conclu-sions. The authors recommend that methodologically rigorous RCTs are warranted to provide improved evi-dence for the use of SMT as a treat-ment option for migraine headaches. SMT represents a viable, safe, poten-tially beneficial intervention that pa-tients may prefer to the potential side-effects (or lack of efficacy) of pharmaceutical interventions. www.canadianchiropractor.ca
Chiropractic + Naturopathic Doctor June 2019: Page 26
