Effectiveness of manual therapy as a prophylactic treatment for migraine: a randomized controlled trial.

The trial enrolled 67 people instead of the 196 the power calculation called for, so it was too small to reliably detect the 25% difference in migraine days it was designed to find. A real but modest effect could easily have been missed. Therapists and GPs knew which treatment each participant was getting, and the people in the trial had a strong preference for manual therapy. That combination can inflate how much better patients say they feel. Half of the eligible patients declined to take part because they wanted manual therapy rather than randomisation, so the participants were selected for wanting physical treatment and may not represent a typical primary care caseload. Recruitment and treatment ran during the COVID-19 pandemic, which disrupted people's daily lives and may have changed how they reported their headaches; four measurements were missed for this reason. The usual care group was not idle. Their GPs prescribed preventive medication much more than expected during the trial, so the trial compares manual therapy with active medical management rather than with no treatment. Four participants in the usual care group (13%) stopped that care because they were unhappy with it, which may have made usual care look worse than it is. The two groups differed at the start: the manual therapy group had more migraine days (7.28 versus 5.52 per four weeks) and better neck flexor endurance (22.66 versus 14.45 seconds). Cervical range of motion was never measured, so the trial cannot say whether changes in neck mobility related to any change in migraine. Single country, single urban region in the Netherlands, with 37 participating GPs.

The authors declare no competing interests. The Healthcare Centre Haarlemmermeer funded local facilities and the time of the researcher and research assistant; the authors state the funder had no role in designing the study, collecting or analysing the data.

Do not read the better perceived-effect scores, the lower pressure pain thresholds at the back of the head, or the drop in other headache days as proof that manual therapy prevents migraine. The trial's primary outcome, migraine days, was no different between groups at any point over the year, and the comparison group was actively treated by their GPs, whose preventive medication use rose from 6% to 39% during the study. The improved ratings may reflect that patients received the treatment they wanted.