Efficacy of cervical physical therapy on pain sensitivity in patients with migraine compared to no treatment, sham treatment or usual medical care: a systematic review and meta-analysis

Objective: To examine the efficacy of cervical physical therapy (e.g. cervical mobilization, exercise, and myofascial treatments) on pressure pain thresholds (PPTs) in patients with migraine, compared to no treatment, sham treatment, or usual medical care. Method: A systematic search was performed in PubMed, Embase.com, Web of Science, SPORTDiscus, Cinahl Plus and PEDro. Two independent reviewers assessed the selected randomized controlled trials (RCTs). The risk of bias was assessed using the Cochrane risk of bias tool 2, and the certainty of evidence was evaluated according to the GRADE approach. The meta-analysis included PPTs from cervical muscles and cephalic muscles. Results: Five papers out of 965 screened papers met our inclusion criteria, of which two originated from the same randomized controlled trial. Four RCTs had some risk of bias due to the absence of a pre-specified analysis plan and missing outcome data. One RCT had a high risk of bias due to a lack of information on concealment and blinding. All studies reported increased PPTs after cervical treatment. However, statistically significant differences were only found for the sternocleidomastoid muscle (mean difference (MD) 1.13 kg/cm²; 95% confidence interval (CI): 0.48 to 1.78) and the frontal muscle (MD 0.53 kg/cm²; 95% CI: 0.07 to 1.00). The certainty of evidence was low to very low. Conclusion: The efficacy of cervical physical therapy on PPTs is uncertain. More studies of high methodological quality are needed to elucidate the pain-modulatory effects of cervical physical therapy in migraine.