Differentiating migraine, cervicogenic headache and asymptomatic individuals based on physical examination findings: a systematic review and meta-analysis

BACKGROUND: Migraine and cervicogenic headache (CGH) are common headache disorders, although the large overlap of symptoms between them makes differential diagnosis challenging. To strengthen differential diagnosis, physical testing has been used to examine for the presence of musculoskeletal impairments in both conditions. This review aimed to systematically evaluate differences in physical examination findings between people with migraine, CGH and asymptomatic individuals. METHODS: The databases MEDLINE, PubMed, CINAHL, Web of Science, Scopus, EMBASE were searched from inception until January 2020. Risk of bias was assessed with the Downs and Black Scale for non-randomized controlled trials, and with the Quality Assessment of Diagnostic Accuracy Studies tool for diagnostic accuracy studies. When possible, meta-analyses with random effect models was performed. RESULTS: From 19,682 articles, 62 studies were included in this review and 41 were included in the meta-analyses. The results revealed: a) decreased range of motion [°] (ROM) on the flexion-rotation test (FRT) (17.67, 95%CI:13.69,21.65) and reduced neck flexion strength [N] (23.81, 95%CI:8.78,38.85) in CGH compared to migraine; b) compared to controls, migraineurs exhibit reduced flexion ROM [°] (− 2.85, 95%CI:-5.12,-0.58), lateral flexion ROM [°] (− 2.17, 95% CI:-3.75,-0.59) and FRT [°] (− 8.96, 95%CI:-13.22,-4.69), reduced cervical lordosis angle [°] (− 0.89, 95%CI:-1.72,-0.07), reduced pressure pain thresholds over the cranio-cervical region [kg/cm(2)], reduced neck extension strength [N] (− 11.13, 95%CI:-16.66,-5.6) and increased activity [%] of the trapezius (6.18, 95%CI:2.65,9.71) and anterior scalene muscles (2.87, 95%CI:0.81,4.94) during performance of the cranio-cervical flexion test; c) compared to controls, CGH patients exhibit decreased neck flexion (− 33.70, 95%CI:-47.23,-20.16) and extension (− 55.78, 95%CI:-77.56,-34.00) strength [N]. CONCLUSION: The FRT and neck flexion strength could support the differential diagnosis of CGH from migraine. Several physical tests were found to differentiate both headache types from asymptomatic individuals. Nevertheless, additional high-quality studies are required to corroborate these findings. STUDY REGISTRATION: Following indications of Prisma-P guidelines, this protocol was registered in PROSPERO on 21/05/2019 with the number CRD42019135269. All amendments performed during the review were registered in PROSPERO, indicating the date and what and why was changed. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12891-021-04595-w.