Cervical neuro-musculoskeletal impairments in people with cervicogenic headache: a systematic review and meta-analysis

Abstract Background: People with cervicogenic headache (CGH) typically present with headache symptoms similar to other headache forms but with distinguishing features of neuro-musculoskeletal impairments. With current diagnostic criteria it is unclear which impairments are important for CGH diagnosis. Objective: To comprehensively review the evidence for cervical neuromusculoskeletal impairments in people with a diagnosis of CGH when compared to asymptomatic controls. Methods: Eight databases were searched for relevant studies evaluating neuro-musculoskeletal impairments in people with CGH. Risk-of-bias and overall quality of the evidence were assessed and meta-analyses performed. Results: Sixteen studies were included, the majority with low risk of bias. In comparison with asymptomatic controls the subjects with CGH presented with reduced combined cervical flexion-extension ROM (MD −9.26˚, 95% CI: −12.24˚, −6.27˚, I2 = 6%), side flexion ROM (MD: −2.97˚, 95% CI: 5.48˚, −0.46˚, I2 = 51%), and rotation ROM (MD: −13.57, 95% CI: −16.10, −11.03, I2 = 99%). Upper cervical rotation ROM was markedly reduced towards the headache side (MD: −15.07˚, 95% CI: −16.61˚, −13.53˚, I2 = 68%). Similarly, cervical flexor (MD: −33.70˚, 95% CI: −47.23˚, −20.16˚, I2 = 0%) and extensor strength (MD: −55.78, 95% CI: −77.56, −34.00, I2 = 0%) was reduced in subjects with CGH along with reduced craniovertebral angle. Kinaesthetic sense was not significantly impaired in subjects with CGH. The overall rating score for certainty of evidence was high to very low for all assessed outcomes. Conclusion: People with CGH have significantly decreased cervical ROM and muscle function with level of evidence ranging from high to very low.