The importance of craniovertebral and cervicomedullary angles in cervicogenic headache.

PURPOSE Many studies have indicated that cervicogenic headache may originate from the cervical structures innervated by the upper cervical spinal nerves. To date, no study has investigated whether narrowing of the craniovertebral angle (CVA) or cervicomedullary angle (CMA) affects the three upper cervical spinal nerves. The aim of this study was to investigate the effect of CVA and/or CMA narrowing on the occurrence of cervicogenic headache. MATERIALS AND METHODS Two hundred and five patients diagnosed with cervicogenic headache were included in the study. The pain scores of patients were determined using a visual analog scale. The nonheadache control group consisted of 40 volunteers. CVA and CMA values were measured on sagittal T2-weighted magnetic resonance imaging (MRI), on two occasions by two radiologists. Angle values and categorized pain scores were compared statistically between the groups. RESULTS Intraobserver and interobserver agreement was over 97% for all measurements. Pain scores increased with decreasing CVA and CMA values. Mean angle values were significantly different among the pain categories (P < 0.001). The pain score was negatively correlated with CMA (Spearman correlation coefficient, rs, -0.676; P < 0.001) and CVA values (rs, -0.725; P < 0.001). CONCLUSION CVA or CMA narrowing affects the occurrence of cervicogenic headache. There is an inverse relationship between the angle values and pain scores.