Interobserver reliability in physical examination of the cervical spine in patients with headache.

OBJECTIVE To assess interobserver reliability of two expert headache neurologists when examining the cervical spine of patients with headache. BACKGROUND The diagnosis of cervicogenic headache involves the physical examination of the cervical spine. METHODS Twenty-four patients diagnosed as having migraine, tension-type headache, or cervicogenic headache were included in the study. After interview, each patient's cervical spine was examined in a structured way. Reliability was assessed by Cohen's kappa. RESULTS Reduced range of motion in the cervical spine showed kappa scores indicating moderate agreement. Provocation of headache revealed moderate-to-substantial agreement. Assessment of zygapophyseal joint pressure pain showed slight-to-fair agreement. The kappa values of the circumscribed characteristic tender points showed agreement ranging from "not better than chance" to "substantial agreement." CONCLUSIONS Our study showed that the interobserver reliability of expert headache neurologists was satisfactory in the majority of the physical examination tests of the cervical spine in patients with different headache syndromes. However, standardization of the clinical tests in order to improve their reliability is recommended.