Physical examination and self-reported pain outcomes from a randomized trial on chronic cervicogenic headache

Objective clinical measures for use as surrogate markers of cervicogenic headache (CGH) pain have not been established. In this analysis, we investigate relationships between objective physical examination (PE) measures with self-reported CGH outcomes.

This is an exploratory analysis of data generated by attention control PE from an open-label randomized clinical trial. Of 80 subjects, 40 were randomized to 8 treatments (spinal manipulative therapy or light massage control) and 8 PE over 8 weeks. The remaining subjects received no PE. Physical examination included motion palpation of the cervical and upper thoracic regions, active cervical range of motion (ROM) and associated pain, and algometric pain threshold evaluated over articular pillars. Self-reported outcomes included CGH and neck pain and disability, number of CGH headaches, and related disability days. Associations between PE and self-reported outcomes were evaluated using generalized linear models, adjusting for sociodemographic differences and study group.

At baseline, number of CGH and disability days were strongly associated with cervical active ROM (P < .001 to .037). Neck pain and disability were strongly associated with ROM-elicited pain (P < .001 to .035) but not later in the study. After the final treatment, pain thresholds were strongly associated with week 12 neck pain and disability and CGH disability and disability days (P < or = .001 to .048).

Cervical ROM was most associated with the baseline headache experience. However, 4 weeks after treatment, algometric pain thresholds were most associated. No one PE measure remained associated with the self-reported headache outcomes over time.