Fig. 4

CCL2 level changes at acute and chronic phase post-injury. The CCL2 level significantly increased between the acute and chronic phase post-injury in the mTBI + CPTH group (*p < 0.05, repeated measures analysis of covariance [RM-ANCOVA]), but not in the mTBI – CPTH group (p = 0.08, RM-ANCOVA). mTBI + CPTH = mild traumatic brain injury and chronic post-traumatic headache, mTBI – CPTH = mild traumatic brain injury without chronic post-traumatic headache