This could explain why the majority of PTH have migraine qualities,18 and why a history of migraine has been associated with prolonged recovery after concussion.2,19 While the pathophysiology of concussion and migraine is complex, many physiological changes following concussion are similar to those described in migraine, including ionic flux, disruption to cerebral metabolism and alteration of neurotransmitters and neuropeptides such as glutamate, calcitonin gene-related peptide, pituitary adenylate-cyclase-activating polypeptide, and substance P.19 The gene discussed is TAC1; the disease is migraine disorder.