PTH and migraine disorder: Evaluation of acute PTH characteristics was completed by use of questionnaire rather than physician evaluation; it is possible that more precise physician evaluation would have further refined evaluation of headache characteristics and allowed for more precise phenotyping of individuals with tension-type, migraine or cervicogenic; however, as noted above, given the significant potential overlap between symptoms due to concussion and, potentially, whiplash injury, it was not felt that attempted precise characterization of acute PTH phenotypes was appropriate.