PTH and Headache: Although prior publications have demonstrated potential predictors for PTH persistence, such as pre-TBI headaches, TBI severity, age, and others, there is a lack of knowledge about the potential contribution of allodynia symptoms for that prediction.32, 33 Although this study did not develop predictive models for PTH persistence based on ASC-12 scores, it demonstrated that baseline measurements of allodynia are higher in those who do not have PTH improvement compared to those who do improve.