According to the Brain Injury Association of Waterloo-Wellington, an estimated 1.3 million Canadians are living with a Traumatic Brain Injury (TBI). 1 They have a profound impact on the lives of patients and their families. Headache is the most common complaint, and it can occur after mild, moderate or severe injury. Post-Traumatic Headache (PTH) is a side effect of a TBI and is generally caused from motor-vehicle accidents, assaults, a sports collision, falling, or accidentally hitting your head.