Girls are more likely than boys to have headaches after suffering a traumatic brain injury such as concussion, a U.S. study found. Of those children with mild head injuries who reported headaches, 59 percent were girls, and with girls -- but not with boys -- the risk of headache increased with age, the study by the University of Pittsburgh Medical Center found. Many of those reporting headaches after even mild head injuries have a history of migraines, and girls are four to six times more likely than boys to suffer from migraines, researchers said. \"Concussion and migraines are evil cousins,\" Micky Collins, director of the UPMC Sports Medicine Concussion Program, told the Pittsburgh Post-Gazette. People with a history of migraines can suffer concussions from traumas too mild to affect those not prone to migraines, and the concussions they suffer are often more severe, he said. \"The evil genie comes out of the bottle.\" Jack Wilberger, chairman of the department of neurological surgery at Allegheny General Hospital, said his experience supported that. \"Women have a greater tendency to migraine headaches,\" Wilberger said. \"It\'s been our experience that women report more headaches after concussion.\"