A headache and other unpleasant symptoms (e.g. visual defects, nausea, and vomiting) that develop after heading a football during soccer. It is thought that a migraine is due to distortion and spasm of basal cerebral blood vessels. This is more likely to occur if the ball is headed incorrectly on the parietal region instead of on the frontal region. Many soccer players head the ball several thousands of times during the course of their careers with no apparent ill-effect. However, a condition similar to punch-drunk syndrome has been reported in some footballers due to repeated minor head injuries.