Migraine 2nd most common cause of a headache.Affects 15% of women and 6% of men over a one year period.Usually an episodic headache and associated with ceain features such as sensitivity to light, sound, or movement. Nausea and vomiting often accompany a headache.May be associated with other symptoms of neurologic dysfunction in varying admixtures.Paresthesias are seen in 33% of people affected by a migraine.Ref: Harrison; 19th edition