Screaming mouths, distorted images and brains being pulled from the skull are some of the things depicted in an unusual art exhibit on display in Boston--paintings by and about headache sufferers. The exhibition contains more than 200 works by New England artists who suffer headaches and were solicited by the Headache Research Foundation to aid the scientific study of the most common of all ailments. The artworks include such titles as "Gripping Headache," "Have You Seen a Psychiatrist," "Living With Life" and "Take Two Aspirin." Dr. Eglius Spierings, director of the Graham Headache Center at Boston's Faulkner Hospital where the exhibit is being shown, also had an exhibit of headache drawings in 1987. "The patients got a good deal of comfort from the work. They realized they were not alone, they were not the only one in the world who felt this way," he said.