As a group leader of the Hyperactive Children's Support Group, I have encountered a few cases where epilepsy was also present, and one of the 'side-effects' of selecting a suitable diet for calming the hyperactivity was the disappearance of the epilepsy.
In one case, the child went for his regular appointment with his paediatrician, who commented on how much calmer the lad was and asked what had happened to bring about the change.
On being told about the new diet, the doctor said the child should eat whatever he wanted. Soon afterward, I had a frantic phone call to say the boy was "fitting all over the place", and "running around on tippy-toes again" - this had also stopped on the new diet. The hospital had wanted to operate and cut the tendons at the back of his heels as he had never walked normally - until the new diet.
The Great Ormond Street hospital studies of the 1980s found that epilepsy could be caused by diet (see the American Journal of Pediatrics, 1989; 114: 51-8). - V.K., Knaresborough