One, the ketogenic diet, is a carefully managed, low-carbohydrate high-fat diet plan that reduces the incidence of seizures in children during and after its use, and the other, the hemispherectomy, is a drastic surgical procedure in which part or all of one highly seizure-prone hemisphere of the brain is removed to alleviate severe epilepsy.

[1][2][3] Freeman advocated for the use of two treatments for pediatric epilepsy that had gone unused for decades: the ketogenic diet and the hemispherectomy.

[5] According to Guy McKhann, the founding director of the Hopkins Department of Neurology, Freeman effected the "resurrection" of the diet "virtually all by himself, against great skepticism and opposition.

"[6] In 1994, Freeman was contacted by Jim Abrahams, a movie director whose son, Charlie, was suffering from epilepsy that had not responded to anticonvulsants.

[7][8] The hemispherectomy, the removal of part or all of one of the hemispheres of the brain, had also fallen almost completely out of use after its development in the 1920s, and it was reintroduced under Freeman when he returned to Hopkins.