The second medical treatment that Dr. Freeman revived was the use of hemispherectomies, or the removal of half of the brain, to end crippling seizures, and in this work he was joined by famed pediatric neurosurgeon Dr. Benjamin Carson.
In an email, Dr. Carson, who is now retired, explained that Dr. Freeman, whom he described as "a wonderful teacher and mentor," got him interested in seizure surgery.
"He helped work out many of the techniques and problems associated with cerebral hemispherectomy as well as many other neurosurgical issues affecting patients from around the world," wrote Dr. Carson. "He cared deeply about the patients and had very admirable relationships with many of them and their parents. His shoes will be hard to fill."
Dr. Eileen P.G. "Patti" Vining, a Johns Hopkins professor of neurology and pediatrics who recently retired as director of the John Freeman Pediatric Epilepsy Center, formerly the Hopkins' epilepsy center, was a student of Dr. Freeman's.
"Hemispherectomies help relieve their burdens. They are better. John was stubborn — he had great courage. When he realized that children with devastating epilepsies involving one half of their brains were doomed, he was able to convince hesitant surgeons to live in the present and begin to perform hemispherectomies again," said Dr. Vining.
"He believed we had better procedures and technologies that would make it safe," she said. "He couldn't and wouldn't abandon those children and their families to a life without rational option. They loved him ever since."
In addition to his work with epilepsy, Dr. Freeman, who believed in maintaining the dignity of individual patients, was the founding chairman of the Johns Hopkins Hospital Ethics Committee and co-director of an undergraduate medical student course in bioethics.
He was also a member of the original faculty of the Johns Hopkins Berman Institute of Bioethics, and established the Freeman Family Fund in Clinical Bioethics to help support the salary of a faculty member to teach that subject.
In 2001, Dr. Freeman and co-author Kevin McDonnell, professor of philosophy at St. Mary's College in Notre Dame, Ind., published the still-influential book, "Tough Decisions: A Casebook in Medical Ethics."
Dr. Freeman's work brought him recognition from the American Epilepsy Society, the Lifetime Achievement Award of the Epilepsy Foundation of America and the Child Neurology Society's Hower Award, its highest honor.
The Hower Award's citation described his 40-year career as one where he "played the role of gadfly, critic, and skeptic, the asker of well-formulated questions."
Dr. Freeman had a well-honed sense of humor which he willing shared with his pediatric patients, keeping them amused and calm during examinations.
"John said about himself that he was a curmudgeon," recalled Dr. Vining. "But he didn't accept the classic definition of a crusty, ill-tempered old man. He thought of himself as willing to point out errors or hypocrisy with a sense of humor."
Dr. Freeman enjoyed playing tennis, backgammon and hiking.
"He enjoyed cooking and especially liked making soup," said his wife of 57 years, the former Elaine Kaplan, who retired from Hopkins Medicine, where she had been vice president of corporate communications.
Funeral services will be held at 2 p.m. Monday at Sol Levinson and Bros. Inc., 8900 Reisterstown Road.
In addition to his wife and daughter, Dr. Freeman is survived by two sons, Andrew D. Freeman of Baltimore and Joshua L. Freeman of Chevy Chase; a brother, Donald D. Freeman of Silver Spring; a step-sister, Laura Lippman Sager of New York City; and six grandchildren.