Johnson completed his residency in neurology at Harvard Medical School and Massachusetts General Hospital.
[2] Johnson's first faculty appointment was as an assistant, then associate, professor of neurology at Case Western Reserve University.
During his career, Johnson had supervised the post-doctoral training of many notable scientists, including Janice E. Clements, Diane Griffin, and Opendra "Bill" Narayan.
Johnson helped to examine the first chimpanzee to show signs of Kuru after Gajdusek experimentally inoculated it with brain matter from a human victim.
The committee released a report in 2004, stressing the need for further and expanded research into prion diseases[4][5] Johnson's honors and awards include: