Dr. Keegan trained in Neurology at the University of Saskatchewan in Saskatoon, Canada. He then completed two years subspecialty fellowship in Neuroimmunology and Multiple Sclerosis at Mayo Clinic in Rochester Minnesota. He joined the faculty of the Mayo Clinic in 2001 where he is a Consultant, Professor of Neurology and Head of the Division of Multiple Sclerosis and Autoimmune Neurology.
He is a clinician and performs clinically-based and translational research including clinical presentations of MS and its mimickers, paraneoplastic myelopathies, progressive MS and the use of plasma exchange for severe multiple sclerosis attacks. His research is published in high quality journals including Lancet, Brain, Neurology, Annals of Neurology and JAMA Neurology.
Relevant publications include defining progressive solitary sclerosis, and "paucisclerotic" MS showing that severe MS progression may occur from a single definable MS plaque, defining clinical factors that are associated with improved patient response to plasma exchange including the first study to clearly show a difference in patient response to MS therapy based on pathological subtype. He defined a unique inflammatory CNS disease syndrome that he named Chronic Lymphocytic Inflammation with Pontine Perivascular Enhancement Responsive to Steroids or "CLIPPERS" and leads an international consortium aimed at elucidating its etiology and optimal treatments.
He is the principal investigator for Mayo Clinic on a number of multi-center therapeutic clinical trials in MS. He was the founding section editor of the Clinical Pathological Cases for the journal Neurology, a chief Editor of eMedicine and he is on the Editorial board of MS and Related Disorders. His book Common Pitfalls in Multiple Sclerosis and CNS Demyelinating Diseases was recently published by Cambridge University Press.