Editor's note: The original text has been revised and updated.
As Gavin Giovannoni, MBBCh, PhD, an esteemed British multiple sclerosis (MS) expert, set out for his Saturday morning run on Nov. 7, 2020, the world's weighty problems swirled through his head. Brexit, a U.S. election, a global pandemic, not to mention the daily struggles of his patients with their degenerative illness. As professor and chair of neurology at the Blizard Institute at Barts and the London School of Medicine and Dentistry, Giovannoni's running had been an important release for him during the various stages of the lockdown. He'd lost some weight, logged more distance, and even run a marathon in under 3 hours and 20 minutes a few weeks earlier. At 56 he sometimes felt the aches of a long-distance runner. He suspected he had some arthritis in his hips, he could feel it when he ran, but still, he just kept going, motivated by the times he logged on his Garmen watch and pushing himself to keep pace with others in the Strava online running community.
Dr Gavin Giovannoni
That particular Saturday, working to still his mind, an audiobook piping through his noise-canceling earbuds, Giovannoni stepped off the curb on Acre Lane in the South London district of Brixton, and was
