THE LONG HAUL

In his compact office at Northwestern Medicine’s Searle Medical Research Building in Streeterville, Igor Koralnik leans into one of two computer screens perched atop his uncluttered desk. The neurologist’s team of doctors, researchers, and medical students has assembled for a video meeting to reveal their latest findings about patients with long-term effects from COVID-19. Koralnik, now 60, softly yet insistently directs a question at a young doctor presenting fresh data. ■ “What jumps to your mind?” he asks. “What is something that we’ve never, ever thought about?” ■ Senior neuroimmunology fellow Gina Perez-Giraldo says she’s surprised the rates of depression and anxiety are higher for long-COVID patients who weren’t hospitalized than for those who were — 16 percent compared with 9 percent. It’s counterintuitive because you’d think milder cases would lead to fewer ongoing complications.

But that’s not the case. Lingering post-COVID headaches, for instance, are also more common among patients who have not been hospitalized. Same for the loss of smell and taste. Brain fog, an umbrella term covering various neurocognitive symptoms, is present at similar levels among the hospitalized and nonhospitalized, but the causes may differ. For the former, “we think it’s mostly caused by brain damage during hospitalization,” Koralnik tells me, citing the trauma of being on a ventilator. For the latter, it more likely stems from the virus lingering in the body or the autoimmune system’s reaction to it.

These are just some of the perplexing findings about a condition that has confounded medical experts from the start. The Centers for Disease Control and Prevention defines long COVID, also known as “post-COVID conditions,”