Brain Fog Isn't a Fog. It's Something Far Worse

You've heard about "brain fog" in relation to COVID, but likely not like this. Writing for the Atlantic, Ed Yong delves into the symptom that plagues some long COVID sufferers, and plagues might be too soft a word. As one primary-care specialist from the University of Oxford puts it, brain fog is "disabling and destructive." Yong quickly clarifies that it's not a loose term but rather one that typically refers to "a disorder of 'executive function'"—the mental processes we use to plan, schedule, concentrate, and multitask. One of his anecdotes makes clear how devastating it is to suddenly lose that ability: "Angela Meriquez Vázquez told me it once took her two hours to schedule a meeting over email: She’d check her calendar, but the information would slip in the second it took to bring up her inbox."

So why is a symptom so severe also so often dismissed? As Yong explains, virus-induced brain fog (and the term brain fog itself) is decades old, but the research into it isn't. As one neurologist explains, the field of cognitive neurology has long been focused on degenerative diseases like Alzheimer’s. "Few researchers know that viruses can cause cognitive disorders in younger people, so few study their effects," writes Yong. Many of the cognitive tests that exist were developed, again, for dementia and the elderly, so they're not a great measure. Yong lays out the potential way in which COVID causes brain fog (it involves inflammation), and it's a hypothesis with a silver lining. Neuroinflammation, and by extension brain fog, could be reversible; the same wouldn't be true if brain fog resulted from, say, a die-off of neurons. (Read the full piece.)