This study shows links between Long COVID’s neurological effects, including brain fog and cognitive decline, and brain blood vessel integrity, offering hope for new treatments and diagnostic methods.
https://www.nature.com/articles/s41593-024-01576-9 (open access)
Not exactly—although an MRI w/wout contrast may show some microvascular ischemia or cortical volume loss. Based on the study there may be some clues from secondary inflammatory markers, but those aren’t specific (other things can elevate them beyond long COVID).
I think this will likely remain a clinical diagnosis for several years until we understand more.