Long COVID-associated neurological symptoms and brain fog: Understanding the mechanism of neuroinflammation, BBB disruption, diagnostics, and therapeutics.

Long COVID affects at least 10% of those with severe disease, and many experience neurological symptoms and brain fog. More than 200 symptoms are reported, yet a detailed understanding remains limited. This article summarizes current knowledge of neurological symptoms, brain fog, molecular mechanisms, neuroinflammation, blood-brain barrier disruption, diagnostics, and available therapeutics. Our review highlights the lack of diagnostics and treatments for these patients. We catalog the ongoing clinical trials, identify the urgent need for further therapeutics, and stress that advances in understanding pathophysiology will drive new treatments. We urge prioritizing animal model studies and improving diagnostics to accelerate the discovery and delivery of effective treatments for long COVID neurological symptoms.