More than four years after the onset of the COVID-19 pandemic, scientists are still working to fully understand the lingering effects of infection with SARS-CoV-2. One of the most concerning outcomes is Long COVID, a chronic condition that can emerge after the initial illness and bring a wide range of lasting health problems.

Among its most common and disruptive symptoms is cognitive impairment, often described as “brain fog.” Studies suggest that over 80% of people living with Long COVID experience this issue, which can make it difficult to work or handle daily responsibilities. With hundreds of millions of cases worldwide, the condition has become both a major public health concern and a growing socioeconomic burden.

Despite how widespread Long COVID is, its root causes remain unclear. Some imaging studies have revealed changes in brain structure, but these findings have not explained the molecular processes that lead to cognitive symptoms. Because the molecules that regulate communication between neurons are extremely difficult to study directly, researchers currently lack objective biomarkers that could confirm a Long COVID diagnosis or guide the development of effective treatments.

A Breakthrough in Brain Imaging
To address this challenge, a research team led by Professor Takuya Takahashi from the Graduate School of Medicine at Yokohama City University, Japan, has made a significant breakthrough in understanding the cause of Long COVID brain fog