Post-COVID-19 neurological sequelae not due to brain injury, study finds

In a recent study from the University of Gothenburg, it was shown that all participants achieve normalization of biomarkers of CNS injury, regardless of previous severity of disease or persistent neurological symptoms. Indicating that post-COVID-19 neurological sequelae are not due to active brain injury.

Central nervous system damage and signs of brain damage have been described since the start of the SARS-CoV-2 pandemic. A previous study by the same group showed that hospital patients receiving oxygen therapy or intensive care often showed signs of brain damage by measuring the blood biomarker of brain damage.

Additionally, in recent months it has become increasingly evident that after the acute phase of COVID-19, many patients still suffer from persistent neurological disability. This often includes lethargy, fatigue, or impaired cognitive function. This consequence is now called the post COVID condition.

The mechanism behind how COVID-19 causes persistent neurological symptoms is still not fully understood. In a follow-up study, the researchers sought to study longitudinal trajectories of the same plasma biomarkers in patients who recovered from COVID-19, with and without persistent neurological symptoms.

Standardization of markers

The study presented in EBioMedicine, recruited 100 COVID-19 patients from Sahlgrenska University Hospital in Gothenburg, Sweden. The study population was divided into groups according to the severity of the disease; Mild, moderate and severe COVID-19. Blood samples were taken at an acute phase interval of the disease, 3 and 6 months after infection. In the acute phase, patients requiring hospitalization and receiving oxygen therapy or mechanical ventilation experienced an increase in NfL (neurofilament light chain protein), a biomarker that increases with neuronal damage, and pGFA (protein glial fibrillar acid), a biomarker that indicates astrocytic injury or overactivation. At follow-up, all biomarkers returned to their normal baseline values.

In addition, at 3 and 6 months of clinical follow-up, 50 patients out of the 100 individuals recruited reported one or more neurological symptoms, the most common symptoms being fatigue, “brain fog” and cognitive impairment, such as memory. . loss and lack of concentration. Remarkably, there was no difference in the frequency of symptoms among the disease severity groups.

Other important research

The results of this study highlight the importance of further research to validate the extent of persistent neurological symptoms and recovery, but also to investigate the true cause of this disease. This is of great importance from a scientific and public health point of view in the search for better management of this group of patients.

Nelly Kanberg, first author, Doctorate in Infectious Disease at Sahlgrenska Academy, University of Gothenburg and Resident Physician at the Department of Infectious Diseases, Sahlgrenska University Hospital

Magnus Gisslén, Professor of Infectious Diseases at the Sahlgrenska Academy and Chief Medical Officer at the Department of Infectious Diseases at Sahlgrenska University Hospital, leads the Academy’s clinical research on COVID-19. The results of this study are, according to him, of great importance and encouraging for patients with long-lasting symptoms after COVID-19.

“Neurological complications are common in COVID-19 and in some patients may persist for several months after the acute phase. It is reassuring that high concentrations of brain damage markers return to normal 3-6 months after the acute phase of COVID-19, indicating that no continuing brain damage is present and that there is good chances of recovery also in patients with post-cerebral persistence. acute neurological and cognitive symptoms, ”explains Gisslén.