Post-COVID cognitive deficits at one year are global and associated with elevated brain injury markers and grey matter volume reduction: national prospective study
The study, “Post-COVID cognitive deficits at one year are global and associated with elevated brain injury markers and grey matter volume reduction: national prospective study” provides crucial insights into the long-term cognitive impacts of COVID-19.
Here is a detailed summary:
Abstract and Background: This prospective national longitudinal study investigated cognitive deficits in 351 hospitalized COVID-19 patients compared to 2,927 matched controls. The research found global cognitive deficits associated with elevated brain injury markers and reduced grey matter volume in the anterior cingulate cortex one year post-hospital admission. The severity of the initial COVID-19 infection, psychiatric symptoms post-acute phase, and history of encephalopathy were linked to greater deficits. Importantly, corticosteroid treatment during the acute phase appeared to protect against cognitive deficits, supporting the hypothesis that brain injury in COVID-19 is immune-mediated.
Study Hypotheses and Population: The study aimed to assess whether COVID-19 is associated with measurable post-acute cognitive deficits, with specific cognitive domains more impaired than others. The study included COVID-19 patients without prior neurological diagnoses, evaluating cognitive performance, self-reported measures, neuroimaging, and serum sampling. The participants’ median age was 54 years, with a majority being male and of white ethnicity.
- Cognitive Impairments: Patients showed significant cognitive deficits across all domains, with no evidence of domain-specific deficits. Memory concerns were strongly predictive of cognitive impairment.
- Recovery Trajectory: Some recovery in cognitive performance was noted, but there was a plateau, suggesting incomplete recovery. Raised Tau levels and infection early in the pandemic were linked to reduced recovery.
- Clinical Factors and Cognitive Impairment: Depression, multimorbidity, and severity of COVID-19 were associated with greater cognitive impairment. Corticosteroid treatment showed a protective effect.
- Serum Markers: Elevated serum neurofilament light chain and glial fibrillary acidic protein levels indicated ongoing neuronal and astrocytic injury.
- Neuroimaging Findings: Neuroimaging revealed reduced grey matter volume in the anterior cingulate cortex, correlated with cognitive deficits. The study also found correlations between specific brain regions and cognitive functions.
Conclusion and Implications: The study concluded that COVID-19 leads to global cognitive impairment, associated with structural brain changes and elevated brain injury markers. These findings suggest that post-COVID cognitive deficits may be immune-mediated. The study’s strengths include its robust longitudinal cognitive assessment and high-quality clinical data. However, limitations such as potential biases and underpowered analysis of recovery trajectories were noted. The findings underscore the need for clinicians to acknowledge the subjective experiences of patients and the necessity for further research to develop targeted therapeutic interventions.