Brain hypometabolism and cognitive impairment in long COVID: Insights from [18F]FDG-PET-CT imaging and neurocognitive...

Despite the progressive socioeconomic and healthcare recovery following the SARS-CoV-2 pandemic, its sequelae remain markedly evident today. Among them, Long COVID significantly impairs patient functionality and quality of life. Neurocognitive impairment stands out as one of its most debilitating manifestations.

We assessed 16 patients diagnosed with Long COVID and neurocognitive dysfunction, quantifying the degree of impairment using cognitive evaluation tests and comparing these results with findings from prior [18F]FDG-PET-CT brain scans.

The mean cognitive test scores demonstrated significant impairment. Patients predominantly exhibited mild hypometabolism across various regions, with the cerebellum identified as the most frequently affected area. Those with more pronounced [18F]FDG-PET-CT abnormalities exhibited greater cognitive deficits. Greater hypometabolism and thalamic involvement were associated with lower cognitive assessment score.

We support the role of cerebral hypometabolism in the development of neurocognitive impairment associated with Long COVID, although its underlying pathophysiological mechanisms remain to be elucidated. We further endorse the potential link between cerebellar hypometabolism and cognitive decline. Greater severity in brain [18F]FDG-PET-CT abnormalities and thalamic dysfunction may correlate worse cognitive impairment.