Altered Brain Glucose Metabolism in COVID-19 disease: An activation likelihood estimation Meta-analysis

PurposeCOVID-19, caused by the SARS-CoV-2 virus, has significantly altered modern society and lifestyles. We investigated its impact on brain glucose metabolism by meta-analyzing existing studies that utilized 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) scans of the brain. MethodsWe conducted a systematic search of MEDLINE and EMBASE databases from inception to August 2023 for English-language publications using the keywords "positron emission tomography," "single-photon emission computed tomography," and "COVID-19." We included original research articles that reported changes in brain glucose metabolism following COVID-19 infection. ALE values from these studies were aggregated and tested against a null hypothesis that anticipated a random distribution of ALE values, which proved to be significantly higher than chance. ResultsWe identified eight papers that met our inclusion criteria. Significant increases in brain glucose metabolism were noted in the left anterior cingulate gyrus, right thalamus, and brainstem. In children with COVID-19, decreased glucose metabolism was observed in the right and left cerebellum, left amygdala/hippocampus, left anterior cingulate gyrus, and right amygdala. In adults with COVID-19, decreased metabolism was seen in the right temporal lobe, brainstem (acute phase), left posterior cingulate gyrus, left precuneus, right cerebellum, right insula, right anterior cingulate gyrus, left occipital lobe, and left globus pallidus (chronic phase). ConclusionCOVID-19 impacts brain glucose metabolism, typically manifesting as areas of decreased metabolism in 18F-FDG PET scans, though increases are also observed. These changes in metabolism vary with the patients age and the time elapsed between the diagnosis of COVID-19 and the PET scan.