Abstract / Summary
Abstract Purpose : Brain [18F]-FDG-PET often reveals cerebral hypometabolism in post-COVID-19 patients experiencing neurocognitive issues, but its prognostic value remains uncertain. We evaluated the long-term utility of [18F]-FDG PET in this population. Materials and Methods: We reviewed the prospective SYNPOCov cohort (NCT05610436), including WHO-defined post-COVID-19 patients with confirmed SARS-CoV-2 who underwent brain PET scans and had ≥1 year of follow-up. Final clinical outcomes were adjudicated as good (no residual disability), partial (improvement but persistent disability), or stable by an expert adjudication committee. PET scans were compared with those of age- and sex-matched pre-pandemic healthy controls (n=39). Regional metabolic values were extracted from significant clusters (voxel-level p < 0.005; cluster-level p < 0.05, FWE-corrected) and associated with demographic and clinical data. Results: Seventy patients were included (48.3±11.9 years; 69% female; 26.4 ± 9.5 months follow-up), of whom 19, 34, and 17 were classified as having good, partial, and stable clinical outcomes respectively. Baseline imaging demonstrated hypometabolism in four clusters: right frontal, parietal and lateral temporal cortex, and cerebellum. Metabolic values in the right frontal and lateral temporal clusters were significantly lower in previously hospitalized patients and with pre-Omicron variants (p=≤0.04 and p=≤0.03 respectively). However, neither baseline regional metabolism nor its longitudinal evolution on follow-up PET scans (n=30) was associated with long-term clinical outcome. Conclusion: Brain [¹⁸F]-FDG PET remains a valuable biomarker of cerebral involvement in post-COVID-19 neurocognitive disorder, revealing metabolic signatures associated with acute disease severity and viral variant. While not predictive of long-term outcome, PET findings improve understanding of factors underlying persistent cerebral dysfunction. Trial registration number and date of registration: NCT05610436; 2022-01-07