RT Journal Article SR Electronic T1 Brain Stem Glucose Hypermetabolism in Amyotrophic Lateral Sclerosis/Frontotemporal Dementia and Shortened Survival: An 18F-FDG PET/MRI Study JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 777 OP 784 DO 10.2967/jnumed.121.262232 VO 63 IS 5 A1 Matteo Zanovello A1 Gianni Sorarù A1 Cristina Campi A1 Mariagiulia Anglani A1 Alessandro Spimpolo A1 Sara Berti A1 Cinzia Bussè A1 Stefano Mozzetta A1 Annachiara Cagnin A1 Diego Cecchin YR 2022 UL http://jnm.snmjournals.org/content/63/5/777.abstract AB A few 18F-FDG PET/CT studies have revealed the presence of brain hypermetabolism in the brain stem and cervical spinal cord of patients within the amyotrophic lateral sclerosis/frontotemporal dementia (ALS/FTD) continuum. We aimed to investigate this finding through a hybrid PET/MRI system, allowing a more precise depiction of the spatial pattern of metabolic changes in the brain stem and cervical spinal cord. Methods: Twenty-eight patients with a diagnosis of ALS or a diagnosis of the behavioral variant of FTD plus motoneuron disease, as well as 13 control subjects, underwent 18F-FDG PET/MRI. Mean normalized 18F-FDG uptake in the midbrain/pons, medulla oblongata, and cervical spinal cord as defined on the individual’s MRI scans were compared between groups. Furthermore, the associations between regional 18F-FDG uptake and clinical and demographic characteristics—including gene mutation, type of onset (bulbar, spinal, dementia), and clinical characteristics—were investigated. Results: A significant (P < 0.005) increment in glucose metabolism in the midbrain/pons and medulla oblongata was found in ALS/FTD patients (spinal-ALS and FTD–motor neuron disease subgroups) in comparison to controls. No relevant associations between clinical and metabolic features were reported, although medulla oblongata hypermetabolism was associated with shortened survival (P < 0.001). Conclusion: Increased glucose metabolism in the brain stem might be due to neuroinflammation, one of the key steps in the pathogenic cascade that leads to neurodegeneration in ALS/FTD. 18F-FDG PET/MRI could be a valuable tool to assess glial changes in the ALS/FTD spectrum and could serve as a prognostic biomarker. Large prospective initiatives would likely shed more light on the promising application of PET/MRI in this setting.