TY - JOUR T1 - Brain Stem Glucose Hypermetabolism in Amyotrophic Lateral Sclerosis/Frontotemporal Dementia and Shortened Survival: An <sup>18</sup>F-FDG PET/MRI Study JF - Journal of Nuclear Medicine JO - J Nucl Med SP - 777 LP - 784 DO - 10.2967/jnumed.121.262232 VL - 63 IS - 5 AU - Matteo Zanovello AU - Gianni Sorarù AU - Cristina Campi AU - Mariagiulia Anglani AU - Alessandro Spimpolo AU - Sara Berti AU - Cinzia Bussè AU - Stefano Mozzetta AU - Annachiara Cagnin AU - Diego Cecchin Y1 - 2022/05/01 UR - http://jnm.snmjournals.org/content/63/5/777.abstract N2 - 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 &lt; 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 &lt; 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. ER -