¹⁸F-FDG-PET imaging of rat spinal cord demonstrates altered glucose uptake acutely after contusion injury

Spinal cord injury (SCI) results in an acute reduction in neuronal and glial cell viability, disruption in axonal tract integrity, and prolonged increases in glial activity and inflammation, all of which can influence regional metabolism and glucose utilization. To date, the understanding of glucose uptake and utilization in the injured spinal cord is limited. Positron emission tomography (PET)-based measurements of glucose uptake may therefore serve as a novel biomarker for SCI. This study aimed to determine the acute and sub-acute glucose uptake pattern after SCI to determine its potential as a novel non-invasive tool for injury assessment and to begin to understand the glucose uptake pattern following acute SCI. Briefly, adult male Sprague-Dawley rats were subjected to moderate contusion SCI, confirmed by locomotor function and histology. PET imaging with [¹⁸F] Fluorodeoxyglucose (FDG) was performed prior to injury and at 6 and 24 h and 15 days post-injury (dpi). FDG-PET imaging revealed significantly depressed glucose uptake at 6 h post-injury at the lesion epicenter that returned to sham/naïve levels at 24 h and 15 dpi after moderate injury. FDG uptake at 15 dpi was likely influenced by a combination of elevated glial presence and reduced neuronal viability. These results show that moderate SCI results in acute depression in glucose uptake followed by an increase in glucose uptake that may be related to neuroinflammation. This acute and sub-acute uptake, which is dependent on cellular responses, may represent a therapeutic target.