Fluorodeoxyglucose Positron Emission Tomography Patterns Associated with Repetitive Mild Traumatic Brain Injury

Conclusions: Subjects with TBI ≥ 3 have significantly higher glucose uptake in the dorsal thalamus and cingulate gyrus when compared to subjects with TBI ≤ 2. Cerebral glucose uptake is generally thought to be associated with physiologic metabolism within the gray matter structures of the brain associated with activation of neuronal tissue. An alternative source of increased glucose uptake could be from inflammatory processes. Prior studies with 11C-PK11195 PET, a marker of microglial activation, have demonstrated a link between traumatic brain injury and chronic inflammation which may predispose mTBI subjects to neurodegeneration.[4] These studies provide evidence of microglial activation leading to thalamic inflammation many years after TBI. Inflammation might produce the patterns observed in PET FDG uptake differences as seen in Figure 1. Moreover, a dynamic inflammatory process in response to mTBI might explain the evolution of symptoms and risk for potential neurodegenerative processes. A physiologic inflammatory response may result in slow healing and improvement in symptoms over time as microglial cells perform the function of removing injured neurons and neuronal cell components. This may be seen as a mild increase in the metabolic activity associated with the white matter tracts which are generally accepted to be the most vulnerable to mild head trauma. However, in the setting of recurrent mTBI, the inflammatory process may be chronically activated leadi...
Source: Journal of Nuclear Medicine - Category: Nuclear Medicine Authors: Tags: Neurology & amp; Psychiatry Imaging Posters Source Type: research