HIGH-RESOLUTION FLUORODEOXYGLUCOSE POSITRON-EMISSION-TOMOGRAPHY SHOWSBOTH GLOBAL AND REGIONAL CEREBRAL HYPOMETABOLISM IN MULTIPLE-SCLEROSIS

The authors study brain regional glucose metabolism prospectively in m ultiple sclerosis (MS) using high-resolution 2-[F-18]fluoro-2-deoxy-D- glucose positron emission tomography (FDG PET) in 25 MS patients of th e Dent Neurologic Institute compared with 6 healthy subjects. Glucose metabolism is measured in 20 regions of interest using a line-profile technique. Compared with control subjects, a 9% reduction in total bra in glucose metabolism is noted in MS patients (p < 0.05). Hypometaboli sm is widespread, including the cerebral cortex, subcortical nuclei, s upratentorial white matter, and infratentorial structures. This reduct ion represents absolute regional decreases ranging from 3% to 18%. The most dramatic absolute reductions occur in the superior mesial fronta l cortex, superior dorsolateral frontal cortex, mesial occipital corte x, lateral occipital cortex, deep inferior parietal white matter, and pens. The regional hypometabolism in the superior mesial frontal corte x and superior dorsolateral frontal cortex is statistically significan t (p < 0.05), whereas the changes in the mesial occipital cortex (p = 0.07) and the lateral occipital cortex (p = 0.09) approach significanc e. The authors' findings suggest that widespread cerebral dysfunction occurs in MS, and that diaschisis or neuronal system disconnection res ulting from white matter disease plays a major role. Cortical gray mat ter hypometabolism may also reflect direct MS involvement. The quantit ative cerebral abnormalities detected by FDG PET may serve as a marker of disease activity in understanding the pathophysiological expressio n and therapeutic response of MS.