¹⁸F-FDG PET mapping of regional brain activity in runners

Background. To examine regional metabolic changes in the human brain induced by free running in upright posture. Methods. Experimental design: regional brain changes in glucose uptake induced by running were examined by comparing brain images obtained by positron emission tomography (PET) and 18F-fluorodeoxyglucose (FDG). Setting: the study was conducted at a research institute and involved participation of healthy young volunteers. Data sampling and analysis required special imaging device and special computer hardware/software. Participants: subjects were 17 healthy male volunteers. They were divided at random into two equal groups, those who ran 4-5 km and the others sat in the room. Measures: differences in regional cerebral glucose uptake between runners and control groups were assessed statistically. Plasma glucose level was also measured and global cerebral uptake was estimated. Results. Running was associated with a relative increase of glucose uptake in the temporoparietal association cortex, occipital cortex, premotor cortex and the cerebellar vermis. The highest activity was noted in the temporoparietal association cortex. Activity of the primary sensorimotor cortex was higher in the superomedial part (leg motor area) than the lateral part (thorax and arm). Conclusions. Running augmented energy consumption in the parieto-occipital region relative to the motor area, probably due to the higher energy consumption necessary for integration of multimodal sensory information than for generation of motor output. Our results indicate that FDG PET is a useful tool for brain mapping under various physiological conditions.