Increased visual cortex glucose metabolism contralateral to angioma in children with Sturge-Weber syndrome

Functional reorganization after focal brain injury can lead to altered cerebral metabolism of glucose. Sturge-Weber syndrome (SWS) with unilateral involvement is a clinical model for evaluating the effects of early focal brain injury on brain metabolism and function. In this study, 2-deoxy-2[(18)F]fluoro-D-glucose (FDG) positron emission tomography (PET) was used to measure glucose metabolism in cortex and basal ganglia, both ipsilateral and contralateral to the angioma, in 17 children (eight males, nine females; age range 1y 8mo-10y 4mo; mean 5y 7mo [SD 2y 11mo]) with unilateral SWS and epilepsy. The PET findings were compared with those of a control group of 11 age-matched children (four males, seven females; age range 3y-10y 8mo; mean 6y [SD 2y 10mo]) with partial epilepsy but normal magnetic resonance imaging and PET scans. In the SWS group, visual and parietal cortex showed decreased glucose metabolism on the side of the angioma (p=0.001) but increased metabolism on the contralateral side (p=0.002). In particular, glucose metabolism was very high in contralateral visual cortex of childrenwith SWS, showing severe occipital hypometabolism on the side of the angioma. Eight children with visual field defect showed increased metabolism in the contralateral visual cortex (p=0.012). These findings indicate that early, severe unilateral cortical damage in SWS may induce increased glucose metabolism in the contralateral visual cortex, probably reflecting reorganization.