ObjectiveThe aim of this study was to understand the relationship between IQ and glucose metabolism in brain cells in a wide variety of epilepsy subjects. MethodsThe study participants were 78 children with epilepsy and 15 healthy children for comparison. All participants were administered the Chinese Wechsler Intelligence Scale for Children (C-WISC). The verbal intelligence quotient (VIQ), performance intelligence quotient (PIQ) and full scale intelligence quotient (FIQ) were compared between epileptic children and typically developing children. 78 patients underwent interictal positron emission computed tomography (PET) using 2-deoxy-2[18F]fluoro-D-glucose (FDG) as the tracer for evaluating brain glucose metabolism. ResultsVIQ, PIQ and FIQ based on the C-WISC were significantly lower in epileptic children than those in the healthy comparison group (P < 0.001, P=0.001 and P < 0.001, respectively). The IQ of patients with normal metabolism, unifocal abnormal hypometabolism and multifocal abnormal hypometabolism determined by PET differed significantly. The extent of the abnormal hypometabolism was negatively correlated with the FIQ (rs=-0.549, P < 0.001). In patients with lateralized hypometabolism based on PET, the VIQ/PIQ discrepancy (︱VIQ-PIQ︱≥15 points)scores differed significantly between the left hemisphere abnormal hypometabolism and right hemisphere abnormal hypometabolism subgroups, being negative values in the left and positive values in the right subgroups(P=0.004). ConclusionsBrain metabolic abnormalities are correlated with IQ, and perfoming interictal PET along with C-WISC can better assess the extent of severity of cognitive impairment and VIQ/PIQ discrepancy.