ICTAL PATTERNS OF CEREBRAL GLUCOSE-UTILIZATION IN CHILDREN WITH EPILEPSY

To determine seizure propagation patterns, we analyzed ictal positron emission tomography (PET) studies of regional cerebral glucose utiliza tion in 18 children (11 male and 7 female aged 2 weeks to 16 years) wi th epilepsy (excluding infantile spasms IS). Three major metabolic pat terns were determined based on degree and type of subcortical involvem ent: Nine children had type I; asymmetric glucose metabolism of striat um and thalamus. Of these, the 7 oldest children showed unilateral cor tical hypermetabolism (always including frontal cortex) and crossed ce rebellar hypermetabolism. Two infants (aged <1 year) had a similar ict al PET pattern but no cerebellar asymmetry, presumably owing to immatu rity of corticopontocerebellar projections. Five children had type II, symmetric metabolic abnormalities of striatum and thalamus; this patt ern was accompanied by hippocampal or insular cortex hypermetabolism, diffuse neocortical hypometabolism and absence of any cerebellar abnor mality. Four children had type III, hypermetabolism restricted to cere bral cortex. This classification can accommodate ictal PET and single photon emission computed tomography (SPECT) patterns described by othe r investigators. Future studies should be directed at the clinical rel evance of this classification, particularly with regard to epilepsy su rgery.