FDG-PET in children and adolescents with partial seizures: role in epilepsy surgery evaluation

We used FDG-PET to measure interictal glucose metabolism in 16 children and adolescents (mean age 14.7 years) and complex partial seizures (CPS) (mean seizure onset age 5.0 years). Video-EEG localized the epileptic foci. Glucose metabolism was determined in 14 paired anatomic areas using a standard template. PET hypometabolism was defined as greater than 15% asymmetry. Nine of the 13 (69%) patients with a unilateral EEG focus had regional hypometabolism ipsilateral to the epileptogenic zone. Three subjects had bilateral EEG foci; all had nonfocal PET. MRI (15 patients) concurred with EEG and PET in two, and was normal in seven of nine with focal hypometabolism. One of seven patients with normal PET had a focal MRI abnormality. FDG-PET results are similar to those found in adults, but are present earlier in the natural history of CPS (9.7 vs 22.2 years duration epilepsy) than previously reported. The presence of FDG-PET hypometabolism may be associated with a poor response to drug treatment. PET can identify metabolic abnormalities associated with epileptic foci in children and adolescents and is useful in directing surgical intervention for the control of refractory complex partial epilepsy.