[MS6-3B-4] 18Flourine-FlouroDeoxyglucose PET(18F-FDG PET) in Pre-surgical Evaluation of Refractory Childhood Epilepsy
[Objective] To assess the utility of 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) in pre-surgical evaluation of children with refractory epilepsy and identify factors predictive of FDG-PET findings.
[Method] Cross sectional study of 120 children (median age 10.9 years) with refractory epilepsy who had FDG-PET examination because of (a) no obvious lesions MRI (n=73) or (b) multiple/ poorly demarcated lesions or non-concordant localisation (n=47).
[Results] 56/73 children (80%) with normal MRI showed FDG hypometabolism, the pattern being focal in 16 children, unilateral in 8 and bilateral in 27. Unifocal or lateralised interictal EEG discharges were predictive of focal FDG hypometabolism (p=0.02). 16/73 had a symptomatic generalised epilepsy (SGE) phenotype; of these, none showed focal FDG hypometabolism. FDG-PET confirmed localisation in 31/47 children (66%) with lesional epilepsies and excluded 11 from surgical consideration because of bilateral/ widespread involvement. Acquired lesions were more likely to give rise to bilateral FDG hypometabolism compared to congenital lesions (p=0.005). Overall, 53/120 children (44%) had FDG-PET findings to support epilepsy surgery. After a median follow up of 20 months, 15/24 (63%) of operated children thus far are seizure free. In contrast, only 14% of children on continued medical treatment are currently seizure free.
[Conclusions] FDG-PET detects abnormalities in a significant proportion of children with normal brain MRI and is a useful adjunct tool for selecting candidates for epilepsy surgery. Focal or lateralised interictal EEG abnormalities predict focal FDG-PET hypometabolism. FDG-PET utility is more limited in patients with an SGE phenotype and acquired lesions.
[Method] Cross sectional study of 120 children (median age 10.9 years) with refractory epilepsy who had FDG-PET examination because of (a) no obvious lesions MRI (n=73) or (b) multiple/ poorly demarcated lesions or non-concordant localisation (n=47).
[Results] 56/73 children (80%) with normal MRI showed FDG hypometabolism, the pattern being focal in 16 children, unilateral in 8 and bilateral in 27. Unifocal or lateralised interictal EEG discharges were predictive of focal FDG hypometabolism (p=0.02). 16/73 had a symptomatic generalised epilepsy (SGE) phenotype; of these, none showed focal FDG hypometabolism. FDG-PET confirmed localisation in 31/47 children (66%) with lesional epilepsies and excluded 11 from surgical consideration because of bilateral/ widespread involvement. Acquired lesions were more likely to give rise to bilateral FDG hypometabolism compared to congenital lesions (p=0.005). Overall, 53/120 children (44%) had FDG-PET findings to support epilepsy surgery. After a median follow up of 20 months, 15/24 (63%) of operated children thus far are seizure free. In contrast, only 14% of children on continued medical treatment are currently seizure free.
[Conclusions] FDG-PET detects abnormalities in a significant proportion of children with normal brain MRI and is a useful adjunct tool for selecting candidates for epilepsy surgery. Focal or lateralised interictal EEG abnormalities predict focal FDG-PET hypometabolism. FDG-PET utility is more limited in patients with an SGE phenotype and acquired lesions.