Surgical Outcomes in Children with Intractable Temporal Lobe Epilespy:Electroencephalographic and Pathologic Findings

Kim, Sun Hui; Kim, Joon Sung; Kim, Chan Jong; Woo, Young Jong; Lee, Min Cheol; Kim, Hyoung Ihl

Abstract

PURPOSE: Epilepsy surgery has become increasingly available in children with medically intractable epilepsy including temporal lobe epilepsy(TLE). TLE in children, however, has many different clinical and electrophysiologic characteristics which make presurgical evaluation difficult. The aim of this study is to evaluate the electroencephalographic(EEG) features which might be one of the predictors of postsurgical seizure outcomes in TLE.
METHODS
Standard EEG, video-EEG, subdural or depth EEG were investigated in 12 children who underwent anterior temporal lobectomy, and their seizure semiology, MRI, and pathologic findings were also reviewed. Postsurgical seizure outcomes were divided into favorable(class I, II) and unfavorable(class III, IV) groups by using the Engel's classification.
RESULTS
Half of the patients showed favorable outcomes, whose pathologic findings revealed hippocampal sclerosis or gliosis. Such pathologic findings were not demonstrated in MRI. Interictal epileptiform discharges were concordant with the location of the ictal onset in only 2 cases of the favorable outcomes. For the other 4 cases in the favorable group, focal ictal onset patterns were clearly evident in video-EEG monitorings or invasive EEG studies. Six cases in the unfavorable group showed unlocalized or multifocal interictal or ictal discharges -extratemporal, bitemporal or generalized epileptic activities- even in the invasive EEG studies. Five of them revealed cortical dysplasia in the pathology.
CONCLUSION
The postsurgical seizure outcomes of hippocampal sclerosis or gliosis were more favorable than those of cortical dysplasia. Invasive EEG recordings should be considered for the localization of epileptic foci in the presurgical evaluation of children with intractable TLE.