To assess the possibility of streamlining the decision process for epilepsy surgery in children with intractable epilepsy, the value of MRI, video EEG, and SPECT was investigated retrospectively in a study of 353 patients at the Lingfield Epilepsy Centre, Great Ormond Street Hospital, and Institute of Child Health, London, UK). Of 238 children offered resective surgery, 215 (92%) had a unilateral localized lesion on MRI, 20 (8%) had bilateral imaging abnormalities, and 3 had normal imaging. In the group with unilateral localized structural abnormalities, EEG telemetry did not affect a decision to operate. In children with bilateral MRI abnormalities or normal scan, the probability of resective surgery was 78% in those with EEG-localized ictal onset compared to 9% with nonlocalized EEG (p<0.001). SPECT did not affect a decision to operate in any group. Children with medically intractable epilepsy and localized lesions on MRI may not need ictal EEG recordings or SPECT in the evaluation for epilepsy surgery. The value of EEG telemetry in selected cases requires further investigation. [1]

COMMENT. The clinical and MRI findings are usually sufficient evidence on which to base a decision to offer resective surgery in the majority of children with medically intractable epilepsy. Ictal EEG video recordings provide confirmatory evidence of focal lesions, but in situations with limited resources, they may be reserved for children with bilateral MRI changes or normal MRI. SPECT findings do not influence a decision to operate. The role of ictal EEG in estimating prognosis following surgery requires further study. Psychological assessment is an additional factor in the decision making process for epilepsy surgery and in the evaluation of its benefits.

Extratemporal ictal clinical features in hippocampal sclerosis are most frequent in cases with severe hippocampal atrophy but do not affect surgical outcome, in a study at the University of Verona, Italy; and National Hospital, London, UK. [2]