EVALUATION OF TECHNETIUM-99M-ECD IN CHILDHOOD EPILEPSY

In childhood epilepsy, it is difficult, but of critical importance, to determine whether surgical intervention might be beneficial for an in dividual patient. Because both established procedures-MRI and electroe ncephalography (EEG)-have limitations, interictal and ictal regional c erebral blood flow (rCBF) SPECT has proven to be a valuable adjunctive method in the presurgical evaluation of children. Methods: We evaluat ed the usefulness of the new rCBF tracer Tc-99m-ECD in 14 children wit h focal epilepsy (mean age 9.7 yr). Eleven interictal and 8 ictal stud ies were performed. Results were correlated with ictal and interictal surface EEG, MRI and histological findings and the postsurgical outcom e. Results: On the basis of the presurgical evaluation, nine patients underwent surgery. MRI studies demonstrated pathological features with possible relation to epilepsy in 50%. Overall, interictal Tc-99m-ECD SPECT Showed areas of hypoperfusion in 80% of patients. Ictal rCBF SPE CT was informative in all patients, including one who showed bifrontal hyperperfusion in accordance with EEG results. Conclusion: Technetium -99m-ECD has proven to be of value for interictal and ictal rCBF SPECT in childhood epilepsy. No side effects during or after tracer adminis tration were noticed. Ictal and interictal rCBF SPECT showed good corr elation with MRI and EEG results in patients in whom correlation with the postoperative situation was possible and presented additional sign ificant information in those patients with normal MRI and uninterpreta ble EEG results. No false lateralizations occurred. In children with f ocal epilepsy, interictal rCBF SPECT may accelerate the application of long-term electrocorticography (ECoG) in patients with normal MRI res ults. Ictal rCBF SPECT may also help to avoid ECoG, if a focal hyperpe rfusion correlates with a focal MRI abnormality, and the surface EEG g ives no contradictory information.