Correlation of99mTc-HMPAO SPECT with EEG monitoring: prognostic value for outcome of epilepsy surgery in children

Sixteen children who had focal cortical resections for medically intractable epilepsy were preoperatively evaluated with99mtechnetium-labelled hexamethylpropyleneamineoxime single photon emission computed tomography (99mTc-HMPAO SPECT). Video-EEG monitoring was performed in all patients. Outcome was assessed according to the criteria of Engel et al. [1], at a mean follow up length of 13.4 ± 8.7 months, in all patients. Interictal SPECT showed appropriate localization in 11/15 cases, of whom nine had a class 1 outcome and two had class 2 and 4 outcomes. Interictal SPECT did not correlate with ictal EEG in 4/15 patients, of whom two had a class 1 outcome, and two had class 3 and 4 outcomes. Two postictal studies obtained in group I showed good correlation with the area of ictal EEG onset, and both patients had a class 1 outcome. Interictal HMPAO SPECT imaging, when positively correlated with the ictal EEG focus or with the site of surgery determined by other means, may have prognostic value for outcome of cortical resections for epilepsy in children. The use of ictal and post-ictal studies shows promise for further improving prognostic information in this population.