Abstracts

To determine whether ictal SPECT with prolonged injection of ^99mTc-ethyl cysteinate dimer (ECD) during repeated spasms in infantile spasm (IS) is better to identify the epileptic focus, or not. We compared the ictal SPECT with interictal SPECT by visual inspection in 7 patients (5 male, 2 female; age range from 7 months to 5 years) with IS including patients later evolved to periodic spasm. Ictal SPECTs were obtained by prolonged continuous slow injection of ECD during video/EEG monitoring. The prolonged Injection means that injected procedure was done during 2minutes from an first ictal spasms. The characteristics and number of clinical spasms and EEG features during clustered spasms, are also reviewed in association with ictal SPECT findings. We analyzed the ictal hyper-perfusion areas to compare the EEG, routine MRI, and PET findings to determine the epileptogeic region in IS. 1) Localized cortical hyper-perfusion was seen in all cases in ictal SPECT as compared with interictal study.
2) Hyper-perfusion area in ictal SPECT was concordant to suspected epileptogenic area from ictal video/EEG monitoring in 7 cases(100%), PET findings in 5 cases(71%) and MRI findings in 2 cases(29%).
3) Hyper-perfusion was also seen in subcortical structures; thalamus in 6 cases (86%), and basal ganglia in 6 cases (86%). Ictal SPECT with prolonged injection during repeated spasms in cluster showed highly concordance to the ictal EEG area and it may be highly sensitive to determine the epileptic cortical pathology in IS.