Abstracts

RATIONALE: Our aims were to identify: (1) the characteristic MR findings of cortical dyslamination with cytomegaly including destructive lesions ; (2) the relationship between MR findings and pathologic characteristics; (3) the diagnostic role of functional neuroimaging studies in the patients with cortical dyslamination and cytomegaly. METHODS: The series consisted of 23 adult patients who had pathologically proven cortical dyslamination with cytomegaly. The abnormalities found on MRI were subdivided according to the patterns of involvement. They were also compared with pathologic characteristics. Gold standard for correct localization of neuroimagings was defined to be the resected lobe. By visual qualitative analysis, FDG-PET and ictal SPECT were classified as localizing, lateralizing, non-lateralizing, false-localizing, and false-lateralizing. RESULTS: Focal abnormalities were found in 14 cases. Six cases showed typical MRI findings of focal cortical dysplasia consisted of focal areas of cortical thickening with or without poor gray-white matter differentiation. Focal subcortical high signal intensities on T2-weighted images occurred in two cases. Six patients had focal destructive pattern. Three of five cases with normal MRI and four of eight cases with non-destructive cortical dysplasia pattern had balloon cells. However, balloon cells were not found in six patients with destructive MRI pattern. FDG-PET localized the epileptogenic lobe in 13 of 20 cases (65.0%) and ictal SPECT did in 11 of 18 cases (61.1%). FDG-PET and ictal SPECT also correctly localized epileptogenic lobe in four and two cases with normal MRI respectively. CONCLUSIONS: Two distinct patterns of abnormal MRI were found. It might mean different pathogenesis, such as time of insult. FDG-PET and ictal SPECT have confirmatory and independent diagnostic role in the localization of epileptogenic foci.