ICTAL IMAGING USING FUNCTIONAL MAGNETIC-RESONANCE

Magnetic resonance imaging (MRI) can now provide maps of human brain f unction with high spatial and temporal resolution. This noninvasive te chnique can also map the cortical activation that occurs during focal seizures, as demonstrated here by the results obtained using a convent ional 1.5 T clinical MRI system for the investigation of a l-year-old boy suffering from frequent partial motor seizures of his right side. FLASH images (TE = 60 ms) were acquired every 10 s over a period of 25 min, and activation images derived by subtracting baseline images fro m images obtained during clinical seizures. Functional MRI revealed se quential activation associated with specific gyri within the left hemi sphere with each of five consecutive clinical seizures, and also durin g a period that was not associated with a detectable clinical seizure. The activated regions included gyri that were structurally abnormal. These results demonstrate (a) that functional MRI can potentially prov ide new insights into the dynamic events that occur in the epileptic b rain and their relationship to brain structure; and (b) that there is the possibility of obtaining similar information in the absence of cli nical seizures, suggesting the potential for studies in patients with interictal electrical disturbances.