Fig. 1.

Diagnostic evaluation for seizure localization.

(a) Interictal scalp EEG showing a left temporal spike. Scalp EEG during seizures (not shown) did not reveal a clear ictal pattern. (b) 3 Tesla brain MRI with axial (left) and coronal (right) T2 FLAIR sequences showing suspected FCD (arrowheads) extending from the left transverse temporal gyrus to the lateral ventricle (full extent of lesion not appreciable in single slices). (c) MEG showing spike dipoles (triangles with lines) clustering near the lesion. (d) Intracranial recording of seizure onset showing initial emergence of low-voltage fast activity in the lesional depth electrode channels with early involvement of the anterior STG, an area that was subsequently resected. Other seizures started in the lesional depth electrode but showed early spread to cortex of the angular gyrus and posterior STG (not shown). Vertical lines in (a) and (d) are spaced by 1 s.