Between 2000 and 2006, of 34 consecutive patients with TTFCD, 17 had a lesion located in the central area. MRI was considered normal in eight, although in five a subtle gyral abnormality was disclosed on further analysis. A 18FDG PET scan performed in 16 cases demonstrated focal hypometabolism in 15 that correlated with abnormalities on MRI when visible. SEEG performed in 13 cases revealed typical abnormalities for TTFCD in 10 cases. At resection, cortical and subcortical stimulations of the dysplastic cortex did not elicit a motor response.
Postoperative motor or sensory deficit was observed in 13 patients 鈥?severe in four 鈥?which subsequently resolved completely in seven. Six patients had a minor permanent, motor or sensory deficit. Four patients were reoperated for seizure recurrence and residual dysplastic tissue was found at reoperation in three cases. Average postoperative follow-up was 3.7 years. Sixteen patients (94%) were in Engel Class I (65%in Class IA).
This study suggests that surgical resection of central region TTFCD may be associated with favorable seizure outcome and no or minor functional permanent disability. In cases of seizure relapse, reoperation can be performed without further permanent deficit and lead to seizure-free outcome. Future techniques for intraoperative detection of these lesions could optimize their complete resection in functional areas.