Postoperative Electroclinical Features in Epilepsy Patients With Seizures After Anteromesial Temporal Resection

ABSTRACT

BACKGROUND: Anteromesial temporal resection (AMTR) is well established as effective in patients with intractable mesial temporal epilepsy. However, little electroclinical information is available relevant to poor surgical outcome after AMTR. We examined the postoperative electroclinical features based on postoperative MRI and video-EEG monitoring (VEM) in patients with poor surgical outcome. METHODS: We reviewed clinical features and postoperative VEM results in 20 patients with failure in AMTR. According to the postoperative electroclinical features, we classified them into mesial temporal (MT), bitemporal (BT), extramesial temporal (XMT), combined (C), and unclassified groups. The postoperative VEM results were compared among the groups. Surgical outcome was assessed in five patients who underwent reoperation. RESULTS: Patients comprised 6 MT, 2 BT, 6 XMT, 1 C, and 6 unclassified. Aura and automatism were more frequent in MT (50.0%, 83.3%) than in XMT (16.7%, 33.3%). Theta to delta rhythm, during the ictal onset and build-up period, was more frequent in MT (83.3%, 66.7%) than in XMT (33.3%, 33.3%). The ictal onset and build-up pattern of ictal EEG were most frequently localized to the frontotemporal region in MT (66.7%, 100.0%), while there was no predominantly localized region in XMT. The surgical outcome after reoperation was better in MT group than in XMT and C groups. CONCLUSIONS: Postoperative MRI and VEM are useful to assess the postoperative electroclinical features in failed AMTR. Reoperation of the residual mesiotemporal structures after confirming epileptogenic foci may have good surgical outcome.