Abstracts

Rationale: Rationale: Temporopolar grey/white matter abnormalities (GWMA) are abnormal findings observed on MRI in patients with temporal lobe epilepsy (TLE) and hippocampal sclerosis (HS) described as increased signal intensity in the white matter together with loss of grey/white matter demarcation on T2-weighted and fluid attenuation inversion recovery (FLAIR) sequences. The surgical outcome of patients with these temporopolar signal abnormalities has not yet been established. Post-surgically, Choi et al. (1999) found a significant higher proportion of seizure-free patients in the group with GWMA, whereas other studies (MITCHELL et al., 1999; CARRETE et al., 2007; GARBELLI et al., 2012; SCHIJNS et al., 2011) showed no differences in postoperative seizure outcomes. The aim of this study was to investigate, in a long post-surgical follow-up, the impact of GWMA on postoperative prognosis. Methods: Methods: We reviewed 122 patients with medically refractory TLE and MRI findings of unequivocal and unilateral HS, who had undergone epilepsy surgery and a minimum postoperative follow-up of 5 years. Patients were divided into two groups, based on the findings of the presurgical MRI evaluation: those with GWMA (Group 1) and patients with normal signal and grey/white matter definition in the temporal pole (Group 2). Results: Results: Postoperative follow-up varied from 60 to 139 months, with a mean of 89 months. Overall, GWMA were found in 52% of patients. The proportion of those classified as seizure-free (Engel class I) in Groups 1 and 2 were 73.4% and 69%, respectively (p = 0.59). When patients were subdivided in complete seizure-free (Engel class IA) or not (Engel classes IB-D, II-IV), there were 21.9% of Engel class IA patients in Group 1 and 20.7% in Group 2 (p = 0.87). Conclusions: Conclusion: GWMA did not influence the postoperative seizure outcomes of patients with TLE and HS, even after an extended duration of post-surgical follow-up.