Temporopolar blurring in temporal lobe epilepsy with hippocampal sclerosis and long-term prognosis after epilepsy surgery

摘要

Purpose: We conducted a retrospective study in order to investigate the clinical significance of temporopolar grey/white matter abnormalities (GWMA) in patients with temporal lobe epilepsy (TLE) and unilateral hippocampal sclerosis (HS) with a long post-surgical follow-up. Methods: The study comprised 122 consecutive patients with medically refractory TLE and unilateral HS who underwent epilepsy surgery and had a minimum postoperative follow-up of 5 years. Patients were divided into two groups, based on findings of pre-surgical MRI: group 1 with GWMA and 2 with normal signal and grey/white matter definition in temporal pole. Demographic and clinical data were reviewed and compared between groups. Results: GWAAA were found in 52.5% of patients, always ipsilateral to HS. Compared with group 2, group 1 patients had earlier epilepsy onset (mean, 9.3 vs 14.4 years, P=0.001), a higher occurrence of first seizure <2 years of age (25.8% vs 10.5%, P = 0.036; OR = 2.96 [95% Cl = 1.07-8.19]), and greater prevalence of left HS (76.6% vs 43.1%, P<0.001; OR = 4.31 [95% Cl = 1.98-9.38]). No differences were found in gender, presence or type of initial precipitating injury, history of secondary generalized seizures, duration of epilepsy, seizure frequency before surgery, neuro-psychological evaluation and presence or lateralization of pre-surgical interictal epileptiform discharges. Postoperative follow-up varied from 5 to 11.5 years (mean 7.4) and was similar in both groups (P=0.155). The proportion of patients classified as seizure-free (Engel class I) at last follow-up in groups 1 and 2 were 73.4% and 69%, respectively (P=0.689). Similarly, the percentages of seizure-free patients with no antiepileptic drugs at last evaluation were not different between groups (P=0.817). In logistic regression analysis, left HS (P=0.001; OR = 4.166 [95% Cl = 1.86-9.34]) and age at epilepsy onset <2 years (P=0.047; OR = 3.885 [95% Cl = 1.86—17.50]) were independently associated with risk of having GWAAA. Conclusion: GWAAA are frequent findings in patients with TLE and HS, and may help lateralize the epileptogenic zone. Our data support the hypothesis that GWAAA are caused by seizure-related insults during the critical period of cerebral myelination. GWAAA did not influence the postoperative seizure outcome of patients with TLE and HS, even after an extended duration of post-surgical follow-up.