Long-term postoperative-atrophy of contralateral hippocampus and cognitive function in unilateral refractory MTLE with unilateral hippocampal sclerosis

Author(s)

Fernandes, Daniela Alves ^[1] ; Yasuda, Clarissa Lin ^{[1, 2]} ; Lopes, Tatila Martins ^[1] ; Ghizoni, Enrico ^{[3, 1]} ; Alessio, Andrea ^[1] ; Tedeschi, Helder ^[3] ; de Oliveira, Evandro ^[3] ; Cendes, Fernando ^{[1, 2]}

Affiliation

^[1] Univ Estadual Campinas, UNICAMP, MRI Unit, Hosp Clin, Neuroimaging Lab, BR-13083888 Campinas, SP - Brazil

^[2] Univ Estadual Campinas, UNICAMP, Epilepsy Serv, BR-13083888 Campinas, SP - Brazil

^[3] Univ Estadual Campinas, UNICAMP, Hosp Clin, Dept Neurol, Neurosurg Div, BR-13083888 Campinas, SP - Brazil

• Document type: Journal article
• Source: Epilepsy & Behavior; v. 36, p. 108-114, JUL 2014.
• Web of Science Citations: 6

Abstract

Objective: This study aimed to evaluate long-term atrophy in contralateral hippocampal volume after surgery for unilateral MTLE, as well as the cognitive outcome for patients submitted to either selective transsylvian amygdalohippocampectomy (SelAH) or anterior temporal lobe resection (ATL). Methods: We performed a longitudinal study of 47 patients with MRI signs of unilateral hippocampal sclerosis (23 patients with right-sided hippocampal sclerosis) who underwent surgical treatment for MTLE. They underwent preoperative/postoperative high-resolution MRI as well as neuropsychological assessment for memory and estimated IQ To investigate possible changes in the contralateral hippocampus of patients, we included 28 controls who underwent two MRIs at long-term intervals. Results: The volumetry using preoperative MRI showed significant hippocampal atrophy ipsilateral to the side of surgery when compared with controls (p < 0.0001) but no differences in contralateral hippocampal volumes. The mean postoperative follow-up was 8.7 years ( +/- 2.5 SD; median = 8.0). Our patients were classified as Engel I (80%), Engel II (18.2%), and Engel III (1.8%). We observed a small but significant reduction in the contralateral hippocampus of patients but no volume changes in controls. Most of the patients presented small declines in both estimated IQ and memory, which were more pronounced in patients with left TLE and in those with persistent seizures. Different surgical approaches did not impose differences in seizure control or in cognitive outcome. Conclusions: We observed small declines in cognitive scores with most of these patients, which were worse in patients with left-sided resection and in those who continued to suffer from postoperative seizures. We also demonstrated that manual volumetry can reveal a reduction in volume in the contralateral hippocampus, although this change was mild and could not be detected by visual analysis. These new findings suggest that dynamic processes continue to act after the removal of the hippocampus, and further studies with larger groups may help in understanding the underlying mechanisms. (C) 2014 Elsevier Inc. All rights reserved. (AU)

• FAPESP's process: 10/02492-0 - Relationship between hippocampal volume and surgical resection volume with seizure control and memory performance in patients with mesial temporal lobe epilepsy undergoing surgical treatment
• Grantee: Daniela Alves Fernandes
• Support Opportunities: Scholarships in Brazil - Master