Long-term Seizure Freedom in Frontal Lobe Epilepsy Is Associated with Anterior Thalamo-cortical Disconnection
Abstract number :
1.324
Submission category :
9. Surgery / 9A. Adult
Year :
2022
Submission ID :
2204436
Source :
www.aesnet.org
Presentation date :
12/3/2022 12:00:00 PM
Published date :
Nov 22, 2022, 05:25 AM
Authors :
Davide Giampiccolo, MD – National Hospital for Neurology and Neurosurgery/UCL Institute of Neurology; Roman Rodionov, PhD – University College London; Lawrence Binding, MSc – UCL; Jane De Tisi, BA – UCL; Andrew McEvoy, MB BS BSc Hons FRCS SN – UCL; Fahmida Chowdhury, MB BS BSc Hons MRCP PhD – UCL; John Duncan, MA DM FRCP FMedSci – UCL; Anna Miserocchi, MD – UCL
This abstract has been invited to present during the Neuroimaging platform session
Rationale: In frontal lobe surgery for focal drug-resistant epilepsy, seizure freedom is variable even when a lesion is totally removed. This may reflect a broader network dysfunction composed of white matter pathways that extend beyond the lesion. Among these pathways, callosal connections or glutamatergic thalamo-cortical projections may be relevant, as these have shown to transmit or even initiate seizures. We aim to use disconnectome maps to investigate patterns of frontal lobe disconnections associated with seizure freedom.
Methods: A total of 64 patients (46 lesional, 18 non-lesional) who underwent surgery focal, drug-resistant epilepsy in the frontal lobe were included. Seizure outcome was evaluated at four different time points (1, 3, and 5 years). Resection cavities were normalized to the MNI space and used for disconnection analysis implement in BCB toolkit using white matter atlases (Tractotron) or tract-wise voxel-based analysis (disconnectome maps). Pattern of disconnection in Tractotron were analysed using a Chi-square analysis and disconnectome maps were analysed using voxelwise non-parametric permutation two-sample t-test, both corrected for multiple comparison.
Results: In the first year, disconnection of at least one of these three tracts (forceps minor (pcorrected < 0.01), the dorsal cingulum (pcorrected < 0.0001), the anterior thalamic radiation (pcorrected < 0.05)) was associated with seizure freedom. After three and five years, seizure freedom was associated with individual disconnection of anterior thalamocortical and cortico-striatal projections (pcorrected = 0.008 and 0.004, respectively). Finally, to test whether seizure recurrence was associated with thalamocortical dysregulation, we further analysed long-term seizure outcome in a restricted group of patients with complete lesion resection who were seizure free at one year. In this group, anterior thalamocortical (pcorrected < 0.01) and anterior cortico-striatal (pcorrected < 0.01) disconnections were also independently associated with seizure freedom after three years.
Surgery