Abstracts

Disrupted Cerebellar Pathways in Temporal Lobe Epilepsy with Focal to Bilateral Tonic-Clonic Seizures

Abstract number : 2.501
Submission category : 5. Neuro Imaging / 5B. Functional Imaging
Year : 2023
Submission ID : 1390
Source : www.aesnet.org
Presentation date : 12/3/2023 12:00:00 AM
Published date :

Authors :
Presenting Author: John Phamnguyen, BMSc MBBS FRACP – Royal Brisbane and Women's Hospital

Elaine Kuan, BE – Centre for Advanced Imaging; Puneet Dheer, BTech. MTech – Department of Computer Science and Engineering – Indian Institute of Technology; Viktor Vegh, BAS. BE. PhD – Centre for Advanced Imaging; David Reutens, MD FRACP PhD – Centre for Advanced Imaging

Rationale:
Focal to bilateral tonic-clonic seizures (FBTCS) are associated with lower quality of life, unfavourable surgical outcomes, and greater risk for sudden unexpected death in epilepsy (SUDEP). The cerebellum has been shown to be actively engaged during tonic-clonic seizures and atrophy of the cerebellar vermis has been observed in individuals with SUDEP. The exact role of the cerebellum in FBTCS is unknown, although cerebellar stimulation results in seizure reduction, suggesting an inhibitory modulatory role. We evaluated the organisation of cerebellar networks associated with FBTCS in temporal lobe epilepsy (TLE).

Methods:
10-min resting-state fMRI data were collected from 30 TLE patients classified into equal active (recent FBTCS) and inactive (never or distant FBTCS) groups. Simultaneous EEG-fMRI was performed to exclude EEG seizures or frequent interictal discharges. Cortical and subcortical parcellation into 170 regions of interest (ROIs) included 26 cerebellar ROIs corresponding to anatomical lobules. Functional connectivity was assessed using Fisher’s Z transformation of Pearson’s correlation coefficient between the signal time courses in pairs of ROIs. Data from individuals with RTLE were flipped across the midline to ensure correspondence between hemisphere of seizure origin.

Results:
Age, gender, and handedness in patient and control groups were similar. The Kruskal-Wallis test revealed a significant difference between active, inactive and control groups in the connectivity between the posterior vermis and lateral cerebellar lobules crus I (χ² = 13.136, p < 0.01) and crus II (χ² = 10.953, p = 0.004). Post-hoc analysis using the Mann-Whitney U test revealed significantly reduced functional connectivity between the posterior vermis and lateral cerebellar lobules in those with active compared to inactive FBTCS (p< 0.001) or controls (p = 0.004) and no difference between inactive FBTCS and controls (p = 0.972).
Neuro Imaging