Authors :
Presenting Author: Xiyu Feng, MSc – UCL Great Ormond Street Institute of Child Health
Freya Prentice, PhD – UCL Great Ormond Street Institute of Child Health
Maria H. Eriksson, PhD – UCL Great Ormond Street Institute of Child Health
Aswin Chari, MD PhD – UCL
Jon Clayden, PhD – UCL Great Ormond Street Institute of Child Health
Hua Xie, PhD – Children's National Hospital
Leigh Sepeta, PhD – Children's National Hospital
Martin Tisdall, MBBS, MD – Great Ormond Street Hospital
torsten Baldeweg, PhD – UCL
Rory Piper, MD PhD – UCL
Rationale:
The thalamus plays a key role in propagating epileptic activity1, yet its nuclei-specific involvement in pediatric focal epilepsy is less understood. Thalamic nuclei have shown distinct efficacy as neuromodulation targets, and their connectivity patterns may predict surgical2 and stimulation outcomes3. This study used multimodal neuroimaging to investigate structural and functional alterations of thalamic nuclei in children with focal epilepsies and to explore associations with post-surgical seizure outcomes.
Methods:
Figure 1 presents the method flowchart. We retrospectively studied 142 children with focal epilepsies—86 with temporal lobe epilepsy (TLE), 37 with frontal lobe epilepsy (FLE), and 19 with posterior quadrant epilepsy (PQE)—alongside 72 healthy controls. The thalamus was divided into four nuclei groups. Volumes were extracted from T1-weighted MRI. Thalamic “hubness,” reflecting its degree of connectedness in whole-brain networks, was estimated using a node strength measure derived from task fMRI connectivity. We compared each epilepsy group to controls and examined clinical associations, including the presence of hippocampal sclerosis (HS; 31 of the 86 TLE cases), a history of focal to bilateral tonic-clonic seizures (FBTCS), and post-surgical seizure outcomes. Multiple comparisons were corrected using the False Discovery Rate method; in the following results, only findings with corrected p-values < .05 are reported.