Thalamocortical structural connectivity in children with focal epilepsy: A diffusion MRI, case-control study.

Area of Science:

• Neuroscience
• Pediatric Neurology
• Medical Imaging

Background:

• Personalized surgical and neuromodulation strategies require patient-specific thalamic connectivity data.
• Such data are currently lacking in pediatric epilepsy cohorts.
• Focal-onset epilepsy in children presents unique challenges for treatment planning.

Purpose of the Study:

• To investigate thalamocortical structural connectivity profiles in children with focal-onset epilepsy.
• To compare these profiles across different seizure-onset zones.
• To explore the relationship between thalamic connectivity and surgical outcomes.

Main Methods:

• A case-control study involving 81 children with focal-onset epilepsy and 63 controls.
• Preoperative 3-Tesla diffusion MRI (dMRI) was used to generate structural connectomes.
• Tractography and parcellations (Lausanne, THOMAS) quantified connectivity strength of four thalamic nuclei (AV, CM, MDPf, PUL).

Main Results:

• Patients exhibited higher overall thalamic structural connectivity strength compared to controls.
• Reduced anteroventral (AV) connectivity was specific to the hippocampal sclerosis group.
• Connectivity and volume asymmetries in thalamic nuclei were associated with postoperative seizure freedom.

Conclusions:

• Pediatric focal epilepsies demonstrate distinct structural thalamocortical connectivity and volumetric profiles.
• Thalamic structural connectivity and volumetric asymmetries are linked to seizure freedom after surgery.
• Findings support the potential for thalamic connectivity signatures in precision surgical planning for pediatric epilepsy.