Abnormal functional connectivity profiles predict drug responsiveness in patients with temporal lobe epilepsy

Area of Science:

• Neuroscience
• Epilepsy Research
• Medical Imaging

Background:

• Temporal Lobe Epilepsy (TLE) is a chronic neurological disorder characterized by recurrent seizures.
• Predicting drug responsiveness in TLE is crucial for effective patient management.
• Understanding functional brain connectivity alterations is key to identifying TLE subtypes and treatment outcomes.

Purpose of the Study:

• To investigate functional connectivity differences between seizure-free and non-seizure-free TLE patients.
• To identify neuroimaging predictors for antiseizure medication responsiveness in TLE.
• To explore the relationship between brain network disruptions and seizure control in TLE.

Main Methods:

• Prospective recruitment of 52 TLE patients with undetermined medication responsiveness and 55 healthy controls.
• Acquisition of functional magnetic resonance imaging (fMRI) data during a verbal fluency task.
• Analysis of activation profiles, task-residual functional connectivity (trFC), and generalized psychophysiological interactions (gPPI), alongside logistic regression for predictive modeling.

Main Results:

• Non-seizure-free TLE patients exhibited attenuated trFC between the hippocampus and bilateral brain networks compared to seizure-free patients.
• Significant group differences in gPPI were observed in the precuneus, middle frontal gyrus, and inferior parietal lobule.
• A predictive model demonstrated high accuracy (AUC = .879) in identifying non-seizure-free patients.

Conclusions:

• Disrupted functional connectivity between the hippocampus and key brain networks (Default Mode Network, Cognitive Control Network, language network) is associated with persistent seizures and language decline in TLE.
• Hippocampal connectivity abnormalities, particularly to the Default Mode Network, serve as predictive biomarkers for drug responsiveness in TLE, independent of hippocampal sclerosis.