Network dysfunction underlying verbal fluency deficits in newly diagnosed epilepsy: a resting-state fMRI functional...

Area of Science:

• Neuroscience
• Cognitive Neurology
• Epilepsy Research

Background:

• Verbal fluency impairment is a common cognitive deficit in epilepsy, increasing disease burden.
• Current anti-seizure medications often fail to improve cognition and may worsen it.
• Understanding neural mechanisms in newly diagnosed epilepsy (NDE) is crucial for targeted interventions.

Purpose of the Study:

• To explore brain network abnormalities in NDE patients.
• To investigate the relationship between these abnormalities and verbal fluency deficits.

Main Methods:

• Resting-state functional magnetic resonance imaging (fMRI) in 100 NDE patients and 54 controls.
• Independent component analysis for whole-brain functional connectivity (FC).
• Character and semantic verbal fluency tests (VFTs), correlation, and mediation analyses.

Main Results:

• NDE patients showed reduced intra-network FC in visual, auditory, and sensorimotor networks compared to controls.
• FC in the left auditory network (IFG, STG) correlated with VFT scores.
• Abnormal FC within the left auditory network mediated the link between seizure frequency and verbal fluency deficits.

Conclusions:

• NDE patients exhibit widespread perceptual network dysfunction.
• Abnormal FC of the IFG and STG in the left auditory network is a neural substrate connecting seizure burden to verbal fluency deficits.
• Findings support network-level interventions for epilepsy-related cognitive impairment.