Impaired prefrontal cortex-thalamus pathway in intractable temporal lobe epilepsy with aberrant executive control function: MRI evidence

Abstract

ObjectivesThis study aimed to assess structural and functional connectivity alterations of the prefrontal cortex (PFC)-thalamus axis in individuals with unilateral intractable temporal lobe epilepsy (TLE) showing executive control function (ECF) impairment and to explore the potential mechanism. MethodsThirty-eight individuals with intractable left TLE and twenty-nine healthy controls (HCs) were recruited for diffusion tensor imaging (DTI) and resting-state fMRI (rs-fMRI) scanning. According to the ECF state, patients were assigned to normal and impaired ECF groups. Functional connectivity (FC) and probabilistic diffusion tractography of the PFC- thalamus pathway were assessed. The general linear model (GLM) was employed for comparing fiber number (FN) and FC between groups. Pearson correlation analysis of FC, FN and ECF test scores was performed. ResultsFC and FN of left DLPFC-thalamus pathway were significantly increased in the impaired ECF group compared with the normal ECF and HC groups. However, FC and FN were not correlated with ECF score. ConclusionsThese findings indicated increased connectivity between DLPFC and the ipsilateral thalamus might reflect nonfunctional nerve remodeling along the seizure pathway. SignificanceThe present findings suggest that the DLPFC-thalamus pathway may be an important structure for exploring the mechanisms of TLE with ECF dysfunction.