Altered anterior‐posterior connectivity through the arcuate fasciculus in temporal lobe epilepsy

Abstract

How the interactions between cortices through a specific white matter pathway change during cognitive processing in patients with epilepsy remains unclear. Here, we used surface-based structural connectivity analysis to examine the change in structural connectivity with Broca’s area/the right Broca’s homologue in the lateral temporal and inferior parietal cortices through the arcuate fasciculus (AF) in 17 patients with left temporal lobe epilepsy (TLE) compared with 17 healthy controls. Then, we investigated its functional relevance to the changes in task-related responses and task-modulated functional connectivity with Broca’s area/the right Broca’s homologue during a semantic classification task of a single word. The structural connectivity through the AF pathway and task-modulated functional connectivity with Broca’s area decreased in the left midtemporal cortex. Furthermore, task-related response decreased in the left mid temporal cortex that overlapped with the region showing a decrease in the structural connectivity. In contrast, the region showing an increase in the structural connectivity through the AF overlapped with the regions showing an increase in task-modulated functional connectivity in the left inferior parietal cortex. These structural and functional changes in the overlapping regions were correlated. The results suggest that the change in the structural connectivity through the left frontal–temporal AF pathway underlies the altered functional networks between the frontal and temporal cortices during the language-related processing in patients with left TLE. The left frontal–parietal AF pathway might be employed to connect anterior and posterior brain regions during language processing and compensate for the compromised left frontal–temporal AF pathway.

Cortical thickness variation of the maternal brain in the first 6 months postpartum: associations with parental self-efficacy

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The left dorsolateral prefrontal cortex and caudate pathway: New evidence for cue-induced craving of smokers

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Dynamic gray matter and intrinsic activity changes after epilepsy surgery

“…Significant gray matter atrophy (GMA) has been shown in ipsilateral extratemporal structures including ipsilateral thalamus, parietal lobe, cingulate gyrus, and regions contralateral to the epileptogenic focus, 3,7,8 which was also found to be progressive with the course of epilepsy, 9,10 even in patients with a prolonged period of seizure freedom 11 . Furthermore, studies also demonstrated disturbed functional brain networks including networks connected to the mesial temporal structures, the thalamo‐cortical circuit, default mode network (DMN) at resting state, and cognitive task‐related brain networks 12–20 …”

“…11 Furthermore, studies also demonstrated disturbed functional brain networks including networks connected to the mesial temporal structures, the thalamo-cortical circuit, default mode network (DMN) at resting state, and cognitive task-related brain networks. [12][13][14][15][16][17][18][19][20] Surgical procedures, as ATL the most adopted, are assumed to resect the most important component or the core hub of the epileptic network, rendering post-surgical seizure freedom. The brain would be reorganized structurally and functionally after surgery which may be related to postoperative seizure outcome and neuropsychological changes.…”