Early recovery of interhemispheric functional connectivity after corpus callosotomy

Abstract

Objective To investigate whether interhemispheric functional connectivity (FC) recovers in the first year after total callosotomy. Methods Eight epilepsy patients undergoing total callosotomy were recruited. Resting‐state functional magnetic resonance imaging was acquired before and after surgery. The precallosotomy and postcallosotomy interhemispheric and intrahemispheric FC was analyzed by using graph theory and voxel‐mirrored homotopic connectivity (VMHC). The seizure outcome was scored using the Engel surgical outcome scale. Results After callosotomy (mean postoperative interval = 4 months), the network density, average node degree, characteristic path length, and global efficiency of the whole interhemispheric networks were significantly decreased, compared to those in the precallosotomy networks. However, postcallosotomy interhemispheric FC and homotopic VMHC were not significantly reduced in bilateral frontal and temporal lobes. The network density and average node degree of the intrahemispheric networks were significantly increased. The characteristic path length and global efficiency of intrahemispheric networks were unchanged. Significance The interhemispheric FC may be preserved or recover early within the first postoperative year after total callosotomy, particularly in the frontal and anterior temporal lobes.

Relationship between illness duration, corpus callosum changes, and sustained attention dysfunction in major depressive disorder

“…First, the cortical homotopic regions connected by CC sub-regions 2 (premotor and supplementary motor cortices) and 5 (parietal, temporal, and occipital cortices) are much larger than the significant clusters identified in the voxel-wise VMHC correlation analyses, which may lead to a disproportional change pattern of the measured functional and structural connectivity. Second, although the CC serves as the major pathway for inter-hemispheric information transfer (58,59), there is mounting evidence that other pathways contribute to inter-hemispheric synchronization, e.g., intact functional coupling between the hemispheres in individuals with complete agenesis of the CC (60) and early recovery of inter-hemispheric functional connectivity in epilepsy patients after total corpus callosotomy (61).…”

Is bilateral corticospinal connectivity impaired in patients with chronic obstructive pulmonary disease?

“…Interestingly, a recent study reported the recovery of the interhemispheric pathway within the first year following corpus callosotomy in epilepsy patients (Hung et al . 2019). Structural strengthening of the pathways between the motor areas and the cerebellum was reported in a complete commissurotomy patient, indicating that structural compensation is possible (Nomi et al .…”

The structural basis for interhemispheric functional connectivity: Evidence from individuals with agenesis of the corpus callosum

“…To evaluate the overall network topology of FC in AgCC subjects, we adopted a graph-theoretic approach ( Hung et al, 2019 ). For the region of interest (ROI) based network analyses, the mean time course was extracted from 116 cortical and subcortical ROIs from the automatic anatomic labeling (AAL) atlas.…”

“…Lastly, we used topographic theory on DTI and rs-fMRI data to study the global SC and FC at the network level in AgCC and HC. VMHC quantifies the FC between each voxel in one hemisphere and its mirrored counterpart in the other hemisphere ( Hung et al, 2019 , Owen et al, 2013b , Ridley et al, 2016 ). Graph-based approaches model the brain as a complex network represented graphically by a collection of nodes and edges.…”