Decreased homotopic functional connectivity in traumatic brain injury

Abstract

Introduction Homotopic functional connectivity (HoFC), the synchrony in activity patterns between homologous brain regions, is a fundamental characteristic of resting-state functional connectivity (RsFC). Methods We examined the difference in HoFC, computed as the correlation between atlas-based regions and their counterpart on the opposite hemisphere, in 16 moderate–severe traumatic brain injury patients (msTBI) and 36 healthy controls. Regions of decreased HoFC in msTBI patients were further used as seeds for examining differences between groups in correlations with other brain regions. Finally, we computed logistic regression models of regional HoFC and fractional anisotropy (FA) of the corpus callosum (CC). Results TBI patients exhibited decreased HoFC in the middle and posterior cingulate cortex, thalamus, superior temporal pole, and cerebellum III. Furthermore, decreased RsFC was found between left cerebellum III and right parahippocampal cortex and vermis, between superior temporal pole and left caudate and medial left and right frontal orbital gyri. Thalamic HoFC and FA of the CC discriminate patients as msTBI with a high accuracy of 96%. Conclusion TBI is associated with regionally decreased HoFC. Moreover, a multimodality model of interhemispheric connectivity allowed for a high degree of accuracy in disease discrimination and enabled a deeper understanding of TBI effects on brain interhemispheric reorganization post-TBI.

Reduced homotopic interhemispheric connectivity in psychiatric disorders: evidence for both transdiagnostic and disorder specific features

“…Strong homotopic rsFC has also been found in the middle occipital gyrus (MOG), inferior parietal lobule (IPL), precentral gyrus (preCG), middle frontal gyrus (MFG), inferior temporal gyrus (ITG), superior temporal gyrus (STG), and anterior insula (aINS) across different tasks (Toro et al ., 2008 ). Homotopic interhemispheric rsFC can be extensively reduced by traumatic brain injury (Li et al ., 2017a ; Mäki-Marttunen et al ., 2013 ; Ovadia-Caro et al ., 2012 ; Raizman et al ., 2022 ; Song et al ., 2022 ) and predict the degree of consciousness or coma severity in disorders of consciousness (Mäki-Marttunen et al ., 2013 ; Ovadia-Caro et al ., 2012 ). Both animal model (Bukhari et al ., 2018 ) and human (Nir et al ., 2022 ) studies have also reported that loss of consciousness produced by general anesthesia reduces the strength of homotopic interhemispheric rsFC and correspondingly increases hemispheric lateralization.…”

ENIGMA’s simple seven: Recommendations to enhance the reproducibility of resting-state fMRI in traumatic brain injury

“…Specifically, TBI patients demonstrated increased prefrontal connectivity in SC-FC networks, relative to controls. In a study by Raizman and colleagues (2023) , the discriminatory power of their logistic regression models yielded higher accuracy if FA (fractional anisotropy) of the corpus callosum was modeled alongside functional connectivity values. Despite these promising multimodal findings, these studies often derived the structural connectivity measures in the form of a single score (e.g., FA value of a white matter tract).…”