Neuroanatomical and functional alterations of insula in mild traumatic brain injury patients at the acute stage.

Abstract

Cognitive impairment is a major cause of disability and decline in quality of life in mild traumatic brain injury (mTBI) survivors, but the underlying pathophysiology is still poorly understood. The insula has extensive connections to other cortex and is believed to responsible for integrating external and internal processes and controlling cognitive functions. To explore this hypothesis, we investigated early alterations in the gray matter volume (GMV) and brain functional connectivity (FC) of insula in mTBI patients within 7days after injury and any possible correlations with cognitive function. A total of 58 mTBI patients at the acute stage and 32 matched healthy controls were recruited and underwentT1-weighted magnetic resonance imaging (MRI)andresting-state functional MRI scans within 7days of injury. FC was characterized using seed-based region of interest analysis method. The patients' cognitive function was evaluated with Montreal Cognitive Assessment (MoCA) score. The resulting of GMV and FC of insula were correlated with cognitive alterations. We found that the GMV was significantly reduced only in the right insula in mTBI patients and no significant GMV increase was observed in either hemisphere. mTBI patients demonstrated decreased FC in the right parahippocampal gyrus and increased FC in the right supramargianl gyrus. In addition, compared to the healthy controls, the mTBI patients in the acute stage presented a decline in the visuospatial/executive (p = 0.013) and attention (p = 0.038) subcategories. In the mTBI group, the changes in GMV in the right insula were positively correlated with poor attention performance (r = 0.316, p = 0.016). Our data demonstrated alterations of the GMV and resting-stateFC of the right insula in mTBI patients at the acute stage. These early changes in GMV and resting-state FC perhaps serve as a potential biomarker for improving the understanding of cognitive decline for mTBI in the acute setting.