Objective

In the event of neural injury, the homologous contralateral brain areas may play a compensatory role to avoid or limit the functional loss. However, this dynamic strategy of functional redistribution is not clearly established, especially in the pathophysiological context of diffuse low-grade glioma. Our aim here was to assess the extent to which unilateral tumor infiltration of the insula dynamically modulates the functional connectivity of the contralesional one.

Methods

Using resting-state functional connectivity MRI, a seed-to-ROI approach was employed in 52 insula-centered glioma patients (n = 30 left and 22 right) compared with 19 age-matched healthy controls.

Results

Unsurprisingly, a significant decrease of the inter-insular connectivity was observed in both patient groups. More importantly, the analyses revealed a significant increase of the contralesional insular connectivity towards both cerebral hemispheres, especially in cortical areas forming the visual and the sensorimotor networks. This functional redistribution was not identified when the analyses were performed on three control regions for which the homologous area was not impaired by the tumor. This overall pattern of results indicates that massive infiltration of the insular cortex causes a significant redeployment of the contralesional functional connectivity.

Conclusion

This general finding suggests that the undamaged insula plays a role in the functional compensation usually observed in this patient population, and thus provides compelling support for the concept of homotopic functional plasticity in brain-damaged patients.

中文翻译：

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以岛叶为中心的弥漫性低级别胶质瘤功能连接的同位重分布

 客观的

当神经损伤时，对侧同源脑区可能发挥代偿作用，避免或限制功能丧失。然而，这种功能重新分配的动态策略尚未明确建立，特别是在弥漫性低级别胶质瘤的病理生理背景下。我们的目的是评估单侧岛叶肿瘤浸润动态调节对侧岛叶功能连接的程度。

 方法

使用静息态功能连接 MRI，对 52 名脑岛中心神经胶质瘤患者（ n = 30 名左侧和 22 名右侧）采用种子到 ROI 方法，并与 19 名年龄匹配的健康对照进行比较。

 结果

不出所料，两组患者的岛间连接均显着下降。更重要的是，分析显示，对侧岛叶与两个大脑半球的连接显着增加，特别是在形成视觉和感觉运动网络的皮质区域。当对同源区域未受到肿瘤损害的三个对照区域进行分析时，没有发现这种功能重新分布。结果的总体模式表明岛叶皮质的大量浸润导致对侧功能连接的显着重新部署。

 结论

这一总体发现表明，未受损的岛叶在该患者群体中通常观察到的功能补偿中发挥着作用，从而为脑损伤患者的同伦功能可塑性的概念提供了令人信服的支持。