Herbet Guillaume, Yordanova Yordanka N, Duffau Hugues
Department of Neurosurgery, Gui de Chauliac Hospital, Montpellier University Medical Center, 80, Avenue Augustin Fliche, 34295, Montpellier, France.
Institute for Neuroscience of Montpellier, INSERM 1051, Team "Plasticity of Central Nervous System, Human Stem Cells and Glial Tumors", Saint Eloi Hospital, Montpellier University Medical Center, 34091, Montpellier, France.
Brain Topogr. 2017 Nov;30(6):747-756. doi: 10.1007/s10548-017-0574-y. Epub 2017 Jun 28.
Left spatial neglect is a debilitating condition that may occur after lesion of many cortical territories in the right hemisphere. At the subcortical level, the second and third branches of the right superior longitudinal fasciculus has emerged as strong candidates in conveying information exchanges within the attention networks as their damage has been repeatedly associated to spatial neglect in neuromodulation and neuropsychological studies. Yet, a few cases of spatial neglect have also been observed after damage to the right inferior fronto-occipital fasciculus (IFOF), suggesting an involvement of this associative connectivity in spatial attention. Here we report three rare cases of patients having undergone a wide-awake craniotomy with direct electrostimulation for right temporal glioma. An intraoperative monitoring of spatial cognition was performed using a standard line bisection task. Responsive cortical sites were observed in the supramarginal gyrus and the posterior part of both the middle and superior temporal gyri. Critically, in all patients, significant rightward deviations were observed by the stimulation of the white matter deep in the temporal lobe, along the roof of the inferior horn of the lateral ventricle-a well-known anatomical landmark to identify the IFOF. Disconnection analyses confirmed the high probability of IFOF disconnection during neglect-related stimulations. Taken together, our findings provide support for a role of the right IFOF in spatial cognition. We discuss these results in the light of the newly discovered fronto-parietal connections of the IFOF and suggest that some subcomponents of this tract might be involved in between-system integration within the attention network.
左侧空间忽视是一种致残性病症，可能在右侧半球多个皮质区域受损后出现。在皮质下水平，右侧上纵束的第二和第三分支已成为在注意力网络内传递信息交流的有力候选者，因为在神经调节和神经心理学研究中，它们的损伤一再与空间忽视相关联。然而，在右侧额枕下束（IFOF）受损后也观察到了一些空间忽视病例，这表明这种联合连接在空间注意力中起作用。在此，我们报告三例罕见病例，这些患者因右侧颞叶胶质瘤接受了清醒开颅直接电刺激手术。使用标准的线段二等分任务对空间认知进行术中监测。在缘上回以及颞中回和颞上回后部观察到了反应性皮质位点。关键的是，在所有患者中，刺激颞叶深处沿着侧脑室下角顶部的白质时，均观察到明显的向右偏差——这是识别IFOF的一个著名解剖标志。去连接分析证实了在与忽视相关的刺激过程中IFOF断开的高可能性。综上所述，我们的研究结果支持右侧IFOF在空间认知中的作用。我们根据新发现的IFOF额顶连接来讨论这些结果，并表明该束的一些子成分可能参与注意力网络内的系统间整合。
