Department of Neurosurgery, Hôpital Gui de Chauliac, Montpellier University Medical Center, Montpellier, France.
J Neurosurg. 2012 Sep;117(3):466-73. doi: 10.3171/2012.6.JNS111981. Epub 2012 Jul 13.
Preservation of the visual field in glioma surgery, especially avoidance of hemianopia, is crucial for patients' quality of life, particularly for driving. Recent studies used tractography or cortical occipital stimulation to try to avoid visual deficit. However, optic radiations have not been directly mapped intraoperatively. The authors present, for the first time to their knowledge, a consecutive series of awake surgeries for cerebral glioma with intrasurgical identification and preservation of visual pathways using subcortical electrical mapping.
Fourteen patients underwent awake resection of a glioma (1 WHO Grade I, 11 WHO Grade II, 2 WHO Grade III) involving the optic radiations. The patients had no presurgical visual field deficit. Intraoperatively, a picture-naming task was used, with presentation of 2 objects situated diagonally on a screen divided into 4 quadrants. An image was presented in the quadrant to be saved and another image was presented in the opposite quadrant. Direct subcortical electrostimulation was repeatedly performed without the patient's knowledge, until optic radiations were identified (transient visual disturbances). All patients underwent an objective visual field assessment 3 months after surgery.
All patients experienced visual symptoms during stimulation. These disturbances led the authors to stop the tumor resection at that level. Postoperatively, only 1 patient had a permanent hemianopia, despite an expected quadrantanopia in 12 cases. The mean extent of resection was 93.6% (range 85%-100%).
Online identification of optic radiations by direct subcortical electrostimulation is a reliable and effective method to avoid permanent hemianopia in surgery for gliomas involving visual pathways.
在胶质瘤手术中保留视野，特别是避免偏盲，对患者的生活质量至关重要，尤其是对驾驶能力而言。最近的研究使用束路追踪或皮质枕叶刺激来试图避免视觉缺陷。然而，视放射尚未在术中直接进行定位。作者首次报告了一系列连续的清醒开颅手术，通过皮质下电刺激术中识别和保留视觉通路，用于治疗累及视放射的脑胶质瘤。
14 名患者接受了涉及视放射的胶质瘤（1 级 WHO，11 级 WHO，2 级 WHO）的清醒切除术。患者术前无视野缺损。术中使用命名任务，在屏幕上对角呈现 2 个物体，屏幕分为 4 个象限。将图像显示在要保存的象限中，而将另一个图像显示在对侧象限中。在患者不知情的情况下，反复进行直接皮质下电刺激，直到识别出视放射（短暂的视觉障碍）。所有患者在术后 3 个月均接受了客观的视野评估。
所有患者在刺激过程中均出现视觉症状。这些干扰导致作者在该层面停止肿瘤切除。术后，尽管 12 例患者预计会出现象限盲，但仅有 1 例患者出现永久性偏盲。平均切除范围为 93.6%（范围 85%-100%）。
通过直接皮质下电刺激术中实时识别视放射是一种可靠且有效的方法，可避免涉及视通路的胶质瘤手术中的永久性偏盲。
