Della Puppa Alessandro, De Pellegrin Serena, Lazzarini Anna, Gioffrè Giorgio, Rustemi Oriela, Cagnin Annachiara, Scienza Renato, Semenza Carlo
Departments of 1 Neurosurgery and.
J Neurosurg. 2015 May;122(5):1038-41. doi: 10.3171/2014.10.JNS14261. Epub 2014 Nov 21.
Preservation of calculation processing in brain surgery is crucial for patients' quality of life. Over the last decade, surgical electrostimulation was used to identify and preserve the cortical areas involved in such processing. Conversely, subcortical connectivity among different areas implicated in this function remains unclear, and the role of surgery in this domain has not been explored so far. The authors present the first 2 cases in which the subcortical functional sites involved in calculation were identified during right parietal lobe surgery. Two patients affected by a glioma located in the right parietal lobe underwent surgery with the aid of MRI neuronavigation. No calculation deficits were detected during preoperative assessment. Cortical and subcortical mapping were performed using a bipolar stimulator. The current intensity was determined by progressively increasing the amplitude by 0.5-mA increments (from a baseline of 1 mA) until a sensorimotor response was elicited. Then, addition and multiplication calculation tasks were administered. Corticectomy was performed according to both the MRI neuronavigation data and the functional findings obtained through cortical mapping. Direct subcortical electrostimulation was repeatedly performed during tumor resection. Subcortical functional sites for multiplication and addition were detected in both patients. Electrostimulation interfered with calculation processing during cortical mapping as well. Functional sites were spared during tumor removal. The postoperative course was uneventful, and calculation processing was preserved. Postoperative MRI showed complete resection of the tumor. The present preliminary study shows for the first time how functional mapping can be a promising method to intraoperatively identify the subcortical functional sites involved in calculation processing. This report therefore supports direct electrical stimulation as a promising tool to improve the current knowledge on calculation processing connectivity.
在脑外科手术中保留计算处理能力对患者的生活质量至关重要。在过去十年中，手术电刺激被用于识别和保留参与此类处理的皮质区域。相反，参与该功能的不同区域之间的皮质下连接尚不清楚，并且手术在这一领域的作用迄今尚未得到探索。作者报告了首例2例在右侧顶叶手术中识别出参与计算的皮质下功能位点的病例。两名患有位于右侧顶叶的神经胶质瘤的患者在MRI神经导航辅助下接受了手术。术前评估未发现计算缺陷。使用双极刺激器进行皮质和皮质下映射。通过以0.5 mA的增量逐步增加幅度（从1 mA的基线开始）来确定电流强度，直到引发感觉运动反应。然后，进行加法和乘法计算任务。根据MRI神经导航数据和通过皮质映射获得的功能结果进行皮质切除术。在肿瘤切除过程中反复进行直接皮质下电刺激。在两名患者中均检测到了参与乘法和加法的皮质下功能位点。电刺激在皮质映射期间也干扰了计算处理。在肿瘤切除过程中保留了功能位点。术后过程顺利，计算处理能力得以保留。术后MRI显示肿瘤完全切除。本初步研究首次表明功能映射如何能够成为术中识别参与计算处理的皮质下功能位点的一种有前景的方法。因此，本报告支持直接电刺激作为一种有前景的工具，以增进我们对计算处理连接性的现有认识。
