Modeling of post-surgical brain and skull defects in the EEG inverse problem with the boundary element method
Modeling of post-surgical brain and skull defects in the EEG inverse problem with the boundary element method
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DOI：
10.1016/s1388-2457(01)00714-3
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发表时间：
2002-01-01
影响因子：
4.7
通讯作者：
Gotman, J
中科院分区：
文献类型：
--
作者：
Bénar, CG;Gotman, J
目的：为了获得准确的EEG逆解的患者接受手术，我们已经研究了将脑和颅骨缺陷在现实的头models.Methods的可行性和影响：我们首先测量的导电性的甲基丙烯酸酯用于颅骨成形术。然后，我们设计了真实的边界元方法头部模型与颅骨钻孔，甲基丙烯酸酯塞或颞叶切除。我们模拟了位于缺陷附近的偶极子在71个电极位置（10/10系统）产生的电势。然后，我们使用无缺陷的头部模型在这些电位上拟合偶极子。我们还运行模拟在嘈杂的情况下，并具有较高的颅骨和脑脊液（CSF）conductivity.Results：最大的错误被发现为钻孔，定位误差高达20毫米的径向偶极子位于30毫米以下的孔和放大系数为8。甲基丙烯酸酯塞导致高达5 mm和0.5的误差;切除仅导致2 mm和1.3的误差。有噪声时的结果与无噪声时的结果一致。颅骨电导率加倍导致误差减少了10- 20%，而脑脊液电导率加倍则使误差增加了31%。结论：我们已经表明，当源位于缺陷附近时，在真实的头部模型中加入颅骨缺陷是很重要的。非典型前颞叶切除术大小的脑腔可以省略，对偶极子定位没有显著影响。(C)2002爱思唯尔科学爱尔兰有限公司保留所有权利。
Objectives: In order to obtain accurate EEG inverse solutions in patients subjected to surgery, we have studied the feasibility and influence of incorporating brain and skull defects in realistic head models.Methods: We first measured the conductivity of the methacrylate used for cranioplasty. Then, we designed realistic boundary element method head models with a skull burr hole, a methacrylate plug or a temporal-lobe resection. We simulated the potentials that would be produced at 71 electrode locations (10/10 system) by dipoles located near the defects. Then, we fitted dipoles on these potentials using a defect-free head model. We also ran simulations in a noisy situation and with higher skull and cerebrospinal fluid (CSF) conductivity.Results: The largest errors were found for burr holes, with a localization error up to 20 mm for a radial dipole located 30 mm below the hole and an amplification factor of 8. Methacrylate plugs lead to errors up to 5 mm and 0.5; the resection only lead to errors of 2 mm and 1.3. Results obtained with noise were consistent with those obtained without noise. Doubling the skull conductivity led to errors that were reduced by 10-20%, while doubling CSF conductivity increased the errors by up to 31%.Conclusions: We have shown that it is important to incorporate skull defects in realistic head models when sources are located near the defects and precision is sought. Brain cavities of the size of atypical anterior temporal lobe resection may be omitted without a significant impact on dipole localization. (C) 2002 Elsevier Science Ireland Ltd. All rights reserved.