Dipole localization using simulated intracerebral EEG

被引:23
作者
Chang, N
Gulrajani, R
Gotman, J
机构
[1] McGill Univ, Montreal Neurol Inst, Dept Neurophysiol, Montreal, PQ H3A 2B4, Canada
[2] McGill Univ, Dept Physiol, Montreal, PQ H3A 2B4, Canada
基金
加拿大健康研究院;
关键词
depth EEG; inverse problem; beamforming; RAP-MUSIC; source localization; dipole modeling;
D O I
10.1016/j.clinph.2005.07.002
中图分类号
R74 [神经病学与精神病学];
学科分类号
摘要
Objective: In the clinical interpretation of intracerebral EEGs, epileptic foci are commonly identified by visually analyzing the amplitude of the potentials. This is potentially misleading since electrodes record activity from several sources, but the nearest ones generate large amplitudes that can overpower distant sources. Our objective was to improve foci detection in intracerebral recordings by applying source localization methods. Methods: Data were simulated by placing 3 sources in a semi-infinite medium near 3 intracerebral electrodes. Potentials were generated and contaminated with white and correlated noise. Two inverse problem algorithms, beamforming and RAP-MUSIC, were used to calculate equivalent dipoles. Results: Simulations for each noise types showed that the two methods detected the source locations accurately, with RAP-MUSIC reporting lower orientation errors. With correlated noise, beamforming reconstructed original source waveforms poorly. A spatial resolution analysis was performed, in which beamforming adequately distinguished sources separated by 1.2 cm, whereas RAP-MUSIC separated Sources as close as 0.4-0.6 cm. Conclusions: Both source localization methods proved useful in detecting the location of dipolar Sources based on simulated intracerebral potentials. For all simulations, RAP-MUSIC was more accurate than beamforming. Significance: It is possible to use source localization methods traditionally applied to scalp recordings for improving source detection from intracerebral recordings. (c) 2005 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.
引用
收藏
页码:2707 / 2716
页数:10
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