Sutherling W W, Akhtari M, Mamelak A N, Mosher J, Arthur D, Sands S, Weiss P, Lopez N, DiMauro M, Flynn E, Leah R
Huntington Medical Research Institutes, Pasadena, CA, USA.
Brain Topogr. 2001 Winter;14(2):101-16. doi: 10.1023/a:1012940812742.
Localizations were compared for the same human seizure between simultaneously measured MEG and iEEG, which were both co-registered to MRI. The whole-cortex neuromagnetometer localized a dipole in a sphere phantom, co-registered to the MEG sensor array, with an error of 1.4 mm. A focal afterdischarge seizure was induced in a patient with partial epilepsy, by stimulation at a subdural electrocorticography (ECoG) electrode with a known location, which was co-registered to the MRI and to the MEG sensor array. The simultaneous MEG and ECoG during the 30-second seizure was measured and analyzed using the single, moving dipole model, which is the localization model used clinically. The dipole localizations from simultaneous whole cortex 68-channel MEG and 64-channel ECoG were then compared for the repetitive spiking at six different times during the seizure. There were two main regions of MEG and ECoG activity. The locations of these regions were confirmed by determining the location clusters of 8,000 dipoles on ECoG at consecutive time points during the seizure. The mean distances between the stimulated electrode location versus the dipole location of the MEG and versus the dipole location of the ECoG were each about one (1) centimeter. The mean distance between the dipole locations of the MEG versus the dipole locations of the ECoG was about 2 cm. These errors were compared to errors of MEG and ECoG reported previously for phantoms and for somatosensory evoked responses (SER) in patients. Comparing the findings from the present study to those from prior studies, there appeared to be the expected stepwise increase in mean localization error progressing from the phantom, to the SER, to the seizure.
对同时测量的MEG和iEEG在同一人类癫痫发作时的定位进行了比较，二者均与MRI进行了配准。全脑磁强计在与MEG传感器阵列配准的球形模型中定位一个偶极子，误差为1.4毫米。通过刺激已知位置的硬膜下皮层脑电图（ECoG）电极，在一名部分性癫痫患者中诱发局灶性放电后癫痫发作，该电极与MRI以及MEG传感器阵列进行了配准。在30秒的癫痫发作期间，同时测量MEG和ECoG，并使用单一移动偶极子模型进行分析，这是临床上使用的定位模型。然后比较了在癫痫发作期间六个不同时间点重复放电时，同时进行的全脑68通道MEG和64通道ECoG的偶极子定位。MEG和ECoG活动有两个主要区域。通过确定癫痫发作期间连续时间点ECoG上8000个偶极子的位置簇，确认了这些区域的位置。刺激电极位置与MEG偶极子位置以及与ECoG偶极子位置之间的平均距离均约为1厘米。MEG偶极子位置与ECoG偶极子位置之间的平均距离约为2厘米。将这些误差与先前报道的针对模型以及患者体感诱发电位（SER）的MEG和ECoG误差进行了比较。将本研究的结果与先前研究的结果进行比较，从模型到SER再到癫痫发作，平均定位误差似乎呈现出预期的逐步增加。
