Xiao Zheng, Xiang Jing, Holowka Stephanie, Hunjan Amrita, Sharma Rohit, Otsubo Hiroshi, Chuang Sylvester
Department of Diagnostic Imaging, Brain and Behavior Program, Research Institute, The Hospital for Sick Children, Toronto, Canada.
Pediatr Radiol. 2006 Jan;36(1):16-21. doi: 10.1007/s00247-005-0013-1. Epub 2005 Oct 21.
Magnetoencephalography (MEG) is a novel noninvasive technique for localizing epileptic zones. Tuberous sclerosis complex (TSC) is often associated with medically refractory epilepsy with multiple epileptic zones. Surgical treatment of TSC requires accurate localization of epileptogenic tubers.
The objective of this study was to introduce a new MEG technique, synthetic aperture magnetometry (SAM), to volumetrically localize irritable zones and clarify the correlations between SAM, dipole modeling and anatomical tubers.
Eight pediatric patients with TSC confirmed by clinical and neuroimaging findings were retrospectively studied. MEG data were recorded using a whole-cortex CTF OMEGA system. Sleep deprivation was employed to provoke epileptiform activity. Irritable zones were localized using both dipole modeling and SAM.
MRI detected 42 tubers in the eight patients. Dipole modeling localized 28 irritable zones, and 19 out of the 28 zones were near tubers (19/42, 45%). SAM found 51 irritable zones, and 31 out of the 51 zones were near tubers (31/42, 74%). Among the 51 irritable zones determined by SAM, thirty-five zones were in 1-35 Hz, nine zones were in 35-60 Hz, and seven zones were in 60-120 Hz.
The new method, SAM, yielded very plausible equivalent sources for patients who showed anatomical tubers on MRI. Compared to conventional dipole modeling, SAM appeared to offer increased detection of irritable zones and beneficial volumetric and frequency descriptions.
脑磁图（MEG）是一种用于定位癫痫灶的新型无创技术。结节性硬化症（TSC）常与伴有多个癫痫灶的药物难治性癫痫相关。TSC的手术治疗需要准确确定致痫性结节的位置。
本研究的目的是引入一种新的MEG技术，即合成孔径磁力测量法（SAM），以对激惹区进行容积定位，并阐明SAM、偶极子建模与解剖学结节之间的相关性。
回顾性研究8例经临床和神经影像学检查确诊为TSC的儿科患者。使用全脑CTF OMEGA系统记录MEG数据。采用睡眠剥夺诱发癫痫样活动。使用偶极子建模和SAM对激惹区进行定位。
MRI在8例患者中检测到42个结节。偶极子建模定位了28个激惹区，其中28个区中的19个靠近结节（19/42，45%）。SAM发现了51个激惹区，其中51个区中的31个靠近结节（31/42，74%）。在SAM确定的51个激惹区中，35个区在1 - 35Hz，9个区在35 - 60Hz，7个区在60 - 120Hz。
新方法SAM为MRI上显示有解剖学结节的患者提供了非常合理的等效源。与传统的偶极子建模相比，SAM似乎能增加激惹区的检测，并提供有益的容积和频率描述。
