Cortical current imaging in human infants with babySQUID

使用babySQUID 对人类婴儿进行皮质电流成像

• 批准号: 7186020
• 负责人: Yoshio Okada
• 金额: $ 19.69万
• 依托单位: UNIVERSITY OF NEW MEXICO
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-06-01 至 2009-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7186020
• 关键词: Adult; Affect; Appearance; Area; Beds; Biomedical Research; Birth; Body part; Brain; Brain region; Cerebral Palsy; Characteristics; Child; Depressed mood; Development; Electrical Resistance; Electroencephalography; Epilepsy; Evolution; Head; Human; Image; Infant; Infarction; Invasive; Life; Localized; Magnetoencephalography; Measurement; Measures; Neurons; Noise; Operative Surgical Procedures; Patients; Pattern; Perinatal; Phase; Property; Research Personnel; Resolution; Scalp structure; Side; Signal Transduction; Sleep; Slow-Wave Sleep; Source; Squid; Surface; Surgical sutures; System; Theta Rhythm; Thick; Time; base; cranium; density; design; falls; gamma-Aminobutyric Acid; hemiparesis; improved; infancy; instrument; magnetic field; neocortical; neonate; nervous system disorder; next generation; programs; prototype; relating to nervous system; response; sensor; simulation; tool

DESCRIPTION (provided by applicant): This exploratory project will evaluate the usefulness of a newly developed instrument called baby SQUID for assessing brain functions in human infants. The baby SQUID is a high-resolution magnetoencephalography (MEG) system designed to detect cortical activity in infants with an unprecedented level of sensitivity and spatial resolution. An array of 76 MEG sensors can be placed 6 mm from the scalp, rather than -20 mm as in conventional MEGs. Since the combined thickness of scalp and skull is -4 mm in neonates, MEG signals can be measured at 10 mm, rather than 25 mm, from brain surface. Since MEG signals fall off as a square of distance, they should be as much as 5 times stronger for the baby SQUID compared to conventional MEG systems. In the next phase of development, the gap will be reduced from 6 mm to 3 mm so that the signals would be about 10 times stronger. The spatial resolution is about 3-4 times higher than the conventional systems because of the smaller gap and higher sensor density (12-14 mm channel spacing instead of 30-40 mm for adult MEGs). Preliminary results show that spontaneous activity can be measured clearly with high SNR and evoked activity can be measured with very little signal averaging from healthy infants. Unlike EEG, MEG signals are not distorted by the fontanels and sutures in the skull. This property of MEG greatly simplifies the interpretation of the signals. Due to these characteristics of MEG and baby SQUID, it is possible to perform a cortical current imaging (CCI). Instead of the dipole approach, our simulation study shows that the baby SQUID provides images of the cortical neuronal current distribution. We propose to use the CCI to determine cortical activity in healthy infants and infants with cerebral palsy (CP) and with neocortical epilepsy. Aim 1 will characterize the spontaneous activity from different regions of the brain with a focus on elucidating the basis of localized spindles seen in healthy babies. We predict that the generators can be identified due to the high sensitivity and spatial resolution. Aim 2 will measure spontaneous and somatically evoked activity in CP infants with hemiparesis. The evoked response will localize the projection areas of different parts of the body. Preliminary studies have shown a profound level of plasticity in both the affected and unaffected cortices. We predict that the spontaneous activity from these specific projection areas, identified by the CCI, is abnormal in the unaffected as well as affected side. Aim 3 will measure the epileptiform activity in infants with neocortical epilepsy. We predict that the CCI will be able to distinguish functionally discrete areas in the zone producing the spikes. Human brain development is an area of biomedical research that is still in its infancy because of difficulties in finding tools that are safe and yet powerful. We believe that this project, if successful, will open new windows into brain development in healthy infants as well as infants with various neurological disorders.

描述（由申请人提供）：本探索性项目将评估一种新开发的称为婴儿SQUID的仪器对评估人类婴儿大脑功能的有用性。婴儿SQUID是一种高分辨率脑磁图（MEG）系统，旨在以前所未有的灵敏度和空间分辨率检测婴儿的皮质活动。76个脑磁图传感器阵列可以放置在距离头皮6毫米的地方，而不是像传统的脑磁图那样放置在距离头皮20毫米的地方。由于新生儿头皮和颅骨的总厚度为-4毫米，因此MEG信号可以在距离大脑表面10毫米处测量，而不是25毫米。由于MEG信号随着距离的平方而下降，因此与传统MEG系统相比，它们对婴儿SQUID的强度应该高达5倍。在下一阶段的开发中，该间隙将从6毫米缩小到3毫米，从而使信号强度提高10倍左右。由于缝隙更小，传感器密度更高（通道间距为12-14 mm，而不是成人meg的30-40 mm），因此空间分辨率约为传统系统的3-4倍。初步结果表明，健康婴儿的自发活动可以用高信噪比清晰地测量，诱发活动可以用很少的信号平均测量。与脑电图不同的是，脑磁图的信号不会被颅囟和颅骨缝所扭曲。MEG的这一特性大大简化了信号的解释。由于MEG和幼SQUID的这些特征，可以进行皮质电流成像（CCI）。我们的模拟研究表明，代替偶极子方法，婴儿SQUID提供皮层神经元电流分布的图像。我们建议使用CCI来确定健康婴儿和脑瘫（CP）和新皮质癫痫婴儿的皮质活动。目的1将描述来自大脑不同区域的自发活动，重点是阐明在健康婴儿中看到的局部纺锤波的基础。我们预测，由于高灵敏度和空间分辨率，可以识别出发生器。目的2将测量患有偏瘫的CP婴儿的自发和躯体诱发活动。唤起的反应将定位身体不同部位的投射区域。初步研究表明，受影响的和未受影响的大脑皮层都具有高度的可塑性。我们预测，由CCI识别的这些特定投影区域的自发活动在未受影响的一侧和受影响的一侧都是异常的。目的3将测量新生儿新皮质癫痫的癫痫样活动。我们预测CCI将能够在产生尖峰的区域中区分功能离散的区域。人类大脑发育是生物医学研究的一个领域，目前仍处于起步阶段，因为很难找到安全而强大的工具。我们相信，如果这个项目成功，将为健康婴儿以及患有各种神经系统疾病的婴儿的大脑发育打开新的窗口。