BACKGROUND Rett syndrome is a neurodevelopmental disorder caused by a mutation in the X-linked MECP2 gene. Individuals with Rett syndrome typically develop normally until around 18 months of age before undergoing a developmental regression, and the disorder can lead to cognitive, motor, sensory, and autonomic dysfunction. Understanding the mechanism of developmental regression represents a unique challenge when viewed through a neuroscience lens. Are circuits that were previously established erased, and are new ones built to supplant old ones? One way to examine circuit-level changes is with the use of electroencephalography (EEG). Previous studies of the EEG in individuals with Rett syndrome have focused on morphological characteristics, but few have explored spectral power, including power as an index of brain function or disease severity. This study sought to determine if EEG power differs in girls with Rett syndrome and typically developing girls and among girls with Rett syndrome based on various clinical characteristics in order to better understand neural connectivity and cortical organization in individuals with this disorder. METHODS Resting state EEG data were acquired from girls with Rett syndrome (n = 57) and typically developing children without Rett syndrome (n = 37). Clinical data were also collected for girls with Rett syndrome. EEG power across several brain regions in numerous frequency bands was then compared between girls with Rett syndrome and typically developing children and power in girls with Rett syndrome was compared based on these clinical measures. 1/ƒ slope was also compared between groups. RESULTS Girls with Rett syndrome demonstrate significantly lower power in the middle frequency bands across multiple brain regions. Additionally, girls with Rett syndrome that are postregression demonstrate significantly higher power in the lower frequency delta and theta bands and a significantly more negative slope of the power spectrum. Increased power in these bands, as well as a more negative 1/ƒ slope, trended with lower cognitive assessment scores. CONCLUSIONS Increased power in lower frequency bands is consistent with previous studies demonstrating a "slowing" of the background EEG in Rett syndrome. This increase, particularly in the delta band, could represent abnormal cortical inhibition due to dysfunctional GABAergic signaling and could potentially be used as a marker of severity due to associations with more severe Rett syndrome phenotypes.

中文翻译：

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脑电波频谱功率可作为Rett综合征女孩皮质功能和疾病严重程度的标志。

背景技术Rett综合征是由X连锁的MECP2基因中的突变引起的神经发育障碍。患有Rett综合征的个体通常会正常发育直至18个月左右，然后再经历发育退化，该疾病可能导致认知，运动，感觉和自主神经功能障碍。从神经科学的角度来看，了解发育退化的机制代表着一个独特的挑战。是否清除了以前建立的电路，并且建立了新的电路以取代旧的电路？检查电路级变化的一种方法是使用脑电图（EEG）。先前对Rett综合征患者的EEG的研究集中在形态特征上，但很少探索频谱功率，包括作为脑功能或疾病严重程度指标的功率。这项研究试图根据各种临床特征来确定具有Rett综合征的女孩（通常是发育中的女孩）和具有Rett综合征的女孩之间的脑电图能力是否有所不同，以便更好地了解患有这种疾病的个体的神经连接性和皮质组织。方法静息状态脑电图数据来自患有Rett综合征的女孩（n = 57）和典型的未患有Rett综合征的儿童（n = 37）。还收集了患有Rett综合征的女孩的临床数据。然后比较具有瑞特综合症的女孩和通常发育中的儿童在多个频带中跨多个脑区域的脑电图能力，并根据这些临床指标比较具有瑞特综合症的女孩的脑电图。还比较了各组之间的1 /ƒ斜率。结果Rett综合征的女孩表现出跨多个大脑区域的中频功率显着降低。此外，患有Rett综合征的女性在回归后表现出在较低频率的delta和theta频段具有更高的功率，并且功率谱的负斜率更高。这些频段的功率增加，并且1 /ƒ斜率更负，趋势是认知评估得分较低。结论较低频带中功率的增加与先前的研究一致，表明Rett综合征的背景脑电图“变慢”。这种增加，特别是在三角洲地区，