Frequency-Specific Alterations of Local Synchronization in Idiopathic Generalized Epilepsy.
Recurrently and abnormally hypersynchronous discharge is a striking feature of idiopathic generalized epilepsy (IGE). Resting-state functional magnetic resonance imaging has revealed aberrant spontaneous brain synchronization, predominately in low-frequency range (<0.1 Hz), in individuals with IGE. Little is known, however, about these changes in local synchronization across different frequency bands. We examined alterations to frequency-specific local synchronization in terms of spontaneous blood oxygen level-dependent (BOLD) fluctuations across 5 bands, spanning 0 to 0.25 Hz. Specifically, we compared brain activity in a large cohort of IGE patients (n = 86) to age- and sex-matched normal controls (n = 86). IGE patients showed decreased local synchronization in low frequency (<0.073 Hz), primarily in the default mode network (DMN). IGE patients also exhibited increased local synchronization in high-frequency (>0.073 Hz) in a "conscious perception network," which is anchored by the pregenual and dorsal anterior cingulate cortex, as well as the bilateral insular cortices, possibly contributing to impaired consciousness. Furthermore, we found frequency-specific alternating local synchronization in the posterior portion of the DMN relative to the anterior part, suggesting an interaction between the disease and frequency bands. Importantly, the aberrant high-frequency local synchronization in the middle cingulate cortex was associated with disease duration, thus linking BOLD frequency changes to disease severity. These findings provide an overview of frequency-specific local synchronization of BOLD fluctuations, and may be helpful in uncovering abnormal synchronous neuronal activity in patients with IGE at specific frequency bands.
From the Center for Cognition and Brain Disorders and the Affiliated Hospital (JW, G-JJ, Y-FZ, WL), Hangzhou Normal University; Zhejiang Key Laboratory for Research in Assessment of Cognitive Impairments (JW, G-JJ, Y-FZ, WL), Hangzhou; Department of Medical Imaging (ZZ, QX, YH, WL, GL), Jinling Hospital, Nanjing University School of Medicine; Department of Medical Imaging (ZW), Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing; Department of Radiology (QJ), Taishan Medical University, Tai'an; and Department of Neurology (FY), Jinling Hospital, Nanjing University School of Medicine, Nanjing, China.
Jue
J
Wang
Zhiqiang
Z
Zhang
Gong-Jun
GJ
Ji
Qiang
Q
Xu
Yubin
Y
Huang
Zhengge
Z
Wang
Qing
Q
Jiao
Fang
F
Yang
Yu-Feng
YF
Zang
Wei
W
Liao
Guangming
G
Lu
D000293:Adolescent; D000328:Adult; D001921:Brain / Q000473:pathology*; D004829:Epilepsy, Generalized / Q000473:pathology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D010092:Oximetry; D012720:Severity of Illness Index; D055815:Young Adult