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• Significant brain areas are re-combined to form an epilepsy network in CAE. • Multi-focal source activity may indicate more brain areas are involved in seizures. • Imaging findings may provide a reference for clinical characteristics. Epilepsy is considered as a network disorder. However, it is unknown how normal brain activity develops into the highly synchronized discharging activity seen in disordered networks. This study aimed to explore the epilepsy brain network and the significant re-combined brain areas in childhood absence epilepsy (CAE). Twenty-two children with CAE were recruited to study the neural source activity during ictal-onset and interictal periods at frequency bands of 1–30 Hz and 30–80 Hz with magnetoencephalography (MEG) scanning. Accumulated source imaging (ASI) was used to analyze the locations of neural source activity and peak source strength. Most of the participants had more active source activity locations in the ictal-onset period rather than in the interictal period, both at 1–30 Hz and 30–80 Hz. The frontal lobe (FL), the temporo-parietal junction (T-P), and the parietal lobe (PL) became the main active areas of source activity during the ictal period, while the precuneus (PC), cuneus, and thalamus were relatively inactive. Some brain areas become more excited and have increased source activity during seizures. These significant brain regions might be re-combined to form an epilepsy network that regulates the process of absence seizures. The study confirmed that important brain regions are reorganized in an epilepsy network, which provides a basis for exploring the network mechanism of CAE development. Imaging findings may provide a reference for clinical characteristics. [ABSTRACT FROM AUTHOR]

Our aim was to explore the pathophysiological mechanism of cognitive function changes in early untreated children with benign childhood epilepsy with centrotemporal spikes (BECTS). Magnetoencephalography (MEG) was performed in 33 children with BECTS and 18 healthy children. Wechsler Intelligence Scale for Children, fourth edition (WISC-IV) was used to divide children with BECTS into two groups. Normal cognitive function was defined as a full-scale intelligence quotient (FSIQ) of > 80, while decreased cognitive function was defined as a FSIQ of < 80. Accumulated source imaging was used to evaluate the neuromagnetic source activity in multifrequency bands. Of the 33 patients with early untreated BECTS, a total of 17 had a FSIQ of < 80 and 16 had FSIQ of > 80. The course of epilepsy and number of seizures in the FSIQ < 80 group were higher than that in the FSIQ > 80 group. Our MEG results showed that in the 4–8 Hz frequency band, both patient groups had inactivation of the posterior cingulate cortex (PCC) region compared with the healthy control group. In the 30–80 Hz frequency band, the FSIQ < 80 group showed inactivation of the PCC region compared with both the healthy control group and the FSIQ > 80 group. In the 80–250 Hz frequency band, the FSIQ < 80 group had inactivated of the medial frontal cortex (MFC) region compared with the healthy control group. In the 30–80 Hz frequency band, the strength of neuromagnetic source in patients with BECTS with FSIQ < 80 was higher than that in the FSIQ > 80 group and the healthy control group. The magnetic source inactivation of the MFC and PCC regions during the interictal time may be the reason for cognitive decline in early untreated children with BECTS. Children with BECTS with cognitive decline had a longer course of epilepsy and more seizures. The magnetic source localization in the 4–8 Hz frequency band may be a new imaging marker for the diagnosis of new BECTS. • BECTS children with cognitive decline have magnetic source inactivation. • Magnetic source localization may be a new imaging marker. • BECTS children with cognitive decline had a longer course of epilepsy and more seizures. [ABSTRACT FROM AUTHOR]

• The absence state of absence seizures might be associated with reduced input of external stimulus. • Stronger delta-band signals have the potential to prevent the initiation of generalized spike-and-wave discharges (GSWDs). • Both the frontal and occipital lobes are crucial in the progression of absence seizures. • The duration of GSWDs could be shortened in the future by enhancing the inhibitory effect of low-frequency signals. Childhood absence epilepsy (CAE) is characterized by impaired consciousness and distinct electroencephalogram (EEG) patterns. However, interictal epileptiform discharges (IEDs) do not lead to noticeable symptoms. This study examines the disparity between ictal and interictal generalized spike-and-wave discharges (GSWDs) to determine the mechanisms behind CAE and consciousness. We enrolled 24 patients with ictal and interictal GSWDs in the study. The magnetoencephalography (MEG) data were recorded before and during GSWDs at a sampling rate of 6000 Hz and analyzed across six frequency bands. The absolute and relative spectral power were estimated with the Minimum Norm Estimate (MNE) combined with the Welch technique. All the statistical analyses were performed using paired-sample tests. During GSWDs, the right lateral occipital cortex indicated a significant difference in the theta band (5–7 Hz) with stronger power (P = 0.027). The interictal group possessed stronger spectral power in the delta band (P < 0.01) and weaker power in the alpha band (P < 0.01) as early as 10 s before GSWDs in absolute and relative spectral power. Additionally, the ictal group revealed enhanced spectral power inside the occipital cortex in the alpha band and stronger spectral power in the right frontal regions within beta (15–29 Hz), gamma 1 (30–59 Hz), and gamma 2 (60–90 Hz) bands. GSWDs seem to change gradually, with local neural activity changing even 10 s before discharge. During GSWDs, visual afferent stimulus insensitivity could be related to the impaired response state in CAE. The inhibitory signal in the low-frequency band can shorten GSWD duration, thereby achieving seizure control through inhibitory effect strengthening. [ABSTRACT FROM AUTHOR]

• AFQ revealed different patterns of white matter alterations in BECTS and CAE. • BECTS and CAE both showed the most severe white matter abnormalities in the right AF. • Structural asymmetry in CAE was significantly reduced in the IFOF and AF. • Neuroanatomical differences may underlie the different profiles of BECTS and CAE. To investigate whether patients with benign childhood epilepsy with centrotemporal spikes (BECTS) and childhood absence epilepsy (CAE) show distinct patterns of white matter (WM) alterations and structural asymmetry compared with healthy controls and the relationship between WM alterations and epilepsy-related clinical variables. We used automated fiber quantification to create tract profiles of fractional anisotropy (FA) and mean diffusivity (MD) in twenty-six patients with BECTS, twenty-nine patients with CAE, and twenty-four healthy controls. Group differences in FA and MD were quantified at 100 equidistant nodes along the fiber tract and these alterations and epilepsy-related clinical variables were correlated. A lateralization index (LI) representing the structural asymmetry of the fiber tract was computed and compared between both patient groups and controls. Compared with healthy controls, the BECTS group showed widespread FA reduction in 43.75% (7/16) and MD elevation in 50% (8/16) of identified fiber tracts, and the CAE group showed regional FA reduction in 31.25% (5/16) and MD elevation in 25% (4/16) of identified fiber tracts. In the BECTS group, FA and MD in the right anterior thalamic radiation positively and negatively correlated with the number of antiepileptic drugs, respectively, and MD in the right arcuate fasciculus (AF) positively correlated with seizure frequency. In the CAE group, the LI values were significantly lower in the inferior fronto-occipital fasciculus and the AF. The two childhood epilepsy syndromes display different patterns of WM alterations and structural asymmetry, suggesting that neuroanatomical differences may underlie the different profiles of BECTS and CAE. [ABSTRACT FROM AUTHOR]