Objectives: The objective of the study was to detect functional changes in the brain of cognitive impairment-temporal lobe epilepsy (CI-TLE) patient and to sort out the possible mechanism involved in CI in CI-TLE patients using resting-state functional magnetic resonance imaging (RS-fMRI). Material and Methods: Fifty-eight TLE cases were included, which was divided into 44 TLE patients without CI (cognitive not impairment [CNI]-TLE) and 14 TLE patients with CI (CI-TLE). The normal control (NC) group consisted of 40 participants. RS-fMRI data preprocessing was carried out in statistical parametric mapping (SPM) software. The data were realigned, coregistered, normalized, and finally smoothened and then were taken for amplitude of low-frequency fluctuation (ALFF) calculation in RS-fMRI data analysis toolkit (REST) software. For data analysis, voxel-wise two-sample t-test was carried out between TLE group and NC group; CI-TLE group and cognitive not impairment-TLE (CNI-TLE) group in SPM software, a cluster >10 voxels and P < 0.01 was considered to be significant. Results: Compared to NC, the TLE patients showed increased ALFF activation mostly in parahippocampal gyrus (PG), frontal lobe, midbrain, pons, insula, inferior temporal gyrus, and anterior cingulate gyrus (ACG) while decreased ALFF value was seen in posterior cingulate gyrus, cuneus, cerebellum posterior lobe, inferior parietal lobule (IPL), and superior temporal gyrus. Compared to CNI-TLE, CI-TLE patients showed increased ALFF in middle temporal gyrus (MTG), cuneus, ACG, IPL, middle frontal gyrus (MFG), superior frontal gyrus (SFG), cerebellum posterior lobe, and decreased ALFF cluster in the corpus callosum and MFG. Conclusion: Between TLE and NC, we found increased ALFF activation in PG, frontal lobe, thalamus, insula, midbrain, and pons in TLE patient. Between CI and CNI TLE, area of executive control network and default model network, especially in MTG, ACG, IPL, MFG, and SFG, had increased ALFF value in CI-TLE patient. Activation of these areas should be because of the decompensation mechanism.

The stark discrepancy in the prognosis of epilepsy is closely related to brain damage features and underlying mechanisms, which have not yet been unraveled. In this study, differences in the epileptic brain functional connectivity states were explored through a network-based connectivity analysis between intractable mesial temporal lobe epilepsy (MTLE) patients and benign epilepsy with centrotemporal spikes (BECT). Resting state fMRI imaging data were collected for 14 MTLE patients, 12 BECT patients and 16 healthy controls (HCs). Independent component analysis (ICA) was performed to identify the cortical functional networks. Subcortical nuclei of interest were extracted from the Harvard-Oxford probability atlas. Network-based statistics were used to detect functional connectivity (FC) alterations across intranetworks and internetworks, including the connectivity between cortical networks and subcortical nuclei. Compared with HCs, MTLE patients showed significant lower activity between the connectivity of cortical networks and subcortical nuclei (especially hippocampus) and lower internetwork FC involving the lateral temporal lobe; BECT patients showed normal cortical-subcortical FC with hyperconnectivity between cortical networks. Together, cortical-subcortical hypoconnectivity in MTLE suggested a low efficiency and collaborative network pattern, and this might be relevant to the final decompensatory state and the intractable prognosis. Conversely, cortical-subcortical region with normal connectivity remained well in global cooperativity, and compensatory internetwork hyperconnectivity caused by widespread cortical abnormal discharge, which might account for the self-limited clinical outcome in BECT. Based on the fMRI functional network study, different brain network patterns might provide a better explanation of mechanisms in different types of epilepsy.

A core feature of drug-resistant epilepsy is hyperexcitability in the motor cortex, and low-frequency repetitive transcranial magnetic stimulation (rTMS) is a suitable treatment for seizures. However, the antiepileptic effect causing network reorganization has rarely been studied. Here, we assessed the impact of rTMS on functional network connectivity (FNC) in resting functional networks (RSNs) and their relation to treatment response. Fourteen patients with medically intractable epilepsy received inhibitive rTMS with a figure-of-eight coil over the vertex for 10 days spread across two weeks. We designed a 6-week follow-up phase divided into four time points to investigate FNC and rTMS-induced timing-dependent plasticity, such as seizure frequency and abnormal interictal discharges on electroencephalography (EEG). For psychiatric comorbidities, the Hamilton Depression Scale (HAM-D) and the Hamilton Anxiety Scale (HAM-A) were applied to measure depression and anxiety before and after rTMS. FNC was also compared to that of a cohort of 17 healthy control subjects. The after-effects of rTMS included all subjects that achieved the significant decrease rate of more than 50% in interictal epileptiform discharges and seizure frequency, 12 (14) patients with the reduction rate above 50% compared to the baseline, as well as emotional improvements in depression and anxiety (p &lt; 0.05). In the analysis of RSNs, we found a higher synchronization between the sensorimotor network (SMN) and posterior default-mode network (pDMN) in epileptic patients than in healthy controls. In contrast to pre-rTMS, the results demonstrated a weaker FNC between the anterior DMN (aDMN) and SMN after rTMS, while the FNC between the aDMN and dorsal attention network (DAN) was greater (p &lt; 0.05, FDR corrected). Importantly, the depressive score was anticorrelated with the FNC of the aDMN-SMN (r = −0.67, p = 0.0022), which was markedly different in the good and bad response groups treated with rTMS (p = 0.0115). Based on the vertex suppression by rTMS, it is possible to achieve temporary clinical efficacy by modulating network reorganization in the DMN and SMN for patients with refractory epilepsy.

Results showed that 1) the ReHo values of right V3 and bilateral MT/V5 for older adults were significantly lower than that of younger adults, as well as the ALFF of bilateral MT/V5, and these functional metrics were significantly negatively correlated with individuals' MCT; 2) The FCs between V2 and left primary motor cortex, V3 and left secondary visual cortex, MT/V5 and left premotor cortex, as well as the FCs between V1, V2, V3 and MT/V5 regions for the older adults were significantly stronger than that of younger adults, and these FCs were correlated with individuals' MCT; 3) Older adults' K, E nodal and b of most nodes in temporal lobe were significantly lower than younger adults, and the E nodal of the right temporal cortex were significantly negatively correlated with individuals' MCT; 4) Older adults' global network properties including small-world parameters (C p , γ, L p , λ, and σ) and network efficiency (E glob and E loc) were all significantly lower than younger adults', with C P and E loc significantly negatively correlated with their MCT. These findings suggested that the decline of GMS for the elderly was associated not only with functional changes in the dorsal visual pathway, especially in the MT/V5, but may also with functional changes in broader areas of the whole brain, which supported the theory of "dedifferentiation".