Thalamo-cortical network dysfunction in temporal lobe epilepsy

Assenza, Giovanni; Lanzone, Jacopo; Insola, Angelo; Amatori, Giulia; Ricci, Lorenzo; Tombini, Mario; Lazzaro, Vincenzo Di

doi:10.1016/j.clinph.2019.10.017

Cited by 17 publications

(7 citation statements)

References 51 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Hence, a drop in microstate metrics can be considered as disentanglement and instability of the neural network generating the microstate topography, whereas an increase may be a sign of dysfunctional hyperactivity (Zappasodi et al 2017 ). This is interesting since epilepsy has been increasingly recognized as a disorder of cortical networks (Englot et al 2015 ; Assenza et al 2020 ), and several studies have proposed that the EEG of people with epilepsy is characterized by abnormally synchronized networks and enhanced hyperconnectivity of the epileptogenic focus (Mormann et al 2000 ; Iandolo et al 2021 ; Ricci et al 2021 ). Taken together, our results and previous works suggest a scenario in which LEV is able to disrupt a probably hyperfunctioning and abnormally active epileptic network.…”

Section: Discussionmentioning

confidence: 99%

Levetiracetam Modulates EEG Microstates in Temporal Lobe Epilepsy

et al. 2022

Self Cite

View full text Add to dashboard Cite

To determine the effects of Levetiracetam (LEV) therapy using EEG microstates analysis in a population of newly diagnosed Temporal Lobe Epilepsy (TLE) patients. We hypothesized that the impact of LEV therapy on the electrical activity of the brain can be globally explored using EEG microstates. Twenty-seven patients with TLE were examined. We performed resting-state microstate EEG analysis and compared microstate metrics between the EEG performed at baseline (EEGpre) and after 3 months of LEV therapy (EEGpost). The microstates A, B, C and D emerged as the most stable. LEV induced a reduction of microstate B and D mean duration and occurrence per second (p < 0.01). Additionally, LEV treatment increased the directional predominance of microstate A to C and microstate B to D (p = 0.01). LEV treatment induces a modulation of resting-state EEG microstates in newly diagnosed TLE patients. Microstates analysis has the potential to identify a neurophysiological indicator of LEV therapeutic activity. This study of EEG microstates in people with epilepsy opens an interesting path to identify potential LEV activity biomarkers that may involve increased neuronal inhibition of the epileptic network.

show abstract

Section: Discussionmentioning

confidence: 99%

Levetiracetam Modulates EEG Microstates in Temporal Lobe Epilepsy

et al. 2022

Self Cite

View full text Add to dashboard Cite

show abstract

“…On the other hand, we hope to add subcortical nuclear analysis, such as analysis of the thalamus and its posterior movement circuit of the basal ganglia, in our further studies. As mentioned above, the thalamus plays a hub role related to the pathological manifestation in epilepsy (Bestmann et al, 2004 ; Jobst and Cascino, 2017 ; Assenza et al, 2020a , b ). Basal ganglia involved in movement circus discussion may help to better explain our results with respect to the interaction between the pDMN and SMN.…”

Section: Discussionmentioning

confidence: 99%

Antiepileptic Efficacy and Network Connectivity Modulation of Repetitive Transcranial Magnetic Stimulation by Vertex Suppression

Aisikaer

Chen

et al. 2021

Front. Hum. Neurosci.

View full text Add to dashboard Cite

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 < 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 < 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.

show abstract

“…High-frequency somatosensory evoked potentials (HF-SEPs) have been the target of recent investigations examining focal epilepsy as a network disease rather than an isolated dysfunction of narrow cortical regions (55). It was found that these HF-SEP's had a significantly longer duration in the affected hemisphere compared to the unaffected hemisphere as well as compared to controls, therefore reflecting interictal functional impairments of the thalamo-cortical network.…”

Section: Signal To Noise Ratiomentioning

confidence: 99%

Are High Frequency Oscillations in Scalp EEG Related to Age?

et al. 2022

View full text Add to dashboard Cite

BackgroundHigh-frequency oscillations (HFOs) have received much attention in recent years, particularly in the clinical context. In addition to their application as a marker for pathological changes in patients with epilepsy, HFOs have also been brought into context with several physiological mechanisms. Furthermore, recent studies reported a relation between an increase of HFO rate and age in invasive EEG recordings. The present study aimed to investigate whether this relation can be replicated in scalp-EEG.MethodsWe recorded high-density EEG from 11 epilepsy patients at rest as well as during motor performance. Manual detection of HFOs was performed by two independent raters following a standardized protocol. Patients were grouped by age into younger (<25 years) and older (>50 years) participants.ResultsNo significant difference of HFO-rates was found between groups [U = 10.5, p = 0.429, r = 0.3].ConclusionsLack of replicability of the age effect of HFOs may be due to the local propagation patterns of age-related HFOs occurring in deep structures. However, limitations such as small sample size, decreased signal-to-noise ratio as compared to invasive recordings, as well as HFO-mimicking artifacts must be considered.

show abstract

Thalamo-cortical network dysfunction in temporal lobe epilepsy

Cited by 17 publications

References 51 publications

Levetiracetam Modulates EEG Microstates in Temporal Lobe Epilepsy

Levetiracetam Modulates EEG Microstates in Temporal Lobe Epilepsy

Antiepileptic Efficacy and Network Connectivity Modulation of Repetitive Transcranial Magnetic Stimulation by Vertex Suppression

Are High Frequency Oscillations in Scalp EEG Related to Age?

Contact Info

Product

Resources

About