scholarly journals Functional Connectivity of the Anterior Nucleus of the Thalamus in Pediatric Focal Epilepsy

2021 ◽  
Vol 12 ◽  
Author(s):  
Rory J. Piper ◽  
Chayanin Tangwiriyasakul ◽  
Elhum A. Shamshiri ◽  
Maria Centeno ◽  
Xiaosong He ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Focal Epilepsy ◽  
Epileptiform Activity ◽  
Epileptogenic Zone ◽  
Healthy Children ◽  
Anterior Nucleus ◽  
Epileptiform Discharges ◽  
Significant Difference ◽  
Before And After ◽  
Drug Resistant Epilepsy

Objective: Whilst stimulation of the anterior nucleus of the thalamus has shown efficacy for reducing seizure frequency in adults, alterations in thalamic connectivity have not been explored in children. We tested the hypotheses that (a) the anterior thalamus has increased functional connectivity in children with focal epilepsy, and (b) this alteration in the connectome is a persistent effect of the disease rather than due to transient epileptiform activity.Methods: Data from 35 children (7–18 years) with focal, drug-resistant epilepsy and 20 healthy children (7–17 years) were analyzed. All subjects underwent functional magnetic resonance imaging (fMRI) whilst resting and were simultaneously monitored with scalp electroencephalography (EEG). The fMRI timeseries were extracted for each Automated Anatomical Labeling brain region and thalamic subregion. Graph theory metrics [degree (DC) and eigenvector (EC) centrality] were used to summarize the connectivity profile of the ipsilateral thalamus, and its thalamic parcellations. The effect of interictal epileptiform discharges (IEDs) captured on EEG was used to determine their effect on DC and EC.Results: DC was significantly higher in the anterior nucleus (p = 0.04) of the thalamus ipsilateral to the epileptogenic zone in children with epilepsy compared to controls. On exploratory analyses, we similarly found a higher DC in the lateral dorsal nucleus (p = 0.02), but not any other thalamic subregion. No differences in EC measures were found between patients and controls. We did not find any significant difference in DC or EC in any thalamic subregion when comparing the results of children with epilepsy before, and after the removal of the effects of IEDs.Conclusions: Our data suggest that the anterior and lateral dorsal nuclei of the thalamus are more highly functionally connected in children with poorly controlled focal epilepsy. We did not detect a convincing change in thalamic connectivity caused by transient epileptiform activity, suggesting that it represents a persistent alteration to network dynamics.

scholarly journals Synaptic Reshaping and Neuronal Outcomes in the Temporal Lobe Epilepsy

2021 ◽  
Vol 22 (8) ◽  
pp. 3860
Author(s):  
Elisa Ren ◽  
Giulia Curia
Keyword(s):  
Animal Models ◽  
Temporal Lobe Epilepsy ◽  
Temporal Lobe ◽  
Current Knowledge ◽  
Focal Epilepsy ◽  
Ex Vivo ◽  
Hippocampal Sclerosis ◽  
Control Group ◽  
Epileptogenic Zone ◽  
Epileptiform Discharges

Temporal lobe epilepsy (TLE) is one of the most common types of focal epilepsy, characterized by recurrent spontaneous seizures originating in the temporal lobe(s), with mesial TLE (mTLE) as the worst form of TLE, often associated with hippocampal sclerosis. Abnormal epileptiform discharges are the result, among others, of altered cell-to-cell communication in both chemical and electrical transmissions. Current knowledge about the neurobiology of TLE in human patients emerges from pathological studies of biopsy specimens isolated from the epileptogenic zone or, in a few more recent investigations, from living subjects using positron emission tomography (PET). To overcome limitations related to the use of human tissue, animal models are of great help as they allow the selection of homogeneous samples still presenting a more various scenario of the epileptic syndrome, the presence of a comparable control group, and the availability of a greater amount of tissue for in vitro/ex vivo investigations. This review provides an overview of the structural and functional alterations of synaptic connections in the brain of TLE/mTLE patients and animal models.

scholarly journals INCREASED TISSUE TRANSGLUTAMINASE LEVELS ARE ASSOCIATED WITH INCREASED EPILEPTIFORM ACTIVITY IN ELECTROENCEPHALOGRAPHY AMONG PATIENTS WITH CELIAC DISEASE

2015 ◽  
Vol 52 (4) ◽  
pp. 272-277 ◽  
Author(s):  
Sedat IŞIKAY ◽  
Şamil HIZLI ◽  
Serkan ÇOŞKUN ◽  
Kutluhan YILMAZ
Keyword(s):  
Celiac Disease ◽  
Tissue Transglutaminase ◽  
Pearson Correlation ◽  
Epileptiform Activity ◽  
Control Group ◽  
Healthy Children ◽  
Newly Diagnosed ◽  
Laboratory Findings ◽  
Significant Difference ◽  
Medical Histories

Background - Celiac disease is an autoimmune systemic disorder in genetically predisposed individuals precipitated by gluten ingestion. Objective - In this study, we aimed to determine asymptomatic spike-and-wave findings on electroencephalography in children with celiac disease. Methods - A total of 175 children with the diagnosis of celiac disease (study group) and 99 age- and sex-matched healthy children as controls (control group) were included in the study. In order to determine the effects of gluten free diet on laboratory and electroencephalography findings, the celiac group is further subdivided into two as newly-diagnosed and formerly-diagnosed patients. Medical histories of all children and laboratory findings were all recorded and neurologic statuses were evaluated. All patients underwent a sleep and awake electroencephalography. Results - Among 175 celiac disease patients included in the study, 43 were newly diagnosed while 132 were formerly-diagnosed patients. In electroencephalography evaluation of patients the epileptiform activity was determined in 4 (9.3%) of newly diagnosed and in 2 (1.5%) of formerly diagnosed patients; on the other hand the epileptiform activity was present in only 1 (1.0%) of control cases. There was a statistically significant difference between groups in regards to the presence of epileptiform activity in electroencephalography. Pearson correlation analysis revealed that epileptiform activity in both sleep and awake electroencephalography were positively correlated with tissue transglutaminase levels (P=0.014 and P=0.019, respectively). Conclusion - We have determined an increased epileptiform activity frequency among newly-diagnosed celiac disease patients compared with formerly-diagnosed celiac disease patients and control cases. Moreover the tissue transglutaminase levels were also correlated with the presence of epileptiform activity in electroencephalography. Among newly diagnosed celiac disease patients, clinicians should be aware of this association and be alert about any neurological symptoms.

Evidence From Meta-Analysis Supports Ictal Magnetoencephalographic Source Imaging as an Accurate Method in Presurgery Evaluation of Patients With Drug-Resistant Epilepsy

2020 ◽  
Vol 51 (6) ◽  
pp. 403-411
Author(s):  
Malthe Brændholt ◽  
Mads Jensen
Keyword(s):  
Focal Epilepsy ◽  
Brain Area ◽  
Meta Analysis ◽  
Accurate Method ◽  
Epileptogenic Zone ◽  
Source Imaging ◽  
Magnetic Source Imaging ◽  
Surgery Outcome ◽  
Accurate Localization ◽  
Significant Difference

Background. Successful epilepsy surgery relies on localization and removal of the brain area responsible for initializing the seizures called the epileptogenic zone (EZ). Intracranial EEG (icEEG) is gold standard of this localization but has several limitations like invasiveness and limited covered area. A noninvasive method with accurate localization precision is therefore desirable. The aim of this article is to investigate the following hypotheses: (1) Ictal onset zone as localized by magnetic source imaging (iMSI) can reliably localize the EZ in focal epilepsy and (2) this localization is as good as that of icEEG. Methods. Six original studies and a total of 59 unique patients were included in a meta-analysis. Results. Sensitivity and specificity of iMSI based on surgery outcome were 77% (95% CI 60%-90%) and 75% (95% CI 53%-90%), respectively. Specificity of iMSI was statistically higher than that of icEEG. There was no significant difference between sensitivity of iMSI and icEEG. Conclusion. The meta-analysis supports that iMSI is an accurate method, achieving similar sensitivity and higher specificity than icEEG. However, at present the use of the method is limited by short recording times. A limitation that might be overcome in the future using technical advances.

Altered Structural and Functional Feature of Striato-Cortical Circuit in Benign Epilepsy with Centrotemporal Spikes

2015 ◽  
Vol 25 (06) ◽  
pp. 1550027 ◽  
Author(s):  
Cheng Luo ◽  
Yaodan Zhang ◽  
Weifang Cao ◽  
Yue Huang ◽  
Fei Yang ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Focal Epilepsy ◽  
Brain Morphology ◽  
Brain Maturation ◽  
Epilepsy Syndrome ◽  
Healthy Children ◽  
Functional Feature ◽  
Motor Network ◽  
Cortical Circuit ◽  
Benign Epilepsy

Benign epilepsy with centrotemporal spikes (BECT) is the most common form of childhood idiopathic focal epilepsy syndrome. We investigated quantitative evidence regarding brain morphology and functional connectivity features to provide insight into the neuroanatomical foundation of this disorder, using high resolution T1-weighted magnetic resonance imaging (MRI) and resting state functional MRI in 21 patients with BECT and in 20 healthy children. The functional connectivity analysis, seeded at the regions with altered gray-matter (GM) volume in voxel-based morphometry (VBM) analysis, was further performed. Then, the observed structural and functional alteration were investigated for their association with the clinical and behavior manifestations. The increased GM volume in the striatum and fronto-temporo-parietal cortex (striato-cortical circuit) was observed in BECT. The decreased connections were found among the motor network and frontostriatal loop, and between the default mode network (DMN) and language regions. Additionally, the GM of striatum was negatively correlated with age at epilepsy onset. The current observations may contribute to the understanding of the altered structural and functional feature of striato-cortical circuit in patients with BECT. The findings also implied alterations of the motor network and DMN, which were associated with the epileptic activity in patients with BECT. This further suggested that the onset of BECT might have enduring structural and functional effects on brain maturation.

Varicella Vaccine (VarilRix) in Children with Acute Lymphoblastic Leukemia.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 4436-4436
Author(s):  
Teresa Jackowska Ass ◽  
Robert Wasilewski ◽  
Elzbieta Górska ◽  
Maria Wasik ◽  
Teresa Loch
Keyword(s):  
Acute Lymphoblastic Leukemia ◽  
B Lymphocytes ◽  
Lymphoblastic Leukemia ◽  
Varicella Vaccine ◽  
White Blood Cells ◽  
Healthy Children ◽  
Varicella Zoster ◽  
Significant Difference ◽  
Before And After ◽  
History Of

Abstract Background: To assess the effectiveness of vaccination against varicella in children with acute lymphoblastic leukemia (ALL). Methods: 105 children without a history of varicella, were qualified for immunization against varicella with VARILRIX (Oka-strain varicella vaccine). 48 children had ALL and 57 were healthy. 25 of the children with ALL were receiving maintenance therapy, 23 children were after chemotherapy. Results: White blood cells (WBC), lymphocytes, and sub-populations of T- and B-lymphocytes were compared in the healthy and leukemic children before and after vaccination. The ALL children had significantly lower counts of WBC and lymphocytes before vaccination. After vaccination there were no significant differences in the counts of WBC in the healthy and leukemic children. However the ALL children had significantly lower mean counts of lymphocytes. Before vaccination the leukemic children showed a significantly lowered percentage of T-lymphocytes with decreased CD4+ and increased CD8+, what resulted in a lowered CD4 to CD8 ratio. After vaccination, only increased numbers of T CD8+ lymphocytes and a lowered CD4 to CD8 ratio were present while there was no significant difference in CD4. In the healthy and leukemic children alike there was no statistically significant difference between B-lymphocytes (CD 19+) and NK cells. In 10 children (20%), out of the 48 ALL vaccines, varicelliform rash occurred ~1 month after immunization. No adverse effects we observed in healthy children. Seroconversion to varicella-zoster virus was higher in healthy children and ALL children who had skin rash after vaccination. Two ALL children and three healthy ones had varicella one-two years after the vaccination. Those children received only single vaccine doses (double vaccine doses received children above 12 years). Conclusion: Varicella vaccine was safe and immunogenic in leukemic children during maintenance and after chemotherapy.

scholarly journals Benign epileptiform discharges of childhood and associated conditions

2018 ◽  
Vol 13 (3) ◽  
pp. 7-24
Author(s):  
K. Yu. Mukhin
Keyword(s):  
Neurological Disorders ◽  
Focal Epilepsy ◽  
White Matter Lesions ◽  
Perinatal Period ◽  
Brain Maturation ◽  
Healthy Children ◽  
Epileptiform Discharges ◽  
Detailed Classification ◽  
Associated Conditions

This article provides a detailed description of benign epileptiform discharges of childhood (BEDC) as one of electroencephalography patterns in children. We emphasize that BEDC are not specific for both idiopathic (genetic) focal epilepsy and epilepsy in general. BEDC can be observed in a number of various disorders and also in neurologically healthy children. We developed a detailed classification of BEDC-associated states that are divided into 3 groups: neurologically healthy children, children with various forms of epilepsy, and patients with various neurological disorders without epilepsy. We found that there are 2 main factors responsible for BEDC in electroencephalogram: genetic predisposition and white matter lesions, usually occurring during the antenatal or perinatal period. BEDC should be considered rather a manifestation of congenital abnormalities in brain maturation than a marker of epilepsy. We also discuss the need for therapy in patients with BEDC-associated states.

scholarly journals Strategic hospital partnerships: improved access to care and increased epilepsy surgical volume

2018 ◽  
Vol 44 (5) ◽  
pp. E9 ◽  
Author(s):  
Sumeet Vadera ◽  
Alvin Y. Chan ◽  
Lilit Mnatsankanyan ◽  
Mona Sazgar ◽  
Indranil Sen-Gupta ◽  
...  
Keyword(s):  
Access To Care ◽  
Epilepsy Surgery ◽  
Focal Epilepsy ◽  
Surgical Care ◽  
Invasive Monitoring ◽  
Strategic Partnerships ◽  
Significant Difference ◽  
Before And After ◽  
The University ◽  
Improve Patient

OBJECTIVESurgical treatment of patients with medically refractory focal epilepsy is underutilized. Patients may lack access to surgically proficient centers. The University of California, Irvine (UCI) entered strategic partnerships with 2 epilepsy centers with limited surgical capabilities. A formal memorandum of understanding (MOU) was created to provide epilepsy surgery to patients from these centers.METHODSThe authors analyzed UCI surgical and financial data associated with patients undergoing epilepsy surgery between September 2012 and June 2016, before and after institution of the MOU. Variables collected included the length of stay, patient age, seizure semiology, use of invasive monitoring, and site of surgery as well as the monthly number of single-surgery cases, complex cases (i.e., staged surgeries), and overall number of surgery cases.RESULTSOver the 46 months of the study, a total of 104 patients underwent a total of 200 operations; 71 operations were performed in 39 patients during the pre-MOU period (28 months) and 129 operations were performed in 200 patients during the post-MOU period (18 months). There was a significant difference in the use of invasive monitoring, the site of surgery, the final therapy, and the type of insurance. The number of single-surgery cases, complex-surgery cases, and the overall number of cases increased significantly.CONCLUSIONSPartnerships with outside epilepsy centers are a means to increase access to surgical care. These partnerships are likely reproducible, can be mutually beneficial to all centers involved, and ultimately improve patient access to care.

scholarly journals The use of simultaneous stereo-electroencephalography and magnetoencephalography in localising the epileptogenic focus in refractory focal epilepsy

2021 ◽  
Author(s):  
Umesh Vivekananda ◽  
Chunyan Cao ◽  
Wei Liu ◽  
Jing Zhang ◽  
Fergus Rugg-Gunn ◽  
...  
Keyword(s):  
Focal Epilepsy ◽  
Epileptiform Activity ◽  
Case Series ◽  
Seizure Freedom ◽  
Interictal Spikes ◽  
Significant Difference ◽  
Surgical Evaluation ◽  
Deep Source ◽  
Deep Sources ◽  
Epileptogenic Foci

Abstract Both magnetoencephalography and stereo-electroencephalography are used in presurgical epilepsy assessment, with contrasting advantages and limitations. It is not known whether simultaneous stereo-electroencephalography-magnetoencephalography recording confers an advantage over both individual modalities, in particular whether magnetoencephalography can provide spatial context to epileptiform activity seen on stereo-electroencephalography. 24 adult and paediatric patients who underwent stereo-electroencephalography study for pre-surgical evaluation of drug-resistant focal epilepsy, were recorded using simultaneous stereo-electroencephalography-magnetoencephalography, of which 14 had abnormal interictal activity during recording. The 14 patients were divided into two groups; those with detected superficial (n = 7) and deep (n = 7) brain interictal activity. Interictal spikes were independently identified in stereo-electroencephalography and magnetoencephalography. Magnetoencephalography dipoles were derived using a distributed inverse method. There was no significant difference between stereo-electroencephalography and magnetoencephalography in detecting superficial spikes (p = 0.135) and stereo-electroencephalography was significantly better at detecting deep spikes (p = 0.002). Mean distance across patients between stereo-electroencephalography channel with highest average spike amplitude and magnetoencephalography dipole was 20.7+/- 4.4 mm. for superficial sources, and 17.8 +/- 3.7 mm. for deep sources, even though for some of the latter (n = 4) no magnetoencephalography spikes were detected and magnetoencephalography dipole was fitted to a stereo-electroencephalography interictal activity triggered average. Removal of magnetoencephalography dipole was associated with 1 year seizure freedom in 6/7 patients with superficial source, and 5/6 patients with deep source. Although stereo-electroencephalography has greater sensitivity in identifying interictal activity from deeper sources, a magnetoencephalography source can be localised using stereo-electroencephalography information, thereby providing useful whole brain context to stereo-electroencephalography and potential role in epilepsy surgery planning.In the largest case series to date, Vivekananda et al. perform simultaneous magnetoencephalography and stereo-electroencephalography in refractory focal epilepsy patients. They demonstrate that for deep brain epileptogenic foci, magnetoencephalography dipoles could be derived from average stereo-electroencephalography data, thereby overcoming a traditional limitation of magnetoencephalography of reduced sensitivity for deep sources.

scholarly journals Thalamocortical dysrhythmia in intraoperative recordings of focal epilepsy

2019 ◽  
Vol 121 (6) ◽  
pp. 2020-2027 ◽  
Author(s):  
Daniel J. Martire ◽  
Simeon Wong ◽  
Mirriam Mikhail ◽  
Ayako Ochi ◽  
Hiroshi Otsubo ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
High Frequency ◽  
Large Scale ◽  
Focal Epilepsy ◽  
Critical Role ◽  
Epileptogenic Zone ◽  
Thalamocortical Dysrhythmia ◽  
High Frequency Activity ◽  
Frequency Coupling ◽  
Cross Frequency Coupling

Resonant interactions between the thalamus and cortex subserve a critical role for maintenance of consciousness as well as cognitive functions. In states of abnormal thalamic inhibition, thalamocortical dysrhythmia (TCD) has been described. The characteristics of TCD include a slowing of resting oscillations, ectopic high-frequency activity, and increased cross-frequency coupling. Here, we demonstrate the presence of TCD in four patients who underwent resective epilepsy surgery with chronically implanted electrodes under anesthesia, continuously recording activity from brain regions at the periphery of the epileptogenic zone before and after resection. Following resection, we report an acceleration of the large-scale network resting frequency coincident with decreases in cross-frequency phase-amplitude coupling. Interregional functional connectivity in the surrounding cortex was also increased following resection of the epileptogenic focus. These findings provide evidence for the presence of TCD in focal epilepsy and highlight the importance of reciprocal thalamocortical oscillatory interactions in defining novel biomarkers for resective surgeries. NEW & NOTEWORTHY Thalamocortical dysrhythmia (TCD) occurs in the context of thalamic dysfacilitation and is characterized by slowing of resting oscillations, ectopic high-frequency activity, and cross-frequency coupling. We provide evidence for TCD in focal epilepsy by studying electrophysiological changes occurring at the periphery of the resection margin. We report acceleration of resting activity coincident with decreased cross-frequency coupling and increased functional connectivity. The study of TCD in epilepsy has implications as a biomarker and therapeutic target.

Sign in / Sign up

Export Citation Format

Share Document