scholarly journals Alfentanil Mediated Activation of Epileptiform Activity in the Electrocorticogram During Resection of Epileptogenic Foci

1997 ◽  
Vol 24 (1) ◽  
pp. 29-36 ◽  
Author(s):  
Keene Daniel L. ◽  
David Roberts ◽  
Splinter William M. ◽  
Michael Higgin ◽  
Enrique Ventureyra
Keyword(s):  
Epileptiform Activity ◽  
Epileptic Seizures ◽  
Surgical Excision ◽  
Electrographic Seizure ◽  
Epileptiform Discharges ◽  
Before And After ◽  
Electrographic Seizures ◽  
Balanced Anaesthesia ◽  
Epileptogenic Foci ◽  
Significant Activation

ABSTRACT:Purpose:Alfentanil is a potent, short-acting opioid agent which has been used during balanced anaesthesia in children undergoing the surgical excision of epileptic foci. After the observation that this agent had the potential to induce epileptic seizures, we questioned the frequency of this occurrence in this group of patients.Method:Twelve patients (6 males, 6 females) undergoing surgical excision of an epileptic foci were prospectively followed. For each patient an electrocorticogram was recorded for 30 minutes before and after receiving alfentanil 20 pg/kg intravenously. The frequency of epileptiform abnormalities before and after drug administration was evaluated. When the electrocorticogram no longer showed the effects of alfentanil administration, methohexital 0.5 ug/kg was given intravenously.Results:Alfentanil induced significant activation of epileptiform discharges among 83% of these patients. Twenty-five per cent had an electrographic seizure. In comparison, methohexital induced significant activation of epileptiform discharges in 50% of these patients. None experienced electrographic seizures.Conclusions:As alfentanil can induce electrographic seizures in patients known to have epilepsy, caution is advised in its use in this group of patients.

TRANSCRANIAL MAGNETIC STIMULATION (TMS) MODULATES EPILEPTIFORM DISCHARGES IN PATIENTS WITH FRONTAL LOBE EPILEPSY: A PRELIMINARY EEG-TMS STUDY

2012 ◽  
Vol 23 (01) ◽  
pp. 1250035 ◽  
Author(s):  
VASILIOS K. KIMISKIDIS ◽  
DIMITRIS KUGIUMTZIS ◽  
SOTIRIOS PAPAGIANNOPOULOS ◽  
NIKOLAOS VLAIKIDIS
Keyword(s):  
Frontal Lobe ◽  
Brain Connectivity ◽  
Epileptiform Activity ◽  
Epileptic Focus ◽  
Noninvasive Brain Stimulation ◽  
Electrographic Seizure ◽  
Epileptiform Discharges ◽  
Induced Changes ◽  
Epileptogenic Foci ◽  
Stimulation Technique

Background: TMS is being increasingly used as a noninvasive brain stimulation technique for the therapeutic management of partial epilepsies. However, the acute effects of TMS on epileptiform discharges (EDs, i.e. interictal epileptiform activity and subclinical electrographic seizure patterns) remain unexplored. Objective: To investigate whether TMS can modulate EDs in partial epilepsy. Methods: In Experiment Set 1, the safety of the TMS protocol was investigated in 10 well-controlled by anti-epileptic drugs (AEDs) epileptic patients. In Experiment Set 2, the effects of TMS on EDs were studied in three subjects with intractable frontal lobe epilepsies, characterized by particularly frequent EDs. TMS was applied over the electrographic focus with a circular and a figure of eight coil while recording EEG with a 60-channel TMS-compatible EEG system. The effectiveness of TMS in aborting EDs was investigated using survival analysis and brain connectivity analysis. Results: The TMS protocol was well-tolerated. TMS was an effective method to abort EDs even when adjusting for its latency with respect to ED onset (CMH test, p < 0.0001). While the effective brain connectivity around the epileptic focus increased significantly during EDs (p < 0.01), with TMS administration the increase was not statistically significant. Conclusion: TMS can modulate EDs in patients with epileptogenic foci in the cortical convexity and is associated with reversal of ED-induced changes in brain connectivity.

scholarly journals Incidence of Electrographic Seizures in Patients With COVID-19

2021 ◽  
Vol 12 ◽  
Author(s):  
Brandon L. Waters ◽  
Andrew J. Michalak ◽  
Danielle Brigham ◽  
Kiran T. Thakur ◽  
Amelia Boehme ◽  
...  
Keyword(s):  
Critical Illness ◽  
Case Series ◽  
Nasopharyngeal Swab ◽  
Convulsive Status Epilepticus ◽  
Retrospective Case ◽  
Predictive Values ◽  
Electrographic Seizure ◽  
Epileptiform Discharges ◽  
Interictal Epileptiform Discharges ◽  
Electrographic Seizures

Critical illness and sepsis are commonly associated with subclinical seizures. COVID-19 frequently causes severe critical illness, but the incidence of electrographic seizures in patients with COVID-19 has been reported to be low. This retrospective case series assessed the incidence of and risks for electrographic seizures in patients hospitalized with COVID-19 who underwent continuous video electroencephalography monitoring (cvEEG) between March 1st, 2020 and June 30th, 2020. One hundred and twenty-two patients were initially identified who resulted SARS-CoV-2 nasopharyngeal RT-PCR swab positivity with any electroencephalography order placed in the EMR. Seventy-nine patients met study inclusion criteria: age ≥18 years, &gt;1 h of cvEEG monitoring, and positive SARS-CoV-2 nasopharyngeal swab PCR. Six (8%) of the 79 patients suffered electrographic seizures (ES), three of whom suffered non-convulsive status epilepticus. Acute hyperkinetic movements were the most common reason for cvEEG in patients with ES (84%). None of the patients undergoing cvEEG for persistent coma (29% of all patients) had ES. Focal slowing (67 vs. 10%), sporadic interictal epileptiform discharges (EDs; 33 vs. 6%), and periodic/rhythmic EDs (67 vs. 1%) were proportionally more frequent among patients with electrographic seizures than those without these seizures. While 15% of patients without ES had generalized periodic discharges (GPDs) with triphasic morphology on EEG, none of the patients with ES had this pattern. Further study is required to assess the predictive values of these risk factors on electrographic seizure incidence and subsequent outcomes.

scholarly journals Influence of Sleep and Sleep Deprivation on Ictal and Interictal Epileptiform Activity

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Antonio Díaz-Negrillo
Keyword(s):  
Sleep Deprivation ◽  
Epileptiform Activity ◽  
Epileptic Seizures ◽  
Future Research ◽  
Reciprocal Relation ◽  
Physiological Factors ◽  
Rigorous Approach ◽  
Epileptiform Discharges ◽  
Interictal Epileptiform Discharges ◽  
The Relationship

Sleep is probably one of the most important physiological factors implicated both in epileptic seizures and interictal epileptiform discharges. The neurophysiology concerning the relationship between sleep and epilepsy is well described in the literature; however, the pathological events that culminate in the seizures are poorly explored. The present paper intends to make a rigorous approach to the main mechanisms involved in this reciprocal relation. Knowledge of sleep and sleep deprivation effects in epilepsy stands as crucial in the understanding of how seizures are produced, their possible lines of treatment, and future research.

scholarly journals Epileptiform Activity in Neurocritical Care Patients

2012 ◽  
Vol 39 (3) ◽  
pp. 328-337 ◽  
Author(s):  
Andreas H. Kramer ◽  
Nathalie Jette ◽  
Neelan Pillay ◽  
Paolo Federico ◽  
David A. Zygun
Keyword(s):  
Risk Factors ◽  
Neurocritical Care ◽  
Diagnostic Yield ◽  
Epileptiform Activity ◽  
Eeg Monitoring ◽  
Use Of Resources ◽  
Epileptiform Discharges ◽  
Glascow Coma Scale ◽  
Electrographic Seizures ◽  
Interictal Discharges

Background:Non-convulsive seizures have been reported to be common in neurocritical care patients. Many jurisdictions do not have sufficient resources to enable routine continuous electroencephalography (cEEG) and instead use primarily intermittent EEG, for which the diagnostic yield remains uncertain. Determining risk factors for epileptiform activity and seizures could help identify patients who might particularly benefit from EEG monitoring.Methods:We performed a cohort study involving neurocritical care patients with admission Glascow Coma Scale (GCS) scores =≤ 12, who underwent ≥ 1 EEG. EEGs were reviewed for presence of interictal discharges, periodic epileptiform discharges (PEDs), and seizures. Multivariate analysis was used to identify predictors of these findings and to describe their prognostic implications.Results:393 patients met inclusion criteria. 34 underwent cEEG, usually because epileptiform activity was first detected on a routine EEG. The prevalence of PEDs or electrographic seizures was 13%, and was highest with anoxic encephalopathy and central nervous system infections. Other independent predictors for epileptiform activity included a history of convulsive seizure(s), increasing age, deeper coma, and female gender. Although patients with epileptiform activity had higher mortality, this association disappeared after adjustment for confounders.Conclusion:Approximately 7-8 neurocritical care patients must undergo intermittent EEG monitoring in order to diagnose one with PEDs or seizures. The predictors we identified could potentially help guide use of resources. Repeated intermittent studies, or cEEG, should be considered in patients with multiple risk factors, or when interictal discharges are identified on an initial EEG. It remains unclear whether aggressive prevention and treatment of electrographic seizures improves neurologic outcomes.

scholarly journals Enhanced Propagation of Epileptiform Activity Through the Kindled Dentate Gyrus

1998 ◽  
Vol 79 (4) ◽  
pp. 1726-1732 ◽  
Author(s):  
J. Behr ◽  
K. J. Lyson ◽  
I. Mody
Keyword(s):  
Dentate Gyrus ◽  
Entorhinal Cortex ◽  
Epileptiform Activity ◽  
Normal Function ◽  
Chronic Epilepsy ◽  
Epileptiform Discharges ◽  
Gating Mechanism ◽  
Electrographic Seizures ◽  
Gaba Antagonist ◽  
Area Ca3

Behr, J., K. J. Lyson, and I. Mody. Enhanced propagation of epileptiform activity through the kindled dentate gyrus. J. Neurophysiol. 79: 1726–1732, 1998. Extracellular recordings were performed in combined hippocampal-entorhinal cortex (HC-EC) slices obtained from control and commissural kindled rats to investigate the propagation of epileptiform activity from the entorhinal cortex (EC) to the hippocampus (HC) after chronic epilepsy. Lowering extracellular Mg2+ concentration in control slices induced epileptiform activity consisting of spontaneous epileptiform bursts in area CA3 and of electrographic seizures in the EC. In contrast, the CA3 region of HC-EC slices obtained from kindled rats displayed significantly longer lasting epileptiform bursts and electrographic seizures. The electrographic seizures that were absent in controls propagated from the EC because disconnecting the HC from the EC stopped their occurrence in the CA3, whereas epileptiform bursts persisted with an unaltered pattern and frequency. Thus the area CA3 is affected by kindling and contributes to the spread of epileptiform activity within the EC-HC complex. We developed a method to induce focal epileptiform activity in the EC by locally perfusing the γ-aminobutyric acid-A (GABA) antagonist bicuculline (50 mM) in 10 mM KCl containing artificial cerebrospinal fluid. This method enabled us to investigate the propagation of epileptiform discharges from the disinhibited EC to the DG without affecting the DG with the epileptogenic medium. We show here that kindling facilitates the propagation of epileptiform activity through the DG. These data are consistent with the normal function of the DG as a filter limiting the spread of epileptiform activity within the HC-EC complex. This gating mechanism breaks down after chronic epilepsy induced by kindling.

scholarly journals Dynamics of high-frequency synchronization during seizures

2013 ◽  
Vol 109 (10) ◽  
pp. 2423-2437 ◽  
Author(s):  
Giri P. Krishnan ◽  
Gregory Filatov ◽  
Maxim Bazhenov
Keyword(s):  
High Frequency ◽  
Epileptiform Activity ◽  
Epileptic Seizures ◽  
Temporal Analysis ◽  
Neuronal Firing ◽  
Extracellular Potassium ◽  
Epileptiform Discharges ◽  
Baseline Activity ◽  
High Frequency Activity

Pathological synchronization of neuronal firing is considered to be an inherent property of epileptic seizures. However, it remains unclear whether the synchrony increases for the high-frequency multiunit activity as well as for the local field potentials (LFPs). We present spatio-temporal analysis of synchronization during epileptiform activity using wide-band (up to 2,000 Hz) spectral analysis of multielectrode array recordings at up to 60 locations throughout the mouse hippocampus in vitro. Our study revealed a prominent structure of LFP profiles during epileptiform discharges, triggered by elevated extracellular potassium, with characteristic distribution of current sinks and sources with respect to anatomical structure. The cross-coherence of high-frequency activity (500–2,000 Hz) across channels was reduced during epileptic bursts compared with baseline activity and showed the opposite trend for lower frequencies. Furthermore, the magnitude of cross-coherence during epileptiform activity was dependent on distance: electrodes closer to the epileptic foci showed increased cross-coherence and electrodes further away showed reduced cross-coherence for high-frequency activity. These experimental observations were re-created and supported in a computational model. Our study suggests that different intrinsic and synaptic processes can mediate paroxysmal synchronization at low, medium, and high frequencies.

scholarly journals The effect of rehabilitation treatment on the electroencephalography results and the course of epilepsy in children with cerebral palsy

2021 ◽  
Vol 12 (4) ◽  
pp. 197-204
Author(s):  
M. Yu. Bobylova ◽  
M. D. Shanavazova ◽  
M. A. Askevova ◽  
B. A. Abusueva
Keyword(s):  
Cerebral Palsy ◽  
Epileptiform Activity ◽  
Epileptic Seizures ◽  
Eeg Activity ◽  
Children With Cerebral Palsy ◽  
Before And After ◽  
Transcranial Micropolarization ◽  
History Of ◽  
Group 2 ◽  
Group 1

Introduction. Cerebral palsy is often combined with epilepsy and epileptiform electroencephalographic (EEG) activity. Currently, the question of how rehabilitation with cerebral palsy is dangerous in relation to the provocation of epileptic seizures is relevant. Objective: to study the effect of cerebral palsy rehabilitation on epilepsy in a standard rehabilitation center. Material and methods. We examined 80 children with various forms of cerebral palsy and epileptiform EEG activity. The patients were divided into two groups: children of Group 1 never had epileptic seizures, children of Group 2 had a history of epileptic seizures of more than 6 months ago. The follow-up was 12 months during which children underwent EEG before and after rehabilitation courses. Depending on the risks associated with provoking epileptic seizures, patients were prescribed rehabilitation procedures of various intensities: Vojta kinesiotherapy, massage, physiotherapeutic treatment in the form of transcranial micropolarization and paraffin therapy. Results. During the study, epileptic seizures developed in 5 patients (12.5%) from Group 1 and in 7 children (17.5%) from Group 2. In all cases, rare focal seizures were recorded (1–2 times a year). All patients with seizures during our study had a history of seizures under the age of 1 year. The onset of seizures was quickly stopped by the basic antiepileptic drugs in monotherapy. Epileptic seizures developed in children with moderate to severe cerebral palsy on GMFCS (Gross Motor Function Classification System) and a history of neonatal seizures. We attributed both of these to risk factors. In children with cerebral palsy and epilepsy in remission of 6 months or more, massage and Vojta therapy did not provoke epileptic seizures. The effect of epileptiform activity on the severity of motor status and on cognitive functions in cerebral palsy has not been established in our study. Conclusion. According to our data, rehabilitation measures do not have a significant impact on the risk of developing epilepsy.

scholarly journals Effect of Wrist Tapping on Interhemispheric Coherence in Patients with Juvenile Myoclonic Epilepsy

2021 ◽  
Vol 11 (1) ◽  
pp. 73-77
Author(s):  
Ekaterina Narodova ◽  
Natalia Shnayder ◽  
Vladislav Karnaukhov ◽  
Olesya Bogomolova ◽  
Kirill Petrov ◽  
...  
Keyword(s):  
Healthy Volunteers ◽  
Epileptic Seizures ◽  
Juvenile Myoclonic Epilepsy ◽  
Myoclonic Epilepsy ◽  
Control Group ◽  
Alpha Band ◽  
Epileptiform Discharges ◽  
Interhemispheric Coherence ◽  
Before And After ◽  
The Brain

The aim of this study was to assess the dynamics of interhemispheric coherence (IC) as an indicator of integration of different areas of the brain and their participation in the performance of certain functions before and after wrist tapping (WT), using the author's method in juvenile myoclonic epilepsy (JME). Methods and Results: The study included 81 subjects of working age, including 51 clinically healthy volunteers (median age of 39[21;56] years) and 30 patients (median age of 27[23;38] years) with JME. Analysis of IC in the electrode pairs Fp1-Fp2, F3-F4, C3-C4, T3-T4 was performed using a computer encephalographic complex. A coherent EEG analysis was used to identify and evaluate the relationships between different areas of the brain. Based on the change in the coherence coefficients (CCs), the level of integrative activity of brain structures was quantified. In healthy volunteers, before and after WT, we observed a statistically significant decrease in CCs for the beta-1 band in the pairs Fp1-Fp2, F3-F4, and C3-C4 (P<0.05), while in the pair T3-T4, changes in CCs were not statistically significant (P>0.05). At the same time, a statistically significant decrease in CCs in the alpha band was found only in the frontal regions in the pairs Fp1-Fp2 and F3-F4 (P<0.05). No statistically significant changes were found in all the studied pairs in the theta band. When comparing CCs in JME patients in beta–1 and theta bands, before and after WT, we did not find statistically significant changes in CCs in all the studied electrode pairs. However, in the alpha band, we found a statistically significant decrease in CCs in the frontal region in the F3-F4 (P=0.0038) and C3-C4 electrode pairs (P=0.034). The results of the study of interhemispheric integration showed statistically significant differences between patients with JME and the control group. Conclusion: WT according to the author's method does not provoke the occurrence of interictal epileptiform discharges on the EEG and epileptic seizures in patients with JME. Coherent analysis showed positive changes in interhemispheric integrations of neurons in the beta–1 and alpha frequency ranges, mainly in the anterior hemispheres.

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 Induction of Tertiary Phase Epileptiform Discharges after Postasphyxial Infusion of a Toll-Like Receptor 7 Agonist in Preterm Fetal Sheep

2021 ◽  
Vol 22 (12) ◽  
pp. 6593
Author(s):  
Kenta H.T. Cho ◽  
Mhoyra Fraser ◽  
Bing Xu ◽  
Justin M. Dean ◽  
Alistair J. Gunn ◽  
...  
Keyword(s):  
Moderate Hypertension ◽  
Epileptiform Activity ◽  
Ischemic Brain Injury ◽  
Toll Like Receptor ◽  
Fetal Sheep ◽  
Ischemic Brain ◽  
Tlr Agonists ◽  
Epileptiform Discharges ◽  
Subcortical Regions ◽  
Total Burden

Background: Toll-like receptor (TLR) agonists are key immunomodulatory factors that can markedly ameliorate or exacerbate hypoxic–ischemic brain injury. We recently demonstrated that central infusion of the TLR7 agonist Gardiquimod (GDQ) following asphyxia was highly neuroprotective after 3 days but not 7 days of recovery. We hypothesize that this apparent transient neuroprotection is associated with modulation of seizure-genic processes and hemodynamic control. Methods: Fetuses received sham asphyxia or asphyxia induced by umbilical cord occlusion (20.9 ± 0.5 min) and were monitored continuously for 7 days. GDQ 3.34 mg or vehicle were infused intracerebroventricularly from 1 to 4 h after asphyxia. Results: GDQ infusion was associated with sustained moderate hypertension that resolved after 72 h recovery. Electrophysiologically, GDQ infusion was associated with reduced number and burden of postasphyxial seizures in the first 18 h of recovery (p < 0.05). Subsequently, GDQ was associated with induction of slow rhythmic epileptiform discharges (EDs) from 72 to 96 h of recovery (p < 0.05 vs asphyxia + vehicle). The total burden of EDs was associated with reduced numbers of neurons in the caudate nucleus (r2 = 0.61, p < 0.05) and CA1/2 hippocampal region (r2 = 0.66, p < 0.05). Conclusion: These data demonstrate that TLR7 activation by GDQ modulated blood pressure and suppressed seizures in the early phase of postasphyxial recovery, with subsequent prolonged induction of epileptiform activity. Speculatively, this may reflect delayed loss of early protection or contribute to differential neuronal survival in subcortical regions.

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