scholarly journals A STUDY ON COMPARATIVE YIELDS OF STANDARD SHORT TERM ELECTROENCEPHALOGRAM AND LONG TERM ELECTROENCEPHALOGRAM RECORDING IN SUSPECTED EPILEPSY PATIENTS

2021 ◽  
Vol 71 (5) ◽  
pp. 1727-31
Author(s):  
Saima Shafait ◽  
Wasim Alamgir ◽  
Imran Ahmad ◽  
Saeed Arif ◽  
Jahanzeb Liaqat ◽  
...  
Keyword(s):  
Diagnostic Yield ◽  
Extended Period ◽  
Final Analysis ◽  
Epileptiform Discharge ◽  
Military Hospital ◽  
Recording Time ◽  
Epileptiform Discharges ◽  
Interictal Epileptiform Discharges ◽  
Interictal Epileptiform Discharge ◽  
Electroencephalogram Eeg

Objective: To compare the yield of interictal epileptiform discharges on prolonged (1-2 hours) electroencephalogram (EEG) as compared to standard routine (30 minutes) electroencephalogram (EEG). Study Design: Comparative observational study. Place and Duration of Study: Pak Emirates Military Hospital, Rawalpindi from Oct 2019 to Sep 2020. Methodology: A total of 364 outdoor patients with suspected epilepsy were recruited for the study. Out of these 55 electroencephalograms were excluded after applying exclusion criteria and 309 were included for final analysis. Electro-encephalograms were recorded using a 10-20 international system of electrode placement. The duration of each standard electroencephalogram was 30 minutes. It was followed by recording for an extended period of 60 minutes at least. The time to the appearance of the first abnormal interictal epileptiform discharge was noted. For analytical purposes, epileptiform discharges were classified as “early” if they appeared within the first 30 minutes and as “late” if appeared afterward. All electro-encephalograms were evaluated independently by two neurologists. Results: A total of 309 electroencephalograms were included for final analysis. Interictal epileptiform discharges were seen in 48 (15.6%) recordings. The mean time to appearance of first interictal epileptiform discharge was 14.6 ± 19.09 minutes. In 36 (11.7%) cases, discharges appeared early (within the first 30 minutes) whereas in the remaining 12 (3.9%) cases, discharges appeared late. This translates into a 33% increase in the diagnostic yield of electroencephalogram with an extended period of recording. Conclusion: Extending the electroencephalogram recording time results in a significantly better diagnostic yield of outdoor electroencephalogram.

scholarly journals Automated Inter-Ictal Epileptiform Discharge Detection from Routine EEG

2021 ◽  
Author(s):  
Duong Nhu ◽  
Mubeen Janmohamed ◽  
Lubna Shakhatreh ◽  
Ofer Gonen ◽  
Patrick Kwan ◽  
...  
Keyword(s):  
Royal Melbourne Hospital ◽  
Epileptiform Discharges ◽  
Interictal Epileptiform Discharges ◽  
Model Variant ◽  
Eeg Recordings ◽  
Generalized Epilepsy ◽  
Electroencephalogram Eeg ◽  
Health Hospital ◽  
Epilepsy Monitoring

Epilepsy is the most common neurological disorder. The diagnosis commonly requires manual visual electroencephalogram (EEG) analysis which is time-consuming. Deep learning has shown promising performance in detecting interictal epileptiform discharges (IED) and may improve the quality of epilepsy monitoring. However, most of the datasets in the literature are small (n≤100) and collected from single clinical centre, limiting the generalization across different devices and settings. To better automate IED detection, we cross-evaluated a Resnet architecture on 2 sets of routine EEG recordings from patients with idiopathic generalized epilepsy collected at the Alfred Health Hospital and Royal Melbourne Hospital (RMH). We split these EEG recordings into 2s windows with or without IED and evaluated different model variants in terms of how well they classified these windows. The results from our experiment showed that the architecture generalized well across different datasets with an AUC score of 0.894 (95% CI, 0.881–0.907) when trained on Alfred’s dataset and tested on RMH’s dataset, and 0.857 (95% CI, 0.847–0.867) vice versa. In addition, we compared our best model variant with Persyst and observed that the model was comparable.

scholarly journals Prospective evaluation of interrater agreement between EEG technologists and neurophysiologists

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Isabelle Beuchat ◽  
Senubia Alloussi ◽  
Philipp S. Reif ◽  
Nora Sterlepper ◽  
Felix Rosenow ◽  
...  
Keyword(s):  
Interrater Agreement ◽  
Prospective Evaluation ◽  
False Negatives ◽  
Predictive Values ◽  
Epileptiform Discharges ◽  
Interictal Epileptiform Discharges ◽  
Eeg Recordings ◽  
Taking Action ◽  
Electroencephalogram Eeg ◽  
Eeg Pattern

AbstractWe aim to prospectively investigate, in a large and heterogeneous population, the electroencephalogram (EEG)-reading performances of EEG technologists. A total of 8 EEG technologists and 5 certified neurophysiologists independently analyzed 20-min EEG recordings. Interrater agreement (IRA) for predefined EEG pattern identification between EEG technologists and neurophysiologits was assessed using percentage of agreement (PA) and Gwet-AC1. Among 1528 EEG recordings, the PA [95% confidence interval] and interrater agreement (IRA, AC1) values were as follows: status epilepticus (SE) and seizures, 97% [96–98%], AC1 kappa = 0.97; interictal epileptiform discharges, 78% [76–80%], AC1 = 0.63; and conclusion dichotomized as “normal” versus “pathological”, 83.6% [82–86%], AC1 = 0.71. EEG technologists identified SE and seizures with 99% [98–99%] negative predictive value, whereas the positive predictive values (PPVs) were 48% [34–62%] and 35% [20–53%], respectively. The PPV for normal EEGs was 72% [68–76%]. SE and seizure detection were impaired in poorly cooperating patients (SE and seizures; p < 0.001), intubated and older patients (SE; p < 0.001), and confirmed epilepsy patients (seizures; p = 0.004). EEG technologists identified ictal features with few false negatives but high false positives, and identified normal EEGs with good PPV. The absence of ictal features reported by EEG technologists can be reassuring; however, EEG traces should be reviewed by neurophysiologists before taking action.

scholarly journals Interictal Epileptiform Discharge Dynamics in Peri-sylvian Polymicrogyria Using EEG-fMRI

2021 ◽  
Vol 12 ◽  
Author(s):  
Noa Cohen ◽  
Yoram Ebrahimi ◽  
Mordekhay Medvedovsky ◽  
Guy Gurevitch ◽  
Orna Aizenstein ◽  
...  
Keyword(s):  
Case Series ◽  
Epileptic Seizures ◽  
Epileptic Activity ◽  
Scalp Eeg ◽  
Epileptiform Discharges ◽  
Interictal Epileptiform Discharges ◽  
Malformation Of Cortical Development ◽  
Interictal Epileptiform Discharge ◽  
Drug Resistant Epilepsy ◽  
Patients With Epilepsy

Polymicrogyria (PMG) is a common malformation of cortical development associated with a higher susceptibility to epileptic seizures. Seizures secondary to PMG are characterized by difficult-to-localize cerebral sources due to the complex and widespread lesion structure. Tracing the dynamics of interictal epileptiform discharges (IEDs) in patients with epilepsy has been shown to reveal the location of epileptic activity sources, crucial for successful treatment in cases of focal drug-resistant epilepsy. In this case series IED dynamics were evaluated with simultaneous EEG-fMRI recordings in four patients with unilateral peri-sylvian polymicrogyria (PSPMG) by tracking BOLD activations over time: before, during and following IED appearance on scalp EEG. In all cases, focal BOLD activations within the lesion itself preceded the activity associated with the time of IED appearance on EEG, which showed stronger and more widespread activations. We therefore propose that early hemodynamic activity corresponding to IEDs may hold important localizing information potentially leading to the cerebral sources of epileptic activity. IEDs are suggested to develop within a small area in the PSPMG lesion with structural properties obscuring the appearance of their electric field on the scalp and only later engage widespread structures which allow the production of large currents which are recognized as IEDs on EEG.

Characterizing EEG Cortical Dynamics and Connectivity with Responses to Single Pulse Electrical Stimulation (SPES)

2018 ◽  
Vol 28 (06) ◽  
pp. 1750057 ◽  
Author(s):  
Gonzalo Alarcón ◽  
Diego Jiménez-Jiménez ◽  
Antonio Valentín ◽  
David Martín-López
Keyword(s):  
Electrical Stimulation ◽  
Single Pulse ◽  
Oscillatory Behavior ◽  
Temporal Lobectomy ◽  
Dynamic Interactions ◽  
Cortical Dynamics ◽  
Epileptiform Discharges ◽  
Interictal Epileptiform Discharges ◽  
System Equations ◽  
Electroencephalogram Eeg

Objectives: To model cortical connections in order to characterize their oscillatory behavior and role in the generation of spontaneous electroencephalogram (EEG). Methods: We studied averaged responses to single pulse electrical stimulation (SPES) from the non-epileptogenic hemisphere of five patients assessed with intracranial EEG who became seizure free after contralateral temporal lobectomy. Second-order control system equations were modified to characterize the systems generating a given response. SPES responses were modeled as responses to a unit step input. EEG power spectrum was calculated on the 20[Formula: see text]s preceding SPES. Results: 121 channels showed responses to 32 stimulation sites. A single system could model the response in 41.3% and two systems were required in 58.7%. Peaks in the frequency response of the models tended to occur within the frequency range of most activity on the spontaneous EEG. Discrepancies were noted between activity predicted by models and activity recorded in the spontaneous EEG. These discrepancies could be explained by the existence of alpha rhythm or interictal epileptiform discharges. Conclusions: Cortical interactions shown by SPES can be described as control systems which can predict cortical oscillatory behavior. The method is unique as it describes connectivity as well as dynamic interactions.

scholarly journals Reiterating the role of corpus callosum in generalization of interictal and ictal epileptiform discharges: a case report with post-callosotomy intracranial electroencephalography in Lennox–Gastaut syndrome

2021 ◽  
Vol 13 (3) ◽  
pp. 249-253
Author(s):  
S. Gopinath ◽  
A. Pillai ◽  
A. G. Diwan ◽  
J. V. Pattisapu ◽  
K. Radhakrishnan
Keyword(s):  
Corpus Callosum ◽  
Epileptic Encephalopathy ◽  
Drop Attacks ◽  
Epileptiform Discharges ◽  
Interictal Epileptiform Discharges ◽  
Eeg Abnormalities ◽  
Before And After ◽  
Intracranial Electroencephalography ◽  
Electroencephalogram Eeg

Lennox–Gastaut syndrome (LGS) is an epileptic encephalopathy characterized by delayed mental development and intractable multiple seizure types, predominantly tonic. Drop attacks are the commonest and the most disabling type of seizures. Resective surgery is often not possible in LGS as the electroencephalogram (EEG) abnormalities are usually multifocal and generalized, and magnetic resonance image is often either normal or multilesional. We report a case of LGS with bilateral parieto-occipital gliosis where EEG before and after callosotomy demonstrated synchronized bilateral interictal epileptiform discharges and ictal discharges becoming desynchronized and running down. This phenomenon emphasizes the role of the corpus callosum in secondary bilateral synchrony.

Diagnostic yield of seizure recordings and neuroimaging in patients with focal epilepsy without interictal epileptiform discharges

2020 ◽  
Vol 112 ◽  
pp. 107468
Author(s):  
Minori Suzuki ◽  
Kazutaka Jin ◽  
Yu Kitazawa ◽  
Mayu Fujikawa ◽  
Yosuke Kakisaka ◽  
...  
Keyword(s):  
Focal Epilepsy ◽  
Diagnostic Yield ◽  
Epileptiform Discharges ◽  
Interictal Epileptiform Discharges

Diagnostic Yield of Five Minutes Compared to Three Minutes Hyperventilation During Electroencephalography in Children

2021 ◽  
pp. 155005942110582
Author(s):  
Nivetha Vasudevan ◽  
Ranjith Kumar Manokaran ◽  
Saji James
Keyword(s):  
Adverse Events ◽  
Diagnostic Yield ◽  
Paediatric Population ◽  
Epileptiform Discharges ◽  
Interictal Epileptiform Discharges ◽  
Ictal Eeg ◽  
Eeg Abnormalities

Purpose: To investigate whether hyperventilation (HV) for 5 minutes increases the diagnostic yield of electroencephalography (EEG) compared to 3 minutes HV and to determine whether performing HV for 5 minutes is feasible and safe in children. Methods: Data were evaluated from 579 children aged less than 18 years, referred to EEG for epilepsy evaluation. Occurrence of seizures, HV induced interictal epileptiform discharges precipitation and potentiation and adverse events if any were noted during the first 3 minutes and last 2 minutes of HV separately. Results: 398 children (68.7%) completed 5 minutes HV. Seizures were precipitated during the first 3 minutes of HV in 2 children, and during the last 2 minutes in one more child. Inter-ictal EEG abnormalities were precipitated in the first 3 minutes of HV in 31 children, and during the last 2 min in 4 more children. All 398 children completed HV during the last 2 minutes successfully and no adverse events occurred during the last 2 minutes of HV. Conclusion: 33.33% of seizures and 11.5% of inter-ictal EEG abnormalities triggered by HV occurred during the last 2 min of HV. This finding supports the utility of prolonged hyperventilation for 5 minutes. Prolonged HV for 5 minutes increases the diagnostic yield of EEG in paediatric population and it is safe and feasible.

Effects of Interictal Epileptiform Discharges on Cognition

2018 ◽  
Vol 07 (03) ◽  
pp. 082-088 ◽  
Author(s):  
Aag Jennekens-Schinkel ◽  
Joost Meekes
Keyword(s):  
Cognitive Impairment ◽  
Cognitive Deficits ◽  
Cognitive Deficit ◽  
Single Case ◽  
Careful Monitoring ◽  
Epileptiform Discharges ◽  
Interictal Epileptiform Discharges ◽  
Single Case Designs ◽  
Lower Intelligence ◽  
Electroencephalogram Eeg

AbstractInterictal epileptiform discharges (IEDs) are brief events (typically < 1 second, although some authors use a cutoff of up to 3 seconds) in the electroencephalogram (EEG), which are not accompanied by any overt change in behavior or consciousness. IEDs are associated with both chronic cognitive deficits and transient cognitive impairment (TCI). Higher IED load correlates with lower intelligence quotient (IQ) and poorer performance on tests of memory and executive function. TCI has mainly been observed during tasks that place high demands on attention, visuomotor speed, and working memory. There is evidence that IEDs may also directly interfere with episodic memory. Despite the evidence for associations between IEDs and cognitive dysfunction, there is currently scant evidence that IEDs, in fact, cause chronic cognitive deficit in humans. Although causality appears likely in the case of TCI, even here the conditions under which IEDs affect cognition are unclear. The evidence in favor of treating IEDs with medication is very limited. Attempts to treat IEDs should only be made when it is clear that cognitive impairment interferes with activities or participation. Such attempts require strong single-case designs and careful monitoring of both the EEG and cognitive function to establish the efficacy of treatment in individual patients.

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