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

scholarly journals Interictal epileptiform discharges shape large-scale intercortical communication

Brain ◽  
2019 ◽  
Vol 142 (11) ◽  
pp. 3502-3513 ◽  
Author(s):  
Prawesh Dahal ◽  
Naureen Ghani ◽  
Adeen Flinker ◽  
Patricia Dugan ◽  
Daniel Friedman ◽  
...  
Keyword(s):  
Large Scale ◽  
Focal Epilepsy ◽  
Brain Dysfunction ◽  
Normal Brain ◽  
Brain Rhythms ◽  
Epileptiform Discharges ◽  
Interictal Epileptiform Discharges

Focal epilepsy is associated with large-scale brain dysfunction. Dahal et al. reveal that interictal epileptiform discharges modulate normal brain rhythms in regions beyond the epileptic network, potentially impairing processes that rely heavily upon intercortical communication, such as cognition and memory.

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 Unsupervised Learning of Spatiotemporal Interictal Discharges in Focal Epilepsy

Neurosurgery ◽  
2017 ◽  
Vol 83 (4) ◽  
pp. 683-691 ◽  
Author(s):  
Maxime O Baud ◽  
Jonathan K Kleen ◽  
Gopala K Anumanchipalli ◽  
Liberty S Hamilton ◽  
Yee-Leng Tan ◽  
...  
Keyword(s):  
Unsupervised Learning ◽  
Learning Algorithm ◽  
Focal Epilepsy ◽  
Basis Functions ◽  
Spatiotemporal Pattern ◽  
Operating Characteristics ◽  
Temporal Dimension ◽  
Epileptiform Discharges ◽  
Interictal Epileptiform Discharges ◽  
Propagation Network

Abstract BACKGROUND Interictal epileptiform discharges are an important biomarker for localization of focal epilepsy, especially in patients who undergo chronic intracranial monitoring. Manual detection of these pathophysiological events is cumbersome, but is still superior to current rule-based approaches in most automated algorithms. OBJECTIVE To develop an unsupervised machine-learning algorithm for the improved, automated detection and localization of interictal epileptiform discharges based on spatiotemporal pattern recognition. METHODS We decomposed 24 h of intracranial electroencephalography signals into basis functions and activation vectors using non-negative matrix factorization (NNMF). Thresholding the activation vector and the basis function of interest detected interictal epileptiform discharges in time and space (specific electrodes), respectively. We used convolutive NNMF, a refined algorithm, to add a temporal dimension to basis functions. RESULTS The receiver operating characteristics for NNMF-based detection are close to the gold standard of human visual-based detection and superior to currently available alternative automated approaches (93% sensitivity and 97% specificity). The algorithm successfully identified thousands of interictal epileptiform discharges across a full day of neurophysiological recording and accurately summarized their localization into a single map. Adding a temporal window allowed for visualization of the archetypal propagation network of these epileptiform discharges. CONCLUSION Unsupervised learning offers a powerful approach towards automated identification of recurrent pathological neurophysiological signals, which may have important implications for precise, quantitative, and individualized evaluation of focal epilepsy.

scholarly journals Interictal epileptiform discharges in focal epilepsy are preceded by a gradual increase in low-frequency oscillations

2020 ◽  
Author(s):  
Karin Westin ◽  
Gerald Cooray ◽  
Daniel Lundqvist
Keyword(s):  
Gradual Increase ◽  
Focal Epilepsy ◽  
Brain Activity ◽  
Low Frequency ◽  
Negative Influence ◽  
Oscillatory Activity ◽  
Brain State ◽  
Negative Effects ◽  
Epileptiform Discharges ◽  
Interictal Epileptiform Discharges

AbstractEpilepsy is characterized by recurrent seizures and may also have negative influence on cognitive function. In addition to ictal activity, the epileptic brain also gives rise to interictal epileptiform discharges (IEDs). These IEDs constitute the diagnostic hallmark of epilepsy, and have been linked to impaired memory formation and negative effects on neurodevelopment. The neurophysiological dynamics underlying IED generation seem to resemble those underlying seizure development. Understanding the neurophysiological characteristics surrounding and preceding IED development would hence provide valuable insights into the pathophysiology of the epileptic brain. In order to improve this understanding, we aimed to characterize the dynamical activity changes that occurs immediately prior to an IED onset. We used magnetoencephalography (MEG) recordings from nine focal epilepsy patients to characterize the oscillatory activity preceding IED onsets. Our results showed a systematic and gradual increase in oscillatory delta and theta band activity (1-4 Hz and 4-8 Hz, respectively) during this pre-IED interval, reaching a maximum power at IED onset. These results indicate that the pre-IED brain state is characterized by a gradual synchronization that culminates in the neuronal hypersynchronization underlying IEDs. We discuss how IED generation might resemble seizure development, where physiological brain activity similarly undergoes a gradual synchronization that terminates in seizure onset.

scholarly journals Musical components important for the Mozart K448 effect in epilepsy

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Robert J. Quon ◽  
Michael A. Casey ◽  
Edward J. Camp ◽  
Stephen Meisenhelter ◽  
Sarah A. Steimel ◽  
...  
Keyword(s):  
Refractory Epilepsy ◽  
Focal Epilepsy ◽  
Epileptiform Activity ◽  
Brain Regions ◽  
Original Version ◽  
Pharmacological Intervention ◽  
Theta Power ◽  
Epileptiform Discharges ◽  
Interictal Epileptiform Discharges ◽  
Insight Into

AbstractThere is growing evidence for the efficacy of music, specifically Mozart’s Sonata for Two Pianos in D Major (K448), at reducing ictal and interictal epileptiform activity. Nonetheless, little is known about the mechanism underlying this beneficial “Mozart K448 effect” for persons with epilepsy. Here, we measured the influence that K448 had on intracranial interictal epileptiform discharges (IEDs) in sixteen subjects undergoing intracranial monitoring for refractory focal epilepsy. We found reduced IEDs during the original version of K448 after at least 30-s of exposure. Nonsignificant IED rate reductions were witnessed in all brain regions apart from the bilateral frontal cortices, where we observed increased frontal theta power during transitions from prolonged musical segments. All other presented musical stimuli were associated with nonsignificant IED alterations. These results suggest that the “Mozart K448 effect” is dependent on the duration of exposure and may preferentially modulate activity in frontal emotional networks, providing insight into the mechanism underlying this response. Our findings encourage the continued evaluation of Mozart’s K448 as a noninvasive, non-pharmacological intervention for refractory epilepsy.

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.

Prevalence of Interictal Epileptiform Discharges in Children Less Than One Year of Age Referred for Polysomnography

2015 ◽  
Vol 55 (2) ◽  
pp. 122-132
Author(s):  
Adetayo Adeleye ◽  
Alice W. Ho ◽  
Alberto Nettel-Aguirre ◽  
Valerie Kirk ◽  
Jeffrey Buchhalter
Keyword(s):  
Epileptiform Discharges ◽  
Interictal Epileptiform Discharges ◽  
One Year

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.

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