scholarly journals Microscale dynamics of electrophysiological markers of epilepsy

2020 ◽  
Author(s):  
Jimmy C. Yang ◽  
Angelique C. Paulk ◽  
Sang Heon Lee ◽  
Mehran Ganji ◽  
Daniel J. Soper ◽  
...  
Keyword(s):  
Spatial Resolution ◽  
High Frequency ◽  
Time Windows ◽  
List Type ◽  
Spatiotemporal Resolution ◽  
Similar Time ◽  
Human Epilepsy ◽  
High Frequency Oscillations ◽  
Peak Tracking ◽  
Interictal Discharges

AbstractObjectiveInterictal discharges (IIDs) and high frequency oscillations (HFOs) are neurophysiologic biomarkers of epilepsy. In this study, we use custom poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) microelectrodes to better understand their microscale dynamics.MethodsElectrodes with spatial resolution down to 50µm were used to record intraoperatively in 30 subjects. For IIDs, putative spatiotemporal paths were generated by peak-tracking, followed by clustering. For HFOs, repeating patterns were elucidated by clustering similar time windows. Fast events, consistent with multi-unit activity (MUA), were covaried with either IIDs or HFOs.ResultsIIDs seen across the entire array were detected in 93% of subjects. Local IIDs, observed across <50% of the array, were seen in 53% of subjects. IIDs appeared to travel across the array in specific paths, and HFOs appeared in similar repeated spatial patterns. Finally, microseizure events were identified spanning 50-100µm. HFOs covaried with MUA, but not with IIDs.ConclusionsOverall, these data suggest micro-domains of irritable cortex that form part of an underlying pathologic architecture that contributes to the seizure network.SignificanceMicroelectrodes in cases of human epilepsy can reveal dynamics that are not seen by conventional electrocorticography and point to new possibilities for their use in the diagnosis and treatment of epilepsy.HighlightsPEDOT:PSS microelectrodes with at least 50µm spatial resolution uniquely reveal spatiotemporal patterns of markers of epilepsyHigh spatiotemporal resolution allows interictal discharges to be tracked and reveal cortical domains involved in microseizuresHigh frequency oscillations detected by microelectrodes demonstrate localized clustering on the cortical surface

scholarly journals Scalp EEG interictal high frequency oscillations as an objective EEG biomarker of infantile spasms

2020 ◽  
Author(s):  
Hiroki Nariai ◽  
Shaun A. Hussain ◽  
Danilo Bernardo ◽  
Hirotaka Motoi ◽  
Masaki Sonoda ◽  
...  
Keyword(s):  
Slow Wave ◽  
High Frequency ◽  
Slow Wave Sleep ◽  
Wave Activity ◽  
Infantile Spasms ◽  
Slow Wave Activity ◽  
List Type ◽  
Normal Children ◽  
High Frequency Oscillations ◽  
Epileptic Spasms

ABSTRACTObjectiveTo investigate the diagnostic utility of high frequency oscillations (HFOs) via scalp electroencephalogram (EEG) in infantile spasms.MethodsWe retrospectively analyzed interictal slow-wave sleep EEGs sampled at 2,000 Hz recorded from 30 consecutive patients who were suspected of having infantile spasms. We measured the rate of HFOs (80-500 Hz) and the strength of the cross-frequency coupling between HFOs and slow-wave activity (SWA) at 3-4 Hz and 0.5-1 Hz as quantified with modulation indices (MIs).ResultsTwenty-three patients (77%) exhibited active spasms during the overnight EEG recording. Although the HFOs were detected in all children, increased HFO rate and MIs correlated with the presence of active spasms (p < 0.001 by HFO rate; p < 0.01 by MIs at 3-4 Hz; p = 0.02 by MIs at 0.5-1 Hz). The presence of active spasms was predicted by the logistic regression models incorporating HFO-related metrics (AUC: 0.80-0.98) better than that incorporating hypsarrhythmia (AUC: 0.61). The predictive performance of the best model remained favorable (87.5% accuracy) after a cross-validation procedure.ConclusionsIncreased rate of HFOs and coupling between HFOs and SWA are associated with active epileptic spasms.SignificanceScalp-recorded HFOs may serve as an objective EEG biomarker for active epileptic spasms.HighlightsObjective analyses of scalp high frequency oscillations and its coupling with slow-wave activity in infantile spasms were feasible.Increased rate of high frequency oscillations and its coupling with slow-wave activity correlated with active epileptic spasms.The scalp high frequency oscillations were also detected in neurologically normal children (although at the low rate).

scholarly journals Intracranially recorded ictal direct current shifts may precede high frequency oscillations in human epilepsy

2015 ◽  
Vol 126 (1) ◽  
pp. 47-59 ◽  
Author(s):  
Kyoko Kanazawa ◽  
Riki Matsumoto ◽  
Hisaji Imamura ◽  
Masao Matsuhashi ◽  
Takayuki Kikuchi ◽  
...  
Keyword(s):  
Direct Current ◽  
High Frequency ◽  
Human Epilepsy ◽  
High Frequency Oscillations

scholarly journals Trends in the use of automated algorithms for the detection of high‐frequency oscillations associated with human epilepsy

Epilepsia ◽  
2020 ◽  
Vol 61 (8) ◽  
pp. 1553-1569 ◽  
Author(s):  
Kavyakantha Remakanthakurup Sindhu ◽  
Richard Staba ◽  
Beth A. Lopour
Keyword(s):  
High Frequency ◽  
Human Epilepsy ◽  
High Frequency Oscillations ◽  
Automated Algorithms

scholarly journals Interictal high-frequency oscillations in focal human epilepsy

2016 ◽  
Vol 29 (2) ◽  
pp. 175-181 ◽  
Author(s):  
Jan Cimbalnik ◽  
Michal T. Kucewicz ◽  
Greg Worrell
Keyword(s):  
High Frequency ◽  
Human Epilepsy ◽  
High Frequency Oscillations

scholarly journals Pathological and physiological high-frequency oscillations in focal human epilepsy

2013 ◽  
Vol 110 (8) ◽  
pp. 1958-1964 ◽  
Author(s):  
Andrew Matsumoto ◽  
Benjamin H. Brinkmann ◽  
S. Matthew Stead ◽  
Joseph Matsumoto ◽  
Michal T. Kucewicz ◽  
...  
Keyword(s):  
High Frequency ◽  
Motor Task ◽  
High Amplitude ◽  
Spectral Amplitude ◽  
Support Vector ◽  
Frequency Spectra ◽  
Time Frequency ◽  
Human Epilepsy ◽  
High Frequency Oscillations ◽  
Measuring Frequency

High-frequency oscillations (HFO; gamma: 40–100 Hz, ripples: 100–200 Hz, and fast ripples: 250–500 Hz) have been widely studied in health and disease. These phenomena may serve as biomarkers for epileptic brain; however, a means of differentiating between pathological and normal physiological HFO is essential. We categorized task-induced physiological HFO during periods of HFO induced by a visual or motor task by measuring frequency, duration, and spectral amplitude of each event in single trial time-frequency spectra and compared them to pathological HFO similarly measured. Pathological HFO had higher mean spectral amplitude, longer mean duration, and lower mean frequency than physiological-induced HFO. In individual patients, support vector machine analysis correctly classified pathological HFO with sensitivities ranging from 70–98% and specificities >90% in all but one patient. In this patient, infrequent high-amplitude HFO were observed in the motor cortex just before movement onset in the motor task. This finding raises the possibility that in epileptic brain physiological-induced gamma can assume higher spectral amplitudes similar to those seen in pathologic HFO. This method if automated and validated could provide a step towards differentiating physiological HFO from pathological HFO and improving localization of epileptogenic brain.

P6-4 Very high frequency oscillations (over 1000 Hz) in human epilepsy

2010 ◽  
Vol 121 ◽  
pp. S134 ◽  
Author(s):  
N. Usui ◽  
K. Terada ◽  
K. Baba ◽  
K. Matsuda ◽  
F. Nakamura ◽  
...  
Keyword(s):  
High Frequency ◽  
Very High Frequency ◽  
Human Epilepsy ◽  
High Frequency Oscillations ◽  
Very High

Very high frequency oscillations (over 1000Hz) in human epilepsy

2010 ◽  
Vol 121 (11) ◽  
pp. 1825-1831 ◽  
Author(s):  
Naotaka Usui ◽  
Kiyohito Terada ◽  
Koichi Baba ◽  
Kazumi Matsuda ◽  
Fumihiro Nakamura ◽  
...  
Keyword(s):  
High Frequency ◽  
Very High Frequency ◽  
Human Epilepsy ◽  
High Frequency Oscillations ◽  
Very High

scholarly journals The Effect of Deep Brain Stimulation on High Frequency Oscillations in a Chronic Epilepsy Model

2020 ◽  
Vol 93 (2) ◽  
pp. 63-70
Author(s):  
Mihály István ◽  
Bod Réka-Barbara ◽  
Orbán-Kis Károly ◽  
Berki Ádám-József ◽  
Szilágyi Tibor
Keyword(s):  
Deep Brain Stimulation ◽  
Brain Stimulation ◽  
High Frequency ◽  
Basolateral Amygdala ◽  
Time Windows ◽  
Latency Period ◽  
Control Group ◽  
Control Groups ◽  
High Frequency Oscillations ◽  
Deep Brain

Abstract Temporal lobe epilepsy (TLE) is a severe neurological disease which is often pharmacoresistant. Deep brain stimulation (DBS) is a novel method for treating epilepsy; however, its mechanism of action is not fully understood. We aimed to study the effect of amygdala DBS in the pilocarpine model of TLE. Status epilepticus was induced by pilocarpine in male Wistar rats, and spontaneous seizures occurred after a latency period. A stimulating electrode was inserted into the left basolateral amygdala and two recording electrodes into the left and right hippocampus. A stimulus package consisted of 0.1 ms-long biphasic pulses applied regularly at 4 Hz for 50 seconds. This package was repeated four times a day, with 5-minute pauses, for 10 days. We also used an age-matched healthy control group of stimulated animals and another one of sham-operated rats. From the hippocampal local field potentials high frequency oscillations (HFOs) were analyzed as these are promising epilepsy biomarkers. HFOs are short oscillatory events between 80-600 Hz which were detected offline using an open-source application of MATLAB, the RIPPLELAB system. We found that the HFO rate was significantly higher in pilocarpine-treated rats compared to the control groups (0.41 ± 0.14 HFO/min vs. 0.006 ± 0.003 in the stimulated control group and no HFO in the sham-operated group). In the pilocarpine group an instantaneous decrease in HFO rate was observed while the stimulation was on (0.44 ± 0.15 HFO/min vs 0.07 ± 0.03 HFO/min, p=0.017). The effect was short-lived because the frequency of HFOs did not change significantly in the time windows between stimulus packages or during the ten-day stimulation period. The difference of HFO rates between epileptic and control groups could be used in the electrographic assessment of epilepsy. The decreased frequency of HFOs during stimulation may be useful to study the efficacy of DBS.

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