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1.
Martin Pail Pavel Řehulka Jan Cimbálník Irena Doležalová Jan Chrastina Milan Brázdil 《Clinical neurophysiology》2017,128(1):106-114
Objective
The purpose of the presented study is to determine whether there are frequency-independent high-frequency oscillation (HFO) parameters which may differ in epileptic and non-epileptic regions.Methods
We studied 31 consecutive patients with medically intractable focal (temporal and extratemporal) epilepsies who were examined by either intracerebral or subdural electrodes. Automated detection was used to detect HFO. The characteristics (rate, amplitude, and duration) of HFO were statistically compared within three groups: the seizure onset zone (SOZ), the irritative zone (IZ), and areas outside the IZ and SOZ (nonSOZ/nonIZ).Results
In all patients, fast ripples (FR) and ripples (R) were significantly more frequent and shorter in the SOZ than in the nonSOZ/nonIZ region. In the group of patients with favorable surgical outcomes, the relative amplitude of FR was higher in the SOZ than in the IZ and nonIZ/nonSOZ regions; in patients with poor outcomes, the results were reversed. The relative amplitude of R was significantly higher in the SOZ, with no difference between patients with poor and favorable surgical outcomes.Conclusions
FR are more frequent, shorter, and have higher relative amplitudes in the SOZ area than in other regions. The study suggests a worse prognosis in patients with higher amplitudes of FR outside the SOZ.Significance
Various HFO parameters, especially of FR, differ in epileptic and non-epileptic regions. The amplitude and duration may be as important as the frequency band and rate of HFO in marking the seizure onset region or the epileptogenic area and may provide additional information on epileptogenicity. 相似文献2.
Jounhong Ryan Cho Eun Yeon Joo Dae Lim Koo Seung Chyul Hong Seung Bong Hong 《JOURNAL OF CLINICAL NEUROLOGY》2012,8(1):22-34
Background and Purpose
There is growing interest in high-frequency oscillations (HFO) as electrophysiological biomarkers of the epileptic brain. We evaluated the clinical utility of interictal HFO events, especially their occurrence rates, by comparing the spatial distribution with a clinically determined epileptogenic zone by using subdural macroelectrodes.Methods
We obtained intracranial electroencephalogram data with a high temporal resolution (2000 Hz sampling rate, 0.05-500 Hz band-pass filter) from seven patients with medically refractory epilepsy. Three epochs of 5-minute, artifact-free data were selected randomly from the interictal period. HFO candidates were first detected by an automated algorithm and subsequently screened to discard false detections. Validated events were further categorized as fast ripple (FR) and ripple (R) according to their spectral profiles. The occurrence rate of HFOs was calculated for each electrode contact. An HFO events distribution map (EDM) was constructed for each patient to allow visualization of the spatial distribution of their HFO events.Results
The subdural macroelectrodes were capable of detecting both R and FR events from the epileptic neocortex. The occurrence rate of HFO events, both FR and R, was significantly higher in the seizure onset zone (SOZ) than in other brain regions. Patient-specific HFO EDMs can facilitate the identification of the location of HFO-generating tissue, and comparison with findings from ictal recordings can provide additional useful information regarding the epileptogenic zone.Conclusions
The distribution of interictal HFOs was reasonably consistent with the SOZ. The detection of HFO events and construction of spatial distribution maps appears to be useful for the presurgical mapping of the epileptogenic zone. 相似文献3.
Luciana Andrade-Valença Francesco MariJulia Jacobs Maeike ZijlmansAndré Olivier Jean GotmanFrançois Dubeau 《Clinical neurophysiology》2012,123(1):100-105
Objective
We aim to analysis the relationship between HFOs-generating regions and the seizure onset zone (SOZ) in epileptic patients without a visible lesion on MRI.Methods
Intracerebral EEGs were recorded in 17 patients with intractable focal seizures and normal MRIs. The rates of interictal HFOs and spikes inside and outside the SOZ were analyzed as well as the specificity, sensitivity and accuracy of HFOs and spikes to determine the SOZ.Results
The mean rate of spikes, ripples and fast ripples (FR) was higher in the SOZ than in the non-SOZ channels. In regard to the identification of the SOZ the sensitivity was 91% for spikes, 91% for ripples and 66% for FR, the specificity was 30% for spikes, 42% for ripples and 80% for FR, and the accuracy was 44% for spikes, 54% for ripples and 76% for FR.Conclusions
The rates of spikes and HFOs were higher inside than outside the SOZ. However, HFOs are also more specific and accurate than spikes to delineate the SOZ.Significance
Analysis of interictal HFOs during 5-10 min of sleep recording is a good tool to localize the SOZ in patients with epilepsy and normal MRI, and could potentially reduce the duration of chronic intracerebral EEG recordings. 相似文献4.
Manel Vila-Vidal Alessandro Principe Miguel Ley Gustavo Deco Adrià Tauste Campo Rodrigo Rocamora 《Clinical neurophysiology》2017,128(6):977-985
Objective
We introduce a method that quantifies the consistent involvement of intracranially monitored regions in recurrent focal seizures.Methods
We evaluated the consistency of two ictal spectral activation patterns (mean power change and power change onset time) in intracranial recordings across focal seizures from seven patients with clinically marked seizure onset zone (SOZ). We examined SOZ discrimination using both patterns in different frequency bands and periods of interest.Results
Activation patterns were proved to be consistent across more than of recurrent ictal epochs. In all patients, whole-seizure mean activations were significantly higher for SOZ than non-SOZ regions () while activation onset times were significantly lower for SOZ than for non-SOZ regions () in six patients. Alpha-beta bands (8–20 Hz) achieved the highest patient-average effect size on the whole-seizure period while gamma band (20–70 Hz) achieved the highest discrimination values between SOZ and non-SOZ sites near seizure onset (0–5 s).Conclusions
Consistent spectral activation patterns in focal epilepsies discriminate the SOZ with high effect sizes upon appropriate selection of frequency bands and activation periods.Significance
The present method may be used to improve epileptogenic identification as well as pinpoint additional regions that are functionally altered during ictal events. 相似文献5.
Objective
Graph theoretical analysis of functional connectivity data has demonstrated a small-world topology of brain networks. There is increasing evidence that the topology of brain networks is changed in epilepsy. Here we investigated the basal properties of epileptogenic networks by applying graph analysis to intracerebral EEG recordings of patients presenting with drug-resistant partial epilepsies during the interictal period.Methods
Interictal EEG activity was recorded in mesial temporal lobe of 11 patients with mesial temporal lobe epilepsy (MTLE group) and compared with a “control” group of 8 patients having neocortical epilepsies (non MTLE group) in whom depth-EEG recordings eventually showed an ictal onset outside the MTL structures. Synchronization likelihood (SL) was calculated between selected intracerebral electrodes contacts to obtain SL-weighted graphs. Mean normalized clustering index, average path length and small world index S were calculated to characterize network organization.Results
Broadband SL values were higher in the MTLE group. Although a small-world pattern was found in the two groups, normalized clustering index and to a lesser extend average path length were higher in the MTLE group.Conclusions
We demonstrated a trend toward a more regular (less random) configuration of interictal epileptogenic networks. In addition S index was found to correlate with epilepsy duration.Significance
These topological alterations might be a surrogate marker of human focal epilepsy and disclose some changes over time. 相似文献6.
Irina I. Goncharova Susan S. Spencer Robert B. Duckrow Lawrence J. Hirsch Dennis D. Spencer Hitten P. Zaveri 《Clinical neurophysiology》2013,124(11):2119-2128
Objective
The relationship between seizures and interictal spikes remains undetermined. We analyzed intracranial EEG (icEEG) recordings to examine the relationship between the seizure onset area and interictal spikes.Methods
80 unselected patients were placed into 5 temporal, 4 extratemporal, and one unlocalized groups based on the location of the seizure onset area. We studied 4-h icEEG epochs, removed from seizures, from day-time and night-time during both on- and off-medication periods. Spikes were detected automatically from electrode contacts sampling the hemisphere ipsilateral to the seizure onset area.Results
There was a widespread occurrence of spikes over the hemisphere ipsilateral to the seizure onset area. The spatial distributions of spike rates for the different patient groups were different (p < 0.0001, chi-square test). The area with the highest spike rate coincided with the seizure onset area only in half of the patients.Conclusion
The spatial distribution of spike rates is strongly associated with the location of the seizure onset area, suggesting the presence of a distributed spike generation network, which is related to the seizure onset area.Significance
The spatial distribution of spike rates, but not the area with the highest spike rate, may hold value for the localization of the seizure onset area. 相似文献7.
Shennan Aibel Weiss Brent Berry Inna Chervoneva Zachary Waldman Jonathan Guba Mark Bower Michal Kucewicz Benjamin Brinkmann Vaclav Kremen Fatemeh Khadjevand Yogatheesan Varatharajah Hari Guragain Ashwini Sharan Chengyuan Wu Richard Staba Jerome Engel Michael Sperling Gregory Worrell 《Clinical neurophysiology》2018,129(10):2089-2098
Objective
To test the utility of a novel semi-automated method for detecting, validating, and quantifying high-frequency oscillations (HFOs): ripples (80–200?Hz) and fast ripples (200–600?Hz) in intra-operative electrocorticography (ECoG) recordings.Methods
Sixteen adult patients with temporal lobe epilepsy (TLE) had intra-operative ECoG recordings at the time of resection. The computer-annotated ECoG recordings were visually inspected and false positive detections were removed. We retrospectively determined the sensitivity, specificity, positive and negative predictive value (PPV/NPV) of HFO detections in unresected regions for determining post-operative seizure outcome.Results
Visual validation revealed that 2.81% of ripple and 43.68% of fast ripple detections were false positive. Inter-reader agreement for false positive fast ripple on spike classification was good (ICC?=?0.713, 95% CI: 0.632–0.779). After removing false positive detections, the PPV of a single fast ripple on spike in an unresected electrode site for post-operative non-seizure free outcome was 85.7 [50–100%]. Including false positive detections reduced the PPV to 64.2 [57.8–69.83%].Conclusions
Applying automated HFO methods to intraoperative electrocorticography recordings results in false positive fast ripple detections. True fast ripples on spikes are rare, but predict non-seizure free post-operative outcome if found in an unresected site.Significance
Semi-automated HFO detection methods are required to accurately identify fast ripple events in intra-operative ECoG recordings. 相似文献8.
Shoichi Shimamoto Zachary J. Waldman Iren Orosz Inkyung Song Anatol Bragin Itzhak Fried Jerome Engel Richard Staba Ashwini Sharan Chengyuan Wu Michael R. Sperling Shennan A. Weiss 《Clinical neurophysiology》2018,129(1):296-307
Objective
To develop and validate a detector that identifies ripple (80–200?Hz) events in intracranial EEG (iEEG) recordings in a referential montage and utilizes independent component analysis (ICA) to eliminate or reduce high-frequency artifact contamination. Also, investigate the correspondence of detected ripples and the seizure onset zone (SOZ).Methods
iEEG recordings from 16 patients were first band-pass filtered (80–600?Hz) and Infomax ICA was next applied to derive the first independent component (IC1). IC1 was subsequently pruned, and an artifact index was derived to reduce the identification of high-frequency events introduced by the reference electrode signal. A Hilbert detector identified ripple events in the processed iEEG recordings using amplitude and duration criteria. The identified ripple events were further classified and characterized as true or false ripple on spikes, or ripples on oscillations by utilizing a topographical analysis to their time-frequency plot, and confirmed by visual inspection.Results
The signal to noise ratio was improved by pruning IC1. The precision of the detector for ripple events was 91.27?±?4.3%, and the sensitivity of the detector was 79.4?±?3.0% (N?=?16 patients, 5842 ripple events). The sensitivity and precision of the detector was equivalent in iEEG recordings obtained during sleep or intra-operatively. Across all the patients, true ripple on spike rates and also the rates of false ripple on spikes, that were generated due to filter ringing, classified the seizure onset zone (SOZ) with an area under the receiver operating curve (AUROC) of >76%. The magnitude and spectral content of true ripple on spikes generated in the SOZ was distinct as compared with the ripples generated in the NSOZ (p?<?.001).Conclusions
Utilizing ICA to analyze iEEG recordings in referential montage provides many benefits to the study of high-frequency oscillations. The ripple rates and properties defined using this approach may accurately delineate the seizure onset zone.Significance
Strategies to improve the spatial resolution of intracranial EEG and reduce artifact can help improve the clinical utility of HFO biomarkers. 相似文献9.
Purpose : To investigate the effect of sleep stage on the properties of high-frequency oscillations (HFOs) recorded from depth macroelectrodes in patients with focal epilepsy.
Methods : Ten-minute epochs of wakefulness (W), stage 1–2 non-REM (N1-N2), stage 3 non-REM (N3) and REM sleep (R) were identified from stereo-electroencephalography (SEEG) data recorded at 2 kHz in nine patients. Rates of spikes, ripples (>80 Hz), and fast ripples (>250 Hz) were calculated, as were HFO durations, degree of spike–HFO overlap, HFO rates inside and outside of spikes, and inside and outside of the seizure-onset zone (SOZ).
Results : Ripples were observed in nine patients and fast ripples in eight. Spike rate was highest in N1-N2 in 5 of 9 patients, and in N3 in 4 of 9 patients, whereas ripple rate was highest in N1-N2 in 4 of 9 patients, in N3 in 4 of 9 patients, and in W in 1 of 9 patients. Fast ripple rate was highest in N1-N2 in 4 of 8 patients, and in N3 in 4 of 8 patients. HFO properties changed significantly with sleep stage, although the absolute effects were small. The difference in HFO rates inside and outside of the SOZ was highly significant (p < 0.000001) in all stages except for R and, for fast ripples, only marginally significant (p = 0.018) in W.
Conclusions : Rates of HFOs recorded from depth macroelectrodes are highest in non-REM sleep. HFO properties were similar in stages N1-N2 and N3, suggesting that accurate sleep staging is not necessary. The spatial specificity of HFO, particularly fast ripples, was affected by sleep stage, suggesting that recordings excluding REM sleep and wakefulness provide a more reliable indicator of the SOZ. 相似文献
Methods : Ten-minute epochs of wakefulness (W), stage 1–2 non-REM (N1-N2), stage 3 non-REM (N3) and REM sleep (R) were identified from stereo-electroencephalography (SEEG) data recorded at 2 kHz in nine patients. Rates of spikes, ripples (>80 Hz), and fast ripples (>250 Hz) were calculated, as were HFO durations, degree of spike–HFO overlap, HFO rates inside and outside of spikes, and inside and outside of the seizure-onset zone (SOZ).
Results : Ripples were observed in nine patients and fast ripples in eight. Spike rate was highest in N1-N2 in 5 of 9 patients, and in N3 in 4 of 9 patients, whereas ripple rate was highest in N1-N2 in 4 of 9 patients, in N3 in 4 of 9 patients, and in W in 1 of 9 patients. Fast ripple rate was highest in N1-N2 in 4 of 8 patients, and in N3 in 4 of 8 patients. HFO properties changed significantly with sleep stage, although the absolute effects were small. The difference in HFO rates inside and outside of the SOZ was highly significant (p < 0.000001) in all stages except for R and, for fast ripples, only marginally significant (p = 0.018) in W.
Conclusions : Rates of HFOs recorded from depth macroelectrodes are highest in non-REM sleep. HFO properties were similar in stages N1-N2 and N3, suggesting that accurate sleep staging is not necessary. The spatial specificity of HFO, particularly fast ripples, was affected by sleep stage, suggesting that recordings excluding REM sleep and wakefulness provide a more reliable indicator of the SOZ. 相似文献
10.
Shuang Wang Norman K. So Bo Jin Irene Z. Wang Juan C. Bulacio Rei Enatsu Shenyi Dai Zhong Chen Jorge Gonzalez-Martinez Imad M. Najm 《Clinical neurophysiology》2017,128(6):945-951
Objective
This study aimed to identify the subtype of interictal ripples that help delineate the epileptogenic zone in neocortical epilepsy.Methods
Totally 25 patients with focal neocortical epilepsy who had invasive electroencephalography (EEG) evaluation and subsequent surgery were included. They were followed up for at least 2 years. Interictal ripples (80–250 Hz) and fast ripples (250–500 Hz) during slow-wave sleep were identified. Neocortical ripples were defined as type I ripples when they were superimposed on epileptiform discharges, and as type II ripples when they occurred independently. Resection ratio was calculated to present the extent to which the cortical area showing an interictal event or the seizure onset zone (SOZ) was completely removed.Results
Fast ripples and types I and II ripples were found in 8, 19, and 21 patients, respectively. Only the higher resection ratio of interictal fast or type I ripples was correlated to the Engel 1a surgical outcome.Conclusions
Type I ripples could assist in localizing the epileptogenic zone in neocortical epilepsy.Significance
Type I and fast ripples both may be pathological high-frequency oscillations. 相似文献11.
Danilo Bernardo Hiroki Nariai Shaun A. Hussain Raman Sankar Noriko Salamon Darcy A. Krueger Mustafa Sahin Hope Northrup E. Martina Bebin Joyce Y. Wu 《Clinical neurophysiology》2018,129(7):1458-1466
Objectives
We aim to establish that interictal fast ripples (FR; 250–500?Hz) are detectable on scalp EEG, and to investigate their association to epilepsy.Methods
Scalp EEG recordings of a subset of children with tuberous sclerosis complex (TSC)-associated epilepsy from two large multicenter observational TSC studies were analyzed and compared to control children without epilepsy or any other brain-based diagnoses. FR were identified both by human visual review and compared with semi-automated review utilizing a deep learning-based FR detector.Results
Seven out of 7 children with TSC-associated epilepsy had scalp FR compared to 0 out of 4 children in the control group (p?=?0.003). The automatic detector has a sensitivity of 98% and false positive rate with average of 11.2 false positives per minute.Conclusions
Non-invasive detection of interictal scalp FR was feasible, by both visual and semi-automatic detection. Interictal scalp FR occurred exclusively in children with TSC-associated epilepsy and were absent in controls without epilepsy. The proposed detector achieves high sensitivity of FR detection; however, expert review of the results to reduce false positives is advised.Significance
Interictal FR are detectable on scalp EEG and may potentially serve as a biomarker of epilepsy in children with TSC. 相似文献12.
Tommaso Fedele Georgia Ramantani Sergey Burnos Peter Hilfiker Gabriel Curio Thomas Grunwald Niklaus Krayenbühl Johannes Sarnthein 《Clinical neurophysiology》2017,128(7):1220-1226
Objective
Fast ripples (FR, 250–500 Hz) in the intraoperative corticogram have recently been proposed as specific predictors of surgical outcome in epilepsy patients. However, online FR detection is restricted by their low signal-to-noise ratio. Here we propose the integration of low-noise EEG with unsupervised FR detection.Methods
Pre- and post-resection ECoG (N = 9 patients) was simultaneously recorded by a commercial device (CD) and by a custom-made low-noise amplifier (LNA). FR were analyzed by an automated detector previously validated on visual markings in a different dataset.Results
Across all recordings, in the FR band the background noise was lower in LNA than in CD (p < 0.001). FR rates were higher in LNA than CD recordings (0.9 ± 1.4 vs 0.4 ± 0.9, p < 0.001). Comparison between FR rates in post-resection ECoG and surgery outcome resulted in positive predictive value PPV = 100% in CD and LNA, and negative predictive value NPV = 38% in CD and NPV = 50% for LNA. Prediction accuracy was 44% for CD and 67% for LNA.Conclusions
Prediction of seizure outcome was improved by the optimal integration of low-noise EEG and unsupervised FR detection.Significance
Accurate, automated and fast FR rating is essential for consideration of FR in the intraoperative setting. 相似文献13.
Tyler S. Davis John D. Rolston Robert J. Bollo Paul A. House 《Clinical neurophysiology》2018,129(11):2466-2474
Objective
Single-pulse electrical stimulation (SPES) of intracranial electrodes evokes responses that may help identify the seizure onset zone (SOZ); however, lack of automation and response variability has limited clinical adoption of this technique. We evaluated whether automated delivery of low-current SPES could evoke delayed high-frequency suppression (DHFS) of ongoing electrocorticography (ECoG) signals that, when combined with objective analytic techniques, may provide a reliable marker of this zone.Methods
Low-current SPES (1-ms, 3.5-mA biphasic pulses) was delivered to 652 electrodes across 10 patients undergoing ECoG for seizure focus localization. DHFS was measured by calculating the normalized trial-averaged time-frequency power (70–250?Hz) 0.4–1?sec post-stimulation. Electrodes that evoked suppression when stimulated or recorded suppression when stimulation was nearby were used to estimate the SOZ.Results
The estimated SOZ significantly identified the clinical SOZ in 6 of 10 patients (5 of 7 temporal foci) with a false-positive rate of 0–0.06. Stimulation required <2?h, was undetectable by patients, and did not induce seizures or after-discharges.Conclusions
We show that DHFS provides accurate estimates of the clinical SOZ in patients with refractory epilepsy.Significance
This approach may increase the safety, speed, and reproducibility of SOZ identification while reducing cost, subjectivity, and patient discomfort. 相似文献14.
Shuang Wang Irene Z. Wang Juan C. Bulacio John C. Mosher Jorge Gonzalez‐Martinez Andreas V. Alexopoulos Imad M. Najm Norman K. So 《Epilepsia》2013,54(2):370-376
Purpose: Fast ripples are reported to be highly localizing to the epileptogenic or seizure‐onset zone (SOZ) but may not be readily found in neocortical epilepsy, whereas ripples are insufficiently localizing. Herein we classified interictal neocortical ripples by associated characteristics to identify a subtype that may help to localize the SOZ in neocortical epilepsy. We hypothesize that ripples associated with an interictal epileptiform discharge (IED) are more pathologic, since the IED is not a normal physiologic event. Methods: We studied 35 patients with epilepsy with neocortical epilepsy who underwent invasive electroencephalography (EEG) evaluation by stereotactic EEG (SEEG) or subdural grid electrodes. Interictal fast ripples and ripples were visually marked during slow‐wave sleep lasting 10–30 min. Neocortical ripples were classified as type I when superimposed on epileptiform discharges such as paroxysmal fast, spike, or sharp wave, and as type II when independent of epileptiform discharges. Key Findings: In 21 patients with a defined SOZ, neocortical fast ripples were detected in the SOZ of only four patients. Type I ripples were detected in 14 cases almost exclusively in the SOZ or primary propagation area (PP) and marked the SOZ with higher specificity than interictal spikes. In contrast, type II ripples were not correlated with the SOZ. In 14 patients with two or more presumed SOZs or nonlocalizable onset pattern, type I but not type II ripples also occurred in the SOZs. We found the areas with only type II ripples outside of the SOZ (type II‐O ripples) in SEEG that localized to the primary motor cortex and primary visual cortex. Significance: Neocortical fast ripples and type I ripples are specific markers of the SOZ, whereas type II ripples are not. Type I ripples are found more readily than fast ripples in human neocortical epilepsy. Type II‐O ripples may represent spontaneous physiologic ripples in the human neocortex. 相似文献
15.
Objective
Real-time EKG-based automated seizure detection is emerging as a complement or supplement to that based on cortical signals, but its value is unproven. This study assesses the clinically relevance of EKG-based seizure detection by comparing the information content in EKG and ECoG.Methods
ECoGs (6935 h; 241 clinical and 4311 sub-clinical seizures) with simultaneous EKG from 81 subjects undergoing surgical evaluation were used in these analyses. Differences, if any, between clinical and sub-clinical seizures in variables such as intensity, duration and their product severity, were investigated with a multi-variate regression model.Results
Highly statistically significant differences in severity between clinical and sub-clinical seizures were discerned with EKG and ECoG. Furthermore, EKG-based seizure severity was linearly correlated with that estimated using ECoG.Conclusions
These findings support the notion that EKG-based seizure detection is clinically relevant in certain localization-related epilepsies, providing similar information to that yielded by neuronal electrical signals.Significance
The information content equivalence between EKG and ECoG would enable automated seizure detection, quantification and therapy delivery, without resorting to cortical monitoring. The considerably higher S/N and ease of acquisition and processing of EKG compared to ECoG/EEG may foster widespread clinical applications of this novel detection approach. 相似文献16.
Objectives
To investigate patient-specific automated epileptic seizure detection from scalp EEG using a new technique: frequency–moment signatures.Methods
Signatures were calculated from 32 s blocks of data of electrode differences from the right (RH) and left hemisphere (LH). Discrete Fourier transforms of 15 data subsets were calculated per block per hemisphere. The spectral powers at a given frequency from the RH and LH were combined into a single quantity. The signature elements were found by subtracting normalised central moments of the subset distribution from the mean, to measure the consistency of the spectral power at a given frequency over all subsets. The seizure measure was the logarithm of the probability that a signature belonged to a control set of non-seizure signatures.Results
Following the optimisation of signature parameters using three one-day recordings from each of 12 patients, performance was tested on a separate set of data from the same patients. The method had a sensitivity of 91.0% (total 34 seizures) with 0.020 false positives per hour (total 618 h).Conclusions
Frequency–moment signatures promise automated seizure detection sensitivities comparable to visual identification and other published methods, with improved false detection rates.Significance
This technique has the potential to be used more widely in EEG analysis. 相似文献17.
Stephan Meesters Pauly Ossenblok Albert Colon Louis Wagner Olaf Schijns Paul Boon Luc Florack Andrea Fuster 《Clinical neurophysiology》2018,129(6):1276-1290
Objective
The interictal epileptic discharges (IEDs) occurring in stereotactic EEG (SEEG) recordings are in general abundant compared to ictal discharges, but difficult to interpret due to complex underlying network interactions. A framework is developed to model these network interactions.Methods
To identify the synchronized neuronal activity underlying the IEDs, the variation in correlation over time of the SEEG signals is related to the occurrence of IEDs using the general linear model. The interdependency is assessed of the brain areas that reflect highly synchronized neural activity by applying independent component analysis, followed by cluster analysis of the spatial distributions of the independent components. The spatiotemporal interactions of the spike clusters reveal the leading or lagging of brain areas.Results
The analysis framework was evaluated for five successfully operated patients, showing that the spike cluster that was related to the MRI-visible brain lesions coincided with the seizure onset zone. The additional value of the framework was demonstrated for two more patients, who were MRI-negative and for whom surgery was not successful.Conclusions
A network approach is promising in case of complex epilepsies.Significance
Analysis of IEDs is considered a valuable addition to routine review of SEEG recordings, with the potential to increase the success rate of epilepsy surgery. 相似文献18.
Objective
To investigate the feasibility of using noninvasive EEG source imaging approach to image continuous seizure activity in pediatric epilepsy patients.Methods
Nine pediatric patients with medically intractable epilepsy were included in this study. Eight of the patients had extratemporal lobe epilepsy and one had temporal lobe epilepsy. All of the patients underwent resective surgery and seven of them underwent intracranial EEG (iEEG) monitoring. The ictal EEG was analyzed using a noninvasive dynamic seizure imaging (DSI) approach. The DSI approach separates scalp EEGs into independent components and extracts the spatio-temporal ictal features to achieve dynamic imaging of seizure sources. Surgical resection and intracranial recordings were used to validate the noninvasive imaging results.Results
The DSI determined seizure onset zones (SOZs) in these patients were localized within or in close vicinity to the surgically resected region. In the seven patients with intracranial monitoring, the estimated seizure onset sources were concordant with the seizure onset zones of iEEG. The DSI also localized the multiple foci involved in the later seizure propagation, which were confirmed by the iEEG recordings.Conclusions
Dynamic seizure imaging can noninvasively image the seizure activations in pediatric patients with both temporal and extratemporal lobe epilepsy.Significance
EEG seizure imaging can potentially be used to noninvasively image the SOZs and aid the pre-surgical planning in pediatric epilepsy patients. 相似文献19.
Naotaka Usui Kiyohito TeradaKoichi Baba Kazumi MatsudaFumihiro Nakamura Keiko UsuiTakayasu Tottori Shuichi UmeokaShigeru Fujitani Tadahiro MiharaYushi Inoue 《Clinical neurophysiology》2010,121(11):1825-1831
Objective
High frequency oscillations (HFO) of 100–500 Hz have been reported in epileptic human brain. However, the questions of how fast these oscillations can reach, and which frequency range is clinically important remain unanswered. We recorded interictal and ictal very high frequency oscillations (VHFO) of 1000–2500 Hz by subdural electrodes using 10 kHz sampling rate. We describe the characteristics of VHFO, and discuss their underlying mechanism and clinical significance.Methods
Five patients with neocortical epilepsy were studied. All patients underwent intracranial EEG monitoring with subdural electrodes. EEG recording with sampling rate of 10 kHz was conducted. Histopathology revealed malformation of cortical development in all cases.Results
In four of five patients, very high frequency activities of 1000–2500 Hz were detected in highly localized cortical regions (one to four electrodes in individual patient). We named these activities “very high frequency oscillations (VHFO)”. Interictally, VHFO appeared intermittently, and were interrupted by spikes. Sustained VHFO without spikes appeared around the start of seizures.Conclusions
Both interictal and ictal VHFO can be recorded by subdural electrodes. Compared to HFO previously reported, VHFO have much higher frequency, more restricted distribution, smaller amplitude, and different timing of onset.Significance
Recording of VHFO may be useful for identifying the epileptogenic zone. 相似文献20.
Tommaso Fedele Claudio Schönenberger Gabriel Curio Carlo Serra Niklaus Krayenbühl Johannes Sarnthein 《Clinical neurophysiology》2017,128(10):1851-1857