scholarly journals B.03 Registered EEG technologists can accurately identify ictal and interictal epileptiform patterns on routine EEG

Author(s):  
Y Wu ◽  
S Weiss ◽  
C Hahn

Background: Registered EEG technologists (RETs) are trained in both the technical aspects of EEG and in preliminary EEG interpretation. However, there is little research evaluating the accuracy of EEG interpretation by RETs. Methods: Retrospective study of consecutive routine EEG recordings performed at SickKids Hospital. Preliminary reports by RETs and final reports by neurophysiologists were compared in 5 domains: background activity, focal abnormalities, ictal and inter-ictal epileptiform discharges and summary. Results: 500 EEG recordings were analyzed. Sensitivity and specificity of RET reports was high for the assessment of background (85%, 93%), focal slowing (84%, 93%) and inter-ictal epileptiform discharges (92%, 90%). RET reports identified ictal EEG patterns in 32 cases vs. 29 cases identified by neurophysiologists. RET reports were 100% accurate for noting no EEG change for all of 11 cases with non-epileptic events. Conclusions: Preliminary EEG reports by RETs were sensitive and specific for all EEG domains analyzed. In the majority of cases, the preliminary interpretation made by the RET was concordant with the final report of the neurophysiologist. Given these findings, RETs may be able to participate in the screening of routine EEG recordings in order to enhance the productivity of busy EEG laboratories.

Author(s):  
Mohammed M. Jan ◽  
Mark Sadler ◽  
Susan R. Rahey

Electroencephalography (EEG) is an important tool for diagnosing, lateralizing and localizing temporal lobe seizures. In this paper, we review the EEG characteristics of temporal lobe epilepsy (TLE). Several “non-standard” electrodes may be needed to further evaluate the EEG localization, Ictal EEG recording is a major component of preoperative protocols for surgical consideration. Various ictal rhythms have been described including background attenuation, start-stop-start phenomenon, irregular 2-5 Hz lateralized activity, and 5-10 Hz sinusoidal waves or repetitive epileptiform discharges. The postictal EEG can also provide valuable lateralizing information. Postictal delta can be lateralized in 60% of patients with TLE and is concordant with the side of seizure onset in most patients. When patients are being considered for resective surgery, invasive EEG recordings may be needed. Accurate localization of the seizure onset in these patients is required for successful surgical management.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jan Pyrzowski ◽  
Jean- Eudes Le Douget ◽  
Amal Fouad ◽  
Mariusz Siemiński ◽  
Joanna Jędrzejczak ◽  
...  

AbstractClinical diagnosis of epilepsy depends heavily on the detection of interictal epileptiform discharges (IEDs) from scalp electroencephalographic (EEG) signals, which by purely visual means is far from straightforward. Here, we introduce a simple signal analysis procedure based on scalp EEG zero-crossing patterns which can extract the spatiotemporal structure of scalp voltage fluctuations. We analyzed simultaneous scalp and intracranial EEG recordings from patients with pharmacoresistant temporal lobe epilepsy. Our data show that a large proportion of intracranial IEDs manifest only as subtle, low-amplitude waveforms below scalp EEG background and could, therefore, not be detected visually. We found that scalp zero-crossing patterns allow detection of these intracranial IEDs on a single-trial level with millisecond temporal precision and including some mesial temporal discharges that do not propagate to the neocortex. Applied to an independent dataset, our method discriminated accurately between patients with epilepsy and normal subjects, confirming its practical applicability.


2004 ◽  
Vol 19 (3) ◽  
pp. 369-377
Author(s):  
Giorgio Battaglia ◽  
Silvana Franceschetti ◽  
Luisa Chiapparini ◽  
Elena Freri ◽  
Stefania Bassanini ◽  
...  

Patients affected by periventricular nodular heterotopia are frequently characterized by focal drug-resistant epilepsy. To investigate the role of periventricular nodules in the genesis of seizures, we analyzed the electroencephalographic (EEG) features of focal seizures recorded by means of video-EEG in 10 patients affected by different types of periventricular nodular heterotopia and followed for prolonged periods of time at the epilepsy center of our institute. The ictal EEG recordings with surface electrodes revealed common features in all patients: all seizures originated from the brain regions where the periventricular nodular heterotopia were located; EEG patterns recorded on the leads exploring the periventricular nodular heterotopia were very similar both at the onset and immediately after the seizure's end in all patients. Our data suggest that seizures are generated by abnormal anatomic circuitries, including the heterotopic nodules and adjacent cortical areas. The major role of heterotopic neurons in the genesis and propagation of epileptic discharges must be taken into account when planning surgery for epilepsy in patients with periventricular nodular heterotopia. ( J Child Neurol 2005;20:369—377).


2015 ◽  
Vol 126 (8) ◽  
pp. 1493-1497 ◽  
Author(s):  
Greta Gustafsson ◽  
Anders Broström ◽  
Martin Ulander ◽  
Magnus Vrethem ◽  
Eva Svanborg

2005 ◽  
Vol 63 (2b) ◽  
pp. 383-388 ◽  
Author(s):  
Nise Alessandra de Carvalho Sousa ◽  
Patrícia da Silva Sousa ◽  
Eliana Garzon ◽  
Américo C. Sakamoto ◽  
Nádia I.O. Braga ◽  
...  

Seizures in Juvenile Myoclonic Epilepsy (JME) are dependent on the sleep-wake cycle and precipitant factors, among which sleep deprivation (SD) is one of the most important. Still an under diagnosed syndrome, misinterpretation of the EEGs contributes to diagnostic delay. Despite this, a quantitative EEG investigation of SD effects has not been performed. We investigated the effect of SD on EEGs in 41 patients, aged 16-50 yr. (mean 25.4), who had not yet had syndromic diagnosis after a mean delay of 8.2 yr. Two EEG recordings separated by a 48-hour interval were taken at 7 a.m. preceded by a period of 6 hours of sleep (routine EEG) and after SD (sleep-deprived EEG). The same protocol was followed and included a rest wakefulness recording, photic stimulation, hyperventilation and a post-hyperventilation period. The EEGs were analyzed as to the effect of SD on the number, duration, morphology, localization and predominance of abnormalities in the different stages. A discharge index (DI) was calculated. Out of the 41 patients, 4 presented both normal EEG recordings. In 37 (90.2%) there were epileptiform discharges (ED). The number of patients with ED ascended from 26 (70.3%) in the routine EEG to 32 (86.5%) in the sleep-deprived exam. The presence of generalized spike-wave and multispike-wave increased from 20 (54.1%) and 13 (35.1%) in the first EEG to 29 (78.4%) and 19 (51.4%) in the second, respectively (p<0.05 and p<0.01). As to localization, the number of generalized, bilateral and synchronous ED increased from 21 (56.8%) to 30 (81.1%) (p<0.01). The DI also increased; while 8 patients (21.6%) presented greater rate in the routine EEG, 25 (67.6%) did so in the sleep-deprived EEG mainly during somnolence and sleep (p<0.01). Moreover, the paroxysms were also longer in the sleep-deprived EEG. Sleep-deprived EEG is a powerful tool in JME and can contribute significantly to the syndromic characterization of this syndrome.


2020 ◽  
Author(s):  
Wei-ping Liu ◽  
Mian Wang ◽  
Chen Zhang ◽  
Charlie Weige Zhao ◽  
Bo Xiao ◽  
...  

Abstract Background : Autoimmune epilepsy is recognized as a distinct entity of epilepsy with underestimated incidence. Our previous study reported that prompt diagnosis and early-initiated immunotherapy led to better outcome. We proposed to assess the feasibility and reasonability of the Antibody Prevalence in Chinese Patients with Epilepsy and Encephalopathy (APE 2 -CHN) and Response to Immunotherapy in Chinese Patients with Epilepsy and Encephalopathy (RITE 2 -CHN) scores in predicting Chinese patients with autoimmune epilepsy. Methods : We conducted a retrospective study of consecutive patients from Xiangya Hospital, Central South University (01/01/2017-02/28/2019) whose serum and/or cerebrospinal fluid (CSF) samples were examined for autoimmune encephalitis antibodies. Of these, patients with new-onset epilepsy or established epilepsy of unknown etiology were selected in our study. An APE 2 -CHN score was assigned to each patient and a RITE 2 -CHN score was calculated for each patient who received immunotherapy. Results : 191 patients meeting the diagnostic criteria for epilepsy were enrolled in our study. 36 were subsequently identified with specific etiologies. The rest of the 155 patients had an unknown etiology. Central nervous system-specific antibodies were detected in 76 (49.0%) of them, after excluding solely thyroid peroxidase antibody or glutamic acid decarboxylase antibody. N-methyl-D-aspartate receptor antibody (48.7%, 37/76) was the most common antibody specificity, followed by γ-aminobutyric acid type B receptor antibody (14.5%, 11/76). Certain clinical features such as new-onset epilepsy, autonomic dysfunction, viral prodrome, facio-brachial dystonic seizures/oral dyskinesia, inflammatory CSF profile, and mesial temporal magnetic resonance imaging abnormalities correlated with positive antibody results. Sensitivity and specificity of an APE 2 -CHN score ≥ 5 to predict the presence of specific neural auto-antibodies in our study were 85.5% and 58.9%, respectively. In the subset of patients who received immunotherapy (n = 112), sensitivity and specificity of a RITE 2 -CHN score ≥ 8 to predict favorable seizure outcome were 98.6% and 63.2% respectively. Conclusion : The APE 2 -CHN and RITE 2 -CHN scores were preferable tools in predicting positive serologic findings and prognosis of autoimmune epilepsy in Chinese patients with epilepsy.


2019 ◽  
Vol 30 (05) ◽  
pp. 1850060 ◽  
Author(s):  
Lung-Chang Lin ◽  
Chen-Sen Ouyang ◽  
Rong-Ching Wu ◽  
Rei-Cheng Yang ◽  
Ching-Tai Chiang

Numerous nonepileptic paroxysmal events, such as syncope and psychogenic nonepileptic seizures, may imitate seizures and impede diagnosis. Misdiagnosis can lead to mistreatment, affecting patients’ lives considerably. Electroencephalography is commonly used for diagnosing epilepsy. Although on electroencephalograms (EEGs), epileptiform discharges (ED) specifically indicate epilepsy, only approximately 50% of patients with epilepsy have ED in their first EEG. In this study, we developed a deep convolutional neural network (ConvNet)-based classifier to distinguish EEG between patients with epilepsy without ED and controls. Overall, 25 patients with epilepsy without ED in their EEGs and 25 age-matched patients with Tourette syndrome or syncope were enrolled. Their EEGs were classified using the deep ConvNet. When the EEG data without overlapping were used, the accuracy, sensitivity, and specificity were 65.00%, 48.00%, and 82.00%, respectively. The performance measures improved when the input EEG data were augmented through overlapping. With 95% EEG data overlapping, the accuracy, sensitivity, and specificity increased to 80.00%, 70.00%, and 90.00%, respectively. The proposed method could be regarded as a pilot study to demonstrate a proof of concept of a potential diagnostic value of deep ConvNet in patients with epilepsy without ED. Further studies are needed to assist neurologists in distinguishing nonepileptic paroxysmal events from epilepsy.


Sign in / Sign up

Export Citation Format

Share Document