Predicting epileptic seizures from scalp EEG based on attractor state analysis

2017 ◽  
Vol 143 ◽  
pp. 75-87 ◽  
Author(s):  
Hyunho Chu ◽  
Chun Kee Chung ◽  
Woorim Jeong ◽  
Kwang-Hyun Cho
Keyword(s):  
Epileptic Seizures ◽  
Attractor State ◽  
Scalp Eeg ◽  
State Analysis

scholarly journals Potentially Pathological Alpha-Pattern as a Variant of Vigilance EEG in Drug-Resistant Epilepsy

2017 ◽  
Vol 8 (4) ◽  
pp. 48-56
Author(s):  
Aleksandr A. Chukhlovin ◽  
Mikhail V. Aleksandrov ◽  
Sergey A. Lytaev ◽  
Vugar R. Kasumov ◽  
Marina E. Pavlovskaya ◽  
...  
Keyword(s):  
Alpha Rhythm ◽  
Refractory Epilepsy ◽  
Functional Decline ◽  
Clinical Signs ◽  
Epileptic Seizures ◽  
Alpha Activity ◽  
Drug Resistant ◽  
Scalp Eeg ◽  
Russian Scientific Research Institute ◽  
Drug Resistant Epilepsy

As a result of pathomorphosis affecting the mechanisms of electrical activity generation interictal EEG may show reduced epileptiform changes whereas clinically apparent epileptic seizures may be present. In these cases patterns of dominant alpha activity are sometimes recorded on the scalp. In this study variations of alpha activity in patients with refractory epilepsy are classified. A group of 50 refractory epilepsy patients aged between 20 and 55 years who were submitted to Polenov Russian Scientific Research Institute of Neurosurgery in 2014-2017 was included in this study. They underwent scalp EEG as a part of their presurgical assessment. In 12 cases patterns of potentially pathological alpha activity were observed. Three variations of alpha-patterns were described: 1) alpha-rhythm with decreased regional diversity and a marked synchronization in temporal areas; 2) alpha-rhythm with reduced epileptiform complexes integrated into the spindles, 3) decelerated non-rhythmic alpha activity distorted by the higher frequency components. Distinguished varieties of potentially pathological alpha-activity according to their order here represent gradual functional decline of normal thalamo-cortical interaction. Considering clinical manifestation of drug-resistant epilepsy with frequent seizures in these patients, reported varieties of alpha activity can not be interpreted as Landolt’s syndrome (forced normalization of EEG). Invasive electrocorticographic monitoring demonstrated that bursts of sharpened polyphasic waves coinciding with alpha-rhythm on scalp EEG are consistent with epileptic discharges on the brain cortex surface. This allows to think of these components as correlates of epileptic activity. Therefore, on a number of occasions in patients with epilepsy a dissonance between clinical signs and electroencephalographic patterns recorded during restful wakefulness may be observed, when epileptiform components are absent or reduced to nonspecific complexes.

A system to detect the onset of epileptic seizures in scalp EEG

2005 ◽  
Vol 116 (2) ◽  
pp. 427-442 ◽  
Author(s):  
M.E. Saab ◽  
J. Gotman
Keyword(s):  
Epileptic Seizures ◽  
Scalp Eeg

A novel wavelet-based index to detect epileptic seizures using scalp EEG signals

2008 ◽  
Author(s):  
Ali Shahidi Zandi ◽  
Guy A. Dumont ◽  
Manouchehr Javidan ◽  
Reza Tafreshi ◽  
Bernard A. MacLeod ◽  
...  
Keyword(s):  
Epileptic Seizures ◽  
Eeg Signals ◽  
Scalp Eeg

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.

A Rare Cause of Epilepsy: Ulegyria Revisited in a Series of 10 Patients

2021 ◽  
pp. 155005942110433
Author(s):  
Aylin Bican Demir ◽  
Pinar Eser ◽  
Ahmet Bekar ◽  
Bahattin Hakyemez ◽  
İbrahim Bora
Keyword(s):  
Hippocampal Sclerosis ◽  
Age At Onset ◽  
Epileptic Seizures ◽  
Term Infants ◽  
Patients Âgés ◽  
Scalp Eeg ◽  
Imaging Characteristics ◽  
Pathology Reports ◽  
The One ◽  
Operative Notes

Introduction. Ulegyria results from perinatal hypoxic-ischemic brain injury in term infants. The specific mushroom-shaped configuration of ulegyria results from small atrophic circumvolutions at the bottom of a sulcus underlying an intact gyral apex. Clinically, ulegyria is generally associated with epilepsy. Here, we aimed to delineate the characteristics of patients with ulegyria and the epileptic seizures they experience. Material and methods. Medical records including radiology and pathology reports, video-electroencephalographic (EEG) analysis, operative notes, hospital progress and outpatient clinic notes were reviewed retrospectively in a total of 10 ulegyria patients. Results. Patients ages ranged between 24 and 58 years (mean, 32 ± 9.8 years). Past medical history was confirmed for neonatal asphyxia in 2 (20%). Neurological examination was remarkable for spastic hemiparesis in 1 (10%) patient with perisylvian ulegyria and for visual field deficits in 2 patients (20%) with occipital ulegyria. Ulegyria most commonly involved the temporoparietal region (n = 5, 50%) followed by the perisylvian area (n = 2, 20%). Except the one with bilateral perisylvian ulegyria, all patients had unilateral lesions (n = 9, 90%). Hippocampal sclerosis accompanied ulegyria in 2 patients (20%). All patients experienced epileptic seizures. Mean age at seizure onset was 8.8 ± 5.4 years (range, 2-20 years). Interictal scalp EEG and EEG-video monitoring records demonstrated temporoparietal and frontotemporal activities in 5 (50%) and 2 (20%) patients, respectively. The seizures were successfully controlled by antiepileptic medication in 8 patients (n = 8, 80%). The remaining 2 patients (%20) with concomitant hippocampal sclerosis required microsurgical resection of the seizure foci due to medically resistant seizures. Discussion. Ulegyria is easily recognized with its unique magnetic resonance imaging characteristics and clinical presentation in the majority of cases. It is highly associated with either medically resistant or medically controllable epileptic seizures. The treatment strategy depends on the age at onset and extends of the lesion that has a significant impact on the severity of the clinical picture.

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