Diagnostic principles of immature epileptic (proepileptic) EEG activity in rats with genetic predisposition to absence epilepsy

Introduction:Absence epilepsy is a specific neurological disorder characterized by brief episodes of loss of consciousness (absence) accompanied by high-amplitude “spike-wave” discharges in the electroencephalogram (EEG). WAG/Rij rats with a genetic predisposition to absence epilepsy are used as a reliable model of this disease. This model is beneficial for investigating basic mechanisms of absence epilepsy, including the development of spike-wave seizures.Purpose:Establishing diagnostic principles for immature forms of spikewave activity in EEG (so-called proepileptic activity) of WAG/Rij rats.Results:Diagnostic criteria are proposed for proepileptic EEG activity in rats, based on time-frequency analysis with the continuous wavelet transform and skeletons of wavelet surfaces. The algorithm was tested in “epileptic” and “asymptomatic” individuals. Rats with the “epileptic” phenotype demonstrated a decrease in number of proepileptic patterns between 5 and 7 months of age in parallel to an increase in the number of epileptic discharges that might relate to the transformation of proepileptic activity to epileptic. In rats with the “asymptomatic” phenotype, the age-related decline in the number of proepileptic patterns was not accompanied by the occurrence of spike-wave discharges. A decrease in the instantaneous frequency was found in a larger number of proepileptic patterns in “epileptic” WAG/Rij rats as compared to “asymptomatic” individuals.Practical relevance:A similar approach can be used for early diagnosis of absence epilepsy at the preclinical stage in patients with genetic predisposition.

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Age-Dependent Increase of Absence Seizures and Intrinsic Frequency Dynamics of Sleep Spindles in Rats

Neuroscience Journal ◽

10.1155/2014/370764 ◽

2014 ◽

Vol 2014 ◽

pp. 1-6 ◽

Cited By ~ 9

Author(s):

Evgenia Sitnikova ◽

Alexander E. Hramov ◽

Vadim Grubov ◽

Alexey A. Koronovsky

Keyword(s):

Neurological Diseases ◽

Epileptic Activity ◽

Absence Epilepsy ◽

Sleep Spindles ◽

Intrinsic Frequency ◽

Time Frequency ◽

Age Dependent ◽

Spike Wave Discharges ◽

Epileptic Spike ◽

Spike Wave

The risk of neurological diseases increases with age. In WAG/Rij rat model of absence epilepsy, the incidence of epileptic spike-wave discharges is known to be elevated with age. Considering close relationship between epileptic spike-wave discharges and physiologic sleep spindles, it was assumed that age-dependent increase of epileptic activity may affect time-frequency characteristics of sleep spindles. In order to examine this hypothesis, electroencephalograms (EEG) were recorded in WAG/Rij rats successively at the ages 5, 7, and 9 months. Spike-wave discharges and sleep spindles were detected in frontal EEG channel. Sleep spindles were identified automatically using wavelet-based algorithm. Instantaneous (localized in time) frequency of sleep spindles was determined using continuous wavelet transform of EEG signal, and intraspindle frequency dynamics were further examined. It was found that in 5-months-old rats epileptic activity has not fully developed (preclinical stage) and sleep spindles demonstrated an increase of instantaneous frequency from beginning to the end. At the age of 7 and 9 months, when animals developed matured and longer epileptic discharges (symptomatic stage), their sleep spindles did not display changes of intrinsic frequency. The present data suggest that age-dependent increase of epileptic activity in WAG/Rij rats affects intrinsic dynamics of sleep spindle frequency.

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The Time–Frequency Structure of the Spike–Wave Discharges in Genetic Absence Epilepsy

Doklady Biological Sciences ◽

10.1023/b:dobs.0000033274.44589.df ◽

2004 ◽

Vol 396 (1-6) ◽

pp. 194-197 ◽

Cited By ~ 4

Author(s):

A. V. Gabova ◽

D. Yu. Bosnyakova ◽

M. S. Bosnyakov ◽

A. B. Shatskova ◽

G. D. Kuznetsova

Keyword(s):

Absence Epilepsy ◽

Time Frequency ◽

Frequency Structure ◽

Spike Wave Discharges ◽

Spike Wave

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Spike-wave seizures, slow-wave sleep EEG and morphology of substantia nigra pars compacta in WAG/Rij rats with genetic predisposition to absence epilepsy

Brain Research Bulletin ◽

10.1016/j.brainresbull.2021.06.003 ◽

2021 ◽

Author(s):

Evgenia Sitnikova ◽

Elizaveta M. Rutskova ◽

Daria Tsvetaeva ◽

Vladimir V. Raevsky

Keyword(s):

Substantia Nigra ◽

Slow Wave ◽

Genetic Predisposition ◽

Slow Wave Sleep ◽

Absence Epilepsy ◽

Sleep Eeg ◽

Substantia Nigra Pars Compacta ◽

Spike Wave

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Co-existence of Rolandic and 3 Hz Spike-Wave Discharges on EEG in Children with Epilepsy

Canadian Journal of Neurological Sciences / Journal Canadien des Sciences Neurologiques ◽

10.1017/cjn.2018.364 ◽

2018 ◽

Vol 46 (1) ◽

pp. 64-70 ◽

Cited By ~ 3

Author(s):

Anita N. Datta ◽

Laura Wallbank ◽

Peter K. H. Wong

Keyword(s):

Clinical Data ◽

Seizure Control ◽

Age Of Onset ◽

Absence Epilepsy ◽

Childhood Absence Epilepsy ◽

Drug Induced ◽

Favorable Prognosis ◽

Spike Wave Discharges ◽

Spike Wave

AbstractObjectiveBenign epilepsy of childhood with central temporal spikes (BECTS) and absence epilepsy are common epilepsy syndromes in children with similar age of onset and favorable prognosis. However, the co-existence of the electrocardiogram (EEG) findings of rolandic spike and 3 Hz generalized spike-wave (GSW) discharges is extremely rare, with few cases reported in the literature. Our objective was to characterize the EEG findings of these syndromes in children in our center and review the electro-clinical features.MethodsAll EEGs at BC Children’s Hospital are entered in a database, which include EEG findings and clinical data. Patients with both centro-temporal spikes and 3 Hz GSW discharges were identified from the database and clinical data were reviewed.ResultsAmong the 43,061 patients in the database from 1992 to 2017, 1426 with isolated rolandic discharges and 528 patients with isolated 3 Hz GSW discharges were identified, and 20 (0.05%) patients had both findings: 3/20 had BECTS, and subsequently developed childhood absence epilepsy and 17/20 had no seizures characteristic for BECTS. At follow-up, 17 (85%) were seizure-free, 1 (5%) had rare, and 2 (10%) had frequent seizures.ConclusionsThis is the largest reported group of patients to our knowledge with the co-existence of rolandic and 3 Hz GSW discharges on EEGs in one institution, not drug-induced. As the presence of both findings is extremely rare, distinct pathophysiological mechanisms are likely. The majority had excellent seizure control at follow-up, similar to what would be expected for each type of epilepsy alone.

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