Long-term seizure dynamics are determined by the nature of seizures and the mutual interactions between them

Neurobiology of Disease

卷:154

Ondrej Novak¹  John G.R. Jefferys¹  Vojtech Kumpost¹  Jan Chvojka²  Jakub Otahal²  Antonin Posusta²  Jaroslav Hlinka³  Matias I. Maturana³  Barbora Hermanovska⁴  Jan Kudlacek⁴  Premysl Jiruska⁴  Mark J. Cook⁴ 

[1] Department of Circuit Theory, Faculty of Electrical Engineering, Czech Technical University in Prague, Prague, Czech Republic;

[2] Department of Developmental Epileptology, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic;

[3] Department of Physiology, Second Faculty of Medicine, Charles University, Prague, Czech Republic;

关键词: Seizures;    Clustering;    Long-term profile;    Temporal lobe epilepsy;    Tetanus toxin;    Probability;   

DOI  :  

来源: DOAJ

【 摘 要 】

The seemingly random and unpredictable nature of seizures is a major debilitating factor for people with epilepsy. An increasing body of evidence demonstrates that the epileptic brain exhibits long-term fluctuations in seizure susceptibility, and seizure emergence seems to be a consequence of processes operating over multiple temporal scales. A deeper insight into the mechanisms responsible for long-term seizure fluctuations may provide important information for understanding the complex nature of seizure genesis. In this study, we explored the long-term dynamics of seizures in the tetanus toxin model of temporal lobe epilepsy. The results demonstrate the existence of long-term fluctuations in seizure probability, where seizures form clusters in time and are then followed by seizure-free periods. Within each cluster, seizure distribution is non-Poissonian, as demonstrated by the progressively increasing inter-seizure interval (ISI), which marks the approaching cluster termination. The lengthening of ISIs is paralleled by: increasing behavioral seizure severity, the occurrence of convulsive seizures, recruitment of extra-hippocampal structures and the spread of electrographic epileptiform activity outside of the limbic system. The results suggest that repeated non-convulsive seizures obey the ‘seizures-beget-seizures’ principle, leading to the occurrence of convulsive seizures, which decrease the probability of a subsequent seizure and, thus, increase the following ISI. The cumulative effect of repeated convulsive seizures leads to cluster termination, followed by a long inter-cluster period. We propose that seizures themselves are an endogenous factor that contributes to long-term fluctuations in seizure susceptibility and their mutual interaction determines the future evolution of disease activity.

【 授权许可】

Unknown