New findings from Columbia University highlight the influence of genetics over the timing of seizures.
Background
A complex relationship exists between sleep and epilepsy, and although the timing of seizures has been explored for a number of individual seizure types and syndromes, there have been few large-scale studies in subjects with different epilepsy types. In addition to this, the role of genes in seizure timing has not been well studied. The study at Columbia University aimed to address these gaps in knowledge.
Methods
During the study, which is published in the journal Epilepsia, the researchers recruited 1,395 people epilepsy from 546 families enrolled in the Epilepsy Phenome/Genome Project. They examined seizure timing in subjects with different epilepsy types and seizures types, and also looked at members of the same family for similarities in their seizure patterns.
Results
The results indicated that seizures were more likely to occur during sleep in people with non-acquired focal epilepsy (i.e. focal epilepsy that is genetic/present at birth) than in those with generalised epilepsy. Seizures were also shown to be more likely to occur in sleep if they began in the frontal lobe of the brain, rather than in the temporal lobe. Conversely, people with generalised epilepsy were found to be more likely to experience seizures within one hour of waking than those with non-acquired focal epilepsy.
Interestingly, when the researchers looked at within-family seizure patterns, they noticed that first-degree relatives (i.e. parents, siblings or children) had a tendency to experience seizures at similar times in their sleep/wake cycles.
Significance
These findings are important because they show that the timing of seizures is linked to both epilepsy and seizure type. This is also the first evidence for a genetic contribution to the sleep/wake timing of seizures.
Lead author of the study, Dr Melodie Winawer, said: “These results improve our understanding of the biology of sleep and seizures, and can lead to better care of families affected by epilepsy.”
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