For people with epilepsy, sleeping after a seizure can cause more seizures

Sleep may encode seizures in the brain by recycling memory consolidation processes, potentially making them harder to treat and prevent, a new study suggests. But new research also suggests possible ways to counter its effects. It uses electrical stimulation to prevent the brain from “remembering” the seizure, the researchers say.

“This opens up a whole new realm of personalized treatment options for each patient,” said study co-author Vaclav Klemen, a neuroscientist at the Mayo Clinic. He added that electrical stimulation can be customized to each individual’s unique seizure profile.

sleep and seizures

People often struggle to store memories after an epileptic seizure, and research in rats suggests this happens because the brain’s memory storage system strengthens the connections in the neurons that trigger the seizure instead of locking up the memory. However, the link between epilepsy, memory, and sleep has not been adequately evaluated in humans, as most of these studies involve measuring brain activity over just a few days, and the studies are typically conducted in clinics, which are not conducive to a good night’s sleep.

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“Hospitalization can change sleep and seizure patterns due to medication adjustments, stress, noise, and disruption to daily life,” Dr. Erin Conrad, a neuroscientist at the University of Pennsylvania who was not involved in the study, told Live Science in an email.

In the new study, published March 4 in the Journal of Neuroscience, electrodes were implanted in participants sleeping at home over a period of months or years, allowing researchers to collect data over long periods of time without disrupting their sleep. “This gives us a more realistic picture of how sleep changes after a seizure in everyday situations,” Conrad said.

The research team analyzed two groups of participants with drug-resistant epilepsy who attended from 2010 to 2011 at the University of Melbourne in Australia or from 2019 to 2023 at the Mayo Clinic in Minnesota. One group was implanted with a deep brain stimulator that can detect and reduce seizure activity, and the other group was given an investigational seizure advisory system that records brain signals but does not attempt to interrupt seizures. Because the study was small, with a total of 11 participants, the results may not be generalizable to all epilepsy patients, Klemen told Live Science. Nevertheless, this study provides clues about how changes in brain patterns during sleep may underlie the association between epilepsy and memory.

The researchers found that people slept about 24 minutes longer a night after an epileptic seizure, but not all stages of sleep were lengthened.

Rapid eye movement (REM) sleep, which is important for emotional processing and dreaming, was about 12 minutes shorter on the night after an epileptic seizure than on the night between seizures. Dr. Laurent Cheibani, a neuroscientist at the University of Geneva who was not involved in the study, told Live Science in an email that this reduction makes sense because “12 minutes may seem short, but keep in mind that the overall duration of REM sleep is also not that long (typically around 1 hour and 40 minutes).”

Conrad said it’s also important how many minutes of REM sleep you replace. The researchers found that the length and intensity of the deepest stage of sleep, called the slow-wave stage, which is key to storing memories, increased. One hypothesis is that the brain uses memory formation pathways to “remember” how to form future seizures, but the study’s observations alone cannot show that this is the case.

Predicting seizures using sleep patterns

In future studies, the researchers will need to determine whether prolonging the memory-formation phase of sleep actually strengthens epileptic seizures by “remembering” the seizure path.

“Using brain devices that adjust stimulation based on both seizure and sleep patterns is an exciting possibility,” Conrad said. These devices use electrodes to record brain activity and, as soon as a seizure is detected, send electrical impulses to stop it. They use a closed-loop feedback system to improve detection over time as the system recognizes a particular person’s seizure patterns.

“This kind of approach could help test the main idea of ​​the study by seeing whether changes in sleep-related brain activity after a seizure reduce the likelihood of future seizures,” Conrad added. “If the theory holds, this type of adaptive closed-loop system could be a new way to personalize treatment.”

Klemen said the findings suggest that electrical brain stimulation, which disrupts seizure memory formation, could be a future additional treatment alongside drug therapy for patients with drug-resistant epilepsy. “We are serious about finding treatments for patients with severe epilepsy who have no hope with conventional drug therapy,” he said.