The brain may reinforce seizures during sleep by treating them like memories, according to new research.
A study analysing long-term brain recordings from implanted devices in 11 people with epilepsy found that after a seizure, the brain entered a prolonged deep sleep state similar to how it stores new memories.
This process mimics memory consolidation, where the brain strengthens neural pathways linked to recent activity.
The effect was found to persist into the following night’s sleep, suggesting the brain may strengthen abnormal neural circuits rather than recover from the seizure.
The research was carried out at Mayo Clinic.
Lead author Vaclav Kremen, a neuroscientist and engineer, said: “Sleep is one of the brain’s most powerful tools for learning and memory.
“What we’re seeing is that after a seizure, the brain may be engaging the same biological processes used to consolidate memories, but instead reinforcing the networks that generate seizures.”
Researchers compared sleep patterns on nights following seizures with nights when no recent seizures had occurred.
They found the brain consistently entered an intensified state of non-rapid eye movement sleep, known as NREM sleep, the deep sleep phase when the brain processes and stores information.
During this period, slow brain waves became stronger and steeper, particularly in the regions where seizures originate.
At the same time, rapid eye movement sleep, known as REM sleep and important for emotional processing and cognitive health, was reduced.
On average, patients slept longer and spent more time in deep sleep after seizures but experienced less REM sleep compared with seizure-free nights.
The researchers described the process as seizure-related consolidation, a phenomenon in which seizures appear to hijack the brain’s normal learning mechanisms.
Rather than supporting recovery, the post-seizure sleep state may strengthen abnormal neural circuits, increasing the likelihood of further seizures.
Kremen said: “Instead of treating seizures as isolated events, this research shows they may actively shape the brain in ways that promote disease progression.”
Epilepsy affects an estimated 50m people worldwide, and many patients continue to have seizures despite medication.
The findings may help explain why epilepsy can worsen over time and why memory, mood and sleep problems are common in people with the condition.
The study highlights a potential treatment window in the hours and nights following a seizure, when targeted intervention could disrupt the harmful consolidation process.
Gregory Worrell, a neurologist at Mayo Clinic and senior author, said: “If we can safely intervene during this post-seizure window, we may be able to weaken seizure networks rather than reinforce them.”
The researchers said future work will focus on developing adaptive closed-loop brain stimulation systems, which can detect seizures and respond during sleep in real time, with the aim of breaking the cycle and restoring more typical brain activity.
