The brain may inadvertently “learn” to have seizures by treating them like important memories to be stored, according to new research from Mayo Clinic in the United States.
The study, published in the Journal Of Neuroscience, found that after a seizure, the brain enters a deep sleep state that mimics memory storage, and that this effect can persist into the following night’s sleep.
In effect, this “saves” the seizure’s path like a normal memory, strengthening the disease.
The findings suggest new opportunities to prevent epilepsy from worsening by targeting brain activity during the hours immediately following a seizure and during the subsequent night of sleep – a critical period when harmful brain changes may occur.
“Sleep is one of the brain’s most powerful tools for learning and memory,” says study lead author and Mayo Clinic neuroscientist and engineer Dr Vaclav Kremen.
“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.”
Epilepsy affects an estimated 50 million people worldwide, and many patients continue to have seizures despite medication.
Understanding the relationship between seizures and sleep could help explain why epilepsy can worsen over time, and why memory, mood and sleep problems are common in people with the condition.
The study analysed long-term brain recordings from implanted devices in 11 people with epilepsy.
Using these recordings, researchers compared sleep patterns on nights following seizures, to nights when no recent seizures occurred.
They found that after a seizure, the brain consistently entered a prolonged and intensified state of deep sleep, known as non- rapid eye movement (NREM) sleep.
During this period, slow brain waves became stronger and steeper – key features of memory consolidation – particularly within the specific brain regions where seizures originate.
At the same time, rapid eye movement (REM) sleep, which is important for emotional processing and cognitive health, was reduced.
On average, patients slept longer and spent more time in deep sleep after seizures, but they experienced less REM sleep compared with seizure-free nights.
The researchers call this process seizure-related consolidation – a phenomenon in which seizures appear to hijack the brain’s normal learning mechanisms.
Rather than helping the brain recover, this post-seizure sleep state may strengthen abnormal neural circuits, creating a vicious cycle in which each seizure increases the likelihood of future seizures.
“Instead of treating seizures as isolated events, this research shows they may actively shape the brain in ways that promote disease progression,” says Dr Kremen.
Importantly, the findings point to a potential new window for treatment – the hours and nights after a seizure – when targeted intervention could disrupt this harmful learning process.
“If we can safely intervene during this post-seizure window, we may be able to weaken seizure networks rather than reinforce them,” says study senior author and Mayo Clinic neurologist Dr Gregory Worrell.
