For a lot of people, a poor night’s sleep results in a grouchy mood, an extra cup of coffee, or an afternoon nap.
For many people with epilepsy, sleep deprivation lowers the brain’s seizure threshold and can be a seizure trigger. In simple terms, the brain becomes more excitable and less able to keep its electrical activity stable. Sleep normally helps “reset” brain networks and quiet excessive firing. When sleep is shortened or fragmented:
- Neuronal excitability increases, making abnormal electrical bursts more likely.
- Seizure-suppressing mechanisms weaken, especially those linked to deep (slow-wave) sleep.
- Abnormal EEG activity (interictal epileptiform spikes) often increases after poor sleep—even if a seizure does not occur right away.
This is why sleep deprivation is sometimes used intentionally during EEG testing: it can reveal hidden seizure tendencies and provide clinicians with important diagnostic information.
The Importance of Balance in the Brain
Imagine the brain as a see-saw, with excitation on one side and inhibition on the other. Normal brain function depends on keeping these two forces in balance.
Sleep plays a critical role in keeping brain activity balanced and stable. Sleep deprivation tips the see-saw. Inhibitory control weakens, allowing excitatory activity to become less restrained and more likely to trigger seizures. When sleep is inadequate, several protective mechanisms are disrupted:
During healthy sleep, especially deep sleep, the brain strengthens inhibitory pathways that quiet excessive electrical activity. When sleep is reduced, these calming signals weaken, allowing neurons to fire more easily, a condition that increases seizure risk.
2. Lack of sleep increases brain excitability
Sleep deprivation shifts the balance toward excitation. Excitatory signals build up, making brain circuits more reactive and easier to push into a seizure.
3. How sleep deprivation reduces the brain’s ability to give calming signals
One mechanism involved includes a protein called KCC2, which helps regulate a salt called chloride inside brain cells. Chloride is essential for the brain’s main calming signals to work properly. When sleep deprivation reduces KCC2 function, chloride regulation is disrupted, and since inhibition requires chloride, inhibition becomes less effective, and the brain becomes more excitable.
Warning Signs You May Be Sleep Deprived and at Higher Seizure Risk
An important part of managing epilepsy is learning your own body and taking steps to decrease the likelihood of having a seizure. If lack of sleep is a trigger for you, you should be aware of signs that you are sleep deprived. Some of these include:
- Increased auras or subtle seizure-like sensations
- Needing more caffeine than usual to function
- Brain fog, poor concentration, or forgetfulness
For people with epilepsy, sleep is part of treatment—not just lifestyle advice. Improving sleep is one of the important additional strategy alongside taking antiseizure medications consistently. Even small improvements in sleep quality and regularity can meaningfully reduce seizure risk.
This post is part of a series of blogs related to understanding and improving sleep health:
- Why Sleep Loss is a Seizure Trigger
- Practical Steps to Improve Sleep and Brain Health
- Should I Use a Sleep Tracker to Monitor My Sleep? It Depends.
Phil Haydon, Ph.D., is an Emeritus Professor of Neuroscience at Tufts University School of Medicine. His research helped reveal how non-neuronal brain cells contribute to sleep regulation and play important roles in neurological disorders including epilepsy. His scientific work has led to the formation of several biotechnology companies, including GliaCure and Naveris. Beyond the laboratory, Phil is an accomplished offshore sailor and in 2024 won the double-handed division of the Newport–Bermuda Race.