Nocturnal Seizures – Seizures during Sleep

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Sleep and seizures – the facts

  • Sleep deprivation is one of the most commonly reported seizure triggers by people with epilepsy
  • Nocturnal seizures, even if only brief can disrupt sleep and increase daytime drowsiness
  • Drowsiness can increase the risk of daytime seizures for people who would normally only have seizures during sleep
  • Nocturnal seizures may be misdiagnosed as a sleep disorder and vice versa
  • Nocturnal seizures are a risk factor for Sudden Unexpected Death in Epilepsy (SUDEP)
  • Some antiseizure medications can contribute to sleeping difficulties or daytime drowsiness
  • Sleep apnoea is about twice as common in people with poorly controlled epilepsy than in the general population
  • People with epilepsy and a sleep disorder have a poorer quality of life compared to those with no sleep disorder.
  • Treatment of the sleep disorder improves seizure control and quality of life
  • Lastly, sleep disorders can exacerbate seizures and epilepsy can exacerbate certain sleep disorders

Why do so many seizures happen during sleep?

Seizures during sleep can occur with any type of epilepsy. Some people have seizures occurring only during sleep whilst others have both daytime and night-time seizures. People who have only night-time seizures in their sleep are defined as having nocturnal epilepsy.

The International League Against Epilepsy (ILAE) defines nocturnal seizures as ‘seizures occurring exclusively or predominantly (more than 90%) from sleep.

It is estimated around 12 percent of people with epilepsy have nocturnal seizures.

Why do nocturnal seizures occur?

Epileptic seizures are often strongly influenced by the sleep-wake cycle.

In wakefulness, our brain waves remain fairly constant, but when we go off to sleep, we have a change of state – from awake to asleep. Plus, during sleep, there are many changes of state, which are called sleep stages. It is thought that a change of state has an effect on the brains ‘epileptic activity’ in people with epilepsy. Some seizures occur predominantly at a certain stages of sleep.

It’s believed that nocturnal seizures are triggered by changes in the electrical activity in your brain when moving between the different stages of sleep, and between sleep and awakening stage. We go to bed and shift from

  • wakefulness to drowsiness to
  • light sleep to deep sleep to
  • Rapid Eye Movement (REM) sleep
  • and this whole cycle occurs 3-4 times per night.

There are dramatic changes on EEG during these sleep stage changes.

Stages of Sleep

Sleep is divided into 5 stages: Non-REM Stages 1, 2, 3, and 4 and REM sleep.

Seizures don’t seem to happen during REM sleep, but may occur at any other time during the sleep cycle, often in light sleep – that is, stages 1 and 2 of sleep. Nocturnal seizures can also occur when waking or stirring during the night.

This generally means there are more common times at which nocturnal seizures happen:

  • Within the first or second hour after going off to sleep (early nocturnal seizures)
  • One to two hours before the usual time of wakening (early morning seizures)
  • Within the first hour or so after awakening (early morning seizures).

Seizures that occur during sleep may also happen during a daytime nap – they are not limited to night time.

Table 1 Stages of Sleep

Stage 1 – Sleep Onset Non-REM sleep Stage 2 Non-REM sleep Stage 3 Non-REM sleep Stage 4 Non-REM sleep Stage 5 REM sleep
Drowsiness/ very light sleep, easily awoken Light sleep Deep sleep starts Deep sleep “Active” sleep. When you dream
This is when you start falling asleep, and is usually brief. Your brain activity heart rate and breathing start to slow down. You begin to reach a state of total relaxation in preparation for the deeper sleep to come. This is also known as slow wave sleep. Your brain waves further slow but there may still be short bursts of faster of brain activity.
If you were to be suddenly awoken during this stage, you would be groggy and confused, and find it difficult to focus at first.
This is where you experience your deepest sleep of the night. Your brain is mostly slow wave activity, and it’s difficult to wake someone up when they are in this stage. Your blood flow, breathing, and brain activity increases, but your muscles go into a paralysis-like state. The brain activity is similar to when you are awake.

Diagnosing nocturnal seizures

It can be difficult to diagnose nocturnal seizures because they happen during sleep, and the person may not be aware of them happening. Also, nocturnal seizures, particularly focal seizures, can be confused with some sleep disorders.

As with most other forms of epilepsy, a good history of the seizures, or even better, an eyewitness account is very important for diagnosis. The doctor may also suggest a video sleep EEG, often done during the day after being sleep deprived.

If left undiagnosed, the person may suffer from a lot of daytime sleepiness and have undetected seizures, putting them at risk.

This can impact concentration, attention and learning as well as behaviour and emotions resulting in reduced quality of life.

Are there specific types of epilepsy where people have nocturnal seizures?

Nocturnal seizures can happen to anyone with epilepsy, but they are often associated with certain types of epilepsy, including:

Nocturnal seizures can be any type of seizures. Sometimes they may be too subtle to detect.

Can they change to daytime seizures?

If a person has seizures only during sleep for several years, the chances of the seizures happening during wakefulness is small. However this does not mean daytime seizures won’t occur. For example, in situations of extreme stress, sleep deprivation or illness, medication changes or withdrawal, the risk of a seizure is increased, day or night. Daytime seizures may also occur if someone with nocturnal epilepsy decides to take a nap, or even becomes excessively drowsy during the day.

With good seizure and lifestyle management however, the risks of a daytime seizure can be greatly reduced.

How are they managed?

  • It is important to aim for the best seizure control possible because nocturnal seizures can disrupt sleep, sometimes quite a lot. This can then become a cycle of sleep deprivation, which is a known trigger for seizures, and consequently more seizures
  • Treatment of nocturnal seizures is generally the same as daytime seizures, although sometimes the specialist may recommend a higher evening dose of antiseizure medication
  • Medical management of seizures is based on the type of seizures rather than when they occur


When seizures occur only during sleep they are not considered a hazard to driving. In people who have never had a seizure while awake but who have an established pattern of seizures exclusively during sleep, the risk of subsequent seizures while awake is sufficiently low to allow private driving (not commercial), despite continuing seizures while asleep.

In people with an established pattern of sleep-only seizures but a history of previous seizures while awake, the risk of further seizures while awake is higher. Therefore, a longer period of sleep-only seizures is required before driving by this group than in those who have never had a seizure while awake. This applies only to private vehicle drivers.

This information is from Assessing Fitness to Drive 


Sudden Unexpected Death in Epilepsy (SUDEP) is when a person with epilepsy dies suddenly and prematurely and no reason for death is found.

SUDEP deaths are often unwitnessed with many of the deaths occurring overnight during sleep. There may be obvious signs a seizure has happened, though this isn’t always the case.

Although the risk of SUDEP is very low, the risk increases for people with tonic-clonic seizures, especially if they happen at night or when asleep. Click here to take action against this risk

We also have a SUDEP and Safety Checklist which your GP or Epilepsy Nurse can discuss with you.

Practice good sleep habits

Some tips for getting a good night’s sleep include:

  • Keep the same bedtime and rising times as much as possible
  • Work with your internal body clock, so don’t ignore tiredness, go to bed when your body tells you so
  • Make sure your bedroom is a restful and calm place to be. Keep it dark at night and open the blinds when you wake up
  • Shift work is not ideal as it affects sleep times and quality of sleep
  • Don’t use screens – smart phones or tablets – for at least an hour before bedtime
  • Some people who have difficulties sleeping, or have interrupted sleep, use sedatives which may ultimately aggravate the problem. Try to improve your sleep regime with more natural techniques
  • Try not to resort to large amounts of coffee or other forms of stimulants to overcome tiredness. Avoid any caffeinated products or stimulating substances after lunch as this can also affect sleep quality and affect seizures for some people
  • Regular exercise can improve a restful sleep. Don’t exercise within four hours of bedtime though
  • Keep evening activities calm or use relaxation techniques to establish a more efficient sleep pattern. If there are things you are worried about, try not to think about them just before bedtime
  • A regular routine is vital with some people
  • If you have tried and failed to improve your sleep, there are many sleep specialists that can help.


For a person with nocturnal seizures, it is suggested:

  • Choose a low bed, avoid sleeping on a top bunk
  • Keep furniture away from the bedside to prevent injury during a fall
  • Consider using a safety mats on the floor next to the bed if the person tends to fall out of bed during seizures. Such mats are similar to those used in gyms
  • Wall mounted lamps pose less safety risks than ordinary table lamps or study lamps, which can be easily knocked over
  • Smoking in bed is unwise for anyone and particularly so for a person with nocturnal seizures
  • There are a number of devices for night-time seizure monitoring available for use in the home. They are designed to recognise that a seizure has occurred or that breathing has been disrupted, triggering an alarm so that help can be provided. An alarm or device cannot guarantee the safety of a person experiencing nocturnal seizures, however, some families have found monitors to be a useful part of a risk reduction plan and provide peace of mind
  • Some people advocate for the use of special anti-suffocation pillows to allow better airflow around the face. Whilst they are quite porous and allow airflow, the use of these pillows does not guarantee to prevent death from suffocation. The use of a special pillow is a personal choice
  • If there is someone available to help you if you have a seizure, check they know how to put you into the recovery position (onto your side) and what to do in case of emergency. See our First Aid page for advice
  • Finally, people who experience seizures exclusively during sleep may be allowed to drive.

For more information go to:

Sleep and epilepsy – Neurologist Dr Dan McLaughlin speaks about epilepsy and sleep

Factsheet – Nocturnal Seizures


Epilepsy and sleep apnoea

The Impact of Sleep on the Body

The Best Sleeping Position

Sleep Health