Sleep Onset Seizures: Recognising and Managing Seizures During Sleep

Sleep onset seizures are seizures that happen during sleep. They can be hard to spot, so the signs are often noticed in the morning. Because seizures in sleep may go unwitnessed, they carry added risk and are linked to SUDEP, so good seizure control, a safe sleep set-up and, where appropriate, a monitor or alarm all matter.

What are sleep onset seizures?

Sleep onset seizures happen while a person is asleep, or as they are falling asleep or waking.

Some people have seizures only during sleep, while others have them both day and night. Sleep and epilepsy are closely linked: a lack of sleep is a well-recognised seizure trigger, and some seizures are more likely around sleep or first thing in the morning. You can read more in our guide to common and uncommon seizure triggers.

How can you tell if someone has had a seizure in their sleep?

Because no one may witness a night-time seizure, the signs are often noticed the next morning.

Signs that a seizure may have happened during the night can include:

• waking with a bitten tongue or a sore mouth
• having wet the bed
• unexplained injuries, such as bruises
• waking on the floor or in an unusual position
• feeling unusually tired or confused, or having a headache, in the morning
• bedclothes or pillows left in disarray

A partner, parent or carer who is nearby may also hear unusual noises, stiffening or rhythmic movements during the night. Keeping a simple record of these clues helps the epilepsy team build an accurate picture.

Why do night-time seizures need extra attention?

Seizures during sleep often go unwitnessed, which means help may not be at hand, and sleep onset seizures are recognised as a risk factor for SUDEP.

SUDEP (sudden unexpected death in epilepsy) is rare, but research suggests it happens more often at night, and having seizures during sleep, particularly when they are unobserved, is an independent risk factor. The charities Epilepsy Society and Epilepsy Action both highlight this, as does SUDEP Action. Sleeping face down may add to the risk.

This is not a reason to panic. The single most protective step is getting the best possible seizure control with your epilepsy team. Our overview of SUDEP and the research on sleep and SUDEP explain this further.

How can you improve night-time safety?

Good seizure control, a safe sleeping environment and a way to alert someone are the three most useful steps.

• work with your epilepsy specialist to get the best possible seizure control, and take anti-seizure medications (ASMs) as prescribed
• aim for regular, sufficient sleep, as tiredness can trigger seizures
• make the bedroom safer: consider a lower bed and avoid heavy or soft pillows that could obstruct breathing
• think about how someone would know a seizure had happened, especially for a person who sleeps alone

Can seizure alarms and monitors help?

Seizure alarms and monitors can alert someone nearby if a seizure happens at night, but no device detects every seizure.

Options include movement and bed sensors, audio or video monitors, and wearable devices. Epilepsy Society notes that, for people who have seizures in sleep, an alarm that alerts someone who can help may be useful. Devices are a supplement to, not a replacement for, supervision and good seizure management. For a balanced view, see our articles onwhether seizure alert technologies are a reliable safety netand thetypes of epilepsy alert devices and monitors.

When should you seek medical advice?

Tell your GP or epilepsy team if you think you are having seizures in your sleep, if they change, or if they become more frequent.

New, longer or more frequent night-time seizures need a medical review. A seizure that lasts more than five minutes (status epilepticus) is a medical emergency: call 999, and seek urgent help if there is an injury or difficulty breathing.

Frequently asked questions

What causes seizures during sleep?

Sleep changes the brain’s electrical activity, and some forms of epilepsy are more active during sleep or on waking. Sleep deprivation is also a common trigger.

Are sleep onset seizures more dangerous?

They are not necessarily more severe, but because they may be unwitnessed they carry added risk, including a recognised link with SUDEP.

How do I know if I had a seizure while asleep?

Common clues include a bitten tongue, having wet the bed, unexplained injuries, or waking very tired, confused or with a headache.

Do seizure alarms work?

They can alert a carer to many seizures, but none detect every type. They support, rather than replace, good seizure control and supervision.

Can sleep onset seizures be treated?

Yes. They are managed like other seizures, usually with anti-seizure medications (ASMs). Speak to your epilepsy team about the best approach for you.

Confident, competent night-time seizure response

National Epilepsy Training prepares care teams and families to recognise and respond to seizures safely, including emergency medication where it is prescribed.

• recognise seizures that happen during sleep
• respond calmly and safely
• administer buccal midazolam where prescribed, with signed competency

See our epilepsy awareness and buccal midazolam training