If you have epilepsy, you may experience seizures at night. Symptoms may include bedwetting and tongue biting. Doctors typically diagnose seizure disorders with an electroencephalogram.

A seizure is caused by disruptions in the pattern of brain cell communication. The cells in your brain typically communicate through nerve pathways to control your awareness and movements via electrical signals.

If you have any type of epilepsy, you may experience a seizure during sleep. In certain types of epilepsy, seizures occur only during sleep.

Epilepsy is the most common cause of seizures. Doctors make an epilepsy diagnosis when you have two or more unprovoked seizures, at least 24 hours apart, that are not caused by another medical condition.

According to the CDC, as of 2021, about 2.9 million adults in the United States had epilepsy. You may experience the first symptoms of epilepsy at any age, but according to the Epilepsy Foundation, new cases are most often diagnosed in children under 10 years old and adults over 55 years old.

There are many types of seizures, but they fall roughly into two categories: generalized seizures and focal or partial seizures.

Generalized seizures

A generalized seizure happens when abnormal electrical activity occurs in both hemispheres of your brain. This category includes the following two types of seizures:

  • Tonic-clonic seizures: Previously known as grand mal seizures, these involve a stiffening of your body, jerking motions, and usually loss of consciousness.
  • Absence seizures: Previously known as petit mal seizures, these involve brief periods of staring, eye blinking, and small movements in your hands and arms.

Partial seizures

Partial seizures, also called focal or localized seizures, are limited to one hemisphere of your brain. When a partial seizure happens, you may remain conscious but may not know the seizure is happening. Partial seizures can affect behavior, consciousness, and responsiveness. They also can cause involuntary movements.

Many types of epilepsy that are associated with nighttime seizures start in childhood. For example, in children with benign Rolandic epilepsy, about 70% to 80% of seizures occur during sleep.

Types of epilepsy associated with nighttime seizures include:

According to research published in 2014, almost two-thirds of seizures happen between 8 p.m. and 8 a.m. The author of this research article estimates that, among people with seizures:

  • about 20% experience seizures during sleep
  • about 41% experience seizures during the day
  • about 39% experience seizures during the day and night

Some other studies estimate that about 12% of people with epilepsies have nighttime seizures almost exclusively. Both focal and generalized seizures can occur during sleep, but focal seizures are more common.

However, the percentage is hard to estimate because many nighttime seizures may go unnoticed.

People with epilepsy who experience nighttime seizures have more than twice the risk of sudden, unexpected death as people who experience seizures only during the day.

Sleep deprivation is very common among people with epilepsy. This may be a side effect of some antiepileptic medications, and it may also be caused by disrupted sleep patterns associated with epilepsy. Lack of sleep can potentially lead to more frequent seizures since sleep deprivation is one of the main risk factors.

Most common seizure times and sleep stages

Experts believe that sleep seizures are triggered by changes in the electrical activity in the brain during certain stages of sleeping and waking.

Nighttime seizures occur most often in the early morning, around 5 a.m. to 6 a.m., and occur least often shortly after falling asleep. However, this is difficult to estimate. Some types of epilepsy, such as infantile spasms, tend to cause seizures shortly after waking.

Sleep is divided into stages called rapid eye movement (REM) sleep and non-REM sleep. Non-REM sleep is divided into three phases: N1, N2, and N3.

Compared with REM sleep, focal seizures are estimated to occur:

  • 87 times more often in N1
  • 68 times more often in N2
  • 51 times more often in N3

Compared with REM sleep, generalized seizures are estimated to occur:

  • 3.1 times more often in N1
  • 3.13 times more often in N2
  • 6.59 times more often in N3

Focal seizures are far more common during non-REM sleep, which could have to do with the different patterns of brain activity in the hemispheres while sleeping.

It can be hard to recognize nocturnal seizures, especially in children, but the symptoms can include:

  • crying out
  • making unusual noises
  • convulsing
  • wetting the bed
  • experiencing muscle twitches or jerks
  • biting your tongue
  • falling out of bed
  • having trouble waking up
  • waking up suddenly
  • making strange movements or postures while sleeping

Seizures and epilepsy are most common in infants and children under 15 years old. Children who have epilepsy often stop having seizures by the time they reach adulthood.

Parents of new infants sometimes confuse a condition called benign neonatal sleep myoclonus with epilepsy. Infants with myoclonus experience involuntary jerking that often looks like a seizure.

In cases of myoclonus, an electroencephalogram (EEG) will not likely show changes in the brain that are consistent with epilepsy. Additionally, myoclonus is rarely serious. For example, hiccups and jerking during sleep are forms of myoclonus.

It can be tricky to diagnose nocturnal seizures because they occur at night. Sleep seizures can also be confused with a group of sleep disorders called parasomnia. These disorders include:

To determine which form of epilepsy you may have, a doctor will evaluate factors such as:

  • the type of seizures you have
  • the age at which you began having seizures
  • your family history of epilepsy
  • your medical history of seizures
  • other medical conditions you may have

To diagnose epilepsy, a doctor may use:

  • a tracing of electrical activity in your brain recorded by an EEG
  • the structure of your brain as shown on a CT scan or MRI

If you suspect that your infant or child is having nighttime seizures, consult their doctor. You can monitor your child by:

  • using a baby monitor so you can hear and see if a seizure occurs
  • watching for symptoms in the morning, such as unusual sleepiness, headache, and signs of drooling, vomiting, or bedwetting
  • using a seizure monitor, which has features such as motion, noise, and moisture sensors

Speak with a doctor if you believe you or your child is experiencing seizures while sleeping. The doctor can order tests that will confirm whether you’re experiencing seizures.

Medication is the first-line treatment for epilepsy. A doctor will help you find a treatment that works best for you or your child. With proper diagnosis and treatment, most cases of epilepsy can be managed with medications.