Nocturnal seizures

Nocturnal seizures also called ‘asleep seizures’, are seizures that happen when someone is asleep. Nocturnal seizures are related to sleep. While most people have nocturnal seizures while they are sleeping at night which is why they are called nocturnal or ‘nighttime’, if they fall asleep during the day they could have nocturnal seizures or asleep seizures. The term nocturnal seizures does not say what sort of seizures happen, only when they happen.

Nocturnal seizures happen when a person is sleeping. They are most common:

• Right after falling asleep
• Just before waking up
• Soon after waking up

Any seizure can occur during sleep. Nocturnal seizures can happen to anyone with epilepsy, but they are often associated with certain types of epilepsy, including:

• Juvenile Myoclonic Epilepsy (JME)
• Awakening Tonic Clonic (Grand Mal)
• Benign Rolandic (also called Benign Focal Epilepsy of Childhood)
• Electrical Status Epilepticus of Sleep (ESES or CSWS)
• Landau-Kleffner Syndrome (LKS)
• Frontal Onset Seizures (such as Nocturnal Frontal Lobe Epilepsy)

Nocturnal seizures can be any type of seizures. Sometimes they are too subtle to detect. If left undiagnosed, the person may suffer from a lot of daytime sleepiness. This can impact concentration, attention and learning as well as behavior and emotions resulting in reduced quality of life.

The most useful way to diagnose the type of seizure is an electroencephalogram (EEG). This records electrical activity in the brain. The EEG can record unusual spikes or waves in electrical activity patterns. Different types of seizures can be identified with these patterns.

When a patient is experiencing nocturnal seizures, a sleep study is often needed to diagnose the condition. The sleep study will require the patient to stay overnight at the hospital where their brain activity can be monitored during their sleep.

Magnetic resonance imaging (MRI) and computed tomography (CT) scans may be used to look at where the seizures are happening in the brain. The scans can show scar tissue, tumors or structural problems in the brain.

Epilepsy has a complex connection with sleep. Nocturnal seizures or 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 pure nocturnal epilepsy.

The International League Against Epilepsy 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.

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.

For many patients, correct treatment can lower or prevent seizures. In some cases, patients may not have any more seizures for the rest of their life.

Anti-seizure (or anti-epileptic) medications can be very helpful. It may take a few tries to get the right medicine and dose. The doctor will watch for side effects to find the best treatment.

Surgery may be an option if medication can’t control the seizures. A vagus nerve stimulator is sometimes implanted and used with anti-epileptic medication to lower seizures. The vagus nerve stimulator is a tool placed under the skin of the chest. It sends electrical energy through the vagus nerve into the neck and up to the brain.

Certain lifestyle changes may also be used:

• Special high-fat, low-carbohydrate diet (ketogenic diet)
• Getting plenty of sleep
• Avoiding certain triggers, such as lack of sleep

Nocturnal seizures key facts

• One of the most common seizure triggers for many people with epilepsy, is lack of sleep
• Nocturnal seizures disrupt sleep and increase daytime drowsiness
• Drowsiness can increase the risk of daytime seizures for people affected by seizures during sleep
• Nocturnal seizures may be misdiagnosed as a sleep disorder and certain sleep disorders may be misdiagnosed as epilepsy
• Nocturnal seizures are a risk factor for Sudden Unexpected Death in Epilepsy (SUDEP) ¹
• Some antiepileptic drugs can contribute to sleeping difficulties or daytime drowsiness
• Sleep apnoea is approximately 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.

Nocturnal seizures and driving

People who experience seizures exclusively during sleep may be allowed to drive.

Nocturnal seizures causes

The cause of nocturnal seizures is often unknown. However, there are certain seizure conditions that are more likely to experience nocturnal seizures, including:

• Juvenile myoclonic epilepsy
• Awakening tonic-clonic (grand mal)
• Benign Rolandic
• Landau-Kleffner syndrome
• Frontal Lobe Epilepsy

Seizures can be linked to:

• Unusual brain development
• Stroke
• Serious head injury
• Brain tumor
• Brain infection (meningitis or encephalitis)
• Reduced oxygen to the brain

Epileptic seizures are often strongly influenced by the sleep-wake cycle. When you go off to sleep, you have a change of state – from awake to asleep. But 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. As an example, in wakefulness, your brain waves remain fairly constant, but during sleep there are many changes. You 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.	REM sleep means rapid eye movement, which characterises stage 5. 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.

Nocturnal seizures signs and symptoms

Nocturnal seizures also called ‘asleep seizures’, are seizures that happen when someone is asleep. The term nocturnal seizures does not say what sort of seizures happen, only when they happen.

Nocturnal seizures are often unnoticed because the patient is asleep when they happen. However, there are signs that may suggest the patient’s is experiencing these seizures, including:

• Loss of bladder control
• Biting their tongue

If the patient notices these symptoms of interrupted sleep they should talk to their doctor:

• Difficulty concentrating
• Awaking suddenly for an unknown reason
• Feeling drowsy
• Increase in daytime seizures triggered by a lack of sleep

Involuntary muscle movement linked to seizures can include:

• Stiff arms
• Stiff legs
• Jerking body movements.

Doctors generally classify seizures as either focal or generalized, based on how and where abnormal brain activity begins. Seizures may also be classified as unknown onset, if how the seizure began isn’t known.

Focal seizures

Focal seizures result from abnormal electrical activity in one area of your brain. Focal seizures can occur with or without loss of consciousness:

• Focal seizures with impaired awareness. These seizures involve a change or loss of consciousness or awareness. You may stare into space and not respond normally to your environment or perform repetitive movements, such as hand rubbing, chewing, swallowing or walking in circles.
• Focal seizures without loss of consciousness. These seizures may alter emotions or change the way things look, smell, feel, taste or sound, but you don’t lose consciousness. These seizures may also result in the involuntary jerking of a body part, such as an arm or leg, and spontaneous sensory symptoms such as tingling, dizziness and flashing lights.

Symptoms of focal seizures may be confused with other neurological disorders, such as migraine, narcolepsy or mental illness.

Generalized seizures

Seizures that appear to involve all areas of the brain are called generalized seizures. Different types of generalized seizures include:

• Absence seizures. Absence seizures, previously known as petit mal seizures, often occur in children and are characterized by staring into space or by subtle body movements, such as eye blinking or lip smacking. These seizures may occur in clusters and cause a brief loss of awareness.
• Tonic seizures. Tonic seizures cause stiffening of your muscles. These seizures usually affect muscles in your back, arms and legs and may cause you to fall to the ground.
• Atonic seizures. Atonic seizures, also known as drop seizures, cause a loss of muscle control, which may cause you to suddenly collapse or fall down.
• Clonic seizures. Clonic seizures are associated with repeated or rhythmic, jerking muscle movements. These seizures usually affect the neck, face and arms.
• Myoclonic seizures. Myoclonic seizures usually appear as sudden brief jerks or twitches of your arms and legs.
• Tonic-clonic seizures. Tonic-clonic seizures, previously known as grand mal seizures, are the most dramatic type of epileptic seizure and can cause an abrupt loss of consciousness, body stiffening and shaking, and sometimes loss of bladder control or biting your tongue.

Nocturnal seizures diagnosis

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.

Tests may include:

• A neurological exam. Your doctor may test your behavior, motor abilities and mental function to determine if you have a problem with your brain and nervous system.
• Blood tests. Your doctor may take a blood sample to check for signs of infections, genetic conditions, blood sugar levels or electrolyte imbalances.
• Lumbar puncture. If your doctor suspects an infection as the cause of a seizure, you may need to have a sample of cerebrospinal fluid removed for testing.
• An electroencephalogram (EEG). In this test, doctors attach electrodes to your scalp with a paste-like substance. The electrodes record the electrical activity of your brain, which shows up as wavy lines on an EEG recording. The EEG may reveal a pattern that tells doctors whether a seizure is likely to occur again. EEG testing may also help your doctor exclude other conditions that mimic epilepsy as a reason for your seizure. Depending on the details of your seizures, this test may be done as an outpatient in the clinic, overnight at home with an ambulatory device or over a few nights in the hospital.
• Computerized tomography (CT). A CT scan uses X-rays to obtain cross-sectional images of your brain. CT scans can reveal abnormalities in your brain that might cause a seizure, such as tumors, bleeding and cysts.
• Magnetic resonance imaging (MRI). An MRI scan uses powerful magnets and radio waves to create a detailed view of your brain. Your doctor may be able to detect lesions or abnormalities in your brain that could lead to seizures.
• Positron emission tomography (PET). A PET scan uses a small amount of low-dose radioactive material that’s injected into a vein to help visualize active areas of the brain and detect abnormalities.
• Single-photon emission computerized tomography (SPECT). A SPECT test uses a small amount of low-dose radioactive material that’s injected into a vein to create a detailed, 3-D map of the blood flow activity in your brain that happens during a seizure. Doctors also may conduct a form of a SPECT test called subtraction ictal SPECT coregistered to MRI (SISCOM), which may provide even more-detailed results. This test is usually done in a hospital with overnight EEG recording.

Nocturnal seizures treatment

Nocturnal seizures treatment is based on:

• The type of seizure
• Any underlying conditions
• How often seizures happen
• How severe the seizures are
• The patient’s age
• The patient’s overall health
• The patient’s medical history

Treatment of nocturnal seizures is similar to seizures of a similar nature that occur during the waking hours although sometimes the specialist may recommend a higher evening dose of antiepileptic medication

Medical management of seizures is based on the type of seizures rather than on the time of occurrence.

Dietary therapy

Following a diet that’s high in fat and low in carbohydrates, known as a ketogenic diet, can improve seizure control. Variations on a high-fat, low-carbohydrate diet, such as the low glycemic index and modified Atkins diets, though less effective, aren’t as restrictive as the ketogenic diet and may provide benefit.

Medication

Treatment for seizures often involves the use of anti-seizure medications. Several options exist for anti-seizure medications. The goal is to find the medicine that works best for you and that causes the fewest side effects. In some cases, your doctor might recommend more than one medication.

Finding the right medication and dosage can be complex. Your doctor will consider your condition, your frequency of seizures, your age and other factors when choosing which medication to prescribe. Your doctor will also review any other medications you may be taking, to ensure the anti-epileptic medications won’t interact with them.

Surgery and other therapies

If anti-seizure medications aren’t effective, other treatments may be an option:

• Surgery. The goal of surgery is to stop seizures from happening. Surgeons locate and remove the area of your brain where seizures begin. Surgery works best for people who have seizures that always originate in the same place in their brains.
• Vagus nerve stimulation. A device implanted underneath the skin of your chest stimulates the vagus nerve in your neck, sending signals to your brain that inhibit seizures. With vagus nerve stimulation, you may still need to take medication, but you may be able to lower the dose.
• Responsive neurostimulation. During responsive neurostimulation, a device implanted on the surface of your brain or within brain tissue can detect seizure activity and deliver an electrical stimulation to the detected area to stop the seizure.
• Deep brain stimulation. Doctors implant electrodes within certain areas of your brain to produce electrical impulses that regulate abnormal brain activity. The electrodes attach to a pacemaker-like device placed under the skin of your chest, which controls the amount of stimulation produced.

Practice good sleep habits

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

• Maintain 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
• Don’t use screens – smart phones or tablets – for at least an hour before bedtime
• Shift work is not ideal as it affects sleep times and quality of sleep
• 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
• People with excessive daytime sleepiness often resort to coffee or other forms of stimulants to overcome this, a practice that can also exacerbate seizures, especially if the stimulating substance is used in large amounts. Avoid any caffeinated products or stimulating substances after lunch as this can also affect sleep quality
• 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, don’t 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.

Lifestyle and home remedies

Here are some steps you can take to help with seizure control:

• Take medication correctly. Don’t adjust the dosage before talking to your doctor. If you feel your medication should be changed, discuss it with your doctor.
• Get enough sleep. Lack of sleep can trigger seizures. Be sure to get adequate rest every night.
• Wear a medical alert bracelet. This will help emergency personnel know how to treat you correctly if you have another seizure.
• Be active. Exercising and being active may help keep you physically healthy and reduce depression. Make sure to drink enough water and rest if you get tired during exercise.
• Make healthy life choices. Managing stress, limiting alcoholic beverages and avoiding cigarettes all factor in to a healthy lifestyle.

Personal safety

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 that are now 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. The use of these pillows has not been proven to prevent death from suffocation nor guarantee the safety of a person having nocturnal seizures. 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.

References

1. Latreille V, Abdennadher M, Dworetzky BA, et al. Nocturnal seizures are associated with more severe hypoxemia and increased risk of postictal generalized EEG suppression. Epilepsia. 2017;58(9):e127–e131. doi:10.1111/epi.13841 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5784438