Nocturnal Seizures – Seizures During Sleep
- When do they occur?
- Can they change to daytime seizures?
- How are they managed?
- Sleep and seizures - what are the facts?
Any form of epilepsy may occur during sleep, but some types of epilepsy are more likely to be restricted exclusively to sleep. These are sometimes called Nocturnal Seizures.
Some people have seizures occur only during sleep whilst others have both daytime and nocturnal seizures. Studies have shown that 10 - 45% of people with epilepsy have seizures that occur predominantly or exclusively during sleep or occur with sleep deprivation.
Sleep is divided into many stages. The majority of nocturnal seizures occur in light sleep - soon after falling asleep, before waking or around arousal during the night. This is especially true with temporal lobe seizures, myoclonic seizures, and atypical absence spells.
Although the mechanism is poorly understood, there is evidence that sleep activity may influence seizures. It is thought that the change of state has an influence on the epileptic activity, and during sleep there are a lot of changes. Some seizures also seem to occur predominantly at certain times of the sleep cycle.
As an example, in wakefulness, our brain waves remain fairly constant, but during sleep there are many changes. We go to bed and our brainwaves (EEG) transform from wakefulness to drowsiness to light sleep to deep sleep to Rapid Eye Movement (REM) sleep - and this cycle occurs 3-4 times per night. There are dramatic changes on EEG during these sleep changes.
Seizures may occur at any time during the sleep cycle, but mostly occur in light sleep - that is, stages 1 and 2 of sleep.
Awake • Drowsy • Light Sleep • Deep Sleep • REM Sleep
This generally means there are more common times at which they occur most frequently:
- 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 occur during an afternoon nap - they are not limited to night time.
If a person maintains a pattern of only having seizures during sleep for several years, the probability of the seizures occurring during wakefulness is small. Many nocturnal seizures are tonic-clonic but focal seizures can also occur during sleep.
It is important to aim for optimum control of nocturnal seizures though, because sleep and seizures are closely related.
Nocturnal seizures can interrupt sleep, sometimes significantly. It is well documented that sleep deprivation or a lack of sleep is a known trigger for seizures - and can make more seizures likely.
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. Positive treatment of seizures is based on the type of seizures rather than on the time of occurrence.
- One of the most common seizure triggers for people with epilepsy, is sleep deprivation
- Certain types of seizures are more common during sleep, but may present quite differently if they occur during the day
- Seizures can disrupt sleep and increase daytime drowsiness
- On occasions nocturnal seizures can be misdiagnosed as a sleep disorder and certain sleep disorders can be misdiagnosed as epilepsy (video-EEG recordings can assist with the correct diagnosis)
- Some antiepileptic medications can contribute to sleeping difficulties or daytime drowsiness
- Sleep apnoea is approximately twice as common in those with poorly controlled epilepsy than in the general population
- Treatment of the sleep disorder improves seizure control and quality of life
- Lastly, sleep disorders can exacerbate epilepsy and epilepsy can exacerbate certain sleep disorders
Losing sleep can trigger seizures, and having seizures during sleep can cause daytime drowsiness. Drowsiness itself can increase the risk of daytime seizures for people affected by seizures during sleep.
Some people who have difficulties sleeping, or have interrupted sleep, use sedatives, which may ultimately aggravate the problem.
People with excessive daytime sleepiness often resort to coffee or other forms of stimulants to overcome this, a practice that can exacerbate seizures, especially if the stimulating substance is used in large amounts.
Problems in falling asleep may be overcome by increasing the evening medication, by avoiding the use of stimulating substances, especially in the late afternoon or evening, by calm evening activities, or by using relaxation techniques or behavioural training to establish a more efficient sleep pattern. A regular routine is vital with some people. There are many sleep specialists that can help.
For a person with nocturnal seizures, it is suggested:
- Use low bed with padded headboards. Bunks are not recommended.
- Avoid large soft pillows, which can increase the risk of smothering. Use instead an anti-smother safety pillow or no pillow at all.
- Keep heavy 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 everyone and particularly so for a person with nocturnal seizures. Consider using non-flammable bedding and a smoke alarm.
- Avoid coarse carpets, which can lead to friction burns for those who may fall out of bed. If it's not feasible to replace carpets, a protective mat will suffice.
- Finally, people who experience seizures exclusively during sleep and are often able to drive.
- Manford, Mark. 2003. Practical Guide to Epilepsy. Pg 80 Butterworth/Heinemann USA.
- Svoboda, William D 1979. Learning about Epilepsy - Other Approaches in Seizure Management. University Park Press, Baltimore