Sleep and Epilepsy - YourDoctor.com

Introduction

Sleep is important to all of us. Everyone knows how much clearer we think, how much quicker we react, how much better we perform after a full night of uninterrupted sleep compared with one which is frequently interrupted or too short. For patients with epilepsy, however, sleep is particularly important for a number of reasons. Most seizure types are affected by sleep, although the degree varies widely with both the particular type and the individual patient. This relationship can be important in the diagnosis of seizures, in the prognosis for recovery, and in choosing appropriate treatment. Seizures, in turn, can disrupt sleep with resulting persistent drowsiness and difficulty concentrating even days after a seizure. Finally, many of the medications used to treat epilepsy can adversely affect sleep.

This section will look specifically at each of these areas, so that you can understand the specific importance of sleep in people with epilepsy.

Shaking, jerking, and other things during sleep which can be mistaken for epilepsy

Many strange things can happen during sleep, but many of these are not epilepsy and most are normal. Most common are sudden jerking motions which can occur when falling asleep. During drowsiness, you may experience a single, sometimes violent contraction of some or all of your muscles. This may awaken you with a start. Although a form of myoclonus, these are completely normal. Many people (especially children) experience frightening images, sometimes along with shortness of breath or screaming. These happen during the deeper stages of sleep and are known as sleep terrors. The child or adult may be very disoriented immediately afterward, adding to the possible confusion with seizures. These are also benign, and rarely require treatment unless frequent. Other conditions which are more common in children are somnambulism (sleep walking) and bed wetting. These do not occur during REM sleep. The patient will be totally unaware of what is happening during them.

Other sleep disorders can consist of jerking and occasionally be confused with epilepsy. These include restless legs syndrome, in which a crawling or tingling sensation is felt in the legs when trying to fall asleep and is only relieved by movement. Periodic movements of sleep consist of rhythmic, small movements of one or both legs. This usually does not wake the patient, and as such often does not require treatment. If movements are very violent, there is a possibility that the patient is suffering from REM behavior disorder. In this condition, the normal paralysis which occurs during dreaming does not occur, so that the patient can actually act out dreams. This may require therapy, but is also not a seizure.

Seizures with specific relationships to sleep

Epilepsy is not one disease, and there are many different kinds of seizures. The most common kind of seizures is “partial”, meaning that they begin in one part of the brain. When these are small, the symptoms correspond only to the small area of the brain involved. For instance, a seizure that begins in the motor area of the brain might consist of uncontrolled jerking of one hand. A seizure that begins in the visual area can result in brief changes in vision or a hallucination. As seizures get larger, the symptoms become more dramatic, including confusion, falling, or uncontrolled shaking of all extremities (a “grand mal” seizure). Some patients suffer from “generalized” seizures, which seem to start everywhere in the brain at once. There are several types of generalized seizures. One common type is the brief staring spells experienced mainly by children, also known as “petit mal” or “absence” seizures. Other generalized seizures include “tonic”, consisting of sudden stiffening of all limbs, and “myoclonic” seizures where part or all of the body has sudden, irregular jerking.

Much of the problem with any seizures is that they are random and unpredictable. Most seizures are, in themselves, not dangerous or even terribly disruptive. A one minute seizure without a convulsion, for example, may result in only a brief loss of consciousness with rapid recovery. If this occurs while in bed, it is unlikely to result in injury. But it is the unpredictability of this seizure which makes it much more dangerous. If it occurs at work, for instance, it can result in a loss of productivity. If the patient were driving, it could result in an accident with devastating consequences for the patient, passengers, and others potentially involved.

Some seizure types are not entirely random and a relationship to sleep can be very important. A few even occur in a highly predictable fashion, and if this is known patients and family members can be better prepared for it. Diagnosis of many of these conditions requires careful record keeping by the patient, so that patterns can be identified.

One of the epilepsies which is most specifically related to sleep is called “awakening grand mal” epilepsy. These patients have generalized tonic-clonic (“grand mal”) seizures which occur exclusively in the time period just before or just after awakening. Typically the seizures occur in the morning, although they can also happen upon awakening from a nap. Patients with this disorder can usually be controlled with medication. However, even if seizures persist, they need to be particularly cautious during the times of greatest seizure risk. Patients should not drive, operate machinery, or be a caregiver for small children immediately after awakening.

There are many other epilepsies which usually, but not always, happen upon awakening. Juvenile myoclonic epilepsy usually begins in the teenage years. These patients have rapid, isolated jerks of muscles (similar to what normal people experience as they fall asleep). This may occur once, or repetitively and is called “myoclonus.” In addition, these patients may have grand mal seizures, but these usually occur in the early morning. These patients are also usually controlled on medication.

Other seizure types tend to occur during sleep, but not particularly upon awakening. Frontal lobe seizures are a type of partial epilepsy. In this case, they begin in the frontal lobe, which is behind the forehead. Usually these patients have brief, sometimes violent seizures which happen usually or always during sleep. As with all seizures, they usually last two minutes or less, and can be followed by brief confusion. When they occur exclusively during sleep, they tend to be easier to control with medication.

Children can have a forms of epilepsy where seizures are restricted to sleep. The most common type is called “benign rolandic epilepsy”, named after the brain region in which it starts. The seizures consist of jerking of the face and/or limbs on one side, during which the child is usually alert. Rarely, these can also begin while the child is awake. The diagnosis can sometimes be made by description, but usually an electroencephalogram is helpful. The diagnosis is particularly important to make because all children grow out of this. Treatment is not always recommended, particularly if the seizures are rare and occur only during sleep. If used, anticonvulsants are very effective at controlling this seizure type, usually at a very small dose.

Effects of sleep deprivation on seizures

Seizures are, as mentioned above, unpredictable. However, we know that there are certain conditions which make a seizure more likely to happen. Certain drugs, like cocaine, can cause seizures even in normal people. Many sorts of physical or emotional stress, including illness, can increase the chance of seizures. Lack of sleep is possibly the best known of factors which increase the chance of a seizure. Therefore, it is important that patients with epilepsy avoid severe sleep deprivation. They should also avoid drugs, including alcohol, which interfere with normal sleep.

When epilepsy is diagnosed or is a consideration, and electroencephalogram (EEG) is often obtained. This painless recording of brain waves helps to determine if epilepsy is present and, if so, the type of epilepsy. As certain abnormalities are only seen during sleep, it is important for patients to sleep during the study. Therefore, they will often be asked to come to the test sleep deprived. This may seem contrary to the recommendation to avoid sleep deprivation, however makes for a more accurate and complete test.

Sleep disorders in patients with epilepsy

Sleep problems are common, and having epilepsy in no way prevents patients from also having these. A coexisting sleep disorder can worsen epilepsy which can, as seen below, worsen sleep. Therefore, patients who have epilepsy as well as a sleep disorder can develop a cycle of worsening seizures and sleep which makes treatment of either particularly difficult. All of these disorders are discussed in other sections; here they will be mentioned specifically as they relate to epilepsy.

Many patients with epilepsy are drowsy during the day. This has many causes, but when present should be investigated. This can be related to either persistent seizures or to anticonvulsant medication (see below). Additionally, however, insomnia with resulting drowsiness is common in all Americans. Sleep disruption can come from environmental or external influences (like noise, uncomfortable sleep environment, or drugs including alcohol or caffeine) which disrupt sleep. Because of this, sleep hygiene – the concept of optimizing conditions for sleeping - is particularly important for patients who have epilepsy. This is discussed extensively in the section on treatment of insomnia.

The most troublesome sleep disorder in patients with epilepsy is sleep apnea, a common disorder affecting at least 2% of the population. Sleep apnea is most common in patients who are overweight, and consists of excessive relaxation of the airway during sleep, with resulting airway blockage and apnea (breathing stops). Patients with this condition fall asleep, but as sleep deepens, breathing stops. The brain recognizes the resulting lack of oxygen, and the patient wakes up (usually with a loud snore) and begins to breathe again. He or she may not remember awakening. This repeats itself all night, and the patient never is able to attain normal sleep. This has several effects. One is that the patient is chronically drowsy, and in some severe cases there is risk of falling asleep during various activities including driving. The lack of sleep can worsen seizures, as can the lack of oxygen getting to the brain during sleep. Because of this, many of these patients will continue to have seizures (particularly during sleep) despite treatment with anticonvulsants.

Sleep apnea is important to recognize because treatment of the epilepsy alone will not necessarily result in improvement. Only when sleep apnea is evaluated and treated with both the drowsiness and the seizures improve.

Effects of seizures on sleep

Seizures are usually brief, lasting about one or two minutes. Most patients recover rapidly, and are able to function fairly normally within ten or fifteen minutes (more if the seizure is generalized). However, a substantial number of patients find that they do not function at their best for a day or more. This is also true of many patients who have seizures during their sleep. In some ways sleep seizures are less disruptive; the patient is less likely to suffer direct harm from falling or accidental injury. But these patients may also not be able to concentrate or work well the following day. The reasons for this are not clear, but much of the problem may come from disruption of sleep by seizures.

It is fairly easy to see how seizures could interrupt sleep, at least briefly. But it turns out the effect of a seizure on sleep patterns is much more profound and long-lasting than a simple awakening. Sleep consists of very complicated cycles, during which people progress through different stages of sleep. The lighter stages, 1 and 2, usually happen first upon falling asleep, and account for about half of the total sleep. During a normal night, you will then progress into deeper sleep, stages 3 and 4, which are also known as slow wave sleep. REM (rapid eye movement sleep) occurs next, and is named for the rapid eye movements which occur during this stage. REM is the stage when the most vivid dreams happen. Normally, people cycle through all of these stages several times during the night.

A seizure during sleep not only results in a brief awakening, but also has several effects on the remainder of the night. Sleep becomes lighter, with more stage 1 and more frequent awakenings. The most profound effects are on REM sleep, which is greatly reduced and sometimes eliminated by even a brief seizure early in the night (see figure). Daytime seizures have less effect, but can also reduce REM sleep the following night.

Why are these changes important? The function of REM sleep is not fully known, but there is a lot of evidence that it is important. Many animals, and nearly all mammals, have sleep patterns resembling REM. Sleep is not always easy for animals; for example, dolphins need to surface in order to breathe. They get sleep by allowing half of the brain to sleep at a time, while the other half takes care of breathing. People, too, naturally try to make sure they get enough sleep. When normal people do not get enough REM sleep, the next time they sleep they will have less lighter sleep and more REM to make up for the loss (known as “REM rebound”). All this tells us that sleep, and particularly REM sleep, are important but does not tell us precisely what it does. This is a more difficult question, but there is evidence that REM sleep is essential for at least some types of memory, and probably for concentration as well. Therefore, even if a patient doesn’t feel drowsy he or she may have a persistent problem with memory and concentration the following day.

What can be done about this? There is no known way to create more REM sleep. However, it is clearly essential to try to eliminate all seizures. Patients who are not fully controlled should be referred to an epilepsy center, where they can be evaluated for alternative medications or surgery, which can be curative. Even seizures which are limited to sleep may cause persistent problems. When full control is not possible, patients must pay particular attention to getting sufficient sleep particularly in the day or two following a seizure.

Effects of anticonvulsant medications on sleep

Most patients with epilepsy take anticonvulsant medications. Ideally, these will fully control seizures. In some cases, however, the medications themselves may result in tiredness, memory problems, or difficulty concentrating. The reasons for this are many. A few drugs (particularly barbiturates, like phenobarbital) can act as sedatives. This drug is used less frequently today for that reason. Benzodiazepines [diazepam (Valium), lorazepam (Ativan), and clonazepam (Klonipen, to name a few] are occasionally used for epilepsy but are also sedatives. Both of these classes of medicine change the structure of sleep, particularly affecting REM. At least two other, older medications [phenytoin (Dilantin) and carbamazepine (Tegretol/Carbatrol)] also decrease REM sleep, although these drugs are not considered sedatives. For this reason, it is possible that all of these medications can contribute to memory problems.

As an example, consider a twenty-five year old student with partial seizures, consisting of staring, lip smacking, and interruption of speech. She does not remember what happens during the seizure. Initially she took carbamazepine, but as the dose was increased she felt tired during much of the day and had trouble concentrating on schoolwork. Seizures, however, were controlled and she thought that she was sleeping well. Because of the persistent tiredness she was changed to gabapentin, another seizure medication which does not seem to affect sleep. Almost immediately, she felt more alert and energetic. She still had no seizures, but felt much better. Although she seemed to be sleeping fine, carbamazepine was probably changing the quality of her sleep so that it was less effective. The change in medication corrected this, and once again she was able to function at her best.

Not all patients will be sensitive to particular medications. But if memory or concentration seem to be suffering, particularly if seizures are fully controlled, it is possible that the seizure medication is causing a problem with sleep. Change to another medication should be considered, because many of the newer anticonvulsants [particularly gabapentin (Neurontin) and lamotrigine (Lamictal)] do not seem to have a detrimental effect on sleep.

Diagnostic evaluations in patients with epilepsy and sleep disorders

Most patients suspected of having seizures will have a test known as an electroencephalogram, or EEG. This analyzes brain waves, looking for patterns known to be associated with epilepsy. Abnormalities associated with epilepsy occur more frequently during sleep, so in many cases the doctor will try to obtain a recording during both sleep and wakefulness. This typically happens by coming to the test sleep deprived, or alternatively a medication can be given at the test to induce sleep. If the diagnosis is still uncertain after one or more EEGs, the doctor can recommend a prolonged EEG, which can be done either as an outpatient with equipment that can be carried by the patient, or in the hospital. This allows a long sample of recording and includes deep sleep, which is not typically recorded with a routine EEG.

If it is not clear whether a disorder is epilepsy, or if a diagnosis of epilepsy is known but sleep disruption is present, one of two tests might be helpful. If the main question is sleep disruption, a sleep study should be performed. In this test, the patient sleeps in a laboratory. Breathing, muscle tone, eye movements and brain waves are measured electronically in order to see if sleep patterns are normal and, if not, what sort of problem is present. This is the best method for diagnosis of sleep disorders. If spells resembling epilepsy are occurring, admission to a video-EEG monitoring unit may be required. This test consists of simultaneous recording of video and brain waves, and is the best way to diagnose epilepsy. It allows specialists to view the behavior in question and to determine whether there are abnormalities in brain activity (consistent with seizures) during the episodes. Usually several days in the hospital are required. As there are similarities in the recording, a seizure may be seen with a sleep study, and a sleep disorder can often be diagnosed using video-EEG monitoring. As technology improves it may be possible to do one or both of these tests as an outpatient in many cases.

Conclusion

Sleep is important to everyone, but patients with epilepsy are particularly vulnerable to the effects of sleep deprivation. Conversely, seizures and treatments for seizures can have a detrimental effect on sleep. Optimal care of patients with epilepsy sometimes includes sleep evaluation, and sometimes particular epilepsy medications should be used in order to cause the least possible disruption of sleep. Paying attention to this relationship is essential for patients with epilepsy to achieve their best overall function.

Drug	Adverse effect on sleep
Phenobarbital
Phenytoin (Dilantin)
Carbamazepine (Tegretol)
Valproate (Depakote)
Gabapentin (Neurontin)	None
Lamotrigine (Lamictal)	None
Topiramate (Topamax)	?
Tiagabine (Gabitril)	?
Levetiracetam (Keppra)	?
Oxcarbazepine (Trileptal)	??
Zonisamide (Zonegran)	?

mild sleep disruption

moderate sleep disruption

?unknown, however chemical similarity to carbamazepine makes sleep disruption a possibility

Figure 1: Sleep disruption by a nocturnal seizure. This 55 year old man had frequent partial seizures and daytime drowsiness. When he had no seizures (top), sleep patterns were normal with frequent REM periods. When a seizure occurred early in the night (bottom), he frequently awakened and had almost no REM sleep during the entire night. SZ=seizure, P=postictal; W=wakefulness; REM=REM sleep, 1-4=stages 1-4 of sleep.