Dreams occur during the rapid eye movement (REM) stage of sleep, and you may or may not remember them when you wake. But have you ever had an experience where you weren’t quite sure whether you were awake or asleep? Or a time when you woke suddenly with an intense feeling of confusion?
These experiences are often linked to a group of sleep disorders collectively known as parasomnias.
Parasomnia is characterized by unintentional or unwanted behaviors that occur in the different stages of sleep. There are a wide range of parasomnias characterized by the sleep stage in which they occur and by the type of behavior exhibited.
In this article, we’ll explore the subject of parasomnia in depth to help you learn what it is, what symptoms it produces, and the causes. We’ll also take a look at how they are diagnosed and treated.
What is Parasomnia?
You are likely already familiar with some of the more common sleep disorders including sleep apnea, restless leg syndrome, and narcolepsy but parasomnias are in a class of their own.
The term parasomnia refers to abnormal behaviors that occur during sleep. These behaviors occur unintentionally and often without the patient’s awareness as they are falling asleep or at any point in the sleep cycle.
There are four stages in the human sleep cycle including three stages of non-rapid eye movement (NREM) sleep and REM sleep.
Stage 1 is the lightest stage of NREM sleep defined by the presence of slow eye movements and drowsiness.
Sleep can easily be disrupted in this stage, though muscle tone becomes progressively more relaxed and brain activity slows down. In stage 2, brain waves continue to slow with bursts of rapid activity.
Arousals do not occur as easily, and both body temperature and heart rate begin to decrease.
Stage 3 is deep NREM sleep, and it is the most restorative sleep stage, consisting of slow waves or delta waves. Arousal is more difficult in this stage, and this is the stage in which most parasomnias occur.
REM sleep is the dreaming stage of sleep in which rapid eye movements and faster brain waves occur. Awakening and arousal is easier in this stage but may result in a groggy or sleepy feeling.
Most people go through the four stages of the sleep cycle every 90 to 120 minutes for a total of four to five sleep cycles per night, depending how long they sleep.
Parasomnias occur during an arousal from REM sleep or during a partial arousal from NREM sleep. Some of the most common parasomnias include the following:
- Confusion Arousals
- Nocturnal Sleep-Related Eating Disorder
- REM Sleep Behavior Disorder
- Sleep Hallucinations
- Sleep Paralysis
- Sleep Talking
- Sleep Walking
- Sleep Terrors
Both children and adults can be affected by parasomnia and, in some cases, the patient is unaware of the behavior.
Parasomnias may include any of the following: undesirable movements, unwanted behaviors, emotions, perceptions, or dreams.
Behaviors during a parasomnia episode are unconscious but typically semi-purposeful and goal-directed – they have importance or a clear meaning to the person experiencing them, even if they are asleep.
What Are the Symptoms of Parasomnia?
Because there are so many different types of parasomnia, the symptoms are widely varied. Generally speaking, parasomnias can be divided into two categories based on when they occur during the sleep cycle.
Non-REM parasomnias include confusion arousals, sleep terrors, and sleep walking. REM parasomnias include nightmares, sleep paralysis, and REM Sleep behavior disorder (RBD).
Here is an overview of the symptoms associated with various parasomnias:
Though commonly associated with children, bedwetting can occur in adults as well. It may be either a primary or secondary condition.
As a primary condition, bedwetting occurs when the patient fails to wake when the bladder is full.
Secondary bedwetting typically affects children and is often a sign of severe social or mental stress – it can also be a symptom of a medical problem.
This is a parasomnia in which the patient is awakened from a deep sleep in the early part of the night.
The patient will typically remain in bed but will sit up and look around in a confused manner – they may also cry or become inconsolable. In most cases, episodes are brief, but they can last up to 40 minutes in rare cases.
Attempting to interact with a person experiencing a confusion arousal will only prolong the episode.
These are most commonly seen in younger children and typically resolve on their own by age 5. In rare cases, however, they may continue into adulthood and can be triggered by stress or illness.
A nightmare is a vivid dream that causes feelings of fear, terror, or anxiety during sleep.
Typically the person experiencing a nightmare awakens abruptly from REM sleep and may be able to remember and recount the content of the dream.
This parasomnia typically happens in the second half of the sleep period, and the patient may have a difficult time returning to sleep after.
Nightmares can be triggered by illness, stress, anxiety, trauma, loss of a loved one, or a reaction to medication.
When they occur more than once a week, or if it results in a significant disruption of sleep, it should be diagnosed and treated.
Nocturnal Sleep-Related Eating Disorder
This disorder involves episodes of uncontrolled eating and drinking behaviors that occur during sleep.
The patient may be partially or completely unaware that the behavior is happening and may have no memory of it in the morning.
This condition can be dangerous because there is a risk of ingesting harmful or even toxic substances and you could injure yourself during food preparation.
This disorder can also affect your health if frequent episodes lead to weight gain.
REM Sleep Behavior Disorder
This is a type of parasomnia that occurs during REM Sleep and happens when the patient acts out a dramatic or violent dream.
Normally, REM sleep involves a state of paralysis, but people with REM sleep behavior disorder (RBD) are able to move their limbs and body while dreaming.
This condition is most common in men aged 50 and older, but it can also affect women and young adults. In some cases, RBD is triggered by medications, but it can also be a symptom of a serious neurological disorder.
Different from nightmares, sleep hallucinations occur while the patient is falling asleep or waking up.
They are characterized by a vivid, intense visual or sensory experience that may involve realistic images, sensations of movement, or the feeling that someone else is in the room.
Though rare in children, as many as 40% of adults experience sleep hallucinations, and they often occur with other sleep disorders.
This is a parasomnia in which the patient is unable to move the limbs or body either when falling asleep or waking up.
In this state, the muscles are briefly paralyzed while the brain is fully awake.
Episodes of sleep paralysis can be as short as a few seconds or as long as a few minutes and they can be very distressing to the person experiencing them.
This disorder sometimes runs in families but, in many cases, the cause is unknown. It is often correlated with other sleep disorders such as narcolepsy.
This type of parasomnia is fairly common and is generally harmless. The patient may be observed talking or making nonsensical sounds during sleep, often very loudly.
This parasomnia can occur by itself, or it may be a feature of a different sleep disorder.
Also known as somnambulism, sleep walking is a type of arousal disorder in which the patient appears to be awake, moving around with open eyes, but is actually still asleep.
Sleepwalkers may wake in the middle of an episode feeling confused about their actions, or they may return to bed and go back to sleep without any knowledge of the episode.
This parasomnia usually happens early in the night during deep NREM sleep. It is most common in children ages 6 to 12 but can also affect adults and the elderly. It tends to run in families as well.
Also known as night terrors, sleep terrors occur when the patient abruptly arouses from sleep in a state of terror, often crying or screaming.
The patient may also experience physical symptoms such as increased heart rate, rapid breathing, sweating, or flushed skin.
The patient may be awake, but they are likely to be confused and may not be able to communicate normally.
Sleep terrors are typically brief but can last for 30 or 40 minutes. After the event is over, the patient usually appears to fall back asleep and may not remember the event in the morning.
These events occur during deep NREM sleep, usually in the first half of the night. Some people experiencing sleep terrors will act out their dreams, posing a danger to themselves or others.
This disorder is fairly common in children between the ages of 4 and 12 and affects up to 3% of adults. It does tend to run in families.
What Causes Parasomnia?
The cause of parasomnia is unclear, but it may be related to other disorders – particularly other sleep disorders. It may also be secondary to the use of medications or drugs.
There is also some evidence to suggest that sleep fragmentation caused by various sleep disorders like sleep apnea might play a role.
Though the exact cause of parasomnia is unclear, there are certain risk factors that have been identified. These include the following:
- Age – Certain parasomnias are more common in children (like bedwetting) and are often outgrown over time. If the problem worsens with age or manifests for the first time in adulthood, it may be worth discussing with your doctor.
- Genetics – Many parasomnias seem to run in families, so having a family history of parasomnia or other sleep disorders may increase your risk for developing one.
- Stress – Chronic or acute stress can affect your hormones as well as your brain chemistry, so being under intense stress may cause parasomnias to manifest or worsen. In many cases, the parasomnia will end when the cause of the stress is resolved.
- PTSD – Post-traumatic stress disorder is frequently associated with certain parasomnias such as nightmares and sleep, terrors. Nearly 80% of PTSD sufferers experience nightmares within 3 months of experiencing trauma.
- Medications – It is not common knowledge, but nightmares are a common side effect of certain medications. Medications can also contribute to other parasomnias or worsen sleep disorders.
- Drug Use – Use or abuse of drugs and alcohol can increase your risk for certain parasomnias such as sleepwalking and night terrors. It can also worsen symptoms of existing parasomnias.
Again, parasomnia is often linked to other sleep disorders so having a concurrent sleep disorder may increase your risk for developing the condition.
If you are concerned that you might have parasomnia, talk to your doctor to discuss your symptoms and to rule out an underlying condition.
How is Parasomnia Diagnosed?
Not all parasomnias are cause for concern. For example, occasional sleep talking or a single episode of sleepwalking may not be of any significance.
In children, bedwetting and nightmares often go away with age and parasomnias related to stress may disappear when the cause of the stress is resolved.
If your parasomnia is resulting in a significant sleep disturbance for you or a bed partner, or if there is potential that you might injure yourself, you should talk to your doctor.
Depending on your symptoms, your doctor may recommend that you see a board-certified sleep specialist.
A sleep specialist may perform a routine physical exam as well as taking a history of your symptoms and your family history. From there, he may recommend a two-week sleep diary to track your sleep habits as well as your symptoms, looking for clues about the underlying issue.
You may also be asked to rate the quality of your sleep using the Epworth Sleepiness Scale to determine the degree to which your parasomnia is affecting your sleep.
If these steps alone are not enough to identify the underlying problem, your sleep specialist may recommend an in-lab sleep study known as a polysomnogram.
You’ll be hooked up to monitors which will record your brain waves, breathing rate, heart rate, body movements, and sleep.
It will also reveal any unnatural behaviors that occur during sleep. With the information from these tests, you should be able to get an accurate diagnosis of your parasomnia.
What Are the Treatment Options for Parasomnia?
The best treatment for parasomnia is determined by the diagnosis. In some cases, no treatment may be needed but, in cases of an underlying medical condition or concurrent sleep disorder, you may need treatment to improve your sleep quality and your quality of life.
The exact treatment of parasomnia varies depending on the cause, but there are certain things you can do to improve your safety and to increase your chances of getting a good night’s sleep.
Here are some management tips to improve safety for parasomnia patients:
- Clear the bedroom of objects that could be tripped over
- Keep all windows and exterior doors locked
- Consider installing alarms on the doors to wake you if needed
- Sleep on the ground floor and avoid very high bed frames
In addition to taking safety precautions, you should also take steps to address triggers such as stress, sleep deprivation, and drug or alcohol use.
Sticking to a regular sleep schedule may help you relax enough in the evening to fall and stay asleep.
Engaging in stress-relieving activities may reduce the frequency or severity of your parasomnia episodes and avoiding alcohol or drug use could be very beneficial as well.
Unfortunately, some parasomnias seem to have no cure because their cause is still poorly understood. The best thing you can do is be upfront and honest with your doctor about your symptoms and create a treatment plan together.
Disclaimer: The information on this website is not intended to be used as a substitute for professional medical advice, clinical diagnosis, or treatment. Always seek the advice of your personal physician or another qualified health provider with any questions you may have regarding a medical condition.