Sleepwalking

Biology 202
2000 First Web Report
On Serendip

Sleepwalking

Sarah McCawley

Many people have heard of sleepwalking and even know about symptoms that surround the disorder, but is there more to the story than just waking up during the night and wandering around in an unaware state? What actually causes someone to sleepwalk? To try to understand the answers to these questions it is important to understand not only what kind of disorder it is, but who has the disorder, how frequently it occurs, what the symptoms are, as well as what the treatments are. By exploring these areas, it may be possible to better understand the disorder as well as dispel old notions about it.

The Parasomnias are disorders that intrude into the sleep process and create disruptive sleep-related events. Arousal disorders are parasomnia disorders presumed to be due to an abnormal arousal mechanism. These arousals occur when a person is in a mixed state of being both asleep and awake, generally coming from the deepest stage of nondreaming sleep, stages 3 and 4. This means a person is awake enough to act out complex behaviors but still asleep and not aware or able to remember these actions (1).

One of the most common types of arousal disorders is somnambulism, more commonly known as sleepwalking. Somnambulism affects children much more regularly than adults. In fact, sleepwalking affects approximately 1% to 17% of children and is more frequently seen in boys. Interestingly, 15% of children aged 5-12 years sleepwalk at least once, but only 3-6% sleepwalk more than once (5). It has been noted that the incidence of sleepwalking decreases with age. Although the exact prevalence of sleepwalking in adults is not known, it is estimated to be as high as 10%.(4). It has also been noted that those individuals who start to sleepwalk as adults are more prone to serious problems with it. Because it is found more commonly in children, who are undergoing many physical and chemical changes, if it is seen to start in adults it is thought to be linked to mental disturbances other than fatigue or anxiety. However, mental disturbances can be present without counting as a symptom(3).

No one seems to know exactly what the cause of somnambulism is, but there are theories that have been suggested. Once asleep, it is thought that the part of the brain that controls muscle function is aroused and the "sleepwalker" begins to move even though he or she is still asleep (2). In children, it may be related to fatigue, prior sleep loss, or anxiety. In adults, sleep walking is usually associated with a disorder of the mind but may also be seen with reactions to drugs and/or medications and alcohol, and medical conditions such as partial complex seizures (3). It is also interesting to note that in 10-20% of cases there is a familial history of sleep walking (5), so there is a possibility that it is genetically inheritable.

This past summer, however, there was a breakthrough found during a sleep study in Bern, Switzerland. During the sleep study, a 16-year-old male was hooked up to an electroencephalogram, EEG, to monitor his brain activity. During the second night, he woke up, pulled on the EEG leads, and mumbled some gibberish. The brain activity shifted from smooth waves to a high-voltage burst of delta waves, which can be seen during deep sleep. The EEG showed a commotion of activity in the area of the cingulate cortex, a part of the brain that controls regulation of emotions and certain motor functions. While there was activity in this area, there was no activity in the prefrontal cortex, which governs higher mental functioning. In other words, it appears that sleepwalker are confused and upset and react by walking without consciously knowing that they are doing it (7). Nevertheless, researchers are far from knowing exactly what causes this to happen and how to stop it.

Sleepwalking episodes usually occur within one to two hours of falling asleep, when the person is in non-REM sleep (5). The episodes can last anywhere from a few seconds to thirty minutes (3). During the episode, the sleepwalker may simply sit up and appear awake while actually asleep or they may get up and walk around. They may even perform complex activities such as moving furniture, going to the bathroom, dressing and undressing, and similar activities. Some people even drive a car while actually asleep. One common misconception is that a sleepwalker should not be awakened. It is not dangerous to awaken a sleepwalker, although it is common for the person to be confused or disoriented for a short time on awakening. Another misconception is that a person cannot be injured when sleepwalking. Actually, injuries caused by such things as tripping and loss of balance are common for sleepwalkers (3).

Often treatment is unnecessary, except when the health or safety of the individual is being threatened. Often the person can trip over objects, walk out of the house, fall out of windows, or injure themselves with sharp objects like knives. To avoid incidences that may injure the sleepwalker, it is suggested that you locate the sleepwalker's bedroom on the main floor, if possible and lock the windows and cover them with large, heavy drapes. It is also recommended that you keep the floor clear of harmful objects and remove any hazardous materials and sharp objects from the room and secure them in the house (4). However, there are cases when medical treatments are needed. If sleepwalking is frequent or persistent, examination to rule out other disorders (such as partial complex seizures) may be appropriate. It may also be appropriate to undergo a psychological evaluation to determine causes such as excessive anxiety or stress, or medical evaluation to rule out other causes (6).

Medication may be used in cases where episodes are violent, injurious, frequent, or disruptive. Therapy usually consists of either a benzodiazepine, such as Diazepam(r) or Alprazolam(r), or a tricyclic antidepressant. Among other things, these drugs inhibit chemical processes associated with sleep regulation, which, depending on the patient, may or may not result in fewer episodes of sleepwalking. Biofeedback and hypnosis have also been used effectively with individual sleepwalking patients (4).

All of this information, from the definition of what sleepwalking is to how it is treated, gives some insight into what causes this disorder to occur. However, there is still much more to learn. Just like in the course of studying anything, people must continue to ask questions and look for answers. It is possible that we may never know exactly what causes someone to sleepwalk, if indeed there is one particular reason at all. Is it possible that something in the unconscious controls a sleepwalker's actions? Is it like a quadriplegic's ability to withdraw his foot when pinched without knowing that that he has been pinched? Is the brain somehow disconnected from the body's actions when the person is sleepwalking?

 

WWW Sources

1) PARASOMNIAS - AROUSAL DISORDERS INFORMATION

2) Parasomnias

3) Sleepwalking (Somnambulism)

4) SleepChannel

5) SLEEPWALKING

6) Sleep walking

7) "New Images Shed Light on Mystery of Sleepwalking"

 

 

Continuing conversation (to contribute your own observations/thoughts, write in the Sleepwalking Experiences Forum on Serendip) 01/19/2006, from a Reader on the Web Hi, I am hoping that you can answer a question that I have. I have two 12 year old twin girls and a 9 year old girl. One of my daughters, a twin used to sleepwalk, and had a terrible sezure at 6 years old. She would walk around, scream if touched, would be hard to wake, and would talk to some invisible person, or just talk in her sleep. Due to newly found information I have realised that she had night terrors. My mother's brother, and father both had similar symptoms. They are all fine now... But I am wondering why one twin has it, and the other didn't. I never sleepwalked, although my ex-husband's sister did on occasion. My daughter is doing a research project for science on the subject, and I was just hoping that you could help my find out why. Thanks, From: An unknown writer (please reply shortly)