Sleepwalking is a sleep disorder characterised by walking or other movements while still asleep. Also known as somnambulism. The individual appears awake, but is not, and will not remember his actions. Sleepwalking most often occurs during deep non-REM sleep (stage 3 or stage 4 sleep) early in the night. It can occur during REM sleep near morning. Sleepwalking may include simply sitting up, getting up and walking around, or 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.

Sleepwalking occurs at any age, but most often in children 6 to 12 years old. Hublin et al (1997) Found sleepwalking affects about 20% of children and about 3%.

Eyes open during sleep May have blank facial expression May sit up and appear awake during sleep Walking during sleep Any sort of detailed activity during sleep No recall of the event upon awaking Confusion, disorientation upon awakening Talking is incomprehensible and non-purposeful Night terrors

In children, the cause is usually unknown but may also be related to fatigue, prior sleep loss, fever, or anxiety. In adults, it 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. In the elderly, sleepwalking may be a symptom of an organic brain syndrome or REM behaviour disorders.

Safety measures may be necessary to prevent injury. This may include changing the environment by moving objects such as electrical cords or furniture to reduce tripping and falling. Short-acting tranquilizers have been helpful in reducing the incidence of sleepwalking. Sleepwalking may or may not become less frequent with age. It usually does not indicate a serious disorder, although it can be a symptom of other disorders. Improving sleep cycle may help decrease occurrence of sleepwalking. Prevention Avoid the use of alcohol or central nervous system depressants if prone to sleepwalking. Avoid fatigue or insomnia, because this can instigate an episode of sleepwalking. Avoid or minimize stress, anxiety, and conflict, which can worsen the condition.

Incomplete arousal There appears to be an issue of arousal. EEG monitoring of sleepwalkers shows that typically they have delta activity (a characteristic of deep sleep) with beta activity (characteristic of being awake) mixed in. Researchers believe that sleepwalking occurs when the patient wakes from deep sleep but the arousal is incomplete so as a result they are not fully woken. There appears to be a genetic component to this.

Sleepwalking certainly appears to run in families (Horne 1992) which in itself may suggest a genetic component. Hublin et al (1997) in a study of Finnish twins reported that there is a concordance of 66% for boys and 57% for girls. Again these are high figures suggesting a genetic component.

Bassetti (2002) claims to have isolated a specific gene that may be a risk factor in sleepwalking. HLA DQBI*05 was found to be present in about 50% of sleepwalkers he tested. The same gene was only present in about 25% of non-sleepwalkers. The gene is part of a group of genes involved in the production of the protein HLA and has also been implicated in some cases of narcolepsy. -Small sample size: Out of 74 patients studies only 16 underwent genetic testing and 8 of these were found to have the gene. -Volunteer sampling. -Most sleepwalkers do not seek medical attention or are not even aware of their condition.

Oliverio 2008 Sleepwalking due to delayed development of the complex networks controlling sleep More common in children and that most children grow out of it “During normal sleep the chemical messenger gamma-aminobutyric acid (GABA) acts as an inhibitor that stifles the activity of the brain’s motor system. In children the neurons that release this neurotransmitter are still developing and have not yet fully established a network of connections to keep motor activity under control. As a result, many [kids] have insufficient amounts of GABA, leaving their motor neurons capable of commanding the body to move even during sleep.”

Diathesis-Stress Sleepwalking is closely related to restless leg syndrome (RLS) which is a risk factor for insomnia and as a result excessive tiredness. RLS is a genetic condition. This may help explain the genetic component of sleepwalking. Although there are clearly biological predispositions for somnambulism an important trigger appears to be tiredness.