Every human being spends almost one-third of life sleeping. Despite being such an important component of life, there is still a lot of enigmas about the relation between the brain, the process of sleeping, and the disorders related to sleep.1 Poor or insufficient sleep can be associated with several dysfunctions in body systems such as hormonal, metabolic, and neurological disorders. Sleep disorders are frequent and can have serious consequences on the quality of life and health of patients. Disorders of sleep can manifest as complaints about insufficient sleep, excessive sleep, or abnormal movements during sleep.2
Parasomnias are a group of sleep disorders presented by abnormal, unpleasant motor, verbal, or behavioral episodes that occur during sleep or wake-sleep transitions. The word ‘parasomnia’ is derived from the Greek word ‘para’ meaning beside and the Latin term ‘somnus’ meaning sleep.3 Parasomnias are not the disorders of the process of sleep but the undesirable events that happen majorly during sleep. Sleepwalking is one of the disorders from the group of parasomnias that consists of a series of complex behaviors that are initiated during the deep stages of sleep and results in walking during sleep.4
This article explores sleepwalking, its causes, signs, and symptoms. The prevalence of sleepwalking in various age groups, as well as the risks associated with it.
What is sleepwalking?
Sleepwalking (SW), formally known as somnambulism is a behavioral disorder that happens during the non-rapid eye movement (NREM) slow wave sleep and results in sudden arousal characterized by motor activity, impaired judgment, illusions, relative unresponsiveness to the external stimuli, and partial or complete loss of memory. Sleepwalking affects up to 4% of the adults and is a leading cause of the sleep-related episodes of violence and self-injury.5 Sleepwalking is mainly characterized by:
- Partial arousal during non-rapid eye movement (NREM) sleep, typically presented during the first third of the sleep in slow wave sleep stage.
- Event content may or may not be recalled
- Impaired perception of the environmental stimuli
- Impaired judgment, planning, and problem solving
What kinds of behavior is observed during sleepwalking?
General signs and symptoms: An episode of sleepwalking usually happens in the first third of the night, during non-dreaming, slow-wave sleep. Episodes of sleepwalking vary in complexity and can range from simple activities such as raising the head, opening the eyes, and looking around in a confused manner with mumbling. The person may sit up in bed, scream, speak, swear or mumble. It can extend to leaving the bed, walking around, running, searching in drawers, or handling objects.6 Movements are generally clumsy but if uninterrupted the sleepwalker can safely return unaided or gently aided to lying position and continue their sleep. In extreme situations, due to lack of full awareness and responsiveness, inappropriate emotions, or potentially dangerous behaviors such as driving can be observed.7 Some incidences of homicide or suicide are also reported during the complex behaviors of sleepwalking with event of attacking the person attempting to awaken the sleepwalker.4 The memory of episodes varies between episodes ranges from complete amnesia to partial loss to complete recall of the episode. Loss of pain sensation has also been noted as who sleepwalks are often unaware being injured until they awaken.8
Dangers or violence during sleepwalking: It is not advisable to wake the patient during sleepwalking, instead should be gently guided back to the bed to fall back into deep sleep. The most common emotion experienced during sleepwalking is fear, triggering a fight/flight response. A small count of patients who sleepwalk sometime report violent behavior towards others. The impulsive and violent behavior in sleepwalking is explained by sudden emotional arousal from deep sleep and impaired motor functioning of the brain.8
How common is sleepwalking?
Sleepwalking is commonly observed in the general population. The lifetime prevalence of sleepwalking is estimated to be 29%. It more commonly observed in kids with a peak incidence around 10-13 years, disappearing in about 75% of the affected during adolescence. SW can also persist or appear de novo during adulthood. Studies have reported that sleepwalking develops in approximately 13% during adulthood. The overall prevalence of sleepwalkers is calculated to be about 4%.9 A recent study estimated the lifetime prevalence of sleepwalking to be about 6.9% with no significant difference between children and adults suggesting rare incidence of sleepwalking in adults. They also reported the current prevalence rate of sleepwalking, within the last 12 months, and observed a significant difference in children 5% than in adults 1.5%. This marked difference between the children and adults can be explained by the fact that with age the duration of slow wave sleep reduces, hence fewer chances of sleepwalking with maturation.10
Reasons for sleepwalking
The fundamental reason for parasomnias like sleepwalking is still unknown. During the various stages of sleep cycle, the transition includes from wakefulness to NREM and REM sleep. The NREM sleep occurs in the first half of the sleep and is divided into three stages, stage 1 (N1), stage 2 (N2), and stage 3 (N3). The postulated pathway suggests that the disorders of arousal are presumed to occur because of the incomplete transition or sleep-wake disturbances between the periods of wakefulness and stages of sleep. Sleepwalking is considered as the arousal disorder of the NREM sleep. The NREM parasomnias are most often presented during the slow-wave sleep (SWS or N3) stage.3
The disorders of the arousal such as sleepwalking are also presumed to be triggered by several behavioral and environmental factors as follows:
Hereditary and family history:
Several studies have reported an association between the episodes of sleepwalking and family history.11 Licis AK, et al. (2011) conducted a study in a family of 4 generations to identify the hereditary inheritance and the gene responsible for the pattern of sleepwalking and identified genetics as a predisposing factor for sleepwalking and other NREM parasomnias.12
Sleep deprivation or inadequate sleep:
Lack of sleep or inadequate sleep disturbs the circadian rhythm. Prolonged period of sleep deprivation that is more than 24 hours, appears to be a greater risk factor for the sleepwalking behavior. It leads to increased duration of deep sleep as a rebound sleep and increases the frequency of sleepwalking episodes with more complex behaviours.13
Several types of medications such as anti-anxiety, anti depressants, anti-cholinergic, antiepileptic, and hormone therapy are advocated as active agents to treat the frequent and severe episodes of sleepwalking. On the other hand, an association has been found between some medications and the incidence of sleepwalking.13
Stress and anxiety:
Any form of stress and anxiety can affect sleep. Interrupted or inadequate sleep can increase the chances of sleepwalking. Stress can be induced due to multiple reasons such as physical (pain) or emotional. Stress could be related to discomfort or change such as traveling and sleeping out of the comfort zone.3
Obstructive sleep apnea (OSA):
Obstructive sleep apnea is a sleep disorder in which airway obstruction happens during sleep, causing shortness of breath and difficulty in breathing during sleep. This causes frequent wake episodes and disturbed sleep that may increase the risk of sleepwalking.3
Restless leg syndrome:
It is a sleep disorder presented by a powerful urge to move the limbs while lying down or sleeping. This causes arousal from the deep stages of sleep and increased risk of sleepwalking.3
Diagnosis of sleepwalking:
Sleepwalking is primarily diagnosed by the patient’s clinical history. Sleep laboratory investigations help rule out other disorders of sleep such as nocturnal seizures and rapid eye movement (REM) sleep behavior disorders. There is no diagnostic sleep protocol to confirm the diagnosis of sleepwalking. The major problem in diagnosing sleepwalking with an objective technique such as polysomnography (PSG) is that the behavioral episodes rarely take place in laboratory settings. Moreover, when such events occur, laboratory episodes are less complex than the patient’s home environment. The presence of several features such as frequent arousal from deep sleep, decreased reading for slow wave sleep activity have been proposed as the evidence supporting the diagnosis of sleepwalking but these findings lack sensitivity and specificity.14
Management of sleepwalking:
The management of NREM parasomnias mainly includes the modulation of the triggering factors and ensuring safety. Standard management strategies include a safety plan, reassurance, general measures to improve sleep hygiene, and treating sleep disorders offers an alternative strategy to improve sleep at night. In many cases, sleepwalking requires no active treatment. The treatment for sleepwalking depends on the patient’s age, frequency, and intensity of episodes. Following are the few approaches that may be incorporated for the management of sleepwalking:
Safeguarding the surroundings is an important consideration for people who sleepwalk. Some ways for harm reduction include:15
- Keep sharp objects, knives and weapons locked away and out of reach
- Keep the doors and windows closed and latched
- Clear the floor of any obstructions and sharp items
- If possible, make the patient sleep on ground floor, on a mattress directly on the floor, possibly in a sleeping bag
- Placing alarms and bells on doors
A positive sleep schedule with consistent sleep and wake routines helps in improving the quality and quantity of sleep, which in turn helps with reduction in arousal events by increasing the sleep duration.
Behavioural therapy and sleep hygiene:
Sleepwalkers should not be awakened, but guided gently back to bed and allowed to fall back to sleep. Behavioural therapy includes scheduled awakenings briefly 15-30 minutes before the expected episode of sleepwalking. As sleepwalking happens during a specific stage of sleep cycle, it usually happens around the same time every night. Hence, anticipated awakenings help in reducing sleepwalking events.8 Sleep hygiene refers to an individual’s sleep related habits and environment. Poor sleep hygiene such as having heavy meals or caffeine or alcohol just before bed, not maintaining a proper sleep schedule can interfere with the sleep cycle and acts as a contributing factor for sleep deprivation and increased risk of sleepwalking episode. Improving the overall habits helps in attaining early sleep onset and reducing the chances of sleep deprivation which acts as a triggering factor for sleepwalking. Studies have suggested, along with behavioral modifications hypnotherapy also helps to release repressed emotions or defenses of the unconscious mind.10
When the frequency of episodes is high with psychological complications and stresses. A low dose of benzodiazepine such as diazepam, clonazepam, lorazepam, triazolam are used to induce sedation and sleep to relieve anxiety and stress. Tricyclic antidepressants like imipramine used to treat depression show favorable therapeutic response in sleepwalking. Similarly, Serotonin Selective Re-uptake Inhibitors (SSRIs) such as paroxetine used for depression and panic disorder are also found to be useful in controlling the events of sleepwalking.16 Some studies have reported hormonal therapy such as melatonin therapy can also help in easing the transition between slow wave sleep to rapid eye movement (REM) sleep which reduces the risk of sleepwalking episodes.
Treat underlying causes:
Management of sleep disorders related to the onset of sleep or sleep-waking episodes such as breathing difficulties in obstructive sleep apnea, upper airway resistance syndrome, restless leg syndrome, periodic limb movement, are the best approaches and usually help in eliminating sleepwalking in children and adults.16
Sleep is an important aspect of human life and is closely related to the brain and it’s functioning. A good quality sufficient sleep is proven has proven to improve various basic functions of human body and brain. A minimum of 7-hour uninterrupted sleep is necessary for the brain to reenergize, reorganize, and remove all toxic waste byproducts produced throughout the day. Sleep disorders can be due to disruptions and deprivation of NREM and REM sleep stages. Sleepwalking is a relatively common disorder of arousal of NREM sleep. Sleepwalking is more common in children between the ages of 2-13 years and regresses with adulthood. Sleepwalking is generally benign in nature and most people do not even require treatment. In cases with severe and complex behavior, it is important to treat underlying sleep disorders and behavioral and emotional aspects with behavioral and pharmacological modifications.
Q1. What are the usual things sleepwalkers do?
A1. Sleepwalkers usually sit up in bed and look around confused, talk or mumble or shout, get up from the bed and run away, opening drawers, preparing for the next morning, eat, and in worst case scenarios drive.
Q2. Who are at risk of sleepwalking?
A2. Sleepwalking is commonly seen among children than adults. One long-term study has reported 2 to 13 years as the peak age for sleepwalking. In adults, the prevalence is estimated to be up to 4%.
Q3. What is the main cause of sleepwalking?
A3. The main causes of sleepwalking include hereditary, extreme fatigue due to sleep deprivation, or interrupted sleep. Few disorders like rest leg syndrome, obstructive sleep apnea, and periodic limb movements are also some of the underlying problems that can cause sleepwalking.
Q4. Is it possible to wake a person who is sleepwalking?
A4. Waking a person who is sleepwalking should be done as gently as possible. Several studies have recommended rather than waking up a sleepwalker, it is better to gently guide the person back to bed. It is more likely that the sleepwalkers will not remember the incident in the morning.
Q5. Does the sleepwalker know what they are doing?
A5. Sleepwalkers generally have their eyes wide open, with a confused stare. They are asleep and it is likely not to remember anything about the incidence. Sleepwalking is usually associated with partial or complete memory loss of the episode.
Q6. What type of doctor should you see if you are sleepwalking?
A6. A general physician can help diagnose the problem. Depending upon your history and symptoms, he can refer you to a doctor who specializes in sleep medicine or a neurologist or a pediatrician in cases of infants, children, and teenagers.
Q7. At what stage of sleep, sleepwalking happens?
A7. Sleepwalking is a disorder of arousal of NREM sleep. it usually happens in stage 3 or slow wave sleep or deep sleep stage of the sleep cycle.
Q8. Is sleepwalking dangerous?
A8. Sleepwalking itself is not harmful. But sleepwalking can be dangerous because of complex behaviors like walking around, running, opening windows or driving.
Q9. When should you be worried about sleepwalking?
A9. Sleepwalking episodes more than once or twice to several times a night would be a reason to worry. It may lead to dangerous behavior or injury to the sleepwalker.
Q10. Is sleepwalking treatable?
A10. Treatment for occasional sleepwalking is not necessary. In children who sleepwalk, it typically goes away by the teen years. If sleepwalking leads to the potential for injury, or disruptive to family members, treatment may be needed.
Q11. Do all sleepwalkers walk?
A11. No, not all sleepwalkers walk. Some sleepwalkers just sit in bed, mumble with eyes wide open with a confused look and then go back to sleep.
Q12. For how long does an episode of sleepwalking last?
A12. An episode of sleepwalking could be very brief, a few seconds or minutes to last for 30 minutes or longer. Most episodes last for less than ten minutes and if left undisturbed sleepwalkers generally go back to sleep.
- Eugene AR, Masiak J. The Neuroprotective Aspects of Sleep. MEDtube Sci.2015;3(1):35-40.
- K Pavlova M, Latreille V. Sleep Disorders. Am J Med.2019;132(3):292-299. doi: 10.1016/j.amjmed.2018.09.021.
- Singh S, Kaur H, Singh S, Khawaja I. Parasomnias: A Comprehensive Review. 2018;10(12): e3807. doi: 10.7759/cureus.3807.
- Mume CO. Prevalence of Sleepwalking in an Adult Population. Libyan J Med. 2010;5(1):2143. doi: 10.3402/ljm.v5i0.2143.
- Pilon M, Montplaisir J, Zadra A. Precipitating factors of somnambulism: impact of sleep deprivation and forced arousals. 2008;70(24):2284-90. doi: 10.1212/01.wnl.0000304082.49839.86.
- Arnulf I. Sleepwalking. Curr Biol. 2018 Nov 19;28(22):R1288-R1289. doi: 10.1016/j.cub.2018.09.062.
- Harris M, Grunstein RR. Treatments for somnambulism in adults: assessing the evidence. Sleep Med Rev. 2009;(4):295-7. doi: 10.1016/j.smrv.2008.09.003.
- Stallman HM. Assessment and treatment of sleepwalking in clinical practice. Aust Fam Physician. 2017;46(8):590-593.
- Bargiotas P, Arnet I, Frei M, Baumann CR, Schindler K, Bassetti CL. Demographic, Clinical and Polysomnographic Characteristics of Childhood- and Adult-Onset Sleepwalking in Adults. Eur Neurol. 2017;78(5-6):307-311. doi: 10.1159/000481685.
- Stallman HM, Kohler M. Prevalence of Sleepwalking: A Systematic Review and Meta-Analysis. PLoS One. 2016;11(11):e0164769. doi: 10.1371/journal.pone.0164769.
- Drakatos P, Marples L, Muza R, Higgins S, Gildeh N, Macavei R, Dongol EM, Nesbitt A, Rosenzweig I, Lyons E, d’Ancona G, Steier J, Williams AJ, Kent BD, Leschziner G. NREM parasomnias: a treatment approach based upon a retrospective case series of 512 patients. Sleep Med. 2019;53:181-188. doi: 10.1016/j.sleep.2018.03.021.
- Licis AK, Desruisseau DM, Yamada KA, Duntley SP, Gurnett CA. Novel genetic findings in an extended family pedigree with sleepwalking.Neurology. 2011;76(1):49-52. doi:10.1212/WNL.0b013e318203e964
- Stallman HM, Kohler M, White J. Medication induced sleepwalking: A systematic review. Sleep Med Rev. 2018;37:105-113. doi: 10.1016/j.smrv.2017.01.005.
- Zadra A, Pilon M, Montplaisir J. Polysomnographic diagnosis of sleepwalking: effects of sleep deprivation. Ann Neurol. 2008;63(4):513-9. doi: 10.1002/ana.21339.
- Cochen De Cock V. Sleepwalking. Curr Treat Options Neurol. 2016;18(2):6. doi: 10.1007/s11940-015-0388-8.
- Remulla A, Guilleminault C. Somnambulism (sleepwalking). Expert Opin Pharmacother. 2004;5(10):2069-74. doi: 10.1517/14656522.214.171.1249.