Sleepwalking or Somnambulism: Half Awake, Half Asleep

About 1/3 of our lives is lost in an incompletely understood mystery called sleep. There is no limit to the most complex organ of human body called brain that often fails to understand phenomena generated by itself. I had posted about Sleep paralysis a long back, and the topic of today’s discussion seems to be an exactly opposite phenomenon.

“Silently the senses
Abandon all defenses
A place between sleep and awake
End of innocence, unending masquerade”

From the song “Sleepwalker” by Nightwish

Sleep-walking, also known as Somnambulism is a disorder of arousal that falls under the group of “Parasomnia“. In contrast to dyssomnias, which produce insomnia or excessive sleepiness, parasomnias include those disorders that intrude into or occur during sleep but do not produce a primary complaint of insomnia or excessive sleepiness. Besides sleep-walking, other parasomnias are tooth grinding, sleep talking, nightmares, bed wetting, night terrors, etc.


The most accepted and scientific theory is “Incomplete NREM arousal“:
Incomplete arousal usually occuring during the deepest stage of nondreaming (NREM) sleep, stages 3 and 4 leading to a split state of consciousness in which there is motor wakefulness and psychic sleeping is the cause of somnambulism. It is during this phase of sleep, when the body will toss and turn or you steal the blanket from your partner. In contrast, sleep paralysis occur during dreaming (REM) sleep leading to psychic wakefulness and motor sleeping.

Other theories:

  • Acting out dreams:

In the past, scientists thought that somnambulism is actually a dreamer acting out his/her dream. But this theory has been discarded as the episodes have been found to occur during NREM (non-dreaming) phase of sleep from experiments. This theory has been found to be the basis for REM Sleep Behavior Disorder (RSBD).

  • Trance theory of Alien abduction:

Some people believed sleep-walking to be an involuntary and unconscious movement from one place to another during alien abduction.


  1. Eyes remain wide open and staring straight ahead.
  2. Before walking the person often sits up in the bed to remain awake and occasionally gets up and walks immediately.
  3. Sleep-walkers take no notice of their surroundings. Consciousness of being wide awake is not at all present.
  4. Movements are stiff and awkward.
  5. Difficult to wake up while in the middle of sleep-walking.
  6. Once he or she is awake, the person often is confused and has little recall of the event.
  7. Sleep-walking may suddenly end in inappropriate places or the person may return to bed and continue sleeping.
  8. Sleep-walking episodes usually occur within 1-2 hours of falling asleep.
  9. Span of sleep-walking usually ranges from few seconds to 30 minutes.

Common myths about sleep-walking:

  1. Occurs when you are dreaming
  2. Waking them up in middle can turn them violent
  3. Somnabulists don’t injure themselves when sleep-walking


Sleep-walkers often develop astonishing motor abilities that can more readily be explained by the abnormal waking state than by the sleeping state. They are able to find their way through pieces of furniture placed close to each other, they can walk on op of narrow walls, and even climb around rooftops. Many a sleep-walker has in fact even leaped out of a window and awakened only upon landing on the street with a broken leg.

Some true stories of sleep-walking revealing such astonishing motor abilities that gained publicity:

  1. A 15 year old girl from London had climbed the crane and walked across narrow beam, 130 feet above in the air.
  2. A day nurse named “Lee Hadwin” is a “sleep artist” who sketches brilliantly in his sleep.
  3. A middle-aged woman in Australia had sexual intercourse with strangers in sleep and she didn’t recollect the memory when awake in the following morning (Treated successfully in 2004).
  4. A Toronto-man “Kenneth Park” drove about 23 km and murdered his mother in law in sleep in 1987.
  5. A nurse got arrested in 2003 when she got drunk and drove and peed in the road but in sleep.
  6. A chef named “Robert Wood” walks to kitchen and cooks in sleep.
  7. A 51 year old electrician named “Timothy Brueggeman” died of hypothermia as he sleep-walked out of his home only in underwear and fleece shirt.
  8. A girl named “Anna Ryan” gained 60 pounds due to habit of sleep-eating.
  9. A girl named “Rachel Ward” in 2009, leaped out of window of the first floor and landed on the floor in sleep without breaking a single bone.
  10. A woman was reported in 2008 to be sending emails in sleep and even inviting a friend for dinner and drinks.
  11. A computer expert named “Ian” mowed the lawn naked at night during sleep.

In all of these cases, the sleep-walker was unable to remember anything about their nocturnal activities. Many of these cases prove that somnabulism is of medicolegal importance.


  • Around 17% of children and 4% adults
  • More frequently seen in boys
  • Rare in old age

Risk factors:

  • Sleep deprivation and Obstructive sleep apnea
  • Sleeping pills like Ambien especially when taken with alcohol
  • History of confusional arousals in children
  • Adults awakened for a brief period of time from sleep but unable to recollect anything in the morning have higher tendency to sleep-walk.
  • History of sleep-walking in family.
  • Other parasomnias like night terrors and bed wetting.
  • Adverse effects of neuro-medications like chlorpromazine, lithium, etc.
  • Disorders like schizophrenia, anxiety, parkinsonism, alzheimer’s disease, etc.
  • Travel or unfamiliar surroundings
  • Stress
  • High fever, Migraine headaches
  • Head injuries or stroke

Possible harmful effects:

Being in a sleepwalking state in itself doesn’t harm but the danger lies in the possible activities during the episode:

  1. Injury to self or others
  2. Disruption of other’s sleep

Precautions, Prevention and Treatment:


  1. Not to permit persons inclined toward sleep-walking to sleep alone without being watched over.
  2. Locate sleep-walker’s bedroom on the main floor and lock the windows.
  3. Keep the floor clear of sharps and other harmful objects.


  1. Setting a regular sleep schedule
  2. Reducing stress
  3. Minimizing sleep disturbing factors like noise as they can trigger episode
  4. Avoiding drugs and their combination with alcohol


  1. Treatment is not necessary except when the sleep-walkers have tendency to harm themselves or others.
  2. Diagnosing underlying cause like seizures, stress, anxiety, etc. and treat them
  3. Using antidepressants or benzodiazepine sleeping pills to limit episodes and promote sleep


  1. August 22, 2013
    • August 25, 2013
  2. February 28, 2015

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