by Dr Peter Bladin MD, FRACP, FRCP, FRACP (Edin.) Professor Assoc. Faculty of Health Sciences, University of Melbourne, previously Director of Neurology, Austin Hospital, Heidelberg, Melbourne.


Although, strictly speaking, this heading includes all events accompanying sleep, generally only such conditions as sleep-walking, sleep-talking, sleep-automatisms, sleep-terrors, confusional arousals, nightmares, head-banging, teeth-grinding, periodic movements of sleep and also the phenomena of REM sleep behaviour are subsumed under this heading.

Automatic Behaviour

Generally this phenomenon occurs with episodes of microsleeps and is generally seen in daytime hypersomnolence. But it can be encountered in night-time sleep, along with hallucinations in a half-waking-half-sleeping/dreaming state. It is essentially the same as the daytime phenomenon. It is generally the product of broken disturbed sleep from whatever cause - with the arousal events occurring many times per night so that no real quota of restful sleep is available to the sufferer.

The patient - and certainly avoid confrontational restraint. In such cases, struggling and fighting can result in harm to all parties concerned. Traditionally the presence or absence of events occurring during an episode has been used for diagnostic purposes - this is not a sound policy, for islands of memory can be retained by the sleep-walker when questioned the next day.

Sleep Talking

For the most part, sleep-talking takes in the very early stages of non-REM sleep, but, very occasionally, it has been in REM sleep. All degrees of complexity and coherence can be found in the episodes of sleep talking, but generally there is no rational response to conversation from the outside awake observer. For the most part, sleep-talking without any other problem is commonly seen and is of no sinister clinical significance.

Sleep Walking (Somnambulism)

This is common in children, but can also be found in adults. In this latter instance the phenomenon can pose a problem - it often causes considerable inconvenience in communal living quarters and similar situations. And on rare occasions, and in special situations, sleep-walking can present very considerable difficulties, e.g., naval shipboard-life can present great risks for the sleep walker. In addition, violent automatisms occasioning injury to bystanders sometimes occur, resulting in medico-legal activity - but this is celebrated in single case reports rather than in any volume.

Mostly sleep-walking is seen in the earlier years of life and it arises out of non-REM sleep and in the earlier reaches of the night. Purposeless and poorly performed motor patterns typify such events, and for the most part the sleep-walker does not communicate in any detail with the bystander or observer; most often the walker can be replace in bed by judicious management. Sometimes complications, such as falls or stumbles, pose a danger for the walker, and outside help can help the walker to avoid these. Recollection of such nocturnal events on the following morning is fragmentary and undetailed.

The diagnosis of somnambulism is mostly self-evident. On occasions distinction from nocturnal epileptic attacks can be difficult, but the advent of long-term video-EEG monitoring has given us a great deal of insight into the problem - the content of both the video-tape and the EEG record most often leave no doubt as to diagnosis. Indeed, the use of this form of investigation has opened up many new avenues of diagnosis and research in sleep medicine.

Sleep Terrors (Paver Nocturnus)

This is also a phenomenon of non-REM sleep. Usually seen in younger age groups, it is a condition which is usually easily recognised, and it is often encountered in families from generation to generation. Just occasionally, diagnosis is rendered difficult by some exotic addition to the usual clinical picture - e.g. involuntary urination or defaecation, when the diagnosis of epilepsy is considered. If in doubt, nocturnal video monitoring often gives the solution to such cases.

For the most part, however, such episodes are typified by very obvious fear, and even white-faced, wide-eyed terror on the part of the sleeper, with obvious lack of contact with outside events and observers. Stereotypical behaviour patterns are seen and indicators of the underlying fear are all too obvious: screaming, or confused chatter, rapid hear-beat, sweating, etc. Such episodes are sometimes associated with sleep-walking.

As in sleep-walking, the bystander should interfere as little as possible with the affected person.

Aetiology and Management

Most such phenomena fade with age and maturation, and the progenisis is therefore usually splendid. Watchful expectancy is usually employed unless complications arise.

Mention must be made of the use of psychological findings underpinning aetiological diagnosis in clinical management of both adult and childhood sleep-walkers with or without obvious sleep-terrors. There seems to be no doubt that some patients do give a history of psychological trauma, but others do not, and the actual aetiological and therapeutic role of psychology is as yet uncertain. Its use has vehement supporters of course, but actual scientific evidence of the proportion of cases with demonstrable curative efficacy is as yet uncertain.

There is also no doubt that all such sleep phenomena can be due to intercurrent causes - drugs, fevers etc., and these should be sought and eliminated if thought significant.

Differential diagnosis from other night-time events, such as epileptic seizures, heart and lung ailments, and other entities affecting the brain, depends, of course, upon the entity suspected - and all this is the field of specialist-in-charge and often demands special technology to clarify the situation.

Management of people with sleep-walking and allied disorders is, for the most part, commonsense management of the actual episodes, support and reassurance after the attack; and, in older age groups, the use for limited periods of some of the benzodiazepines is effective, at least in the short term..In this group of sufferers, detailed search for other elements such as an intercurrent medical condition should be undertaken.

Over all, however, as in much of sleep medicine, there is still much progress to be made and this whole area constitutes an ongoing challenge to neuroscience.


In contradistinction to night-terrors, which arise from non-REM sleep, all dreams, including nightmares, arise from REM sleep. The interpretation and significance of dreams has been a field of contention from time immemorial and even now there are as many experts as there are theories.

With that in mind, it is not proposed to deal with this aspect any further. But a few important points can be made with regard to sleep medicine:


Recent work on frontal lobe epilepsy has shown some sleep phenomena are due to this cause and are not parasomnias. For diagnosis, it is sometimes necessary to have the patient submitted to long term video monitoring.


  1. Narcolepsy: Supplement to Journ. Neurology, 1998
  2. Poceta J.S. & Miller M.M.: Sleep Disorders - Diagnosis and Treatment
  3. Kryger M.H., Roth T . & Dement W.C.: Principles & Practice of Sleep Medicine; WB Saunders 1994
  4. Parkes J.D.: Sleep and its Disorders; WB Saunders 1985

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