Confusional arousals are classified as “partial awakenings in which the state of consciousness remains impaired for several minutes without any accompanying major behavioural disorders or severe autonomic responses”. Complete or partial amnesia of the episodes may be present. Signs and symptoms
Confusional arousals are accompanied by mental confusion and disorientation, relative lack of response to environmental stimuli, and difficulty of awakening the subject. Vocalisation accompanied with coherent speech is common. Patients may appear upset, and some of them become aggressive or agitated. As well as for children, attempting to awaken or console an adult patient may increase agitation. Confusional arousals can occur during or following an arousal of deep sleep (see slow-wave sleep) and upon an attempt of awakening the subject from sleep in the morning.In children, confusional arousals can often be reproduced artificially by awakening the child during deep sleep. However, it doesn’t have any clinical significance without deeper investigation. Children living an episode of confusional arousal typically sit up in bed, whimper, cry, moan, and may utter words like “no” or “go away”. They remain distressed and inconsolable despite all parental efforts. Paradoxically, parental efforts can rather increase agitation of the child. The onset of symptoms is usually within 2 and 3 hours of sleep onset (at the time of transition from slow-wave sleep to a lighter sleep stage) and those events can last from 10 to 30 minutes. Patients generally wake up without any recollection of the event. It is necessary to distinguish confusional arousals in adults from children.
Neurological symptomatology
Confusional arousals are associated with behavioural awakening with persistent slow-wave electroencephalographic activity (see slow-wave sleep) during Non-rapid eye movement sleep (NREM). It suggests that sensorimotor network is activated while non sensorimotor areas are still "asleep". The altered state of consciousness may be explained by a hypersynchronous delta activity (see delta wave) in network involving the frontoparietal cortices (suggesting to be "asleep"), and higher frequency activities in sensorimotor, orbitofrontal, and temporal lateral cortices (suggesting an "awakening"). Sleep-related violence and abnormal sexual behaviours
Confusional arousals have often been linked to sleep-related violence (self-injury or injury to the bed partner). The latter highlights important medical and legal issues when such behaviours are suspected and purported to have caused a criminal offense. The first documented case of homicide as a result of confusional arousal was reported in medieval times by the case of the Silesian woodcutter Bernard Schedmaizig. Sleep-related abnormal sexual behaviours (also called sexsomnia or sleep sex) are mainly classified as confusional arousals and more rarely associated to sleepwalking (also known as somnambulism). Even if sleep-related violence may occur during an episode of confusional arousal, it remains extremely rare and there are no specific predisposition to aggression during these episodes. Distinction between sleepwalking and night terrors
Violent behaviours in confusional arousals slightly differ from those in sleepwalking or night terrors. Above all, during an episode of confusional arousal the patient never leaves the bed unlike sleepwalking.