Patients In A Minimally Conscious State Remained Capable Of Dreaming During Their Sleep

The question of have a zizz in patients with seriously altered states of consciousness has rarely been premeditated. Do ‘vegetative’ patients (now also called patients in a state of unresponsive wakefulness) or minimally aware state patients experience normal sleep?

Up until now the distinction between the two untiring populations had not been taken into account by electrophysiological studies. Yet if the vegetative constitution opens no conscious door onto the external world, the state of slightest consciousness for its part assumes a residual consciousness of the environment, certainly fluctuating but tangible.

It is this reformation which has led a group of researchers at the Coma Science Group (University of Liège and CHU Liège) and the universities of Wisconsin and Milan to contrast the sleep of these two types of brain damaged patients. The results of their about are published this week in the journal Brain. They prove once again the necessity of an adapted and specific medical attention for each of these states.

The researchers’ work rested on a illustrative of 11 subjects (6 in a state of minimal consciousness and 5 in a vegetative ceremonial) and made use of high density (256 electrodes) electroencephalography (EEG). The end was to determine the structure of sleep within the two types of patient.

‘We worn as a marker of arousal the fact that the subject had his her eyes unequivocal and muscle tone, and as a marker of sleep the fact that the staunch had closed eyes and muscle inactivity,’ points out Dr Steven Laureys, the Steersman of the Coma Science Group. The high density EEG revealed that the percipience’s electrical activity differed very little between take and wake states in patients in a vegetative state.

On the other disseminate the sleep of patients in a minimally conscious state had characteristics altogether close to that of normal sleep in a health subject. They showed changes in “slack wave” activity in the front of the brain considered important for scholarship and neural plasticity (figure). It also appeared that these patients produced NREM  slow wave sleep and REM (rapid eye movement) siesta, which is the support for dream activity.

‘The aggregate thus indicates that they have access to dreaming,’ emphasises Steven Laureys. ‘As a sequel, we can legitimately suppose that they still have a form of consciousness of self in addendum to a certain consciousness of the external world.’ The study published in Capacity brings to light a relationship between the electrophysiology of sleep and the degree of consciousness in dreadfully brain damaged patients.

Thus, once validated, the method adapted to could constitute an additional tool to evaluate, in a routine clinical surroundings, the potential maintenance of a residual consciousness in these patients.