Several studies in healthy volunteers have suggested that the synchronized functional connectivity in the DMN (Deafult-Mode Network) would sustain the mental content at rest, and when required, a switch in the activity between the DMN and other networks involved in specific congnitive functions, would occur. This interaction permit to make the hypothesis, that baseline brain activity is likely to shape our ongoing " stream of consciousness " and could correlate with conscious perception. The investigators hypothesized that DMN connectivity strength would be related to the level of consciousness of brain-damaged patients. The investigators will follow severely brain-injured patient in coma. Clinical examination using standardized behavioural scales: FOUR score (Full Outline of UnResponsivess), Coma Recovery Scale-Revised); and brain imaging assessesments using MRI (functional and anatomical connectivity, cortical thickness) will be performed at: 3 to 30 (visit 1), and 60 (visit 2) days after insult. If patient recover a normal conscious state between 30 and 60 days, an additional clinical and brain imaging assessment will be performed to identify related changes in brain activity (visit 1*) Monitoring of vital parameters will be performed in patients by a senior anaesthesiologist throughout the experiment.

Inclusion Criteria:

• Brain-damaged patients in coma (trauma or anoxic origin).
• Male and female, ranging in age from 18 to 75 years.

Exclusion Criteria:

• Withdrawal of consent from the patients (or the persons having legal responsibility for them).
• Sedation or general anaesthesia during assessement period (< 24 hours).
• MRI contraindications

We will analyse DMN functional and anatomical connectivity in severely brain-injured patients in coma and during the first two month following brain injury. All patients will be admitted from one of the four Critical Care Units of University Teaching Hospital of Toulouse, France.