The general objective of the comaScore project is to provide an external validation of the accuracy of the comaScore, a score derived from magnetic resonance imaging (MRI), to predict 1 year outcome of patients unresponsive to simple orders after traumatic brain injury (TBI), aneurysmal subarachnoid hemorrhages (aSAH) and cardiac arrest (CA) in the day 7 - day 45 period post brain injury.

The general objective of the comaScore project is to provide an external validation of the accuracy of the comaScore, a score derived from magnetic resonance imaging (MRI), to predict 1 year outcome of patients unresponsive to simple orders after traumatic brain injury (TBI), aneurysmal subarachnoid hemorrhages (aSAH) and cardiac arrest (CA) in the day 7 - day 45 period post brain injury. As recent studies reported late awakeners cases, even in cardiac arrest and, in contrary, that around 10% of patients with acute brain injury remain with permanent disorders of consciousness (DOC), the need of reliable prognosis tool at the early phase, while the patient is still in the ICU, is critical. ComaScore, based on the quantitative analysis of diffusion tensor imaging, was developed from a derivation cohort of 506 patients. It is much more performing than existing tools (IMPACT, OHCA) in this respect.

This study aims to prospectively validate the predictive accuracy of comaScore to predict unfavorable outcome at 1-year after the first insult, in an independent sample (external validation). Unfavorable outcome is defined as a Glascow Outcome Scale Extended (GOSE) of 1 to 3. This scale ranges from 1 to 8. Scores of 1 to 3 correspond to death, vegetative state, minimally conscious state or bedridden.

Patient Inclusion criteria

1. Male or female subject of 18 years old or above
2. Affiliated to a social security system excluding "Aide Médicale d'État (AME)"
3. Hospitalized in an intensive care unit and requiring mechanical ventilation after TBI, aSAH or CA
4. Absence of response to simple orders not explained by sedation alone at inclusion
5. Patient within 7 to 45 days after onset of TBI, aSAH or CA
6. Scheduled MRI within 5 days after inclusion
7. Written informed consent to participate in the study must be obtained proxy/legal representative.

Patient non-inclusion criteria

1. MRI unavailability between day 7 and day 45 after brain injury
2. Origin of coma other than CA, TBI or aSAH
3. Pre-existing serious brain disease prior to coma status
4. Contra-indication to perform MRI
5. Subject protected by the law (curatorship or tutorship)

Patient secondary exclusion criteria

1. Consciousness recovery before MRI exam
2. Contra-indication to perform MRI (appeared / discovered after inclusion)

Healthy controls Inclusion criteria

1. Male or female subject from 18 to 65 years
2. Affiliated to a social security system excluding "Aide Médicale d'État (AME)".
3. No history of previous brain disease
4. No contra-indication to perform an MRI.
5. No pregnancy
6. Voluntarily agrees to participate by providing written informed consent

Healthy controls Non-Inclusion criteria

1. Subject protected by the law (curatorship or tutorship)"