Tertiary lesions responsible of the neurological decline after severe traumatic brain injury (TBI) are partially due to a persistent neuro-inflammation directly modulated by inflammatory mediators during the acute phase and detectable by using both multimodal MRI imaging and biological biomarkers during the acute phase after traumatic brain injury.

The main objective is to identify if the level of IL-1beta in cerebrospinal fluid predict in a reliable and reproducible way, the neuro-radiological evolution evaluated by the comparison of a quantitative MRI performed in post-resuscitation and at one year (quantitative ΔIRM) in traumatic brain injuried patients.

The secondary objectives are:

• To understand the links between the acute and chronic neuro-inflammatory phase in a population of TBI,
• To explore the contribution of the adaptive immune response in the persistent activation of the immune response,
• To Examine the links between persistent neuroinflammation, clinical deterioration and neuroimaging,
• To establish a correlation between the pathology and the physio-pathology of TBI.

Inclusion Criteria:

1. patient ≥ 18 years old at the time of inclusion
2. Written and informed consent obtained from the family / proxy
3. Patient hospitalized in neuro-ICU following severe TBI with GCS ≤ 8 at admission
4. Intubated / ventilated patient scheduled for external ventricular bypass within 24 hours of hospitalization
5. Absence of contraindications to perform an MRI
6. Patient affiliated to a social security scheme (free State medical aid excluded)

Exclusion Criteria:

1. Patient under protection of the law (guardianship or tutorship)
2. TBI of ballistic origin
3. Pregnant woman
4. Pre-existing cerebral disease that can bias the MRI scan evaluation
5. Contraindications to the MRI (pace maker, medical device incompatible with MRI, metal plates, ...)
6. Patient with severe impairment of vital and / or life-threatening function with disability prior TBI
7. Neurological antecedent susceptible to interfere with clinical evolution at one year
8. Severe cardiogenic shock
9. Severe respiratory impairment
10. Extra-brain injuries involving immediate life-threatening
11. Hemoglobin level below 9g / dL