Longitudinal Study of the Default-mode Network Connectivity in Brain Injured Patients Recovering From Coma

Study Overview
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Brief Summary
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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.

Official Title
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Analyse de l'activité cérébrale intrinsèque Pendant le Coma et Lors du Retour à la Conscience

Conditions
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Coma

Participation Criteria
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Eligibility Criteria
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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

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 75 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Coma patients<br> | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change of DMN resting state fMRI connectivity between 1 and 2 month after severe brain injury | To date, the functional significance of DMN resting state connectivity patterns remain unclear. We hypothesized that DMN connectivity strength would be related to the level of consciousness of non-communicative brain-damaged patients, as assessed by standardized behavioural scales (FOUR score, CRS-R). Furthermore, we expected that a disruption of functional connectivity in the DMN could predict brain-damaged patient's recovery. | VISIT1 = coma state (an expected average of 3 to 30 days after brain injury), VISIT2 = recovery phase (an expected average of 30 to 60 days). Finally, in case of full recovery during the recovery phase an additional assessment will be performed (VISIT1*) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Compare functional and structural DMN connectivity between 1 and 2 month after severe brain injury | Functional DMN connectivity will be investigated using probabilistic independent component analysis. Structural connectivity counterpart, will be assessed by diffusor tensor imaging and cortical thickness. | VISIT1 = coma state (an expected average of 3 to 30 days after brain injury), VISIT2 = recovery phase (an expected average of 30 to 60 days). Finally, in case of full recovery during the recovery phase an additional assessment will be performed (VISIT1*) | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Default-mode network, Difussion tensor imaging, Cortical thickness, Coma, Vegetative state, Minimally conscious state, Neural correlate of consciousness