title: Deafferentation in thalamic and pontine areas in severe traumatic brain injury.
abstract: OBJECTIVE
  Severe traumatic brain injury (TBI) is characterized mainly by diffuse axonal injuries (DAI). The cortico-subcortical disconnections induced by such fiber disruption play a central role in consciousness recovery. We hypothesized that these cortico-subcortical deafferentations inferred from diffusion MRI data could differentiate between TBI patients with favorable or unfavorable (death, vegetative state, or minimally conscious state) outcome one year after injury.
  
  
  METHODS
  Cortico-subcortical fiber density maps were derived by using probabilistic tractography from diffusion tensor imaging data acquired in 24 severe TBI patients and 9 healthy controls. These maps were compared between patients and controls as well as between patients with favorable (FO) and unfavorable (UFO) 1-year outcome to identify the thalamo-cortical and ponto-thalamo-cortical pathways involved in the maintenance of consciousness.
  
  
  RESULTS
  Thalamo-cortical and ponto-thalamo-cortical fiber density was significantly lower in TBI patients than in healthy controls. Comparing FO and UFO TBI patients showed thalamo-cortical deafferentation associated with unfavorable outcome for projections from ventral posterior and intermediate thalamic nuclei to the associative frontal, sensorimotor and associative temporal cortices. Specific ponto-thalamic deafferentation in projections from the upper dorsal pons (including the reticular formation) was also associated with unfavorable outcome.
  
  
  CONCLUSIONS
  Fiber density of cortico-subcortical pathways as measured from diffusion MRI tractography is a relevant candidate biomarker for early prediction of one-year favorable outcome in severe TBI.
authors.affiliation: Inserm U1146, CNRS UMR7371, laboratoire d'imagerie biomédicale, Sorbonne universités, UPMC université Paris 06 UMCR2, CHU Pitié-Salpêtrière, 91, boulevard de l'hôpital, 75634 Paris, France; ParIMed Team, LRPE, USTHB, Algiers, Algeria.
authors.forename: M
authors.initials: M
authors.lastname: Laouchedi
authors.affiliation: AP-HP, Pitié-Salpêtrière Hospital, Department of Neuroradiology, Paris, France.
authors.forename: D
authors.initials: D
authors.lastname: Galanaud
authors.affiliation: CHRU de Lille, Department of Neuroradiology, Lille, France.
authors.forename: C
authors.initials: C
authors.lastname: Delmaire
authors.affiliation: Inserm and UPMC université Paris 06, UMR-S 975, CNRS, UMR 7225, centre de recherche de l'institut du cerveau et de la moelle épinière, Paris, France; Institut du cerveau et de la moelle épinière, centre de neuroimagerie de recherche, Paris, France.
authors.forename: S
authors.initials: S
authors.lastname: Fernandez-Vidal
authors.affiliation: Inserm U1146, CNRS UMR7371, laboratoire d'imagerie biomédicale, Sorbonne universités, UPMC université Paris 06 UMCR2, CHU Pitié-Salpêtrière, 91, boulevard de l'hôpital, 75634 Paris, France.
authors.forename: A
authors.initials: A
authors.lastname: Messé
authors.affiliation: Inserm U1146, CNRS UMR7371, laboratoire d'imagerie biomédicale, Sorbonne universités, UPMC université Paris 06 UMCR2, CHU Pitié-Salpêtrière, 91, boulevard de l'hôpital, 75634 Paris, France; MATRICE Project University Paris 1 Panthéon-Sorbonne, Paris, France.
authors.forename: S
authors.initials: S
authors.lastname: Mesmoudi
authors.affiliation: ParIMed Team, LRPE, USTHB, Algiers, Algeria.
authors.forename: F
authors.initials: F
authors.lastname: Oulebsir Boumghar
authors.affiliation: Inserm U1146, CNRS UMR7371, laboratoire d'imagerie biomédicale, Sorbonne universités, UPMC université Paris 06 UMCR2, CHU Pitié-Salpêtrière, 91, boulevard de l'hôpital, 75634 Paris, France.
authors.forename: M
authors.initials: M
authors.lastname: Pélégrini-Issac
authors.affiliation: Inserm U1146, CNRS UMR7371, laboratoire d'imagerie biomédicale, Sorbonne universités, UPMC université Paris 06 UMCR2, CHU Pitié-Salpêtrière, 91, boulevard de l'hôpital, 75634 Paris, France; AP-HP, Pitié-Salpêtrière Hospital, Surgical Neuro-Intensive Care Unit, Paris, France.
authors.forename: L
authors.initials: L
authors.lastname: Puybasset
authors.affiliation: Inserm U1146, CNRS UMR7371, laboratoire d'imagerie biomédicale, Sorbonne universités, UPMC université Paris 06 UMCR2, CHU Pitié-Salpêtrière, 91, boulevard de l'hôpital, 75634 Paris, France.
authors.forename: H
authors.initials: H
authors.lastname: Benali
authors.affiliation: Inserm U1146, CNRS UMR7371, laboratoire d'imagerie biomédicale, Sorbonne universités, UPMC université Paris 06 UMCR2, CHU Pitié-Salpêtrière, 91, boulevard de l'hôpital, 75634 Paris, France. Electronic address: Vincent.Perlbarg@imed.jussieu.fr.
authors.forename: V
authors.initials: V
authors.lastname: Perlbarg
mesh_terms: D000328:Adult; D020833:Diffuse Axonal Injury / Q000473:pathology*; D056324:Diffusion Tensor Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D008297:Male; D011149:Pons / Q000293:injuries* / Q000473:pathology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013788:Thalamus / Q000293:injuries* / Q000473:pathology*; D066127:White Matter / Q000293:injuries / Q000473:pathology
keywords: Diffusion MRI; Pons; Thalamus; Tractography; Traumatic brain injury