title: Thalamic resting-state functional networks: disruption in patients with mild traumatic brain injury.
abstract: OBJECTIVE
  To explore the neural correlates of the thalamus by using resting-state functional magnetic resonance (MR) imaging and to investigate whether thalamic resting-state networks (RSNs) are disrupted in patients with mild traumatic brain injury (MTBI).
  
  
  METHODS
  This HIPAA-compliant study was approved by the institutional review board, and written informed consent was obtained from 24 patients with MTBI and 17 healthy control subjects. The patients had varying degrees of symptoms, with a mean disease duration of 22 days. The resting-state functional MR imaging data were analyzed by using a standard seed-based whole-brain correlation method to characterize thalamic RSNs. Student t tests were used to perform comparisons. The association between thalamic RSNs and performance on neuropsychologic and neurobehavioral measures was also investigated in patients with MTBI by using Spearman rank correlation.
  
  
  RESULTS
  A normal pattern of thalamic RSNs was demonstrated in healthy subjects. This pattern was characterized as representing relatively symmetric and restrictive functional thalamocortical connectivity, suggesting an inhibitory property of the thalamic neurons during the resting state. This pattern was disrupted, with significantly increased thalamic RSNs (P ≤ .005) and decreased symmetry (P = .03) in patients with MTBI compared with healthy control subjects. Increased functional thalamocortical redistributive connectivity was correlated with diminished neurocognitive functions and clinical symptoms in patients with MTBI.
  
  
  CONCLUSIONS
  These findings of abnormal thalamic RSNs lend further support to the presumed subtle thalamic injury in patients with MTBI. Resting-state functional MR imaging can be used as an additional imaging modality for detection of thalamocortical connectivity abnormalities and for better understanding of the complex persistent postconcussive syndrome.
authors.affiliation: Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, 660 First Ave, 4th Floor, New York, NY 10016, USA.
authors.forename: Lin
authors.initials: L
authors.lastname: Tang
authors.forename: Yulin
authors.initials: Y
authors.lastname: Ge
authors.forename: Daniel K
authors.initials: DK
authors.lastname: Sodickson
authors.forename: Laura
authors.initials: L
authors.lastname: Miles
authors.forename: Yongxia
authors.initials: Y
authors.lastname: Zhou
authors.forename: Joseph
authors.initials: J
authors.lastname: Reaume
authors.forename: Robert I
authors.initials: RI
authors.lastname: Grossman
mesh_terms: D000328:Adult; D001930:Brain Injuries / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009415:Nerve Net / Q000503:physiopathology*; D013788:Thalamus / Q000503:physiopathology*