title: Thalamic projection fiber integrity in de novo Parkinson disease.
abstract: OBJECTIVE
  Postmortem studies of advanced PD have revealed disease-related pathology in the thalamus with an apparent predilection for specific thalamic nuclei. In the present study, we used DTI to investigate in vivo the microstructural integrity of 6 thalamic regions in de novo patients with PD relative to healthy controls.
  
  
  METHODS
  Forty subjects (20 with early stage untreated PD and 20 age- and sex-matched controls) were studied with a high-resolution DTI protocol at 3T to investigate the integrity of thalamic nuclei projection fibers. Two blinded, independent raters drew ROIs in the following 6 thalamic regions: AN, VA, VL, DM, VPL/VPM, and PU. FA values were then calculated from the projection fibers in each region.
  
  
  RESULTS
  FA values were reduced significantly in the fibers projecting from the AN, VA, and DM, but not the VPL/VPM and PU, in the PD group compared with the control group. In addition, there was a reduction in FA values that approached significance in the VL of patients with PD. These findings were consistent across both raters.
  
  
  CONCLUSIONS
  The present study provides preliminary in vivo evidence of thalamic projection fiber degeneration in de novo PD and sheds light on the extent of disrupted thalamic circuitry as a result of the disease itself.
authors: Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida 32611, USA.
authors: P J
authors: PJ
authors: Planetta
authors: E T
authors: ET
authors: Schulze
authors: E K
authors: EK
authors: Geary
authors: D M
authors: DM
authors: Corcos
authors: J G
authors: JG
authors: Goldman
authors: D M
authors: DM
authors: Little
authors: D E
authors: DE
authors: Vaillancourt
mesh_terms: D056324:Diffusion Tensor Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009413:Nerve Fibers, Myelinated / Q000473:pathology*; D010300:Parkinson Disease / Q000473:pathology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013788:Thalamus / Q000473:pathology*