title: Reduced volume of the putamen in REM sleep behavior disorder patients.
abstract: OBJECTIVE
  The purpose of this study was to quantify volumes of specific subcortical gray matter nuclei implicated in Parkinson's disease (PD) as a preliminary step for identifying a non-invasive clinical biomarker for PD. We hypothesized that REM sleep behavior disorder (RBD) patients, at risk for developing PD, will demonstrate a pattern of neuronal degeneration reflected in reduced striatal volumes on T1-weighted MRI.
  
  
  METHODS
  We compared measures of RBD patients confirmed by polysomnography (PSG) with groups of age/gender-matched Control subjects and early PD (EPD) patients (Hoehn & Yahr < 2). Clinical measurements included the Unified Parkinson's disease Rating Scales (UPDRS), timed gait and finger tapping tasks, the Parkinson's Disease Questionnaire (PDQ-39), and a time-synchronized video recorded single-night PSG. Volumetric measurements were derived from high-resolution T1-weighted 3 T MRI images.
  
  
  RESULTS
  The matched Control and EPD groups were statistically similar to the RBD group in age, gender, handedness, and total brain volumes. The RBD group had smaller bilateral putamen volumes (both raw and normalized by brain tissue volume), in addition to some clinical impairment on the UPDRS and PDQ-39.
  
  
  CONCLUSIONS
  Reduced putamen volumes may be a structural marker for RBD and reflect a pattern of neurodegeneration that predicts the development of PD.
authors.affiliation: Department of Neurosurgery, University of Texas Houston Medical School, MSB 7.044, 6431 Fannin St., Houston, TX 77030, USA.
authors.forename: Timothy M
authors.initials: TM
authors.lastname: Ellmore
authors.forename: Ashley J
authors.initials: AJ
authors.lastname: Hood
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Castriotta
authors.forename: Erin F
authors.initials: EF
authors.lastname: Stimming
authors.forename: Roger J
authors.initials: RJ
authors.lastname: Bick
authors.forename: Mya C
authors.initials: MC
authors.lastname: Schiess
mesh_terms: D001921:Brain / Q000473:pathology; D002421:Caudate Nucleus / Q000473:pathology; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D016631:Lewy Bodies / Q000473:pathology; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000209:etiology / Q000503:physiopathology; D017286:Polysomnography; D011699:Putamen / Q000473:pathology*; D020187:REM Sleep Behavior Disorder / Q000175:diagnosis / Q000473:pathology*; D012306:Risk