title: Enlarged hyperechogenic substantia nigra as a risk marker for Parkinson's disease.
abstract: BACKGROUND
  SN hyperechogenicity (SN+), determined by transcranial sonography, has been proposed as a risk factor for Parkinson's disease (PD). Recently, we reported a 17.4-fold increased risk for PD in individuals with SN+ older than 50 years within 3 years.
  
  
  METHODS
  This is the second follow-up of a prospective, longitudinal, three-center observational study after 5 years. Of the initial 1,847 at baseline PD-free participants 50 years or older, 1,271 underwent the 5-year reassessment.
  
  
  RESULTS
  Within 5 years, 21 individuals developed incident PD. Participants with SN+ at baseline had a more than 20.6 times increased risk to develop PD in this time span than those without this echo feature.
  
  
  CONCLUSIONS
  We thus confirm our finding of the 3-year follow-up examination in a longer observation time and higher number of individuals with incident PD and suggest SN+ as an important risk marker for PD.
authors.affiliation: Center of Neurology, Department of Neurodegeneration and Hertie Institute for Clinical Brain Research, University of Tuebingen, Tuebingen, Germany. daniela.berg@uni-tuebingen.de
authors.forename: Daniela
authors.initials: D
authors.lastname: Berg
authors.forename: Stefanie
authors.initials: S
authors.lastname: Behnke
authors.forename: Klaus
authors.initials: K
authors.lastname: Seppi
authors.forename: Jana
authors.initials: J
authors.lastname: Godau
authors.forename: Stefanie
authors.initials: S
authors.lastname: Lerche
authors.forename: Philipp
authors.initials: P
authors.lastname: Mahlknecht
authors.forename: Inga
authors.initials: I
authors.lastname: Liepelt-Scarfone
authors.forename: Christoph
authors.initials: C
authors.lastname: Pausch
authors.forename: Niko
authors.initials: N
authors.lastname: Schneider
authors.forename: Alexandra
authors.initials: A
authors.lastname: Gaenslen
authors.forename: Kathrin
authors.initials: K
authors.lastname: Brockmann
authors.forename: Karin
authors.initials: K
authors.lastname: Srulijes
authors.forename: Heiko
authors.initials: H
authors.lastname: Huber
authors.forename: Isabel
authors.initials: I
authors.lastname: Wurster
authors.forename: Heike
authors.initials: H
authors.lastname: Stockner
authors.forename: Stefan
authors.initials: S
authors.lastname: Kiechl
authors.forename: Johann
authors.initials: J
authors.lastname: Willeit
authors.forename: Arno
authors.initials: A
authors.lastname: Gasperi
authors.forename: Klaus
authors.initials: K
authors.lastname: Fassbender
authors.forename: Thomas
authors.initials: T
authors.lastname: Gasser
authors.forename: Werner
authors.initials: W
authors.lastname: Poewe
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers; D015331:Cohort Studies; D003627:Data Interpretation, Statistical; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000000981:diagnostic imaging*; D011446:Prospective Studies; D018570:Risk Assessment; D013378:Substantia Nigra / Q000000981:diagnostic imaging*; D018615:Ultrasonography, Doppler, Color; D017585:Ultrasonography, Doppler, Transcranial
chemical_list: D015415:Biomarkers