title: Light pigmentation phenotype is correlated with increased substantia nigra echogenicity.
abstract: OBJECTIVE
  This study was undertaken to address the question of whether pigmentation may be mechanistically linked with Parkinson's disease.
  
  
  METHODS
  In a cross-sectional, observational study, 116 healthy subjects received transcranial sonography of the substantia nigra. Pigmentation phenotype was assessed using the Fitzpatrick skin phototype classification, and five additional phenotypic pigmentation traits as well as a photographic method (Melanin index) in a subgroup of 46 subjects.
  
  
  RESULTS
  Lighter skin phototype was associated with larger echogenic substantia nigra area and increased prevalence of abnormally enlarged echogenic substantia nigra area. The strongest association of substantia nigra echogenicity and phenotypic pigmentation traits was found for hair color and facial tanning.
  
  
  CONCLUSIONS
  Findings suggest an increasing prevalence of structural abnormality of substantia nigra with decreasing darkness of skin and thus may provide additional evidence in favor of a pathogenic link of pigmentation and Parkinson's disease.
authors.affiliation: Department of Neurology, University of Leipzig, Leipzig, Germany.
authors.forename: Jost-Julian
authors.initials: JJ
authors.lastname: Rumpf
authors.affiliation: Department of Neurology, University of Leipzig, Leipzig, Germany.
authors.forename: Maria
authors.initials: M
authors.lastname: Schirmer
authors.affiliation: Department of Neurology, University of Leipzig, Leipzig, Germany.
authors.forename: Christopher
authors.initials: C
authors.lastname: Fricke
authors.affiliation: Department of Neurology, University of Leipzig, Leipzig, Germany.
authors.forename: David
authors.initials: D
authors.lastname: Weise
authors.affiliation: Department of Dermatology and Venereology, University of Leipzig, Leipzig, Germany.
authors.forename: Justinus Aspasios
authors.initials: JA
authors.lastname: Wagner
authors.affiliation: Department of Dermatology and Venereology, University of Leipzig, Leipzig, Germany.
authors.forename: Jan
authors.initials: J
authors.lastname: Simon
authors.affiliation: Department of Neurology, University of Leipzig, Leipzig, Germany.
authors.forename: Joseph
authors.initials: J
authors.lastname: Classen
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D010641:Phenotype; D010858:Pigmentation / Q000502:physiology*; D013378:Substantia Nigra / Q000000981:diagnostic imaging*; D017585:Ultrasonography, Doppler, Transcranial; D055815:Young Adult
keywords: Parkinson's disease; pigmentation; substantia nigra hyperechogenicity; transcranial sonography