title: Longitudinal study of the substantia nigra in Parkinson disease: A high-field (1) H-MR spectroscopy imaging study.
abstract: BACKGROUND
  The value of biomarkers in early diagnosis and development of therapeutics in Parkinson's disease (PD) is well established.
  
  
  METHODS
  We used proton magnetic resonance spectroscopy in a prospective, longitudinal study of 23 patients with early PD, naïve to dopaminergic therapy, and six age-matched healthy controls to examine the temporal changes in metabolic profile of substantia nigra over a period of 3 months.
  
  
  RESULTS
  N-acetyl aspartate to creatine ratio at month 3 was compared with baseline values in the PD and control groups, as well as the side-to-side difference of the ratio at baseline. By month 3, n-acetyl aspartate to creatine ratio had decreased by 4.4% in patients with PD (P = 0.024), without a concomitant change in healthy controls. The side-to-side asymmetry was significantly higher in the PD group (16.7%) vs. healthy controls (1.6%, P = 0.0024).
  
  
  CONCLUSIONS
  Estimation of change in the n-acetyl aspartate to creatine ratio appears to be a fast, quantifiable, and reliable marker of dopaminergic neuronal viability in PD.
authors.affiliation: The Sastry Foundation Advanced Imaging Laboratory, Department of Neurology, Wayne State University School of Medicine, Detroit, MI, USA.|Movement Disorders Program, Department of Neurology, Wayne State University School of Medicine, Detroit, MI, USA.
authors.forename: Navid
authors.initials: N
authors.lastname: Seraji-Bozorgzad
authors.affiliation: The Sastry Foundation Advanced Imaging Laboratory, Department of Neurology, Wayne State University School of Medicine, Detroit, MI, USA.|Movement Disorders Program, Department of Neurology, Wayne State University School of Medicine, Detroit, MI, USA.
authors.forename: Fen
authors.initials: F
authors.lastname: Bao
authors.affiliation: The Sastry Foundation Advanced Imaging Laboratory, Department of Neurology, Wayne State University School of Medicine, Detroit, MI, USA.|Movement Disorders Program, Department of Neurology, Wayne State University School of Medicine, Detroit, MI, USA.
authors.forename: Edwin
authors.initials: E
authors.lastname: George
authors.affiliation: Department of Neurology, Henry Ford Hospital, Detroit, MI, USA.
authors.forename: Shana
authors.initials: S
authors.lastname: Krstevska
authors.affiliation: Movement Disorders Program, Department of Neurology, Wayne State University School of Medicine, Detroit, MI, USA.
authors.forename: Veronica
authors.initials: V
authors.lastname: Gorden
authors.affiliation: The Sastry Foundation Advanced Imaging Laboratory, Department of Neurology, Wayne State University School of Medicine, Detroit, MI, USA.|Movement Disorders Program, Department of Neurology, Wayne State University School of Medicine, Detroit, MI, USA.
authors.forename: Jessica
authors.initials: J
authors.lastname: Chorostecki
authors.affiliation: Movement Disorders Program, Department of Neurology, Wayne State University School of Medicine, Detroit, MI, USA.
authors.forename: Carla
authors.initials: C
authors.lastname: Santiago
authors.affiliation: Department of Radiology, Wayne State University School of Medicine, Detroit, MI, USA.
authors.forename: Imad
authors.initials: I
authors.lastname: Zak
authors.affiliation: Movement Disorders Program, Department of Neurology, Wayne State University School of Medicine, Detroit, MI, USA.
authors.forename: Christina
authors.initials: C
authors.lastname: Caon
authors.affiliation: The Sastry Foundation Advanced Imaging Laboratory, Department of Neurology, Wayne State University School of Medicine, Detroit, MI, USA.|Movement Disorders Program, Department of Neurology, Wayne State University School of Medicine, Detroit, MI, USA.
authors.forename: Omar
authors.initials: O
authors.lastname: Khan
mesh_terms: D000368:Aged; D001224:Aspartic Acid / Q000031:analogs & derivatives* / Q000378:metabolism; D015415:Biomarkers / Q000378:metabolism; D003401:Creatine / Q000378:metabolism*; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000378:metabolism*; D066244:Proton Magnetic Resonance Spectroscopy / Q000379:methods*; D013378:Substantia Nigra / Q000378:metabolism*
chemical_list: D015415:Biomarkers; D001224:Aspartic Acid; C000179:N-acetylaspartate; D003401:Creatine
keywords: Magnetic resonance spectroscopy imaging; Parkinson's disease; biomarkers; n-acetyl aspartate; substantia nigra