title: Striatal Dopamine Depletion Patterns and Early Non-Motor Burden in Parkinsons Disease.
abstract: BACKGROUND
  The mechanism underlying non-motor symptoms in Parkinson's disease has not yet been elucidated. In this study, we hypothesized that Parkinson patients with more non-motor symptoms have a different pattern of striatal dopamine depletion, particularly in areas other than the sensorimotor striatum, compared to those with fewer non-motor symptoms.
  
  
  METHODS
  We conducted a prospective survey of the degree of non-motor symptoms (using the Korean version of the Non-Motor Symptoms Scale; K-NMSS) in 151 patients with early-stage Parkinson's disease who had undergone a dopamine transporter PET scan as an initial diagnostic procedure. We classified the patients into two groups; high non-motor patients (HNM-PD; K-NMSS score ≥ 41) and low non-motor patients (LNM-PD).
  
  
  RESULTS
  Patients in the HNM-PD group (n = 71) were older, had longer symptom duration, exhibited more severe motor deficits, and had been prescribed higher levodopa-equivalent doses at follow-up than those in the LNM-PD group. However, dopamine transporter binding to the striatal sub-regions and inter-sub-regional binding ratios were comparable between the two groups. A general linear model showed that the HNM-PD group had significantly more severe motor deficits than the LNM-PD group after controlling for age, gender, symptom duration, and dopamine transporter binding to the sensorimotor striatum.
  
  
  CONCLUSIONS
  This study demonstrated that the pattern of striatal dopamine depletion does not contribute to early non-motor burden in Parkinson's disease. Our results suggest that LNM-PD patients may have a more benign course of motor symptom progression than HNM-PD patients.
authors.affiliation: Department of Neurology, Yonsei University College of Medicine, Seoul, South Korea.
authors.forename: Su Jin
authors.identifier: http://orcid.org/0000-0002-9324-3284
authors.initials: SJ
authors.lastname: Chung
authors.affiliation: Department of Neurology, Yonsei University College of Medicine, Seoul, South Korea.|Department of Neurology, Inje University Ilsan Paik Hospital, Goyang, South Korea.
authors.forename: Jae Jung
authors.initials: JJ
authors.lastname: Lee
authors.affiliation: Department of Neurology, Yonsei University College of Medicine, Seoul, South Korea.
authors.forename: Jee Hyun
authors.initials: JH
authors.lastname: Ham
authors.affiliation: Department of Neurology, Yonsei University College of Medicine, Seoul, South Korea.
authors.forename: Byoung Seok
authors.initials: BS
authors.lastname: Ye
authors.affiliation: Department of Neurology, Yonsei University College of Medicine, Seoul, South Korea.|Severance Biomedical Science Institute, Yonsei University College of Medicine, Seoul, South Korea.
authors.forename: Phil Hyu
authors.initials: PH
authors.lastname: Lee
authors.affiliation: Department of Neurology, Yonsei University College of Medicine, Seoul, South Korea.
authors.forename: Young H
authors.initials: YH
authors.lastname: Sohn
mesh_terms: D000368:Aged; D018450:Disease Progression; D004298:Dopamine / Q000172:deficiency*; D050483:Dopamine Plasma Membrane Transport Proteins / Q000378:metabolism; D005260:Female; D006801:Humans; D008297:Male; D009043:Motor Activity; D017072:Neostriatum / Q000378:metabolism*; D010300:Parkinson Disease / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000503:physiopathology; D000072078:Positron Emission Tomography Computed Tomography; D049268:Positron-Emission Tomography
chemical_list: D050483:Dopamine Plasma Membrane Transport Proteins; D004298:Dopamine