title: Onset-related subtypes of Parkinson's disease differ in the patterns of striatal dopaminergic dysfunction: A positron emission tomography study.
abstract: OBJECTIVE
  The young-onset subtype of Parkinson's disease (YOPD) differs from the late-onset subtype (LOPD) in drug responsiveness, incidence of motor complications, and prognosis. The pathophysiology underlying these differences remains largely unknown. This study investigated whether the two subtypes differ in the pattern of dysfunction in striatal (caudate and putamen) dopaminergic system and if the dopamine transporter (DAT) imaging patterns are associated with the clinical features of corresponding PD subtype.
  
  
  METHODS
  We assessed the spatial pattern of striatal dopaminergic dysfunction in 40 YOPD and 47 LOPD with early to mid-stage PD with DAT imaging by positron emission tomography. Two sub-regional parameters (caudate/putamen ratio and asymmetry index) were calculated to measure the spatial pattern of striatal dopaminergic dysfunction.
  
  
  RESULTS
  The caudate/anterior putamen ratios were significantly higher in YOPD than that in the LOPD (P = 0.03 contralateral to the most affected side of the body and P = 0.004 ipsilateral), which was supported by significantly inverse correlations between age of onset and caudate/anterior putamen ratios (r = -0.428, P < 0.001 for the contralateral and r = -0.576, P < 0.001 for the ipsilateral). Sub-regional DAT binding in caudate ipsilateral to affected limbs was significantly correlated with age, while DAT bindings in putamen were significantly inversely correlated with disease duration and UPDRS motor scores.
  
  
  CONCLUSIONS
  The YOPD subtype suffers from an uneven pattern of dopaminergic dysfunction: more sparing of the caudate compared with the putamen, while the LOPD patients is with a relatively uniform pattern.
authors.affiliation: Department of Neurology, Huashan Hospital, Fudan University, Shanghai 200040, China; Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing 100053, China.
authors.forename: Shu-Ying
authors.initials: SY
authors.lastname: Liu
authors.affiliation: Department of Neurology, Huashan Hospital, Fudan University, Shanghai 200040, China.
authors.forename: Jian-Jun
authors.initials: JJ
authors.lastname: Wu
authors.affiliation: Department of Neurology, Huashan Hospital, Fudan University, Shanghai 200040, China.
authors.forename: Jue
authors.initials: J
authors.lastname: Zhao
authors.affiliation: Department of Neurology, Huashan Hospital, Fudan University, Shanghai 200040, China.
authors.forename: Si-Fei
authors.initials: SF
authors.lastname: Huang
authors.affiliation: Department of Neurology, Huashan Hospital, Fudan University, Shanghai 200040, China.
authors.forename: Yi-Xuan
authors.initials: YX
authors.lastname: Wang
authors.affiliation: PET Center, Huashan Hospital, Fudan University, Shanghai 200235, China.
authors.forename: Jing-Jie
authors.initials: JJ
authors.lastname: Ge
authors.affiliation: PET Center, Huashan Hospital, Fudan University, Shanghai 200235, China.
authors.forename: Ping
authors.initials: P
authors.lastname: Wu
authors.affiliation: PET Center, Huashan Hospital, Fudan University, Shanghai 200235, China.
authors.forename: Chuan-Tao
authors.initials: CT
authors.lastname: Zuo
authors.affiliation: Department of Neurology, Huashan Hospital, Fudan University, Shanghai 200040, China. Electronic address: zhtding@hotmail.com.
authors.forename: Zheng-Tong
authors.initials: ZT
authors.lastname: Ding
authors.affiliation: Department of Neurology, Huashan Hospital, Fudan University, Shanghai 200040, China. Electronic address: wangjian336@hotmail.com.
authors.forename: Jian
authors.initials: J
authors.lastname: Wang
mesh_terms: D000328:Adult; D017668:Age of Onset; D000368:Aged; D002250:Carbon Radioisotopes / Q000032:analysis / Q000493:pharmacokinetics; D002421:Caudate Nucleus / Q000737:chemistry / Q000000981:diagnostic imaging* / Q000473:pathology; D003042:Cocaine / Q000031:analogs & derivatives / Q000032:analysis / Q000493:pharmacokinetics; D050483:Dopamine Plasma Membrane Transport Proteins / Q000032:analysis*; D059290:Dopaminergic Neurons / Q000737:chemistry / Q000000981:diagnostic imaging* / Q000473:pathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D059906:Neuroimaging / Q000379:methods*; D009928:Organ Specificity; D010300:Parkinson Disease / Q000145:classification / Q000000981:diagnostic imaging* / Q000473:pathology / Q000503:physiopathology; D049268:Positron-Emission Tomography; D011699:Putamen / Q000737:chemistry / Q000000981:diagnostic imaging* / Q000473:pathology; D019275:Radiopharmaceuticals / Q000032:analysis / Q000493:pharmacokinetics; D014018:Tissue Distribution
chemical_list: D002250:Carbon Radioisotopes; D050483:Dopamine Plasma Membrane Transport Proteins; D019275:Radiopharmaceuticals; C021279:(1R-(exo,exo))-3-(4-fluorophenyl)-8-methyl-8- azabicyclo(3.2.1)octane-2-carboxylic acid, methyl ester; D003042:Cocaine
keywords: Age of onset; Parkinson's disease; Subtype; [(11)C]-CFT PET