title: Odor Identification Test in Idiopathic REM-Behavior Disorder and Parkinson's Disease in China.
abstract: BACKGROUND
  Olfactory dysfunction is common in Parkinson's disease (PD) and idiopathic rapid eye movement sleep behavior disorder (iRBD), which is a risk factor in the development of PD. However, a few studies have conflicting results when comparing dysosmia in the patients with iRBD and PD. There is no study investigating the olfactory function in Chinese patients with iRBD. Additionally, the Sniffin' Sticks screening 12 test (SS-12) contains several odors that are not familiar to people in different cultures.
  
  
  METHODS
  Odor identification was evaluated in iRBD patients (n = 54), PD patients (n = 54) and healthy controls (n = 54). With the identification data, a brief odor identification test was established and then validated in other subjects.
  
  
  RESULTS
  Odor identification scores in iRBD patients were significantly higher than those in PD patients (P<0.001) but lower than those in controls (P<0.001). At the cut-off value of 7.5, the Sniffin' Sticks clearly differentiated iRBD and PD patients from the controls, and the brief test could increase the specificity in diagnosing PD. Neither the Sniffin' Sticks nor the brief test could clearly differentiate PD and iRBD patients from each other.
  
  
  CONCLUSIONS
  Olfaction is more impaired in PD patients than in iRBD patients, possibly due to the heterogeneity of iRBD patients. The Sniffin' Sticks could be a useful tool for differentiating iRBD patients from the healthy population, and it could be useful for screening people at high-risk of PD in China, especially when combined with polysomnography. To reduce the expense and time required for the Sniffin' Sticks test, this study shows that a brief test is feasible.
authors.affiliation: Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China.|Department of Neurology, Guangdong Neuroscience Institute, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong Province, China.
authors.forename: Si-Fei
authors.initials: SF
authors.lastname: Huang
authors.affiliation: Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China.
authors.forename: Kui
authors.initials: K
authors.lastname: Chen
authors.affiliation: Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China.
authors.forename: Jian-Jun
authors.initials: JJ
authors.lastname: Wu
authors.affiliation: Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China.
authors.forename: Feng-Tao
authors.initials: FT
authors.lastname: Liu
authors.affiliation: Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China.
authors.forename: Jue
authors.initials: J
authors.lastname: Zhao
authors.affiliation: Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Lin
authors.affiliation: Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China.
authors.forename: Si-Si
authors.initials: SS
authors.lastname: Guo
authors.affiliation: Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China.
authors.forename: Yi-Xuan
authors.initials: YX
authors.lastname: Wang
authors.affiliation: Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China.
authors.forename: Su-Shan
authors.initials: SS
authors.lastname: Luo
authors.affiliation: Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China.
authors.forename: Yi-Min
authors.initials: YM
authors.lastname: Sun
authors.affiliation: Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China.
authors.forename: Zheng-Tong
authors.initials: ZT
authors.lastname: Ding
authors.affiliation: Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China.|Sleep and Wake Disorders Center of Fudan University, Shanghai, China.
authors.forename: Huan
authors.initials: H
authors.lastname: Yu
authors.affiliation: Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Wang
mesh_terms: D000368:Aged; D016022:Case-Control Studies; D002681:China; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009812:Odorants / Q000032:analysis*; D010300:Parkinson Disease / Q000175:diagnosis* / Q000503:physiopathology; D017286:Polysomnography; D020187:REM Sleep Behavior Disorder / Q000175:diagnosis* / Q000503:physiopathology; D012684:Sensory Thresholds; D012903:Smell