title: The odor stick identification test for Japanese differentiates Parkinson's disease from multiple system atrophy and progressive supra nuclear palsy.
abstract: BACKGROUND
  Progressive supranuclear palsy (PSP) and parkinsonian variant of multiple system atrophy (MSA-P) are clinically difficult to differentiate from idiopathic Parkinson's disease (PD), particularly in the early stages of the disease. Previous reports indicated that the olfactory function is relatively intact or slightly reduced in patients with PSP and MSA-P, suggesting that the odor stick identification test for Japanese (OSIT-J), which is a short and simple noninvasive test that is potentially useful clinically for detecting early-stage PD in Japan, may be useful in the differential diagnosis of early-stage PD from MSA-P and PSP. There is no information on the sensitivity and specificity of OSIT-J in the diagnosis of parkinsonian syndromes such as PSP and MSA-P.
  
  
  METHODS
  We assessed the olfactory function using the OSIT-J test in 94 Japanese patients with idiopathic PD, 15 with MSA-P, 7 with PSP, and 29 age-matched control subjects.
  
  
  RESULTS
  The mean ± SD score of OSIT-J in patients with PD (4.4 ± 2.9) was significantly lower than in patients with MSA-P (8.7 ± 2.2, P < 0.0001), PSP (7.6 ± 2.2, P < 0.0057), and control subjects (10.5 ± 1.3, P < 0.0001). The area under the curve (AUC) of receiver operating characteristic (ROC) to discriminate PD from normal control using OSIT-J scores was 0.97 (95% confidence interval, 0.95-1.00), from MSA-P 0.87 (0.80-0.95), and from PSP 0.81 (0.66-0.96).
  
  
  CONCLUSIONS
  The OSIT-J is a potentially useful clinical test not only for detection of olfactory deficit in PD but also for differentiating PD from MSA-P and PSP.
authors.affiliation: Department of Neurology, Aoto Hospital, Jikei University School of Medicine, 6-41-2 Aoto Katsushika-ku, Tokyo 125-8506, Japan. suzukimd@jikei.ac.jp
authors.forename: Masahiko
authors.initials: M
authors.lastname: Suzuki
authors.forename: Masaya
authors.initials: M
authors.lastname: Hashimoto
authors.forename: Masayuki
authors.initials: M
authors.lastname: Yoshioka
authors.forename: Maiko
authors.initials: M
authors.lastname: Murakami
authors.forename: Keiichi
authors.initials: K
authors.lastname: Kawasaki
authors.forename: Mitsuyoshi
authors.initials: M
authors.lastname: Urashima
mesh_terms: D000368:Aged; D044466:Asian People; D003937:Diagnosis, Differential; D016002:Discriminant Analysis; D005260:Female; D006801:Humans; D008297:Male; D019578:Multiple System Atrophy / Q000175:diagnosis*; D009812:Odorants / Q000032:analysis; D000857:Olfaction Disorders / Q000175:diagnosis* / Q000208:ethnology* / Q000209:etiology; D010300:Parkinson Disease / Q000150:complications / Q000175:diagnosis*; D012372:ROC Curve; D012680:Sensitivity and Specificity; D013494:Supranuclear Palsy, Progressive / Q000175:diagnosis*