title: Retrospective analysis of parkinsonian patients exhibiting normal (123)I-MIBG cardiac uptake.
abstract: BACKGROUND
  Although most patients with Parkinson's disease (PD) show decreased cardiac (123)I-metaiodobenzylguanidine (MIBG) uptake, some exhibit normal uptake. We evaluated the clinical characteristics of such patients.
  
  
  METHODS
  We enrolled 154 non-demented patients showing parkinsonism with normal cardiac MIBG uptake and had been clinically followed up during 29.9 ± 27.6 months. We defined the patients who did not fit the exclusion criteria for PD and demonstrated ≥ 30% reduction in the Unified Parkinson's Disease Rating Scale (UPDRS) motor score after anti-Parkinson agent administration as probable PD. We compared clinical characteristics and the cardiac MIBG heart-to-mediastinum (H/M) ratio between the probable PD group (N=37) and other groups (N=117).
  
  
  RESULTS
  The probable PD group showed significantly higher UPDRS motor scores and greater incidence of tremor/rigidity than those of other groups. In addition, they showed a significantly lower cardiac MIBG H/M ratio in the delayed phase (delayed, p<0.0001). Washout-rate (WR) was significantly higher in probable PD cases (p<0.0001). Among 16 probable PD patients undergoing serial cardiac MIBG scintigraphy, the delayed phase cardiac MIBG H/M ratio showed a significant decrease and WR significantly increased during follow-up periods.
  
  
  CONCLUSIONS
  An increase in WR and lower delayed phase cardiac MIBG uptake were found to be characteristics of such patients.
authors.affiliation: Department of Neurology, Fujita Health University School of Medicine, Toyoake, Aichi 470-1192, Japan.
authors.forename: Yasuaki
authors.initials: Y
authors.lastname: Mizutani
authors.affiliation: Department of Neurology, Fujita Health University School of Medicine, Toyoake, Aichi 470-1192, Japan.
authors.forename: Shinji
authors.initials: S
authors.lastname: Ito
authors.affiliation: Department of Neurology, Fujita Health University School of Medicine, Toyoake, Aichi 470-1192, Japan.
authors.forename: Kenichiro
authors.initials: K
authors.lastname: Murate
authors.affiliation: Department of Neurology, Fujita Health University School of Medicine, Toyoake, Aichi 470-1192, Japan.
authors.forename: Seiko
authors.initials: S
authors.lastname: Hirota
authors.affiliation: Department of Neurology, Fujita Health University School of Medicine, Toyoake, Aichi 470-1192, Japan.
authors.forename: Takao
authors.initials: T
authors.lastname: Fukui
authors.affiliation: Department of Neurology, Fujita Health University School of Medicine, Toyoake, Aichi 470-1192, Japan.
authors.forename: Chika
authors.initials: C
authors.lastname: Hikichi
authors.affiliation: Department of Neurology, Fujita Health University School of Medicine, Toyoake, Aichi 470-1192, Japan.
authors.forename: Tomomasa
authors.initials: T
authors.lastname: Ishikawa
authors.affiliation: Department of Neurology, Fujita Health University School of Medicine, Toyoake, Aichi 470-1192, Japan.
authors.forename: Sayuri
authors.initials: S
authors.lastname: Shima
authors.affiliation: Department of Neurology, Fujita Health University School of Medicine, Toyoake, Aichi 470-1192, Japan.
authors.forename: Akihiro
authors.initials: A
authors.lastname: Ueda
authors.affiliation: Department of Neurology, Fujita Health University School of Medicine, Toyoake, Aichi 470-1192, Japan.
authors.forename: Madoka
authors.initials: M
authors.lastname: Kizawa
authors.affiliation: Department of Neurology, Fujita Health University School of Medicine, Toyoake, Aichi 470-1192, Japan.
authors.forename: Kunihiko
authors.initials: K
authors.lastname: Asakura
authors.affiliation: Department of Neurology, Fujita Health University School of Medicine, Toyoake, Aichi 470-1192, Japan. Electronic address: tmutoh@fujita-hu.ac.jp.
authors.forename: Tatsuro
authors.initials: T
authors.lastname: Mutoh
mesh_terms: D019797:3-Iodobenzylguanidine / Q000493:pharmacokinetics*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004791:Enzyme Inhibitors / Q000493:pharmacokinetics*; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging / Q000187:drug effects*; D006801:Humans; D007457:Iodine Radioisotopes / Q000493:pharmacokinetics; D008297:Male; D008875:Middle Aged; D020734:Parkinsonian Disorders / Q000000981:diagnostic imaging* / Q000503:physiopathology; D012372:ROC Curve; D011877:Radionuclide Imaging; D012189:Retrospective Studies; D012720:Severity of Illness Index
chemical_list: D004791:Enzyme Inhibitors; D007457:Iodine Radioisotopes; D019797:3-Iodobenzylguanidine
keywords: Cardiac (123)I-metaiodobenzylguanidine scintigraphy ((123)I-MIBG); Cardiovascular dysautonomia; Cut-off value; Parkinson's disease; Parkinsonian syndrome; Receiver operator characteristic (ROC) curve; Washout-rate