title: Cardiac sympathetic impairment parallels nigrostriatal degeneration in Probable Dementia with Lewy Bodies.
abstract: OBJECTIVE
  Dementia with Lewy Bodies (DLB) must be distinguished from other types of dementia because of important differences in patient management and outcome. Both reduction in cardiac 123I-metaiodobenzilguanidine (MIBG) uptake and decreased 123I-FP-CIT binding in basal ganglia have been described in DLB. The aim of this study was to assess the relationship between cardiac sympathetic activity and nigrostriatal degeneration in patients with probable DLB.
  
  
  METHODS
  Twenty-eight patients (15 males; mean age 77 years, range 64-88 years) with clinical international criteria of probable DLB were included in the study. All patients underwent a cardiac MIBG scintigraphy and a FP-CIT SPECT. Global cardiac MIBG uptake was semiquantified by means of heart-to-mediastinum ratio (HMR) (normal >1.56). FP-CIT binding in basal ganglia was calculated and compared with an age-matched control group. The relation between cardiac MIBG uptake and FP-CIT uptake in basal ganglia, and the relationship of these two techniques with distinctive symptoms of DLB, features of past medical history and data from the neuropsychological examination were assessed.
  
  
  RESULTS
  Cardiac MIBG uptake was decreased in 23 of 28 patients (HMR=1.32, range 0.95-1.85). The FP-CIT binding in basal ganglia was significantly lower than in control group (2.01±0.5 vs 2.62±0.2, P<0.05). All patients with reduced cardiac HMR showed decreased FP-CIT binding in basal ganglia. There was a positive correlation between the HMR and specific binding ratio of striatum (P<0.01). A high correlation between FP-CIT SPECT and the presence of parkinsonism also was found. No correlation between cardiac MIBG uptake and demographic, clinical or neuropsychological data was found.
  
  
  CONCLUSIONS
  In probable DLB cardiac MIBG uptake and FP-CIT binding in basal ganglia are reduced. The positive correlation between both measures suggests that cardiac sympathetic degeneration and nigrostriatal degeneration parallel similarly in patients with probable DLB.
authors.affiliation: Department of Nuclear Medicine, Autonomous University of Barcelona, Spain. mcamachom@santpau.cat
authors.forename: V
authors.initials: V
authors.lastname: Camacho
authors.forename: M
authors.initials: M
authors.lastname: Marquié
authors.forename: A
authors.initials: A
authors.lastname: Lleó
authors.forename: L
authors.initials: L
authors.lastname: Alvés
authors.forename: C
authors.initials: C
authors.lastname: Artigas
authors.forename: A
authors.initials: A
authors.lastname: Flotats
authors.forename: J
authors.initials: J
authors.lastname: Duch
authors.forename: R
authors.initials: R
authors.lastname: Blesa
authors.forename: T
authors.initials: T
authors.lastname: Gómez-Isla
authors.forename: I
authors.initials: I
authors.lastname: Carrió
authors.forename: M
authors.initials: M
authors.lastname: Estorch
mesh_terms: D019797:3-Iodobenzylguanidine / Q000493:pharmacokinetics; D000368:Aged; D000369:Aged, 80 and over; D001479:Basal Ganglia / Q000000981:diagnostic imaging / Q000378:metabolism; D005260:Female; D006331:Heart Diseases / Q000150:complications* / Q000000981:diagnostic imaging; D006801:Humans; D007457:Iodine Radioisotopes / Q000378:metabolism; D020961:Lewy Body Disease / Q000150:complications* / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D011877:Radionuclide Imaging / Q000379:methods; D019275:Radiopharmaceuticals; D012189:Retrospective Studies; D020955:Striatonigral Degeneration / Q000150:complications* / Q000000981:diagnostic imaging*; D013564:Sympathetic Nervous System / Q000293:injuries; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods; D014326:Tropanes / Q000378:metabolism*
chemical_list: D007457:Iodine Radioisotopes; D019275:Radiopharmaceuticals; D014326:Tropanes; C087552:2-carbomethoxy-8-(3-fluoropropyl)-3-(4-iodophenyl)tropane; D019797:3-Iodobenzylguanidine