title: Different patterns of cardiac sympathetic denervation in tremor-type compared to akinetic-rigid-type Parkinson's disease: molecular imaging with ¹²³I-MIBG.
abstract: The aim of this study was to evaluate the correlation between the clinical motor phenotypes of Parkinson's disease (PD) and ¹²³I-MIBG myocardial uptake. In total, 53 patients with PD [31 males and 22 females, mean age 62±10 years; 19 Hoehn & Yahr (H&Y) stage 1, 9 stage 1.5, 15 stage 2 and 10 at stage 3] were examined and subdivided into different clinical forms on the basis of dominance of resting tremor (n=19, TDT) and bradykinesia plus rigidity (n=34, ART). This status was correlated with the semi-quantitative analysis of ¹²³I-MIBG myocardial uptake. An age-matched control group of 18 patients was recruited (8 males and 10 females, mean age 62.4±16.3 years). ¹²³I-MIBG myocardial uptake significantly correlated with disease duration in early (r²=0.1894; P=0.0028) and delayed images (r²=0.1795; P=0.0037) in PD patients, while no correlation was found when considering age at examination, UPDRS III motor examination section score and H&Y score. PD patients showed a reduced ¹²³I-MIBG myocardial uptake compared to the control group in early (P=0.0026) and delayed images (P=0.0040), and ¹²³I-MIBG myocardial uptake was significantly lower in delayed images in TDT patients compared with ART patients (P=0.0167). A decrease was detected in the heart-to-mediastinum (H/M) ratio in delayed images compared to that of the early images in TDT patients (P=0.0040) and in the whole PD population (P=0.0012), while no differences were found in ART patients (P=0.1043). The results of the present study revealed that the cardiac sympathetic system is more severely impaired in TDT than in ART patients and ¹²³I-MIBG molecular imaging has the potential help in improving therapeutic planning in these patients.
authors.affiliation: Department of Biopathology and Diagnostic Imaging, University                     Tor Vergata, Rome, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Chiaravalloti
authors.forename: A
authors.initials: A
authors.lastname: Stefani
authors.forename: M
authors.initials: M
authors.lastname: Tavolozza
authors.forename: M
authors.initials: M
authors.lastname: Pierantozzi
authors.forename: D
authors.initials: D
authors.lastname: Di Biagio
authors.forename: E
authors.initials: E
authors.lastname: Olivola
authors.forename: B
authors.initials: B
authors.lastname: Di Pietro
authors.forename: M
authors.initials: M
authors.lastname: Stampanoni
authors.forename: R
authors.initials: R
authors.lastname: Danieli
authors.forename: G
authors.initials: G
authors.lastname: Simonetti
authors.forename: P
authors.initials: P
authors.lastname: Stanzione
authors.forename: O
authors.initials: O
authors.lastname: Schillaci
mesh_terms: D019797:3-Iodobenzylguanidine / Q000737:chemistry; D000367:Age Factors; D000368:Aged; D005260:Female; D006321:Heart / Q000503:physiopathology; D006801:Humans; D018476:Hypokinesia / Q000473:pathology*; D007457:Iodine Radioisotopes / Q000737:chemistry; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000378:metabolism; D010300:Parkinson Disease / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000601:surgery; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals / Q000737:chemistry; D012720:Severity of Illness Index; D013562:Sympathectomy; D014202:Tremor / Q000473:pathology*
chemical_list: D007457:Iodine Radioisotopes; D019275:Radiopharmaceuticals; D019797:3-Iodobenzylguanidine