title: Cardiac MIBG scintigraphy is a sensitive tool for detecting cardiac sympathetic denervation in Parkinson's disease.
abstract: [(123)I]Metaiodobenzylguanidine ([(123)I]MIBG) cardiac scintigraphy could be helpful to differentiate Parkinson's disease (PD) from multiple system atrophy (MSA), demonstrating that, in PD with autonomic failure but not in MSA, there is a myocardial postganglionic sympathetic dysfunction. To investigate whether this method is more sensitive than standard autonomic testing to detect early involvement of sympathetic cardiac efferent, we analyse MIBG myocardial uptake in 8 PD patients with normal autonomic testing (nondysautonomia PD group, NDPD) in comparison with 10 PD patients with abnormal autonomic testing (dysautonomia PD group, DPD) and 10 MSA patients. Global MIBG uptake was assessed using the ratio of [(123)I]MIBG uptake in the heart to the upper mediastinum (H/M) on planar scintigraphic data. Regional MIBG uptake was determined on two single photon emission tomography scans in regions of the left ventricle. The mean H/M ratios were significantly different among the three groups (P < 0.0001). H/M ratios of both NDPD and DPD patients groups (H/M = 1.83 +/- 0.50 and 1.24 +/- 0.40, respectively) were significantly lower than in MSA patients (H/M = 2.52 +/- 0.60). However, in NDPD patients, H/M was significantly higher than in DPD patients. When compared to MSA patients, NDPD patients showed a regional reduction in MIBG uptake in all left ventricle regions markedly in the apex and the inferior wall. Our results suggest that MIBG myocardial scintigraphy (analysis of both H/M ratio and regional MIBG uptake) may be more sensitive than standard autonomic testing for the early detection of silent autonomic dysfunction in PD.
authors.affiliation: Service de Médecine Nucléaire, University Rangueil Hospital, Toulouse, France. courbon.f@chu-toulouse.fr
authors.forename: Frédéric
authors.initials: F
authors.lastname: Courbon
authors.forename: Christine
authors.initials: C
authors.lastname: Brefel-Courbon
authors.forename: Claire
authors.initials: C
authors.lastname: Thalamas
authors.forename: Marie-Jeanne
authors.initials: MJ
authors.lastname: Alibelli
authors.forename: Isabelle
authors.initials: I
authors.lastname: Berry
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Montastruc
authors.forename: Olivier
authors.initials: O
authors.lastname: Rascol
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Senard
mesh_terms: D019797:3-Iodobenzylguanidine / Q000493:pharmacokinetics*; D000328:Adult; D000368:Aged; D001342:Autonomic Nervous System Diseases / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology*; D005260:Female; D005728:Ganglia, Sympathetic / Q000000981:diagnostic imaging* / Q000378:metabolism* / Q000503:physiopathology; D006321:Heart / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000378:metabolism*; D010300:Parkinson Disease / Q000150:complications*; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics*; D015899:Tomography, Emission-Computed, Single-Photon
chemical_list: D019275:Radiopharmaceuticals; D019797:3-Iodobenzylguanidine