Cardiac 131I-MIBG scintigraphy in patients with multiple system atrophy

Background 131 I-metaiodobenzylguanidine ( 131 I-MIBG) can be intaked by cardiac sympathetic postganglionic fibre, thus becomes the imaging agent to evaluate cardiac sympathetic nerve function. The aim of this study is to investigate the autonomic nerve dysfunction of patients with multiple system atrophy (MSA) by using cardiac  131 I-MIBG scintigraphy.  Methods Clinical data of 12 MSA patients conforming to the "secord consensus statement on the diagnosis of MSA" was analyzed by Unified Multiple System Atrophy Rating Scale (UMSARS).  131 I-MIBG scintigraphy was performed in 12 MSA patients and 7 age-matched controls. Planar images of the chest were obtained 15 min, 4 h and 24 h after the intravenous injection of 3 mCi 13 131 I-MIBG. Cardiac  131 I-MIBG uptake was quantified by comparing region of interest (ROI) over heart/mediastinum (H/M) ratio.  Results Cardiac 131 131 I-MIBG uptake ratio in MSA group was significantly less than that in control group in 15 min (1.90 ± 0.41 vs 2.38 ± 0.32, P = 0.017) and 4 h (1.96 ± 0.63 vs 2.60 ± 0.55, P = 0.039). There were significant difference ( P < 0.05) between MSA group and control group.  Conclusions Cardiac  131 I-MIBG uptake ratio in MSA group was less than that in control group. This finding suggests cardiac sympathetic degeneration may occur in MSA patients. doi: 10.3969/j.issn.1672-6731.2014.03.018