Objective: This study aimed to clarified the relationship between the degree of MIBG accumulation and clinical factors in patients with MSA.

Background: ¹²³I-MIBG myocardial scintigraphy　considered to be an effective tool for distinguishing Parkinson’s disease (PD) from parkinsonian syndromes including multiple system atrophy (MSA). However, previous studies have reported that a decrease in MIBG accumulation may occur in patients with MSA.

Method: We retrospectively collected data from patients who underwent MIBG myocardial scintigraphy and compared MIBG indices (the early and late heart to mediastinum [H/M] ratio, washout rate; WR) between subjects with MSA and PD. In addition, we evaluated the relationship between clinical characteristics such as clinical subtype and disease duration in patients with MSA. The subjects were 23 patients with multiple system atrophy (MSA) (69.5 ± 9.4 years old; mean ± SD, disease duration 30.4 ± 18.5 months) and PD 30 patients (72.6 ± 6.4 years old, disease duration 28.2 ± 24.9 months) .

Results: Results: 1. H / M ratios at early and late imaging were lower in PD patients than in MSA patients (p <0.001, respectively), and WR was higher in PD patients than in MSA patients (p <0.001, respectively). 2. H / M ratios of early and late images were lower in PD patients compared to MSA-P and MSA-C patients (all p <0.001) and were lower in MSA-P patients than MSA-C patients (p <0.05, respectively). PD patients had higher WR than the other two groups (p <0.05, p <0.001, respectively), and WR in MSA-P patients was higher as compared to MSA-C patients (p <0.005). In PD patients, H / M ratio at late imaging was lower than that at early imaging, whereas in MSA-P patients, H/M ratio was higher at late imaging than that at early imaging. 3. Six of 23 MSA cases (26%) had low H / M ratio at early imaging which was below the cut-off value of 2.2, all of which were MSA-P patients. 4. In 4 of 6 MSA-P cases (67%), MIBG myocardial scintigraphy was performed more than one. HM ratios of both early and late images did not decrease over time.

Conclusion: Conclusion: Unlike in PD, MSA patients almost normal cardiac sympathetic function. Whereas MSA-P patients showed a mild cardiac sympathetic dysfunction without any correlation to disease duration.

« Back to MDS Virtual Congress 2020

MDS Abstracts - https://www.mdsabstracts.org/abstract/the-relationship-between-mibg-myocardial-scintigraphy-and-clinical-factors-in-multiple-system-atrophy/