Abnormal cardiac [¹²³I]‐meta‐iodobenzylguanidine uptake in multiple system atrophy

Abstract

[(123)I]-Meta-iodobenzylguanidine (MIBG) myocardial scintigraphy is useful for distinguishing multiple system atrophy (MSA) from Parkinson disease. In this study, longitudinal observation using MIBG myocardial scintigraphy was carried out in patients with MSA to evaluate the association of myocardial MIBG uptake with clinical features. A total of 96 MIBG examinations were performed in 52 patients with MSA. The heart/mediastinum (H/M) ratio of MIBG uptake at 240 minutes after injection was below the lower limit in 16 patients with MSA (31.3%). Overall, the H/M ratio correlated with neither disease duration nor severity. In the follow-up observations, the H/M ratio did not show any specific trends, in contrast with the continuous decrease observed in patients with Parkinson's disease. This data clearly showed that cardiac MIBG uptake cannot necessarily be preserved in patients with MSA and that approximately 30% of patients with MSA showed decreased MIBG uptake without any correlation to disease duration or severity.

Autonomic involvement in Parkinson's disease: Pathology, pathophysiology, clinical features and possible peripheral biomarkers

“…It has been proposed that these cardiac imaging studies may help distinguish PD from MSA, where MIBG and 6-FDA scans are typically normal [73][74][75][76]. However, impaired MIBG uptake may also occur in some MSA cases with coexistent incidental Lewy body pathology [78]. This is consistent with findings that degeneration of cardiac sympathetic fibers may also occur in some MSA cases [21].…”

“…However impaired MIBG uptake may also occur in a number of MSA cases [78] and may be of limited value in patients who have coexistent subclinical cardiac autonomic neuropathy, as occurs with diabetes mellitus.…”

Role of 123I-Metaiodobenzylguanidine Myocardial Scintigraphy in Parkinsonian Disorders

“…Recent myocardial innervation imaging with 123 I-MIBG scintigraphy also demonstrated a high sensitivity for PD detection and adequate specificity for discriminating between PD and MSA (Köllensperger et al, 2007;Chung et al, 2009;Fröhlich et al, 2010). However, Nagayama et al (2010) recently suggested that MSA cannot consistently be distinguished from PD based on 123 I-MIBG myocardial scintigraphy. Their study clearly showed that cardiac MIBG uptake is not always preserved in patients with MSA and that approximately 30% of patients with MSA showed decreased MIBG uptake without any correlation to disease duration or severity.…”

Functional imaging of non-motor signs in Parkinson's disease

“…In multiple system atrophy (MSA) SPECT and 123 I-MIBG is usually considered as normal but recent studies have shown a [71][72][73]. This indicates that such tool cannot be reliably used for differential diagnosis in the clinical practice.…”