Iodine-123-meta-iodobenzylguanidine Myocardial Scintigraphy in Isolated Autonomic Failure: Potential Red Flag for Future Multiple System Atrophy

Pure autonomic failure is challenging as it can be the presenting feature of a central nervous system syncleinopathy such as Parkinson's disease (PD) or multiple system atrophy (MSA). Because the prognosis of MSA and PD is so different, predictive features for a possible conversion can be extremely valuable. In this paper, we report three cases (two with autopsy proven diagnosis) that had isolated AF for many years before converting to MSA or PD. Of all the tests that were performed during the premotor stage, Iodine-123-meta-iodobenzylguanidine (MIBG) myocardial scintigraphy was predictive of the conversion to MSA. We suggest that MIBG myocardial scintigraphy, when performed in patients with isolated AF, may be a valuable predictor of conversion to MSA. On the contrary, the role of such test in parkinsonian patients irrespective of the presence of AF is still to be clarified.