MIBG Scintigraphy for Differentiating Parkinson's Disease with Autonomic Dysfunction from Parkinsonism-Predominant Multiple System Atrophy

Parkinson's disease (PD) with autonomic dysfunction is difficult to differentiate from Parkinonism-predominant multiple system atrophy (MSA-p). This study aimed to analyze the validity of MIBG scintigraphy for PD with autonomic dysfunction and MSA-p. Thirty-nine patients (PD: 27 patients, MSA-p type: 12) and 12 age-matched controls were prospectively enrolled and underwent MIBG scintigraphy and autonomic function test (AFT). We separately calculated early and delayed heart-to-mediastinal (HIM) ratio and washout rates (WRs). AFT was composed of sympathetic skin reflex and parasympathetic tests based on heart rate variability. Abnormal AFT was observed in 17 (63%) of PD and 10 (83%) of MSA-p. On comparing PD with abnormal AFT with MSA-p, either the early or delayed HIM ratio in PD was not different from that in MSA-p (P > 0.05). Only the WR could differentiate PD with abnormal AFT from MSA-p (47.07 +/- 57.48 vs. 31.39 +/- 31.52, respectively) (P = 0.026). According to the results. WR may be more useful than the early and delayed HI M ratio to distinguish MSA-p from PD with abnormal AFT. Furthermore, the MlBG uptake did not reflect the disease duration or severity. (C) 2009 Movement Disorder Society