Cardiac [¹²³I] metaiodobenzylguanidine scintigraphy for vascular Parkinsonism

The purpose of our study was to prospectively evaluate cardiac [¹²³I]metaiodobenzylguanidine (MIBG) uptake in patients with cerebrovascular disease (CVD) who develop clinical symptoms of vascular Parkinsonism (VP). A total of 19 consecutive patients who developed Parkinsonism during the course of their CVD were enrolled in the study; 15 age-matched subjects, and 29 patients with Parkinson's disease (PD) were also evaluated with cardiac MIBG uptake. MIBG uptake was assessed using the ratio of the heart to the upper mediastinum (H/M) according to planar scintigraphic data. The mean H/M ratio was significantly higher in patients with VP than in those with PD (2.28 ± 0.41 vs. 1.27 ± 0.13; P < 0.001). MIBG uptake did not differ between VP and controls (2.46 ± 0.33; P > 0.05). Our findings suggest that myocardial postganglionic sympathetic dysfunction found in PD is absent in most patients with VP. MIBG single photon emission computed tomography imaging may be useful to help distinguish between PD and VP patients in clinical practice.