Fig. 1

Imaging findings. a A brain MRI performed at 77 years old revealed mild frontal lobe atrophy and mild right-dominant subdural hygroma. b A follow-up MRI performed at 79 years old showed increased subdural hygroma and atrophy in the midbrain tegmentum. c Cardiac ¹²³I-meta-iodobenzylguanidine scintigraphy showed decreased uptake in the delayed phase, suggesting mild sympathetic denervation. d Brain N-isopropyl-p-[¹²³I]iodoamphetamine scintigraphy showed hypoperfusion in the bilateral frontal, parietal, and occipital lobes but not the basal ganglia, thalamus, and cerebellum