A scintigraphical qualitative analysis of peripheral vascular sympathetic function with meta-[123I]iodobenzylguanidine in neurological patients with autonomic failure.

In order to assess qualitatively the sympathetic functions of the peripheral vessels, we performed a scintigraphical study of the entire body with meta-[123I]iodobenzylguanidine (MIBG) in 13 patients with autonomic failure and 11 healthy subjects as control. The patients comprised seven with multiple system atrophy (MSA), two with pure autonomic failure (PAF), three with Parkinson's disease with autonomic failure (PD with AF) and one with familial amyloid polyneuropathy (FAP). No clinical evidence of vascular disease was noted in any of the patients and the control subjects. We investigated their autonomic functions using the head up tilt test as well as norepinephrine and isoproterenol infusion tests. We found that: (i) All of the control subjects showed satisfactory MIBG uptake; (ii) all of the patients with PAF and FAP, most of whom had postganglionic sympathetic lesions, showed supersensitivity and low MIBG uptake; (iii) almost all the patients with MSA, who were considered to have mainly preganglionic sympathetic lesions, showed supersensitivity and diminished MIBG uptake, although the patients with olivopontocerebellar atrophy showed supersensitivity but not diminished MIBG uptake. In conclusion, these results suggest that peripheral vascular scintigraphy using MIBG is useful in detecting peripheral adrenergic dysfunction.