A new and sensitive tool for autonomic dysfunction: Analysis by radiolabelled meta-iodobenzylguanidine (MIBG) in patients with familial amyloidotic polyneuropathy (FAP)

123I-MIBG (5 mCi) scintigraphy was applied and compared with power spectrum and coefficient of variance (CV) of the electrocardiographic R-R interval in 9 patients with familial amyloidotic polyneuropathy (FAP). Although a significant decrease of MIBG uptake was seen in all the patients examined, no change in either the ST or T wave in the electrocardiogram (ECG) nor any ultrasound echocardiography (UCG) abnormalities were recognized. Six of these patients under 201thallium (201TI) scintigraphy exhibited a normal pattern. The electrocardiographic R-R interval, was border-line in one patient and could not be calculated in 3 patients. In contrast, total absence of 123I-MIBG accumulation was recognized in 6 patients and in 3, a partial defect was found. These results suggest that MIBG scintigraphy may be a useful method for the diagnosis of dysautonomia in patients with FAP