A NEW AND SENSITIVE TOOL FOR AUTONOMIC DYSFUNCTION - ANALYSIS BY RADIOLABELED METAIODOBENZYLGUANIDINE (MIBG) IN PATIENTS WITH FAMILIAL AMYLOIDOTIC POLYNEUROPATHY (FAP)

I-123-MIBG (5 mCi) scintigraphy was applied and compared with power sp ectrum 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 electro cardiogram (ECG) nor any ultrasound echocardiography (UCG) abnormaliti es were recognized. Six of these patients under (201)thallium (Tl-201) 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 I-123-MIBG accumulation w as recognized in 6 patients and in 3, a partial defect was found. Thes e results suggest that MIBG scintigraphy may be a useful method for th e diagnosis of dysautonomia in patients with FAP.