[Localized cardiac uptake defect with 123I-MIBG SPECT in a case with pure progressive autonomic failure]

A 60-year-old man with 3 years' history of autonomic nervous system disturbances such as orthostatic hypotension, anhidrosis and atonic bladder is presented. He had an episode of paroxysmal atrial fibrillation as well. He had neither extrapyramidal nor cerebellar signs, and was diagnosed as having pure progressive autonomic failure. His cardiac SPECT with 123I-MIBG showed the loss of uptake at the apex and the inferior wall and the diminished uptake at lateral walls. But 99mTc-tetrofosmin SPECT following an exercise stress showed a normal cardiac uptake. It was suggested that non-cardiac disease-associated postganglionic sympathetic fiber abnormality began from an inferior wall and would extend to a whole heart in this disease. The cardiac 123I-MIBG SPECT is thought to be useful for localizing the denervated area of cardiac sympathetic nervous system.