123I-Metaiodobenzylguanidine Myocardial Scintigraphy in Dementia with Lewy Bodies

Differential diagnosis of dementia with Lewy bodies (DLB) from Alzheimer’s disease (AD) and other dementias is essential for better management. Metaiodobenzylguanidine (MIBG) is a physiological analogue of norepinephrine, and 123I-MIBG myocardial scintigraphy has been used as a noninvasive tool for estimating myocardial sympathetic nerve damage due to various disorders such as heart and neurologic diseases. Degeneration of the cardiac sympathetic nerves is a neuropathological feature of Lewy body diseases including Parkinson’s disease and DLB. Multiple single-center studies, including ours, reported very high sensitivity and specificity of 123I-MIBG myocardial scintigraphy for the differential diagnosis of DLB from AD and other dementias; further, our first multicenter study of DLB with the standardized technique [1] substantiated the high diagnostic accuracy of 123I-MIBG myocardial scintigraphy, which was comparable to that of 123I-N-ω-fluoropropyl-2β-carbomethoxy-3β-(4-iodophenyl) nortropane (FP-CIT) SPECT multicenter study [2]. In the current version of the consensus diagnostic criteria for DLB [3], 123I-FP-CIT SPECT was listed as one of the suggestive features of DLB, whereas 123I-MIBG myocardial scintigraphy was listed as one of the supportive features. As 123I-MIBG myocardial scintigraphy has been proved to have high diagnostic specificity, it is recommended to upgrade the abnormal MIBG myocardial scintigraphy to one of the suggestive features of DLB.