Myocardial scintigraphy may predict the conversion to probable dementia with Lewy bodies.

To compare the usefulness of brain perfusion SPECT and (123)I-metaiodobenzylguanidine ((123)I-MIBG) in predicting the conversion of possible dementia with Lewy bodies (DLB) to probable DLB. We examined 94 patients with possible DLB based on the Consensus Criteria for the Clinical Diagnosis of DLB by N-Isopropyl-p-(123)I-iodoamphetamine ((123)I-IMP) brain perfusion SPECT and (123)I-MIBG myocardial scintigraphy. After 1 year of follow-up, 33 of 94 patients met the criteria for probable DLB. (123)I-IMP brain perfusion SPECT and (123)I-MIBG myocardial scintigraphy were tested as predictors of the conversion from possible DLB to probable DLB. A receiver operating characteristic (ROC) analysis was performed. The areas under the ROC curves for SPECT for predicting the conversion to probable DLB from possible DLB based on the occipital/cerebellum and occipital/striatum cortex ratios of blood flow counts were 0.591 and 0.585, respectively. The areas under the ROC curves for (123)I-MIBG based on the early heart to mediastinum (H/M) ratio, delayed H/M ratio, and washout rate were 0.935, 0.936, and 0.884, respectively. (123)I-MIBG myocardial scintigraphy is a good predictor of the future conversion of possible DLB to probable DLB.