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

Objective: 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.

Methods: 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.

Results: 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.

Conclusions: (123)I-MIBG myocardial scintigraphy is a good predictor of the future conversion of possible DLB to probable DLB.