Article Text
Abstract
Background and purpose We previously reported the usefulness of iodine-123 metaiodobenzylguanidine (123I-MIBG) myocardial scintigraphy for differentiation of dementia with Lewy bodies (DLB) from Alzheimer’s disease (AD) in a cross-sectional multicentre study. The aim of this study was, by using reassessed diagnosis after 3-year follow-up, to evaluate the diagnostic accuracy of 123I-MIBG scintigraphy in differentiation of probable DLB from probable AD.
Methods We undertook 3-year follow-up of 133 patients with probable or possible DLB or probable AD who had undergone 123I-MIBG myocardial scintigraphy at baseline. An independent consensus panel made final diagnosis at 3-year follow-up. Based on the final diagnosis, we re-evaluated the diagnostic accuracy of 123I-MIBG scintigraphy performed at baseline.
Results Sixty-five patients completed 3-year follow-up assessment. The final diagnoses were probable DLB (n=30), possible DLB (n=3) and probably AD (n=31), and depression (n=1). With a receiver operating characteristic curve analysis of heart-to-mediastinum (H/M) ratios for differentiating probable DLB from probable AD, the sensitivity/specificity were 0.77/0.94 for early images using 2.51 as the threshold of early H/M ratio, and 0.77/0.97 for delayed images using 2.20 as the threshold of delayed H/M ratio. Five of six patients who were diagnosed with possible DLB at baseline and with probable DLB at follow-up had low H/M ratio at baseline.
Conclusions Our follow-up study confirmed high correlation between abnormal cardiac sympathetic activity evaluated with 123I-MIBG myocardial scintigraphy at baseline and the clinical diagnosis of probable DLB at 3-year follow-up. Its diagnostic usefulness in early stage of DLB was suggested.
Trial registration number UMIN00003419.
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Footnotes
Contributors MYo, HeA, KKo, YM, KNakaj, HN, AT, JT, JY and MYa were involved in conception and design of the study. JK, TAr, TAs, HF, HH, OI, EI, KKa, KM, EM, KNakas, YN, MS, TT, KUt, KW, YW and MYo were study investigators and recruited the patients. HiA, SN and KUr were members of the clinical evaluation committee. HM, SO and SY assessed myocardial MIBG uptake visually. KNakaj performed the statistical analyses and prepared the paper with JK. JK wrote the initial draft of the paper and all authors contributed to its preparation. The final version was read and approved by all authors with JK and MYa incorporating their additional comments.
Funding The study was funded by the grant of Japan Foundation for Neuroscience and Mental Health.
Competing interests HeA, TAr and KW received honoraria for sponsored lectures from Fujifilm RI Pharma. TAs and SY received honoraria for sponsored lectures and research grant from Fujifilm RI Pharma Co and Nihon Medi-Physics. HF, SN, SO, JT and MYo received honoraria for sponsored lectures from Fujifilm RI Pharma and Nihon Medi-Physics. HH and KUt received honoraria for sponsored lectures from Nihon Medi-Physics. EI received honoraria for consultancies, sponsored lectures and presiding at lecture meetings from Nihon Medi-Physics. OI received honoraria for sponsored lectures and travel costs from Nihon Medi-Physics. KKo received honoraria for sponsored lectures, writing and editing from Fujifilm RI Pharma, and honoraria for sponsored lectures from Nihon Medi-Physics. HM received honoraria for sponsored lectures and travel costs from Fujifilm RI Pharma and Nihon Medi-Physics. KNakaj has collaborative research works with Fujifilm RI Pharma and received research funds for joint research and honoraria for lectures and writing. KNakas received sponsored scholarship and honoraria for presiding at meetings from Fujifilm RI Pharma and honoraria for presiding at lecture meetings from Nihon Medi-Physics. EM received research grant from Fujifilm RI Pharma and honoraria for sponsored lectures from Nihon Medi-Physics and Fujifilm RI Pharma. TT received honoraria for sponsored lectures and presiding at lecture meetings from Nihon Medi-Physics. KUr received research grant from Fujifilm RI Pharma and honoraria for sponsored lectures from Nihon Medi-Physics. MYa received honoraria for sponsored lectures and research grant from Fujifilm RI Pharma. JY received sponsored scholarship, honoraria for sponsored lectures and travel costs from Fujifilm RI Pharma, and honoraria for sponsored lectures and research grant from Nihon Medi-Physics. JK, HiA, EI, KKa, KM, YM, HN, YN, MS, AT and YW declare that they have no conflicts of interest.
Patient consent Obtained.
Ethics approval This study was approved by the Medical Ethics Committee of Kanazawa University and also by institutional review boards of all participating centres.
Provenance and peer review Not commissioned; externally peer reviewed.
Data sharing statement The authors can share data of each participant in this study under the approval of the Medical Ethics Committee of Kanazawa University and institutional review boards of participating centres.