Sakamoto Fumi, Shiraishi Shinya, Tsuda Noriko, Hashimoto Mamoru, Tomiguchi Seiji, Ikeda Manabu, Yamashita Yasuyuki
1 Department of Diagnostic Radiology, Graduate School of Life Sciences, Kumamoto University, Kumamoto, Japan.
2 Department of Neuropsychiatry, Graduate School of Life Sciences, Kumamoto University, Kumamoto, Japan.
Br J Radiol. 2017 Feb;90(1070):20160156. doi: 10.1259/bjr.20160156. Epub 2016 Nov 29.
Since the clinical symptoms of different types of dementia frequently overlap, especially in the earlier stages at onset, it is difficult to distinguish dementia with Lewy bodies (DLB) from other neurodegenerative dementias based on their clinical manifestations alone. Nuclear medicine imaging has been reported as a high-value index for the objective evaluation and diagnosis of DLB. The aim of this study was to evaluate whether nuclear medicine imaging findings may yield core features to be added to the diagnosis of DLB.
We enrolled 332 patients with suspected DLB. All were evaluated by both I-metaiodobenzylguanidine (I-MIBG) myocardial scintigraphy and I-labelled N-isopropyl-p-iodoamphetamine (I-IMP). brain perfusion single-photon emission CT. The final clinical diagnosis indicated probable DLB in 92 patients (40 males, 52 females; mean age ± standard deviation, 77.4 ± 6.4 years; range, 56-89 years); 240 patients (98 males, 142 females; mean age, 75.5 ± 9.0 years; range, 70-87 years) were recorded as being without DLB. The accepted core features used for clinical evaluations were fluctuating cognition, visual hallucinations and Parkinsonism. The nuclear medicine evaluation indices were the severity score of cerebral blood flow on I-IMP scintigraphs of the posterior cingulate and praecuneus and a reduction in the blood flow in the occipital lobe. For I-MIBG evaluation, we recorded the early and delayed heart-to-mediastinum (H/M) ratios and the washout rate.
Univariate and multivariate analyses of fluctuating cognition, visual hallucinations, Parkinsonism and early H/M ratio in patients with probable and without DLB revealed significant differences. Parameters based on I-IMP studies did not show any significant differences by multivariate analysis. The area under the curve for the early H/M ratio was 0.918; for fluctuating cognition, visual hallucinations and Parkinsonism, it was 0.693, 0.760 and 0.611, respectively, by receiver-operating characteristic analysis. The early H/M ratio of <2.0 on I-MIBG scintigraphs was of the highest diagnostic accuracy. The sensitivity, specificity and accuracy for the diagnosis of probable DLB were 82.4%, 96.3% and 92.5%, respectively.
The early H/M ratio obtained by I-MIBG myocardial scintigraphy can serve as a reliable diagnostic index for the core clinical features of DLB. It can be used for the early diagnosis and treatment of DLB. Advances in knowledge: I-MIBG myocardial scintigraphy performed at the initial clinical examination can facilitate the early identification or exclusion of DLB and the early H/M ratio may be a diagnostic biomarker for DLB.
由于不同类型痴呆的临床症状经常重叠，尤其是在发病早期，仅根据临床表现很难将路易体痴呆（DLB）与其他神经退行性痴呆区分开来。核医学成像已被报道为DLB客观评估和诊断的高价值指标。本研究的目的是评估核医学成像结果是否能产生可添加到DLB诊断中的核心特征。
我们纳入了332例疑似DLB患者。所有患者均接受了1-间碘苄胍（I-MIBG）心肌闪烁显像和1-标记的N-异丙基-p-碘安非他明（I-IMP）脑灌注单光子发射计算机断层扫描。最终临床诊断显示92例患者（40例男性，52例女性；平均年龄±标准差，77.4±6.4岁；范围，56-89岁）可能患有DLB；240例患者（98例男性，142例女性；平均年龄，75.5±9.0岁；范围，70-87岁）被记录为无DLB。用于临床评估的公认核心特征为认知波动、视幻觉和帕金森症。核医学评估指标为后扣带回和楔前叶I-IMP闪烁显像上脑血流的严重程度评分以及枕叶血流减少情况。对于I-MIBG评估，我们记录了早期和延迟的心-纵隔（H/M）比值以及洗脱率。
对可能患有和未患有DLB的患者的认知波动、视幻觉、帕金森症和早期H/M比值进行单因素和多因素分析，发现存在显著差异。基于I-IMP研究的参数经多因素分析未显示任何显著差异。早期H/M比值的曲线下面积为0.918；通过受试者工作特征分析，认知波动、视幻觉和帕金森症的曲线下面积分别为0.693、0.760和0.611。I-MIBG闪烁显像上早期H/M比值<2.0具有最高的诊断准确性。诊断可能的DLB的敏感性、特异性和准确性分别为82.4%、96.3%和92.5%。
I-MIBG心肌闪烁显像获得的早期H/M比值可作为DLB核心临床特征的可靠诊断指标。它可用于DLB的早期诊断和治疗。知识进展：在初始临床检查时进行的I-MIBG心肌闪烁显像有助于早期识别或排除DLB，早期H/M比值可能是DLB的诊断生物标志物。
