Late-onset primary psychiatric disease (PPD) and behavioral frontotemporal dementia (bvFTD) present with a similar frontal lobe syndrome. We compare brain glucose metabolism in bvFTD and late-onset PPD and investigate the metabolic correlates of cognitive and behavioral disturbances through FDG-PET/MRI. We studied 37 bvFTD and 20 late-onset PPD with a mean clinical follow-up of three years. At baseline evaluation, metabolism of the dorsolateral, ventrolateral, orbitofrontal regions and caudate could classify the patients with a diagnostic accuracy of 91% (95% CI: 0.81–0.98%). 45% of PPD showed low-grade hypometabolism in the anterior cingulate and/or parietal regions. Frontal lobe metabolism was normal in 32% of genetic bvFTD and bvFTD with motor neuron signs. Hypometabolism of the frontal and caudate regions could help in distinguishing bvFTD from PPD, except in cases with motor neuron signs and/or genetic bvFTD for which brain metabolism may be less informative.

中文翻译：

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行为额颞叶痴呆和伴有额叶综合征的迟发性原发性精神疾病的区域脑代谢的数据驱动分析：PET/MRI 研究

晚发原发性精神疾病（PPD）和行为额颞叶痴呆（bvFTD）表现出类似的额叶综合征。我们比较了 bvFTD 和晚发 PPD 中的脑葡萄糖代谢，并通过 FDG-PET/MRI 研究认知和行为障碍的代谢相关性。我们研究了 37 名 bvFTD 和 20 名迟发性 PPD，平均临床随访时间为三年。在基线评估时，背外侧、腹外侧、眶额区域和尾状核的代谢可以对患者进行分类，诊断准确率为 91%（95% CI：0.81-0.98%）。45% 的 PPD 在前扣带回和/或顶叶区域表现出低度代谢减退。32% 的遗传性 bvFTD 和伴有运动神经元体征的 bvFTD 的额叶代谢正常。额叶和尾状核区域的代谢减退可能有助于区分 bvFTD 和 PPD，但有运动神经元体征和/或遗传性 bvFTD 的情况除外，因为大脑代谢可能提供的信息较少。