Introduction: Semantic dementia (SD) is characterized by fluent speech, anomia, and loss of word and object knowledge with varying degrees of right and left anterior-medial temporal lobe hypometabolism on [¹⁸F] fluorodeoxyglucose (FDG)-PET. We assessed neurobehavioral features in SD patients across 3 FDG-PET-defined metabolic patterns and investigated progression over time. Methods: Thirty-four patients with SD who completed FDG-PET were classified into a left- and right-dominant group based on the degree of hypometabolism in each temporal lobe. The left-dominant group was further subdivided depending on whether hypometabolism in the right temporal lobe was more or less than 2 standard deviations from controls (left+ group). Neurobehavioral characteristics determined using the Neuropsychiatric Inventory Questionnaire (NPI-Q) were compared across groups. Progression of NPI-Q scores and FDG-PET hypometabolism was assessed in 14 patients with longitudinal follow-up. Results: The right-dominant group performed worse on the NPI-Q and had a greater frequency of abnormal behaviors and more severe disinhibition compared to the left-dominant group. Performance on the NPI-Q and severity of disinhibition correlated with right medial and lateral, but not left, temporal lobe hypometabolism. Severity of abnormal behaviors worsened over time in most left-dominant and left+ patients but appeared to improve in the 2 right-dominant patients with longitudinal follow-up. All groups showed progressive worsening of metabolism in both temporal lobes over time, with hypometabolism spreading from anteromedial to posterior temporal regions. However, the degree of temporal lobe asymmetry remained relatively constant over time. Conclusion: In SD, neurobehavioral features, especially disinhibition, are associated with right medial and lateral temporal lobe hypometabolism and commonly develop over time even in patients that present with left-dominant patterns of hypometabolism.
Dement Geriatr Cogn Disord

中文翻译：

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FDG-PET 定义的右旋语义性痴呆的神经行为特征：一项纵向研究


简介：语义性痴呆 (SD) 的特点是言语流利、失忆症、单词和物体知识丧失，以及 [ ¹⁸ F] 氟脱氧葡萄糖 (FDG)-PET 上不同程度的左右前内侧颞叶代谢减退。我们通过 3 种 FDG-PET 定义的代谢模式评估了 SD 患者的神经行为特征，并研究了随时间的进展。方法： 34 例完成 FDG-PET 的 SD 患者根据每个颞叶代谢低下的程度分为左主导组和右主导组。根据右颞叶代谢减退与对照组（左+组）相比是否大于或小于2个标准差，将左主导组进一步细分。使用神经精神问卷调查表 (NPI-Q) 确定的神经行为特征在各组之间进行比较。通过纵向随访评估了 14 名患者的 NPI-Q 评分和 FDG-PET 代谢低下的进展情况。结果：与左侧主导组相比，右侧主导组在 NPI-Q 上表现较差，异常行为频率更高，抑制去抑制更严重。 NPI-Q 的表现和去抑制的严重程度与右侧内侧和外侧颞叶代谢低下相关，但与左侧颞叶代谢低下无关。大多数左为主和左+患者的异常行为严重程度随着时间的推移而恶化，但在纵向随访中，2名右为主的患者似乎有所改善。随着时间的推移，所有组的两个颞叶的代谢均逐渐恶化，代谢低下从前内侧扩散到后颞区。 然而，颞叶不对称程度随着时间的推移保持相对恒定。结论：在 SD 中，神经行为特征，尤其是去抑制，与右侧颞叶内侧和外侧代谢低下相关，并且通常随着时间的推移而发展，即使在表现出左侧代谢低下模式的患者中也是如此。

老年痴呆症认知障碍