Pozzi Federico Emanuele, Licciardo Daniele, Musarra Monica, Jonghi-Lavarini Lorenzo, Crivellaro Cinzia, Basso Gianpaolo, Appollonio Ildebrando, Ferrarese Carlo
Neurology Department, San Gerardo Hospital, 20900 Monza, Italy.
Neuropsychology Department, San Gerardo Hospital, 20900 Monza, Italy.
J Pers Med. 2022 Oct 6;12(10):1665. doi: 10.3390/jpm12101665.
Recent European guidelines recommend using brain FDG-PET to differentiate between Alzheimer's disease (AD) and depressive pseudodementia (DP), with specific hypometabolism patterns across the former group, and typically normal or frontal hypometabolism in the latter. We report the case of a 74 years-old man with DP (MMSE 16/30), whose FDG-PET visual rating and semiquantitative analysis closely mimicked the typical AD pattern, showing severe hypometabolism in bilateral precuneus, parietal and temporal lobes, and sparing frontal areas, suggesting the diagnosis of moderate AD. Shortly after starting antidepressant polytherapy, he underwent formal NPS testing, which revealed moderate impairment of episodic memory and mild impairment on executive and visuospatial tests, judged consistent with neurodegenerative dementia and concomitant depression. Over the following two years, he improved dramatically: repeated NPS assessment did not show significant deficits, and FDG-PET showed restoration of cerebral metabolism. The confirmation of PET findings via semiquantitative analysis, and their reversion to normality with antidepressant treatment, proved the non-neurodegenerative origin of the initial AD-like FDG-PET abnormalities. We review similar cases and provide a comprehensive analysis of their implications, concluding that reversible FDG-PET widespread hypometabolism might represent a biomarker of pseudodementia. Therefore, we suggest caution when interpreting FDG-PET scans of depressed patients with cognitive impairment.
欧洲近期的指南建议使用脑部氟代脱氧葡萄糖正电子发射断层扫描（FDG-PET）来区分阿尔茨海默病（AD）和抑郁性假性痴呆（DP），前一组有特定的代谢减低模式，而后一组通常代谢正常或额叶代谢减低。我们报告了一例74岁患有DP（简易精神状态检查表评分为16/30）的男性病例，其FDG-PET视觉评级和半定量分析与典型的AD模式极为相似，显示双侧楔前叶、顶叶和颞叶严重代谢减低，额叶未受累，提示为中度AD。在开始联合抗抑郁治疗后不久，他接受了正式的神经心理学测试，结果显示情节记忆中度受损，执行和视觉空间测试轻度受损，判断为与神经退行性痴呆及伴发的抑郁相符。在接下来的两年里，他显著改善：重复的神经心理学评估未显示明显缺陷，FDG-PET显示脑代谢恢复。通过半定量分析证实PET结果，并通过抗抑郁治疗使其恢复正常，证明了最初类似AD的FDG-PET异常并非神经退行性起源。我们回顾了类似病例并对其意义进行了全面分析，得出结论：可逆性FDG-PET广泛代谢减低可能是假性痴呆的一个生物标志物。因此，我们建议在解读有认知障碍的抑郁症患者的FDG-PET扫描结果时要谨慎。
