追踪阿尔茨海默病的进展：来自SOMI阶段代谢模式的见解。

Brugnolo Andrea, Orso Beatrice, Girtler Nicola, Ferraro Pilar Maria, Arnaldi Dario, Mattioli Pietro, Massa Federico, Famà Francesco, Argenti Lucia, Biffa Gabriella, Morganti Wanda, Buonopane Silvia, Uccelli Antonio, Morbelli Silvia, Pardini Matteo

Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics, and Mother-Child Health (DINOGMI), University of Genoa, Italy; Clinical Psychology Unit, IRCCS Ospedale Policlinico San Martino, Genoa, Italy.

Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics, and Mother-Child Health (DINOGMI), University of Genoa, Italy.

Cortex. 2024 Feb;171:413-422. doi: 10.1016/j.cortex.2023.11.011. Epub 2023 Nov 30.

BACKGROUND

SOMI (Stages of Objective Memory Impairment) is a novel classification that identifies six stages of memory decline in Alzheimer's Disease (AD) using the Free and Cued Selective Reminding Test (FCSRT). However, the relationship between SOMI stages and brain metabolism remains unexplored. This study aims to investigate the metabolic correlates of SOMI stages using FDG-PET in Mild Cognitive Impairment due to AD (MCI-AD) and early AD patients.

METHODS

One hundred twenty-nine-patients (99 aMCI-AD and 30 AD), and 42 healthy controls (HCs) (MMSE = 29.2 ± .8; age:69.1 ± 8.6 years; education:10.7 ± 3.8 years) who underwent an extensive neuropsychological battery including FCSRT and brain FDG-PET were enrolled. According to their clinical relevance and available sample sizes, SOMI-4 (N = 24 subjects; MMSE score:26.6 ± 2.6: age:75.4 ± 3.2; education:9.9 ± 4.5) and SOMI-5 groups (N = 97; MMSE:25.3 ± 2.6; age:73.9 ± 5.8; education:9.4 ± 4.1) were investigated.

RESULTS

Compared to HCs, SOMI-4 showed hypometabolism in the precuneus, medial temporal gyrus bilaterally, right pecuneus and angular gyrus. SOMI-5 exhibited broader hypometabolism, extending to the left posterior cingulate and medial frontal gyrus bilaterally. The conjunction analysis revealed overlapping areas in the precuneus, medial temporal gyrus bilaterally, and in the right angular gyrus and cuneus. The disjunction analysis identified SOMI-5 specific hypometabolism encompassing left inferior temporal gyrus, uncus and parahippocampal gyrus, and medial frontal gyrus bilaterally (p < .001, p-value (FWE) < .05).

DISCUSSION

SOMI-4 relates to posterior hypometabolism, while SOMI-5 to more extensive hypometabolism further encompassing frontal cortices, suggesting SOMI as a biologically relevant classification system of memory decline.

CONCLUSION

Memory decline staged with SOMI is associated with hypometabolism spreading in amnesic MCI-AD/AD, suggesting its usefulness as a clinical marker of increasing neurodegeneration.

背景

客观记忆损害分期（SOMI）是一种新的分类方法，它使用自由和线索选择性回忆测验（FCSRT）来识别阿尔茨海默病（AD）记忆衰退的六个阶段。然而，SOMI分期与脑代谢之间的关系尚未得到探索。本研究旨在使用氟代脱氧葡萄糖正电子发射断层扫描（FDG-PET）研究AD所致轻度认知障碍（MCI-AD）和早期AD患者中SOMI分期的代谢相关性。

方法

招募了129名患者（99名aMCI-AD和30名AD）以及42名健康对照者（HCs）（简易精神状态检查表（MMSE）=29.2±0.8；年龄：69.1±8.6岁；受教育程度：10.7±3.8年），他们接受了包括FCSRT和脑FDG-PET在内的广泛神经心理学测试。根据其临床相关性和可用样本量，对SOMI-4组（N=24名受试者；MMSE评分：26.6±2.6；年龄：75.4±3.2；受教育程度：9.9±4.5）和SOMI-5组（N=97；MMSE：25.3±2.6；年龄：73.9±5.8；受教育程度：9.4±4.1）进行了研究。

结果

与HCs相比，SOMI-4组在楔前叶、双侧内侧颞叶回、右侧楔叶和角回表现出代谢减低。SOMI-5组表现出更广泛的代谢减低，延伸至双侧左后扣带回和内侧额回。联合分析显示在楔前叶、双侧内侧颞叶回以及右侧角回和楔叶存在重叠区域。分离分析确定SOMI-5组的特异性代谢减低区域包括左侧颞下回、钩回和海马旁回以及双侧内侧额回（p<0.001，p值（FWE）<0.05）。