Abstract:
Olfactory decline is an early symptom of Alzheimer\'s disease (AD) and is a predictor of conversion from mild cognitive impairment (MCI) to AD. Olfactory decline could reflect AD-related atrophy of structures related to the sense of smell. The aim of this study was to verify whether the presence of a clinical diagnosis of AD or MCI is associated with a volumetric decrease in the olfactory bulbs (OB) and the primary olfactory cortex (POC). We conducted two systematic reviews, one for each region and a meta-analysis. We collected articles from PsychNet, PubMed, Ebsco, and ProQuest databases. Results showed large and heterogeneous effects indicating smaller OB volumes in patients with AD (k = 6, g = -1.21, 95% CI [-2.19, -0.44]) and in patients with MCI compared to controls. There is also a trend for smaller POC in patients with AD or MCI compared to controls. Neuroanatomical structures involved in olfactory processing are smaller in AD and these volumetric reductions could be measured as early as the MCI stage.
摘要:
嗅觉减退是阿尔茨海默病(AD)的早期症状,也是轻度认知障碍(MCI)转化为AD的预测因子。嗅觉下降可以反映与嗅觉相关的AD相关结构的萎缩。这项研究的目的是验证AD或MCI的临床诊断的存在是否与嗅球(OB)和初级嗅觉皮层(POC)的体积减少有关。我们进行了两次系统综述,每个区域一个,并进行荟萃分析。我们从PsychNet收集了文章,PubMed,Ebsco,ProQuest数据库结果显示,与对照组相比,AD患者(k=6,g=-1.21,95%CI[-2.19,-0.44])和MCI患者的OB体积较小。与对照相比,患有AD或MCI的患者中也存在较小POC的趋势。在AD中,嗅觉处理中涉及的神经解剖结构较小,并且这些体积减少可以早在MCI阶段进行测量。