Pathological abnormalities first appear in the medial temporal regions including entorhinal cortex and parahippocampus in patients with Alzheimer's disease. Previous studies showed that olfactory decline in elderly subjects was associated with volume reductions in the left hippocampus and left parahippocampus without cognitive impairment. The aim of this study is to investigate the link between olfaction and volume reductions in the medial temporal regions including the parahippocampus, entorhinal cortex, and hippocampal subfields.

中文翻译：

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内嗅皮层和海马旁体积的减少影响老年受试者的嗅觉下降

病理异常首先出现在阿尔茨海默氏病患者的颞内侧区域，包括内嗅皮层和海马旁。先前的研究表明，老年受试者的嗅觉下降与左海马体和左海马体的容量减少有关，而没有认知障碍。这项研究的目的是调查嗅觉与内侧颞区（包括海马旁，内嗅皮层和海马亚区）的体积减少之间的联系。