在阿尔茨海默病患者中,病理异常首先出现在内侧颞区,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和左海马旁的体积减少有关,而没有认知障碍。这项研究的目的是调查嗅觉和包括海马旁在内的内侧颞区体积减少之间的联系。内嗅皮层,和海马子场。
对27名老年受试者和27名年轻对照进行嗅觉敏锐度测量,认知功能,和结构磁共振成像。使用FreeSurfer进行图像处理和灰质体积分割。体积数据采用SPSS统计软件进行分析。
这项研究的有趣结果是,内嗅皮层的体积减少与嗅觉能力下降没有直接关系。左侧内嗅皮层的体积减少与左侧海马旁和齿状回的体积减少相关。然而,左侧海马旁体积减少对嗅觉下降的影响最大,内嗅皮层和齿状回可能也会导致嗅觉下降。
我们的结果表明,嗅觉下降可能直接反映在内侧颞区,因为海马旁体积减少,而不是作为内嗅皮层和海马的形态变化。海马旁可能在记忆检索和嗅觉识别之间的关联中起重要作用。
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.
27 elderly subjects and 27 young controls were measured olfaction acuity, cognitive function, and structural magnetic resonance imaging. Image processing and gray matter volumetric segmentation were performed with FreeSurfer. Volume data were analyzed with SPSS Statistics software.
Interesting results of this study were that volume reduction in the entorhinal cortex was not directly linked with declining olfactory ability. Volume reduction in the left entorhinal cortex was correlated with volume reduction in the left
parahippocampus and dentate gyrus. However, left
parahippocampus volume reduction had the greatest impact on olfactory decline, and the entorhinal cortex and dentate gyrus might additionally contribute to olfactory decline.
Our results indicate that olfactory decline may be directly reflected in the medial temporal regions as reduced parahippocampus volumes, rather than as morphological changes in the entorhinal cortex and hippocampus. The
parahippocampus may play an important role in the association between memory retrieval and olfactory identification.