Vilarello Brandon J, Jacobson Patricia T, Tervo Jeremy P, Waring Nicholas A, Gudis David A, Goldberg Terry E, Devanand D P, Overdevest Jonathan B
Columbia University Vagelos College of Physicians and Surgeons, New York, NY, United States.
Department of Otolaryngology-Head and Neck Surgery, New York-Presbyterian/Columbia University Irving Medical Center, New York, NY, United States.
Front Neurosci. 2023 Jun 29;17:1198267. doi: 10.3389/fnins.2023.1198267. eCollection 2023.
COVID-19 induces both acute and chronic neurological changes. Existing evidence suggests that chemosensory changes, particularly olfactory loss, may reflect central neurological dysfunction in neurodegenerative diseases and mark progression from mild cognitive impairment to Alzheimer's. This scoping review summarizes the available literature to evaluate the relationship between neurocognition and olfaction in young to middle-aged adults with minimal comorbidities following COVID-19 infection.
A literature search of PubMed, Ovid Embase, Web of Science, and Cochrane Library was conducted. Studies underwent title/abstract and full text screening by two reviewers, with a third reviewer resolving any conflicts. Remaining studies underwent data extraction.
Seventeen studies were eligible for data extraction after the review process, where 12 studies found significantly poorer cognition in those suffering from olfactory dysfunction, four studies showed no association between cognition and olfaction, and one study reported lower anosmia prevalence among patients with cognitive impairment.
The majority of studies in this review find that olfactory dysfunction is associated with poorer cognition. More rigorous studies are needed to further elucidate the relationship between olfaction and cognition after COVID-19.
新冠病毒病（COVID-19）会引发急性和慢性神经学变化。现有证据表明，化学感觉变化，尤其是嗅觉丧失，可能反映神经退行性疾病中的中枢神经功能障碍，并标志着从轻度认知障碍发展为阿尔茨海默病。本综述总结了现有文献，以评估在合并症极少的中青年新冠病毒感染康复者中神经认知与嗅觉之间的关系。
对PubMed、Ovid Embase、Web of Science和Cochrane图书馆进行文献检索。研究由两名评审员进行标题/摘要和全文筛选，如有冲突由第三名评审员解决。其余研究进行数据提取。
经过评审过程，17项研究符合数据提取条件，其中12项研究发现嗅觉功能障碍者的认知能力明显较差，4项研究表明认知与嗅觉之间无关联，1项研究报告认知障碍患者的嗅觉丧失患病率较低。
本综述中的大多数研究发现嗅觉功能障碍与较差的认知能力有关。需要更严格的研究来进一步阐明新冠病毒感染康复后嗅觉与认知之间的关系。
