{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,22]],"date-time":"2026-09-22T13:11:34Z","timestamp":1790082694396,"version":"4.0.1"},"reference-count":54,"publisher":"Wiley","issue":"1","license":[{"start":{"date-parts":[[2024,6,8]],"date-time":"2024-06-08T00:00:00Z","timestamp":1717804800000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["Euro J of Neurology"],"published-print":{"date-parts":[[2025,1]]},"abstract":"<jats:title>Abstract<\/jats:title><jats:sec><jats:title>Background and purpose<\/jats:title><jats:p>Studies have found that up to 73% of COVID\u201019 patients experience hyposmia. It is unclear if the loss of smell in COVID\u201019 is due to damage to the peripheral or central mechanisms. This study aimed to explore the impacts of COVID\u201019\u2010induced hyposmia on brain structure and cognitive functions.<\/jats:p><\/jats:sec><jats:sec><jats:title>Methods<\/jats:title><jats:p>The study included 36 hyposmic (h\u2010COV) and 21 normosmic (n\u2010COV) participants who had recovered from mild COVID\u201019 infection, as well as 25 healthy controls (HCs). All participants underwent neurological examination, neuropsychiatric assessment and Sniffin\u2019 Sticks tests. High\u2010resolution anatomical images were collected; olfactory bulb (OB) volume and cortical thickness were measured.<\/jats:p><\/jats:sec><jats:sec><jats:title>Results<\/jats:title><jats:p>Addenbrooke's Cognitive Examination\u2014Revised total and language sub\u2010scores were slightly but significantly lower in the h\u2010COV group compared to the HC group (<jats:italic>p<\/jats:italic>\u2009=\u20090.04 and <jats:italic>p<\/jats:italic>\u2009=\u20090.037). The h\u2010COV group exhibited poorer performance in the Sniffin\u2019 Sticks test terms of discrimination score, identification score and the composite score compared to the n\u2010COV and HC groups (<jats:italic>p<\/jats:italic>\u2009&lt;\u20090.001, <jats:italic>p<\/jats:italic>\u2009=\u20090.001 and <jats:italic>p<\/jats:italic>\u2009=\u20090.002 respectively). A decrease in left and right OB volumes was observed in the h\u2010COV group compared to the n\u2010COV and HC groups (<jats:italic>p<\/jats:italic>\u2009=\u20090.003 and <jats:italic>p<\/jats:italic>\u2009=\u20090.006 respectively). The cortical thickness analysis revealed atrophy in the left lateral orbitofrontal cortex in the h\u2010COV group compared to HCs. A significant low positive correlation of varying degrees was detected between discrimination and identification scores and both OB and left orbital sulci.<\/jats:p><\/jats:sec><jats:sec><jats:title>Conclusion<\/jats:title><jats:p>Temporary or permanent hyposmia after COVID\u201019 infection leads to atrophy in the OB and olfactory\u2010related cortical structures and subtle cognitive problems in the long term.<\/jats:p><\/jats:sec>","DOI":"10.1111\/ene.16378","type":"journal-article","created":{"date-parts":[[2024,6,8]],"date-time":"2024-06-08T09:39:36Z","timestamp":1717839576000},"update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":9,"title":["Cognitive deficits and cortical volume loss in <scp>COVID<\/scp>\u201019\u2010related hyposmia"],"prefix":"10.1111","volume":"32","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-8954-7437","authenticated-orcid":false,"given":"Ha\u015fim","family":"Gezegen","sequence":"first","affiliation":[{"name":"Behavioral Neurology and Movement Disorders Unit, Department of Neurology, Istanbul Faculty of Medicine Istanbul University  Istanbul Turkey"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7896-3681","authenticated-orcid":false,"given":"Ula\u015f","family":"Ay","sequence":"additional","affiliation":[{"name":"Neuroimaging Unit, Istanbul University Hulusi Beh\u00e7et Life Sciences Research Laboratory  Istanbul Turkey"},{"name":"Department of Neuroscience Istanbul University Aziz Sancar Institute of Experimental Medicine  Istanbul Turkey"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Bedia","family":"Samanc\u0131","sequence":"additional","affiliation":[{"name":"Behavioral Neurology and Movement Disorders Unit, Department of Neurology, Istanbul Faculty of Medicine Istanbul University  Istanbul Turkey"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Elif","family":"Kurt","sequence":"additional","affiliation":[{"name":"Department of Neuroscience Istanbul University Aziz Sancar Institute of Experimental Medicine  Istanbul Turkey"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sanem Sultan","family":"Y\u00f6r\u00fck","sequence":"additional","affiliation":[{"name":"Behavioral Neurology and Movement Disorders Unit, Department of Neurology, Istanbul Faculty of Medicine Istanbul University  Istanbul Turkey"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Alpay","family":"Medetalibeyo\u011flu","sequence":"additional","affiliation":[{"name":"Department of Internal Medicine, Istanbul Faculty of Medicine Istanbul University  Istanbul Turkey"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"C\u00f6mert","family":"\u015een","sequence":"additional","affiliation":[{"name":"Department of Otolaryngology, Head and Neck Surgery, Istanbul Faculty of Medicine Istanbul University  Istanbul Turkey"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5792-2888","authenticated-orcid":false,"given":"Erdi","family":"\u015eahin","sequence":"additional","affiliation":[{"name":"Behavioral Neurology and Movement Disorders Unit, Department of Neurology, Istanbul Faculty of Medicine Istanbul University  Istanbul Turkey"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mehmet","family":"Barb\u00fcro\u011flu","sequence":"additional","affiliation":[{"name":"Department of Radiology, Istanbul Faculty of Medicine Istanbul University  Istanbul Turkey"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Faruk U\u011fur","family":"Do\u011fan","sequence":"additional","affiliation":[{"name":"Behavioral Neurology and Movement Disorders Unit, Department of Neurology, Istanbul Faculty of Medicine Istanbul University  Istanbul Turkey"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6032-0856","authenticated-orcid":false,"given":"Ba\u015far","family":"Bilgi\u00e7","sequence":"additional","affiliation":[{"name":"Behavioral Neurology and Movement Disorders Unit, Department of Neurology, Istanbul Faculty of Medicine Istanbul University  Istanbul Turkey"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ha\u015fmet","family":"Hana\u011fas\u0131","sequence":"additional","affiliation":[{"name":"Behavioral Neurology and Movement Disorders Unit, Department of Neurology, Istanbul Faculty of Medicine Istanbul University  Istanbul Turkey"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hakan","family":"G\u00fcrvit","sequence":"additional","affiliation":[{"name":"Behavioral Neurology and Movement Disorders Unit, Department of Neurology, Istanbul Faculty of Medicine Istanbul University  Istanbul Turkey"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[2024,6,8]]},"reference":[{"key":"e_1_2_12_2_1","volume-title":"WHO Coronavirus Disease (COVID\u201019) Dashboard","author":"WHO","year":"2020"},{"key":"e_1_2_12_3_1","doi-asserted-by":"publisher","DOI":"10.1016\/S1473-3099(20)30293-0"},{"key":"e_1_2_12_4_1","doi-asserted-by":"publisher","DOI":"10.3390\/ijms22168912"},{"key":"e_1_2_12_5_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.amjoto.2020.102889"},{"key":"e_1_2_12_6_1","doi-asserted-by":"publisher","DOI":"10.1177\/0194599820922992"},{"key":"e_1_2_12_7_1","doi-asserted-by":"publisher","DOI":"10.1177\/0194599820931820"},{"key":"e_1_2_12_8_1","doi-asserted-by":"publisher","DOI":"10.1002\/alr.23148"},{"key":"e_1_2_12_9_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.tins.2006.11.007"},{"key":"e_1_2_12_10_1","doi-asserted-by":"publisher","DOI":"10.1016\/B978-0-12-374236-0.10022-7"},{"key":"e_1_2_12_11_1","doi-asserted-by":"publisher","DOI":"10.7554\/eLife.47177"},{"key":"e_1_2_12_12_1","doi-asserted-by":"publisher","DOI":"10.1016\/S0278-2626(03)00277-X"},{"key":"e_1_2_12_13_1","doi-asserted-by":"publisher","DOI":"10.1007\/s12035-020-02152-5"},{"key":"e_1_2_12_14_1","doi-asserted-by":"publisher","DOI":"10.1038\/s41586-022-04569-5"},{"key":"e_1_2_12_15_1","doi-asserted-by":"publisher","DOI":"10.3390\/v12010014"},{"key":"e_1_2_12_16_1","doi-asserted-by":"publisher","DOI":"10.1128\/JVI.00404-18"},{"key":"e_1_2_12_17_1","doi-asserted-by":"publisher","DOI":"10.1002\/gps.1610"},{"key":"e_1_2_12_18_1","doi-asserted-by":"publisher","DOI":"10.1080\/01688639708403750"},{"key":"e_1_2_12_19_1","doi-asserted-by":"publisher","DOI":"10.1001\/archpsyc.1961.01710120031004"},{"key":"e_1_2_12_20_1","doi-asserted-by":"publisher","DOI":"10.1037\/0022-006X.56.6.893"},{"key":"e_1_2_12_21_1","doi-asserted-by":"publisher","DOI":"10.1111\/coa.13332"},{"key":"e_1_2_12_22_1","doi-asserted-by":"publisher","DOI":"10.1007\/s00405-006-0173-0"},{"key":"e_1_2_12_23_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.neuroimage.2006.01.015"},{"key":"e_1_2_12_24_1","doi-asserted-by":"publisher","DOI":"10.1007\/s10548-022-00919-8"},{"key":"e_1_2_12_25_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.neuroimage.2006.02.051"},{"key":"e_1_2_12_26_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.neuroimage.2010.07.020"},{"key":"e_1_2_12_27_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.neuroimage.2004.03.032"},{"key":"e_1_2_12_28_1","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.200033797"},{"key":"e_1_2_12_29_1","doi-asserted-by":"publisher","DOI":"10.1093\/cercor\/bhn232"},{"key":"e_1_2_12_30_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.neuroimage.2014.12.006"},{"key":"e_1_2_12_31_1","doi-asserted-by":"publisher","DOI":"10.1093\/cercor\/bhy111"},{"key":"e_1_2_12_32_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.neurobiolaging.2023.11.004"},{"key":"e_1_2_12_33_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.neuroimage.2008.05.004"},{"key":"e_1_2_12_34_1","doi-asserted-by":"publisher","DOI":"10.1002\/hbm.25741"},{"key":"e_1_2_12_35_1","doi-asserted-by":"publisher","DOI":"10.1155\/2023\/6496539"},{"key":"e_1_2_12_36_1","doi-asserted-by":"publisher","DOI":"10.1038\/s41598-021-92224-w"},{"key":"e_1_2_12_37_1","doi-asserted-by":"publisher","DOI":"10.1093\/chemse\/bjh067"},{"key":"e_1_2_12_38_1","doi-asserted-by":"publisher","DOI":"10.1162\/089892999563166"},{"key":"e_1_2_12_39_1","doi-asserted-by":"publisher","DOI":"10.1038\/s41467-021-21057-y"},{"key":"e_1_2_12_40_1","doi-asserted-by":"publisher","DOI":"10.1007\/s00415-022-11047-5"},{"key":"e_1_2_12_41_1","doi-asserted-by":"publisher","DOI":"10.1093\/brain\/awab009"},{"key":"e_1_2_12_42_1","doi-asserted-by":"publisher","DOI":"10.1212\/WNL.0000000000006919"},{"key":"e_1_2_12_43_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.cortex.2022.06.002"},{"key":"e_1_2_12_44_1","doi-asserted-by":"publisher","DOI":"10.1007\/s10072-022-06130-8"},{"key":"e_1_2_12_45_1","doi-asserted-by":"publisher","DOI":"10.3390\/brainsci14030264"},{"key":"e_1_2_12_46_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.bbi.2020.07.037"},{"key":"e_1_2_12_47_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.jad.2021.11.031"},{"key":"e_1_2_12_48_1","doi-asserted-by":"publisher","DOI":"10.1038\/s41593-020-00758-5"},{"key":"e_1_2_12_49_1","doi-asserted-by":"publisher","DOI":"10.1001\/jamaneurol.2020.2065"},{"key":"e_1_2_12_50_1","doi-asserted-by":"publisher","DOI":"10.1016\/0042-6822(89)90446-7"},{"key":"e_1_2_12_51_1","doi-asserted-by":"publisher","DOI":"10.1128\/JVI.02012-06"},{"key":"e_1_2_12_52_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.cell.2022.06.008"},{"key":"e_1_2_12_53_1","doi-asserted-by":"publisher","DOI":"10.3389\/fmed.2022.852998"},{"key":"e_1_2_12_54_1","doi-asserted-by":"publisher","DOI":"10.1093\/infdis\/jiac113"},{"key":"e_1_2_12_55_1","doi-asserted-by":"publisher","DOI":"10.1038\/s41467-022-34244-2"}],"container-title":["European Journal of Neurology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/pdf\/10.1111\/ene.16378","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,1,27]],"date-time":"2025-01-27T05:17:43Z","timestamp":1737955063000},"score":1,"resource":{"primary":{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/10.1111\/ene.16378"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2024,6,8]]},"references-count":54,"journal-issue":{"issue":"1","published-print":{"date-parts":[[2025,1]]}},"alternative-id":["10.1111\/ene.16378"],"URL":"https:\/\/doi.org\/10.1111\/ene.16378","archive":["Portico"],"relation":{},"ISSN":["1351-5101","1468-1331"],"issn-type":[{"value":"1351-5101","type":"print"},{"value":"1468-1331","type":"electronic"}],"subject":[],"published":{"date-parts":[[2024,6,8]]},"assertion":[{"value":"2023-12-20","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2024-05-21","order":2,"name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}},{"value":"2024-06-08","order":3,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}],"article-number":"e16378"}}