Morra Francesco, Minerva Matteo, Valeggia Silvia, Librizzi Giovanni, Tramarin Elena, Scalpelli Caterina, Bordin Anna, Ottaviano Giancarlo, Gaudioso Piergiorgio, Bertoldo Alessandra, Moretto Manuela, Miola Alessandro, Lupia Eleonora, Ceccato Riccardo, Mucignat Carla, Antonini Angelo, Manara Renzo
Department of Neuroradiology, University Hospital Zurich, Zurich, Switzerland.
Neuroradiology, Ospedale dell'Angelo, Mestre, Venice, Italy.
Chem Senses. 2024 Jan 1;49. doi: 10.1093/chemse/bjae040.
Transient or persistent hypo-anosmia is common in SARS‑CoV‑2 infection but olfactory pathway late-term morphometric changes are still under investigation. We evaluated late olfactory bulb (OB) imaging changes and their correlates with the olfactory function in otherwise neurologically asymptomatic COVID-19 patients. Eighty-three subjects (mean-age 43 ± 14 yr; 54 females; time-interval infection/MRI: 129±68 d) were affected by asymptomatic to mild COVID-19 in 2020 and 25 healthy controls (mean-age 40 ± 13 yr; 9 females) underwent 3T-MRI and olfactory function evaluation through anamnestic questionnaire and Sniffin' Sticks. Exclusion criteria were intensive care treatment or neurological involvement other than olfaction. Maximal OB area was measured blindly on high-resolution coronal T2w images by 2 observers. Patients were subdivided into (i) persistently hypo/anosmic, (ii) recovered normosmic, and (iii) never complaining smell dysfunction with proven normal olfactory function. No significant differences were observed among patients' subgroups (P = 0.76). Intraobserver and interobserver reliability were high (r = 0.96 and 0.86). Former COronaVIrus Disease 19 (COVID-19) patients had decreased mean maximal OB area than controls (6.52 ± 1.11 mm2 vs. 7.26 ± 1.17 mm2, P = 0.008) even when considering persistently hypo-anosmic (6.46 ± 0.90, P = 0.006) or normosmic patients at MRI (6.57 ± 1.25, P = 0.04). SARS-CoV-2 infection is associated with mid/late-term morphological changes in the OB, regardless of presence or persistence of olfactory dysfunction. The long-term consequences on olfactory aging need to be further investigated including possible links with neurodegenerative disorders.
短暂性或持续性嗅觉减退在新型冠状病毒2型（SARS-CoV-2）感染中很常见，但嗅觉通路的晚期形态学变化仍在研究中。我们评估了在其他方面无神经症状的新冠肺炎患者嗅球（OB）的晚期影像学变化及其与嗅觉功能的相关性。83名受试者（平均年龄43±14岁；54名女性；感染/MRI时间间隔：129±68天）在2020年感染了无症状至轻度新冠肺炎，25名健康对照者（平均年龄40±13岁；9名女性）接受了3T-MRI检查，并通过回忆问卷和嗅觉棒进行嗅觉功能评估。排除标准为重症监护治疗或除嗅觉外的神经受累。由2名观察者在高分辨率冠状位T2加权图像上盲法测量OB最大面积。患者被分为：（i）持续性嗅觉减退/嗅觉丧失，（ii）嗅觉恢复正常，（iii）从未诉说嗅觉功能障碍且嗅觉功能经证实正常。患者亚组之间未观察到显著差异（P = 0.76）。观察者内和观察者间的可靠性很高（r = 0.96和0.86）。即使考虑持续性嗅觉减退（6.46±0.90，P = 0.006）或MRI时嗅觉正常的患者（6.57±1.25，P = 0.04），新冠肺炎康复患者的OB平均最大面积也低于对照组（6.52±1.11mm²对7.26±1.17mm²，P = 0.008）。无论是否存在嗅觉功能障碍或其持续性如何，SARS-CoV-2感染都与OB的中/晚期形态学变化有关。嗅觉衰老的长期后果需要进一步研究，包括与神经退行性疾病的可能联系。
