Faculty of Medicine of the University of Coimbra, Coimbra, Portugal; Institute for Biomedical Imaging and Life Sciences (CNC.IBILI), University of Coimbra, Coimbra, Portugal; Institute of Nuclear Sciences Applied to Health (ICNAS) and Coimbra Institute for Biomedical Imaging and Life Sciences (CIBIT), University of Coimbra, Coimbra, Portugal.
Faculty of Medicine of the University of Coimbra, Coimbra, Portugal; Department of Otorhinolaryngology, Hospitais da Universidade de Coimbra, Centro Hospitalar e Universitário de Coimbra, Coimbra, Portugal.
Neuroimage Clin. 2019;22:101757. doi: 10.1016/j.nicl.2019.101757. Epub 2019 Mar 12.
Diseases involving cilia dysfunction, such as Usher Syndrome (USH), often involve visual and auditory loss. Psychophysical evidence has suggested that this may also hold true for the peripheral olfactory domain. Here we aimed to go a step further by attempting to establish relations between the integrity of cortical structures and olfactory function in this condition. We investigated olfactory function for USH types 1 (USH1) and 2 (USH2). Bilateral olfactory bulb (OB) volume and olfactory sulcus (OS) depth were also analysed. Thirty-three controls with no previous olfactory deficits were age, sex and handedness-matched to 32 USH patients (11 USH1, 21 USH2). A butanol detection threshold test was performed to measure olfactory function. For OB volume and OS depth, morphometric measurements were performed using magnetic resonance imaging (MRI) based on detailed segmentation by three independent operators. Averaged values across these were used for the statistical analyses. Total intracranial volume was estimated using Freesurfer to account for head size variability. Olfactory threshold was significantly lower in controls when compared to USH, USH1, and USH2. OS depth was found to be shallower in both hemispheres in USH patients when compared with the control group. OB volume was not significantly different between control and USH groups, or respective subgroups. Nevertheless, butanol threshold was negatively correlated with the left OB volume for the USH type 1 subgroup. The main effect of OS depth reduction was found to be mainly due to the comparison between USH2 and controls. Our results provide evidence for morphometric changes and olfactory dysfunction in patients with USH. This correlated with a reduction in left OB volume in the USH1 subgroup, the most severe USH phenotype. The main effect of reduced OS depth was found to stem mainly from USH2 raising questions regarding a possible complex interaction between sensory olfactory loss and central cortical changes in this disease.
涉及纤毛功能障碍的疾病，如 Usher 综合征（USH），常伴有视觉和听觉丧失。心理物理学证据表明，这也适用于外周嗅觉领域。在这里，我们旨在更进一步，试图在这种情况下建立皮质结构完整性与嗅觉功能之间的关系。我们研究了 USH 类型 1（USH1）和 2（USH2）的嗅觉功能。还分析了双侧嗅球（OB）体积和嗅沟（OS）深度。33 名无先前嗅觉缺陷的对照与 32 名 USH 患者（11 名 USH1，21 名 USH2）按年龄、性别和惯用手匹配。通过三位独立操作人员进行详细分割，使用磁共振成像（MRI）进行了丁醇检测阈值测试，以测量嗅觉功能。对于 OB 体积和 OS 深度，使用基于详细分割的 MRI 进行了形态测量，该分割由三位独立操作人员完成。使用这些平均值进行了统计分析。使用 Freesurfer 估计总颅内体积，以考虑头部大小的可变性。与 USH、USH1 和 USH2 相比，对照组的嗅觉阈值明显更低。与对照组相比，USH 患者的双侧 OS 深度均较浅。OB 体积在对照组和 USH 组之间或各自的亚组之间没有显著差异。然而，在 USH1 亚组中，丁醇阈值与左 OB 体积呈负相关。OS 深度降低的主要影响主要归因于 USH2 与对照组之间的比较。我们的研究结果为 USH 患者的形态变化和嗅觉功能障碍提供了证据。这与 USH1 亚组中左 OB 体积的减少相关，这是最严重的 USH 表型。OS 深度降低的主要影响主要来自 USH2，这引发了关于该疾病中感觉嗅觉丧失和中枢皮质变化之间可能存在复杂相互作用的问题。
