Roy-Côté Frédérique, Zahal Rayane, Frasnelli Johannes, Nguyen Dang Khoa, Boucher Olivier
Département de Psychologie, Université de Montréal, Montréal, QC H3C 3J7, Canada.
Centre de Recherche du Centre Hospitalier de l'Université de Montréal, Montréal, QC H2X 0A9, Canada.
Brain Sci. 2021 Feb 5;11(2):198. doi: 10.3390/brainsci11020198.
(1) Background: It is well established that the insula is involved in olfaction, though its specific role in olfactory processing remains uncertain. In this paper, we first review the current literature on the insula and olfaction. Then, we describe the case of a 56-year-old man with a left insular cavernoma that caused olfactory disturbances. (2) Results: Structural neuroimaging studies suggest that insular gray matter volume is related to olfactory function, and functional neuroimaging shows that various types of stimuli lead to either lateralized or bilateral insular activations. Studies using electro-cortical stimulation reveal a specific region of the insular cortex, around the central insular sulcus, that could be related to unpleasant odor processing. Previous cases of insular lesions leading to olfactory disturbances suggest that left-sided insular lesions may more frequently lead to olfactory changes. In our patient with a left insular cavernoma, odors that were previously perceived as pleasant started smelling unpleasant and were hard to distinguish. Despite these subjective complaints, olfactory function assessed with the Sniffin' Sticks test was normal. (3) Conclusions: Current tests may not be sensitive to all types of olfactory impairments associated with insular damage, and further studies should be conducted to develop olfactory tests assessing the hedonic appreciation of odors.
(1) 背景：岛叶参与嗅觉这一点已得到充分证实，但其在嗅觉处理中的具体作用仍不明确。在本文中，我们首先回顾了当前关于岛叶与嗅觉的文献。然后，我们描述了一名56岁男性因左侧岛叶海绵状血管瘤导致嗅觉障碍的病例。(2) 结果：结构神经影像学研究表明，岛叶灰质体积与嗅觉功能相关，功能神经影像学显示，各种类型的刺激会导致单侧或双侧岛叶激活。使用皮层电刺激的研究揭示了岛叶皮质围绕中央岛叶沟的一个特定区域，该区域可能与不愉快气味处理有关。先前岛叶病变导致嗅觉障碍的病例表明，左侧岛叶病变可能更频繁地导致嗅觉变化。在我们患有左侧岛叶海绵状血管瘤的患者中，以前被认为是愉快的气味开始闻起来不愉快且难以区分。尽管有这些主观症状，但用嗅觉棒测试评估的嗅觉功能是正常的。(3) 结论：当前的测试可能对与岛叶损伤相关的所有类型的嗅觉障碍不敏感，应进行进一步研究以开发评估气味享乐感知的嗅觉测试。
