卒中后嗅觉功能障碍：网络机制、临床后果与康复

文献信息

中文摘要

卒中仅次于缺血性心脏病，是全球第二大死亡原因，占全球所有死亡的10%。卒中也是长期神经功能障碍的主要原因，然而嗅觉功能障碍仍是脑血管损伤后一个未被充分认识的结果。尽管嗅觉在食欲、快感、危险检测、记忆、情绪加工和生活质量中具有核心作用，但卒中患者的嗅觉很少被评估。嗅觉系统从嗅上皮和嗅球延伸至初级嗅觉皮层、边缘区、眶额皮层、岛叶、丘脑、海马、更广泛的前额-边缘网络以及小脑。嗅觉系统广泛的解剖组织使其易因卒中或其他病变而频繁受到扰动。卒中后嗅觉缺陷可能源于嗅觉结构的直接损伤、高级嗅觉网络的破坏、神经功能联系不能、嗅探和感觉运动控制的改变或继发性变性。临床上，这些缺陷表现为嗅觉减退、嗅觉丧失、气味识别、辨别和记忆受损、气味愉悦度改变、风味感知下降、食欲丧失或气味引导行为减少。当前证据表明，嗅觉功能障碍可持续至卒中慢性期，尽管由于各研究在人群、时间、测试方法和报告方面差异很大，无法确立单一的患病率估计。本叙述性综述概述了卒中相关嗅觉功能障碍，强调嗅觉通路解剖、病变相关机制、临床后果、测量局限性、康复方法和未来研究重点。我们认为，卒中后嗅觉功能障碍应被理解为一种多维度的网络性疾病，而非简单的二元嗅觉丧失。

英文摘要

Stroke is the second leading cause of death after ischemic heart disease, accounting for 10% of all deaths worldwide. Stroke is also a major cause of long-term neurological disability, yet olfactory dysfunction remains an underrecognized consequence of cerebrovascular injury. Smell is rarely evaluated in stroke patients despite its central role in appetite, hedonia, hazard detection, memory, emotional processing, and quality of life. The olfactory system extends from the olfactory epithelium and olfactory bulb to primary olfactory cortex, limbic regions, orbitofrontal cortex, insula, thalamus, hippocampus, broader fronto-limbic networks and cerebellum. The broad anatomical organization of the olfactory system subjects it to frequent perturbation due to stroke or other lesions. Post-stroke olfactory deficits may result from direct injury to olfactory structures, disruption of higher-order olfactory networks, diaschisis, altered sniffing and sensorimotor control, or secondary degeneration. Clinically, these deficits are manifested as hyposmia, anosmia, impaired odor identification, discrimination and memory, altered odor pleasantness, reduced flavor perception, loss of appetite, or reduced odor-guided behavior. Current evidence indicates that olfactory dysfunction can persist into the chronic phase of stroke, although a single prevalence estimate cannot be established because populations, timing, testing methods, and reporting differ substantially across studies. This narrative review provides an overview of stroke-related olfactory dysfunction, emphasizing olfactory pathway anatomy, lesion-relevant mechanisms, clinical consequences, measurement limitations, rehabilitation approaches, and future research priorities. We argue that post-stroke olfactory dysfunction should be understood as a multidimensional network-based disorder rather than a simple binary loss of smell.