Seyedmirzaei Homa, Rasoulian Pegah, Parsaei Mohammadamin, Hamidi Majid, Ghanbari Amin, Soltani Khaboushan Alireza, Fatehi Farzad, Kamali Arash, Sotoudeh Houman
Sports Medicine Research Center, Neuroscience Institute, Tehran University of Medical Sciences, Tehran, Iran.
Maternal, Fetal, & Neonatal Research Center, Family Research Institute, Tehran University of Medical Sciences, Tehran, Iran.
Brain Imaging Behav. 2025 Feb;19(1):240-252. doi: 10.1007/s11682-024-00934-2. Epub 2024 Oct 10.
Olfactory dysfunction (OD) is a non-motor symptom of Parkinson's Disease, affecting 75-95% of the patients. This symptom usually emerges before the clinical diagnosis, and patients with OD present with more severe forms of PD and need higher doses of therapy. It remains unknown whether OD is just a mere non-motor symptom or if it is a part of a series of pathological changes in different brain regions of the affected patients. We performed a systematic review to find the microstructural correlates of OD in people with PD. The systematic search in PubMed, Scopus, Embase, and Web of Science yielded ten eligible studies. Assessments in most included studies were inconclusive. However, we found variable brain regions and tracts associated with OD. The most repeated areas included the primary olfactory cortex, gyrus rectus, inferior fronto-occipital fasciculus, inferior longitudinal fasciculus, corticospinal tract, uncinate fasciculus, cingulum, and cerebellar peduncle. Despite some limitations, we pointed out the microstructural correlates of OD, which were also present in areas other than the olfactory system. These findings imply that OD might be a manifestation of an unknown, greater pathology in the brain of patients with PD.
嗅觉功能障碍（OD）是帕金森病的一种非运动症状，影响75%至95%的患者。这种症状通常在临床诊断之前出现，且患有OD的患者表现出更严重形式的帕金森病，需要更高剂量的治疗。目前尚不清楚OD仅仅是一种单纯的非运动症状，还是受影响患者不同脑区一系列病理变化的一部分。我们进行了一项系统综述，以寻找帕金森病患者中OD的微观结构相关性。在PubMed、Scopus、Embase和科学网进行的系统检索产生了十项符合条件的研究。大多数纳入研究的评估结果尚无定论。然而，我们发现了与OD相关的不同脑区和神经束。最常出现的区域包括初级嗅觉皮层、直回、额枕下束、下纵束、皮质脊髓束、钩束、扣带和小脑脚。尽管存在一些局限性，但我们指出了OD的微观结构相关性，这些相关性也存在于嗅觉系统以外的区域。这些发现意味着OD可能是帕金森病患者大脑中一种未知的、更广泛病理的表现。
