Department of Neurology, College of Medicine, The Catholic University of Korea, Seoul St. Mary's Hospital, 222 Banpo-daero, Seocho-gu, Seoul, 06591, Republic of Korea.
Division of Nuclear Medicine, Department of Radiology, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
J Neurol. 2024 Sep;271(9):6102-6113. doi: 10.1007/s00415-024-12586-9. Epub 2024 Jul 24.
Hyposmia in Parkinson's disease (PD) had been studied before but had not been detailed by its temporal progression. This study observed how each olfactory subtype evolved in terms of motor symptoms, cardiac sympathetic innervation, and cognition.
Two hundred and three early PD patients were classified as normosmia, hyposmia-converter (hypo-converter), and hyposmia. Their presynaptic monoamine availability at the time of diagnosis was assessed by positron emission tomography imaging using F-N-(3-fluoropropyl)-2beta-carbon ethoxy-3beta-(4-iodophenyl) nortropane and compared across the subtypes. Motor symptoms were evaluated in all patients, cardiac denervation was examined in 183 patients, and cognition in 195 patients were assessed using a neuropsychological battery. The domains were re-assessed 2-4 times, and the longitudinal data were analyzed to discern the natural course of each subtype.
Twenty-nine (14.3%) patients belonged to the normosmia group, 34 (16.7%) to the hypo-converter group, and the rest to the hyposmia (69.0%) group. 85.7% of the total population became hyposmic during an average 3 years of follow-up. The baseline motor symptoms, cardiac denervation, and cognition were comparable across the olfactory subtypes. Across the subtypes, a decline in the presynaptic monoamine densities of the caudate, especially the ventral-anterior subdivisions, correlated inversely with olfaction dysfunction. Over time, motor and cardiac denervation burdens worsened regardless of olfactory subtypes, but hypo-converters experienced faster cognitive deterioration than the other two groups.
The results suggest that the olfactory subtypes have differential significance along the disease course, which might reflect the involvement of different neuro-biochemical circuitries.
帕金森病（PD）患者的嗅觉减退已经过研究，但尚未详细描述其时间进展。本研究观察了每种嗅觉亚型在运动症状、心脏交感神经支配和认知方面的演变。
将 203 名早期 PD 患者分为嗅觉正常、嗅觉减退转化者（hypo-converter）和嗅觉减退者。使用正电子发射断层扫描成像技术，用 F-N-(3-氟丙基)-2β-碳乙氧基-3β-(4-碘苯基)去甲托烷评估他们在诊断时的前突触单胺可用性，并在亚型之间进行比较。对所有患者进行运动症状评估，对 183 名患者进行心脏去神经支配检查，对 195 名患者进行神经心理学测试以评估认知。对各个领域进行了 2-4 次重新评估，并对纵向数据进行了分析，以了解每个亚型的自然病程。
29 名（14.3%）患者属于嗅觉正常组，34 名（16.7%）属于嗅觉减退转化者组，其余属于嗅觉减退者（69.0%）组。在平均 3 年的随访期间，总人群中有 85.7%的人嗅觉减退。嗅觉亚型之间的基线运动症状、心脏去神经支配和认知无明显差异。在所有亚型中，尾状核的前突触单胺密度下降，尤其是腹前部分，与嗅觉功能障碍呈负相关。随着时间的推移，无论嗅觉亚型如何，运动和心脏去神经支配的负担都会恶化，但嗅觉减退转化者的认知恶化速度比其他两组更快。
结果表明，嗅觉亚型在疾病过程中具有不同的意义，这可能反映了不同神经生化回路的参与。
