Olfactory dysfunction (OD) in Parkinson’s disease (PD) appears several years before the presence of motor disturbance. Olfactory testing has the potential to serve as a tool for early detection of PD, but OD is not specific to PD as it affects up to 20% of the general population. Olfaction includes an orthonasal and a retronasal components; in some forms of OD, retronasal olfactory function is preserved. We aimed to evaluate whether combined testing components allows for discriminating between PD-related OD and non-Parkinsonian OD (NPOD). The objective of this study is to orthonasal and retronasal olfactory function in PD patients and compare them to a NPOD group and to healthy controls. We hypothesized that this combined testing allows to distinguish PD patients from both other groups. We included 32 PD patients, 25 NPOD patients, and 15 healthy controls. Both olfactory components were impaired in PD and NPOD patients, compared with controls; however, NPOD patients had significantly better orthonasal scores than PD patients. Furthermore, the ratio of retronasal/orthonasal score was higher in PD than in both other groups. In the NPOD group, orthonasal and retronasal scores were significantly correlated; no such correlation could be observed in PD patients. In summary, PD patients seem to rely on compensatory mechanisms for flavor perception. Combined orthonasal and retronasal olfactory testing may contribute to differentiate PD patients from patients with NPOD.

中文翻译：

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帕金森氏病特别损害了经鼻嗅觉而不是经鼻嗅觉。

帕金森氏病（PD）中的嗅觉功能障碍（OD）出现在运动障碍出现之前的几年。嗅觉测试有潜力作为早期检测PD的工具，但是OD并不是PD特有的，因为它会影响多达20％的普通人群。嗅觉包括鼻和后鼻成分。在某些形式的OD中，保留了鼻后嗅功能。我们旨在评估组合的测试组件是否可以区分PD相关的OD和非帕金森病OD（NPOD）。这项研究的目的是PD患者的鼻和鼻后嗅功能，并将其与NPOD组和健康对照进行比较。我们假设这种组合测试可以将PD患者与其他两组患者区分开。我们包括32名PD患者，25名NPOD患者，和15个健康对照。与对照组相比，PD和NPOD患者的两种嗅觉成分均受损。但是，NPOD患者的鼻子评分明显高于PD患者。此外，PD中鼻后/鼻分数的比率高于其他两组。在NPOD组中，鼻和鼻后分数显着相关。在PD患者中没有观察到这种相关性。总之，PD患者似乎依赖于补偿机制来感知味道。联合的鼻和鼻后嗅觉测试可能有助于区分PD患者和NPOD患者。PD中鼻后/鼻分数的比率高于其他两组。在NPOD组中，鼻和鼻后分数显着相关。在PD患者中没有观察到这种相关性。总之，PD患者似乎依赖于补偿机制来感知味道。联合的鼻和鼻后嗅觉测试可能有助于区分PD患者和NPOD患者。PD中鼻后/鼻分数的比率高于其他两组。在NPOD组中，鼻和鼻后分数显着相关。在PD患者中没有观察到这种相关性。总之，PD患者似乎依赖于补偿机制来感知味道。联合的鼻和鼻后嗅觉测试可能有助于区分PD患者和NPOD患者。