AUTHOR=Guo Peng , Wang Rui-dan , Lian Teng-hong , Ding Du-yu , Zhang Ya-nan , Zhang Wei-Jiao , Li Dan-ning , Li Li-xia , Li Jing-hui , Guan Hui-ying , Yu Shu-yang , Liu Li , Hu Yang , Zuo Li-jun , Yu Qiu-jin , Wang Xiao-min , Zhang Wei 

TITLE=Olfactory Dysfunction and Its Association With Neuropathologic Proteins in Cerebrospinal Fluid From Patients With Parkinson Disease

JOURNAL=Frontiers in Aging Neuroscience

VOLUME=12

YEAR=2020

URL=https://www.frontiersin.org/journals/aging-neuroscience/articles/10.3389/fnagi.2020.594324

DOI=10.3389/fnagi.2020.594324

ISSN=1663-4365

ABSTRACT=<p><bold>Background and Purpose:</bold> Olfactory dysfunction (OD) is a common non-motor symptom of Parkinson disease (PD). However, the relationship between OD and neuropathologic proteins in cerebrospinal fluid (CSF) from PD patients remains unclear.</p><p><bold>Methods:</bold> 166 PD patients were included in the study. Overall olfactory function was assessed by summing up the scores of olfactory threshold, discrimination, and identification by a Sniffin' Sticks test, based on which, patients were divided into PD with OD (PD-OD) and PD with no OD (PD-NOD) groups. CSF samples were obtained from 76 PD patients. The levels of neuropathologic proteins, including α-Synuclein, Aβ1-42, total tau (T-tau), and multiple forms of phosphorylated tau (P-tau) in CSF were measured by an enzyme-linked immunosorbent assay.</p><p><bold>Results:</bold> out of the 166 PD patients, 103 cases (62.0%) had OD. The scores of overall olfactory functions, and olfactory threshold, discrimination, and identification in the PD-OD group were all significantly lower than that in the PD-NOD group (<italic>P</italic> &lt; 0.001). α-Synuclein level in CSF was significantly higher in the PD-OD group than the PD-NOD group (<italic>P</italic> &lt; 0.05), and was significantly and negatively correlated with the scores of overall olfactory function, and olfactory discrimination and identification (<italic>P</italic> &lt; 0.05). Aβ1-42 level in CSF was higher in the PD-OD group than the PD-NOD group, and was significantly and negatively correlated with the olfactory identification score (<italic>P</italic> &lt; 0.05). T-tau level in CSF was significantly lower in the PD-OD group than the PD-NOD group (<italic>P</italic> &lt; 0.05), and was significantly and positively correlated with the olfactory discrimination score (<italic>P</italic> &lt; 0.05). There was no significant difference in P-tau level in CSF between the PD-OD and PD-NOD groups and no correlation between OD score and P-tau level in CSF.</p><p><bold>Conclusions:</bold> PD-OD includes the impairments of olfactory threshold, discrimination, and identification, and is associated with the significant elevation of α-Synuclein and the decrease of the T-tau level in CSF.</p>