Correlation analysis of olfactory function with cognitive function and motor symptoms in patients with Parkinson's disease

Abstract

Objective To investigate the correlation of olfactory function and cognitive function and motor symptoms in patients with primary Parkinson's disease (PD). Methods Total 152 patients with PD diagnosed and treated were recruited from August 2018 to October 2019 in The First Affiliated Hospital of Anhui Medical University. The Chinese Smell Indentification Test (CSIT) was used to evaluate the olfactory recognition function. According to the test results, patients were divided into the normal olfactory group (n=62) and the olfactory disorder group (n=90). The Unified Parkinson's Disease Assessment Scale Ⅲ (UPDRS Ⅲ) was used to evaluate the motor function, the Montreal Cognitive Assessment Scale (MoCA) Beijing edition was used to evaluate the degree of cognitive function, the Hamilton Depression Rating Scale (HAMD) and Hamilton Anxiety Rating Scale (HAMA) were used to assess the patients' depression and anxiety levels. Patients' visual spatial working memory function were tested by the n⁃back test. Pearson correlation analysis and Spearman rank correlation analysis were used to investigate the correlation between olfactory function with cognitive function and motor symptoms in patients with PD. Results CSIT⁃self score (Z=⁃2.081, P=0.037) and CSIT⁃OI score (t=13.966, P=0.000) were lower in patients with anosmia than in those with normal smell. Overall MoCA score (t=3.008, P=0.003), as well as the scores of visuospatial executive function (Z=⁃2.277, P=0.023), naming (Z=⁃2.397, P=0.017), attention (Z=⁃3.203, P=0.001), language (Z=⁃2.229, P=0.026), delayed memory (Z=⁃2.426, P=0.015) were all decreased. The accuracy of 1⁃back test (t=2.341, P=0.027) and 2⁃back test (t=2.406, P=0.024) decreased, and the response time of 0⁃back test (t=⁃2.309, P=0.029) and 2⁃back test (t=⁃2.314, P=0.029) increased. Correlation analysis showed that olfactory function score was positively correlated with total MoCA score (r_s=0.298, P=0.000). Conclusions The olfactory function of PD patients is closely related to cognitive function, PD patients with olfactory disorder have poor visual spatial working memory function. Therefore such patients should be paid more attention to cognitive function and visual spatial working memory function.

doi：10.3969/j.issn.1672⁃6731.2021.10.010