Correlation of olfactory function with cognitive function, apathy and fatigue in patients with early Parkinson’s disease

Objective To investigate the correlation of olfactory function with cognitive function,apathy and fatigue symptoms in patients with early Parkinson's disease(PD).Methods Sixty five patients with early PD were enrolled from January 2015 to December 2017(PD group),and 130 sex and age-matched healthy subjects served as control group.The olfactory function,cognitive function,apathy and fatigue were evaluated with the Sniffin'Sticks olfactory detection,the Montreal cognitive scale(MOCA),the apathy scale and the Parkinson fatigue scale in the two groups.The correlation of the olfactory function with cognitive function,the apathy and the fatigue symptoms in PD group was analyzed.Results The olfactory and cognitive function scores of PD group were significantly lower than those in the control group(P<0.05);while the scores of apathy and fatigue were significantly higher than those of the control group(P<0.05).The Pearson correlation showed that the olfactory function score was positively correlated with the cognitive function score(r=-0.352,P<0.05),and was negatively correlated with the apathy score(r=-0.538,P<0.05),and had no correlation with the fatigue symptom score(P>0.05).Conclusion Patients with early Parkinson's disease present olfactory dysfunction,cognitive impairment,apathy and fatigue,and their olfactory function scores are correlated with the scores of cognitive function and apathy symptoms.