Correlations Between Color Vision And Cognition In Parkinson's Disease

Background: Parkinson's Disease(PD)is a common neurodegenerative disease.Typical motor symptoms are the main basis of clinical recognition and diagnosis.In recent years,it has been found that non motor symptoms of PD patients are more abundant and appear earlier than motor symptoms.At present,some non motor symptoms have been applied to the early diagnosis of PD,such as olfactory,rapid eye movement sleep behavior disorder,etc.;some of them have become the focus of attention due to the impact on the quality of life of patients and caregivers,such as cognitive impairment,etc.;there are also some studies on non motor symptoms are just beginning,such as color vision impairment.Some studies at home and abroad have found that there may be correlations between certain non motor symptoms,such as cognitive function and emotion,mental symptoms,and olfactory function,etc.The purpose of this study is to explore the characteristics and correlation of color vision impairment and cognitive impairment in PD patients,and the correlation between color vision impairment and disease severity.Methods: 40 cases of PD patients from the Department of Neurology of Dalian Friendship Hospital were included as the case group,and 40 healthy people from the physical examination center of Dalian Friendship Hospital matched with their age and gender were included as the control group.All subjects were collected with general demographic data,and the Mini Mental State Examination(MMSE),the Montreal Cognitive Assessment(MOCA),and the Geriatric Depression Scale(GDS).All subjects performed a binocular color vision tested,the Farnsworth-Munsell 100 Hue Test(FMT).The course of PD,Part III score of Unified Parkinson Disease Rating Scale(UPDRS),Hoehn and Yahr(H&Y),medoba,etc.were collected.SPSS 25 software was used to analyze all the data.Two independent samples t-test was used to analyze the difference between the case group and the control group in the score of the scale and the total error score of FMT.Pearson correlation coefficient analysis was used to evaluate the correlation between the total error score of FMT and the score of the scale and clinical characteristics.Results: there was no significant difference between the case group and the control group in age(66.08±4.52 vs 66.43±4.84)years and education(11.15±2.90 vs11.13±2.42)(p > 0.05).Basic information in the case group: The course of disease was(4.03±2.07)years,UPDRS III score(24.03±5.38),and H&Y stage(1.95±0.65).There were 33 cases of cognitive decline and 7 cases of normal cognitive function in40 PD patients.There were 19 cases of cognitive decline and 21 cases of normal cognitive function in 40 normal controls.MOCA score(23.78±1.79)and MMSE score(28.15±1.29)in PD group;MOCA score(25.75±1.45)and MMSE score(28.90±0.96)in normal control group;MOCA score(p= 0.000)and MMSE score(p=0.004)in PD group were significantly lower than those in control group.Compared with the score of cognitive domains of MOCA between the two groups,the visual space and executive function of PD group and control group(3.15±0.77 vs 4.10±0.50),PD group were significantly lower(p = 0.000),attention of PD group and control group(5.10±0.84 vs 5.55±0.60),PD group were significantly lower(p = 0.007),the other cognitive domains of PD group were lower than the control group,but the difference was not statistically significant.It shows that PD patients have cognitive impairment,mainly in visual space,executive function and attention.The GDS score of PD patients was significantly higher than that of the control(11.80±3.42 vs7.95±2.18,p = 0.000),it shows that the depression of PD patients is more obvious than that of the control group.In PD patients and control group,the total error scores of FMT respectively were(168.40±42.34 vs 111.00±25.60),the red areas respectively were(27.70±9.60 vs 20.10±7.39),the green areas respectively were(25.20±9.16 vs20.70±9.58),and the blue areas respectively were(42.90±13.00 vs 30.10±8.30),The total error score(p = 0.000),red area(p = 0.000),green area(p = 0.035),blue area(p= 0.000)in PD group were significantly higher than those in control group.The results showed that there was significant color discrimination disorder in PD group,and it was worse in red,green and blue areas than in the control group.Pearson correlation coefficient analysis showed that the total error score of FMT in PD group was positively correlated with age(r = 0.342,p = 0.031),duration(r = 0.404,p =0.010),H&Y stage(r = 0.455,p = 0.003),UPDRSIII score(r = 0.447,p = 0.004);In PD group,the total error score of FMT was negatively correlated with MMSE score(r=-0.314,p = 0.048),MOCA score(r =-0.501,p = 0.001),visual space and executive function score(r =-0.436,p = 0.005),attention score(r =-0.350,p = 0.027);There was a significant positive correlation between the total error score and GDS score in PD group(r = 0.355,p = 0.025).These results indicate that the color vision function of PD patients is related to age,course of disease,clinical characteristics,cognitive function and depression.Conclusion: Compared with the control group,PD patients have significant cognitive impairment and color vision impairment.Cognitive impairment mainly involves visual space,executive function and attention;The color discrimination ability of PD patients was significantly decreased in the red,green and blue areas compared with the control group;The total error score of FMT in PD patients was correlated with age,course of disease,clinical characteristics,cognitive function and depression.