Cognitive Impairment In Parkinson's Disease

BackgroundParkinson's disease(PD) is one of the neurodegenerative diseases,which occurs chiefly among the middle-aged and elderly people.PD is characterized clinically by static tremor,rigidity,bradykinesia,abnormal gait and posture.In addition to the above-mentioned symptoms,patients with clinical PD are often in the meantime on the existence of non-motor symptoms,such as cognitive dysfunction,emotional changes, autonomic dysfunction and so on.Among them,the incidence of cognitive impairment is rather high.What is worse,a considerable number of the patients even develop dementia,which would influence the daily life and work of the patients to a large extent.ObjectiveThe present research is aimed at investigating the incidence of cognitive dysfunction,and the relationship between cognitive impairment and gender,movement disorders,and emotion(anxiety,depression)Methods64 cases of Parkinson's disease were evaluated by the mini-mental state examination(MMSE),the Montreal Cognitive Assessment Scale(MoCA),Fuld Object Memory Assessment Scale(FOME),Wechsler Intelligence Scale-block design (WISC-BD),Wechsler Adult Intelligence Scale-digit span(WAIS-DS),Hamilton Rating Scale for Depression(HRSD),Hamilton Anxiety Scale(HAMA) and the Unified Parkinson's Disease Rating Scale(UPDRS),modified Hoehn-Yahr rating scale(H-Y). All data were processed with SPSS16.0.Results(1) 54 cases among 64 PD patients,have cognitive dysfunction(with MoCA score), accounting for 84.4%;(2)82.4%of the patients,whose course is not up to two years,develop cognitive dysfunction.Among the 46 male patients,39 cases(84.78%) have cognitive dysfunction, 15 of 18 cases of female patients(83.33%) have cognitive impairment,the different incidence of cognitive impairment between males and females was not significant(X~2= 0.06,P＞0.05);(3) All the 12 cases with depression have cognitive impairment(100%);among the 52 patients without depression,42 cases(80.77%) have cognitive impairment. Therefore,no significant difference has been found in the incidence of cognitive impairment between patients with and without depression(X~2=1.47,P＞0.05).Among the 36 patients with anxiety,32 patients(88.9%) suffer from cognitive impairment, and among the 28 patients without anxiety,22 patients suffer from cognitive impairment (78.6%).That is to say,the incidence difference of cognitive impairment between patients with and without anxiety was not significant(X~2=0.61,P＞0.05);(4) All patients were grouped according to UPDRS scores.The different means of MoCA between Group 1 and Group 4 are found statistically significant(t=3.334,P= 0.004),and the different means of visual-spatial and executive function has also been proved to be statistically significant(t=3.351 P=0.004).However,no statistically significant difference has been found between the means of the remaining areas of cognition; (5) All patients were grouped according to H-Y grades.Statistically significant difference(t=2.262 P=0.034) has been found between the different means of visual-spatial and executive function of Group 1 and Group 3,the other mean differences were not statistically significant;(6) FOME,WISC-BD,WAIS-DS have been used respectively to detect the short-term memory,visual spatial executive functions,and instantaneous memory function;and the abnormal ratios of cognition are found to be 9.4%,26.6%and 4.9% respectively;(7) According to the different impaired limbs with the onset of the disease,the PD patients are divided into three groups,namely,the Left Limb Group,the Right Limb Group,and the Double Limb Group,however,the difference of the means of MoCA between the three groups is not statistically significant(P＞0.05),the different means of MMSE between the three groups also have no statistically significance(P＞0.05).There is no statistically significant difference between the incidence of cognitive impairment(by MoCA)among the three groups evaluated(X~2=1.16,P＞0.05). According to whether the patient has on-and-off phenomenon,patients are divided into two groups.And no statistically significant difference of MoCA or MMSE means has been detected between the two groups(P＞0.05).Conclusion(1)The majority of PD patients develop cognitive impairment,which occurs in the early stage of the disease;Visual-spatial executive dysfunction is common among PD patients;(2)The incidence of PD cognitive dysfunction(except of visual-spatial executive dysfunction) has no relationship with gender,depression or anxiety,dyskinesia and the side of limbs with the onset of the disease.