Study Of Cognitive Neuropsychology In Parkinson’s Disease

ObjectiveParkinson’s disease (PD) is a neurodegenerative disorder characterized by the presence of abnormal motor movements stemming from disturbances of the dopamine system. Studies of patients with PD suggest that the characteristic clinical symptoms are frequently accompanied by impairments in cognitive functions. It is well recognized that there are degeneration of the mesocortical dopamine system and reduced frontal lobe activity observed in the study in PD. Because of the intimate connections between the frontal lobes and the striatum, patients with PD display impairments in various cognitive tasks that primarily depend on the frontal lobes. Therefore, disruptions in the dopaminergic frontostriatal circuit are thought to underlie much PD-related impairment. The current study examined item and source memory by visual pathway in individuals with PD. It was expected that PD patient would demonstrate deficits in source memory compared to a healthy control group. The present study was mainly to investigate BM perception disorders in PD patients by applying both intact and scrambled BM sequences. To explore the relationship bet ween social cognition and social functioning of parkinson disease, and to test the hypothesis that t he basal ganglia is involved in the network of social cognit ion.Methods1. We established a neuropsychological battery to measure the performance of item memory and source memory.35 individuals with Parkinson’s disease and 35 matched healthy controls (HC) were administrated with the battery. Item memory task consists of the learning and recognition of high-frequency national Chinese characters; source memory task consists of the learning and recognition of three modes (character, picture, and image) of objects.2.22 PD patients (in off therapy condition) and 22 healthy controls (NCs) participated in. We used time perception as an implicit measure of the dynamic properties of human movement. In two experiments, intact and scrambled point-light walkers with their inverted stimuli as opposite inanimate motion were presented sequentially. Observers were required to verbally make a two-alternative forced choice to indicate which interval (the first or the second) appeared longer. The statistical analyses were conducted on PSEs (the point of subjective equality).3.20 PD patients and 25 age- and education-matched healthy controls were enrolled in the social cognition tests and empathy test. Social cognition abilities w ere measured with two neuropsychological tasks:eye emotion recognition (happy, surprise, fear, sad, disgust,anger) and faux pas recognition task. Empathy was measured by Interpersonal Relation Inventory- China(IRI-C).Results1. Compared with the healthy controls, the idiopathic PD patients have been impaired source memory (PD, HC:0.65±0.06,0.72±0.09, P=0.001), but not impairment in item memory (PD, HC:0.65±0.07,0.67±0.08, P=0.24).2. For the intact BM condition, there was significant difference for PD patients compared to NCs. For the scrambled one, there was also significant difference for PD patients compared to NCs.3. Patients with parkinson diseases showed a large and highly significant deficit in the faux pas task. Compared with the healthy controls, there was significant difference on cognitve empathy (PT and FS), but emotion empathy (EC and PD) were spared.There was no significant difference between parkinson diseases group and control group in eye emotional recognition. Correlation analysis revealed that, there was a significant correlation between cognitive empathy and faux pas task, while correlation between emotional empathy and faux pas task is no significant.Conclusions1. The present experiment provides evidence for dissociation between item and source memory in PD patients, thereby strengthening the claim that the item or source memory rely on different brain structures. PD patients showed poor source memory, in which dopamine plays a critical role.2. BM perception in PD patients was damaged. And the different patterns of impairment indicated different machanism of local and global BM related to basal ganglia.3. The results confirm that there are deficits of social cognition and empathy in parkinson diseases. And, there was dissociation between cognitive system and emotional system, which may due to the role of dopaminergic drugs.