Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0030567 (Parkinson's disease)
 63,064 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Parkinson's disease (PD) is associated with specific cognitive deficits in the absence of dementia, including the inability to suppress previously learned responses in a changed context. Our goal was to determine whether this set-shifting deficit is sufficient to account for impaired performance on a problem-solving task, or, instead, whether it is necessary to postulate deficits in one or more other cognitive capacities, such as logical deduction. Deductive reasoning and other conceptual abilities were assessed in 15 nondemented subjects with PD who had never been medicated, 15 nondemented subjects with PD who were currently receiving medication, and 15 healthy elderly control subjects. On a deductive reasoning task, Poisoned Food Problems, the PD groups made more errors than the control group. The PD groups' error pattern was characterized by intrusions of information from previous problems. By contrast, the PD groups made appropriate assessments of redundant and irrelevant information that appeared in these problems, and performed normally on other tests of concept formation and problem solving that did not require set shifting, indicating that the capacities for logical deduction and concept formation were intact. The set-shifting deficit, conceptualized as a difficulty in suppressing a prepotent response, appears to be a primary cognitive impairment in PD and presumably arises from dysfunction of the nigrostriatal-dorsolateral prefrontal cortex complex loop.
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PMID:Impaired problem solving in Parkinson's disease: impact of a set-shifting deficit. 808 16

In order to investigate features of cognitive impairment in idiopathic Parkinson's disease (PD) and suitable methods for the cognitive evaluation of patients with PD, 23 PD patients and 15 normal control subjects were studied using neuropsychological tests and auditory event-related potential (ERP). The two groups did not differ from each other in age or education. Clinical severity of the patients based on Hoehn & Yahr's staging ranged from stage I to IV: 7 patients at stage I, 8 at stage II, 7 at stage III and 1 at stage IV. All patients achieved the Mini-Mental State test (MMS) scores of 24 or greater, and none of the patients showed middle or serious grade of dementia based on the Diagnostic and Statistical Manual of Mental Disorders-Third edition-Revised (DSM-III-R). All patients and controls underwent MMS, the Hasegawa's Dementia Screening Scale (HDS), the Wechsler Adult Intelligence Scale-Revised (WAIS-R), the Raven's coloured progressive matrices (RCPM), The Wisconsin Card Sorting Test (WCST) and the Benton Visual Retention Test (BVRT). Auditory ERPs by standard oddball paradigm (two-choice reaction time task) were elicited (band-pass 0.1-50 Hz) from Cz electrode sites on all subjects with a random series of binaural 1,000 (standard; 80%) or 2,000 (target; 20%) Hz tones presented every 2 sec at 70 dB SPL. In RCPM, N100 peak latencies of ERP (target and standard), performance-IQ of WAIS-R (especially block design and digit symbol subtests) and in error scores of BVRT there were striking differences between the two groups (p < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Cognitive function and its evaluation methods in Parkinson's disease--a study including RCPM and ERP]. 812 74

We reconstructed three-dimensional (3D) surface images from data from single-photon emission computed tomography (SPECT) with N-isopropyl-p[123I]-iodoamphetamine (123I-IMP) in 29 patients with Parkinson's disease, 16 patients with Alzheimer's disease and 11 normal control subjects. In patients with nondementing Parkinson's disease, perfusion defects were frequently found in the parietal cortical region at a threshold value of 65%. In demented Parkinson's disease patients, perfusion defects were frequently noted at threshold of 45-65%, and were more marked in the bilateral temporal and parietal cortices. In Alzheimer's disease, perfusion defects were similar to those found in dementing Parkinson's disease. These results suggest that dementia in Parkinson's disease is related to the perfusion reduction of the temporoparietal cortex, and may support the view that Parkinson's disease and Alzheimer's disease overlap in some patients. A 3D display of an 123I-IMP brain tomogram may be useful for detecting cortical lesions in patients with dementia or cognitive impairment.
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PMID:Brain perfusion imaging in Parkinson's disease and Alzheimer's disease demonstrated by three-dimensional surface display with 123I-iodoamphetamine. 813 97

In order to evaluate possible progression in the severity of their cognitive impairment, 34 parkinsonians with intellectual impairment were followed longitudinally for 7 years. Each patient was matched for age, sex, severity and duration of illness, and pharmacological treatment, with a parkinsonian patient without cognitive impairment. Results suggest that cognitive deficits are not static but rather there is a progression in the severity. Furthermore, patients suffering from severe dementia are more likely to die during the follow-up period. The prognosis of Parkinson's disease seems to be changed substantially by the occurrence of dementia. The natural history of parkinsonian dementia does not seem to differ from the history of other forms of dementia with a progressively disabling course leading to a complete loss of autonomy.
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PMID:Neuropsychological follow-up of parkinsonian patients with and without cognitive impairment. 815 82

Tone was evaluated quantitatively in 39 patients with Huntington's disease (HD) by measuring resistance to passive elbow flexion and extension movements on a hydraulic testing device. A velocity dependent increase in resistance to passive elbow flexion and to a lesser extent in resistance to passive extension was found in 10 patients. Increase in muscle tone was related to disease duration but not to the age of the patients nor to the severity of choreatic movements or the amount of cognitive impairment. A hypertonic pattern could be observed also in patients without any medication, and seemed not to be related to neuroleptic treatment. The pattern of tone change in HD is compared to the pattern of hemispasticity in upper motor neuron syndrome and to that of Parkinson's disease. It appears that an increase in muscle tone, with a velocity dependent resistance to flexion more than extension movements, is a frequent feature in advanced stages of Huntington's disease.
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PMID:Muscle tone in Huntington's disease. 815 6

Cognitive functions of 24 patients with early onset parkinsonism (age of onset before 40 years) and 24 controls were investigated by a battery of neuropsychological tests. Patients were shown to be impaired in performance IQ (PIQ), conceptual ability and regulation behavior, memory, visuospatial perception, and manual dexterity. Patients were also shown to have a higher Zung Depression score. However, analysis of the testing scores appeared to indicate that only a small portion of poor performance on neuropsychological tests are depression related. The results demonstrated that patients with early onset parkinsonism, in whom the factor of aging is not as important, still show cognitive dysfunction and suggested that Parkinson's disease itself can cause cognitive impairment.
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PMID:Cognitive dysfunction in early onset parkinsonism. 817 36

The prevalence of cognitive impairment was determined in a random age- and sex-stratified sample of 2,011 elderly Hong Kong Chinese, aged 70 years and over, consisting of subjects living in the community and in institutions. The Information/Orientation Section of the Clifton Assessment Procedure was used as the screening instrument using a cutoff point of 7. The overall age-adjusted prevalence was 5% for men and 22% for women, and 15% for both sexes combined. Univariate analysis identified the following associated factors in order of magnitude of the odds ratio: age; history of Parkinson's disease; functional disability; female sex; low educational level; low social class; history of stroke, and low monthly income. Other diseases, such as heart disease, hypertension, chronic lung diseases or diabetes, were not associated factors. In multivariate analysis, all the above factors remained significant with the exception of a history of stroke. The prevalence figures are comparable to other Caucasian and Chinese studies, and the associated factors identified suggest that there may be room for prevention.
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PMID:Prevalence of cognitive impairment and associated factors among elderly Hong Kong Chinese aged 70 years and over. 819 Feb 6

Studies attempting to relate cognitive impairment to asymmetry of motor symptoms in Parkinson's disease (PD) have found contradictory results. We examined 88 patients with unilateral onset of idiopathic PD who underwent a comprehensive neuropsychological assessment, including language, visuospatial abilities, abstraction and reasoning, attention and mental tracking, set shifting, and memory. Patients whose motor signs began on the left side of the body consistently performed more poorly on the battery of cognitive measures than did patients with right-side onset. Significant differences were found on immediate and delayed verbal recall, word retrieval, semantic verbal fluency, visuospatial analysis, abstract reasoning, attention span, and mental tracking. These differences could not be attributed to differences in the overall severity of motor symptoms at the time of cognitive assessment, or the current pattern of motor asymmetry. This finding suggests that damage to right-hemisphere dopamine systems plays a disproportionately greater role in PD-related cognitive decline than a presumably comparable left-hemisphere dopamine depletion.
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PMID:Side of onset of motor symptoms influences cognition in Parkinson's disease. 821 46

Parkinson's disease is characterized not only by tremor, akinesia and rigidity, but also by frontal cognitive dysfunction, that can be understood as a disturbance in the 'Supervisory Attentional System' (SAS). This concept refers to a system, located in the frontal cortex, that regulates attentional processes under novel, non-routine conditions. The hypothesis that cognitive dysfunction in Parkinson's disease results from a disturbance in the SAS was investigated by recording 'processing negativity' in 33 parkinsonian patients and 17 controls. Processing negativity is an event-related potential that reflects neuronal activity during selective attention. The contribution of the frontal cortex to selective attention can be studied directly using processing negativity. Parkinsonian patients were also scored for clinical symptoms and subjected to a neuropsychological test battery. Processing negativity was clearly disturbed in the parkinsonian patients. Moreover, parkinsonian patients with the lowest scores on 'frontal' neuropsychological tests such as Stroop, Trail Making and Word Fluency, also had the lowest processing negativity. Our results support the hypothesis that cognitive dysfunction in Parkinson's disease might be understood as a disturbance in the frontal regulation of attentional processes. Degeneration of the dopaminergic mesocortical innervation of the frontal cortex in Parkinson's disease is a possible neurochemical substrate of these frontal attentional disturbances.
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PMID:Disturbed frontal regulation of attention in Parkinson's disease. 822 Oct 52

We examined the effects of selected health conditions and sensory functions, socioeconomic status, age, and education on cognitive functioning in 3,974 community-dwelling individuals aged 65-84 years. Logistic regression analysis was used to examine the independent and joint effects of these variables on borderline (Mini-Mental State Exam [MMSE] of 22-25) and poor (MMSE of < or = 21) functioning relative to adequate functioning (MMSE of 26-30). The effect of age and of education on MMSE performance was relatively stable, even after adjusting for age- and education-related health conditions and sensory impairments that also influenced level of cognitive functioning. These conditions included poor vision, Parkinson's disease, diabetes, depression, stroke (in 65-74-year-olds), and low socioeconomic status (in 75-84-year-olds). Education did not modify the effect of these variables on MMSE performance. Additional studies elucidating further the mechanisms that relate these sociodemographic factors to cognitive performance are warranted, as are studies of the relationship between these factors and the incidence of cognitive impairment.
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PMID:Are age and education independent correlates of the Mini-Mental State Exam performance of community-dwelling elderly? 822 99


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