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Results for “Cognitive function”

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At least 163 records · Page 9Linked to original sources

PubMed1990

Long-term effects of cerebellar pathology on cognitive functions.

Twelve patients with circumscribed chronic neocerebellar lesions but without CT-evidence of forebrain damage (other than the effects of shunting) were investigated for deficits of cognitive functions. Two different mechanisms were considered as possible causes of cognitive impairment: (1) Damage to the dentato-thalamo-cortical projection leading to impairments of cortical functions, and (2) prolonged intracranial pressure resulting in diffuse forebrain damage and subcortical dementia. Patients with lesions in the left neocerebellum showed deficits in cognitive operations in three dimensional space, consistent with the right forebrain dominance for spatial functions. Prolonged intracranial pressure, on the other hand, resulted in a mild overall cognitive impairment.

Brain Damage, Chronic↗

PubMed1991

Anticholinergic challenge and cognitive functions: a comparison between young and elderly normal subjects.

Challenges of the central cholinergic function with anticholinergic agents have been shown to produce disruption of cognitive performance in young normal people. The purpose of the study was to compare the effects of a low dose of scopolamine in young and elderly subjects and to determine which cognitive functions are most sensitive to disruption by anticholinergics in an elderly population. Scopolamine (0.2 mg) and placebo were given to 12 normal elderly subjects (mean age 64.1 years) and 14 young subjects (mean age 26.7 years) and neuropsychological tests were designed to measure the functions of verbal memory, praxis and language. Scopolamine significantly impaired new learning in the elderly as measured by Selective Reminding Test (SRT) (p less than 0.04) and SRT delayed recall (p less than 0.05), but had no effect in the young subjects. Following the anticholinergic challenge, the elderly people also showed significantly poorer performance in all tests used for the praxis function. Results suggest a role of the cholinergic neurotransmission in verbal memory and constructional praxis. The language function was not impaired in the elderly and is not affected by anticholinergic agents.

Adult↗

PubMed1975

Pyritinol hydrochloride and cognitive functions: influence on children in slow learner classes.

Pyritinol-HCl was tested for its impact on the cognitive functions of children with learning disabilities. This study is a contribution to scientific discussion on the complicated methodologic problems in evaluating the clinical efficacy of psychopharmacologic agents. Sixty-seven pupils of slow learner classes between the ages of 11 and 16 years were treated for 6 months with 300 mg pyritinol-HCl/24 hr or placebo under strict double-blind conditions. Drug intake was stimulated and controlled by means of intense psychosocial interaction with the mothers of the subjects. The dependence variables used to test medication effects were 22 parameters of cognitive performance measured in psychologic tests for perceptual and intellectual functions which were administered immediately before and after the medication phase. First the gainscores before and after treatment with pyritinol or placebo within the 22 cognitive parameters were statistically compared. In addition, an analysis of covariance on the corrected results of the second test (treating the results of first testing as covariates) and a two group discriminant analysis for overall differences were performed. None of the 22 parameters showed statistically significant treatment effects with respect to average performance (t (pyritinol - placebo) = 1.96 to 1.31), neither could the two groups be separated by discriminant analysis (Hotelling's T2 = 35.4, df - 22 and 43, P = 0.465). With respect to a variability of gainscores, however, in four parameters there was a significantly higher variance in the pyritinol group (F = 1.85-2.33, P less than 0.05, less than 0.02, respectively). This fact may signify that pyritinol-HCl had different effects on different subjects. By means of prognostic stratification we therefore attempted to define objective criteria for a selection of subjects with probable positive treatment effects. None of the 15 tested criteria, such as body weight, age, perceptual handicaps, or reduced short term memory, IQ range, proved, however, to be critical for a prognosis of pyritinol effects within the present test population.

Adolescent↗

PubMed1989

Cognitive functioning after subarachnoid haemorrhage of unknown origin.

Twenty patients, who had sustained a proven subarachnoid haemorrhage (SAH) and in whom cerebral panangiography had failed to reveal any source of the bleeding (SAH-NUD), were subjected to a neuropsychological examination involving memory functions, spatial perceptual organization, visuoconstructive abilities, reasoning, perceptual speed and accuracy, and concept formation. Cognitive functioning in SAH-NUD patients was compared with normal reference values and also related to the cognitive performance of neurologically intact patients having sustained an aneurysmal bleeding (SAH-AN). SAH-NUD patients showed significant reduction of verbal learning and retention, and of abilities involving abstract attitude and concept formation, i.e., functions related to frontotemporal structures. In all other respects the performance of these patients approached normality. Unexpectedly, there were no significant differences in mean test scores separating SAH-NUD from aneurysmal SAH patients. Collapsing the patient groups produced an increased number of significant deviations from normality, which was interpreted as the effect of the contribution of a greater number of relatively more impaired SAH-AN patients. This was supported by the finding that the ratio of impaired individuals to total number of subjects differed in the groups; the proportion of individuals showing cognitive sequelae was larger among SAH-AN patients throughout all comparisons but one. Although SAH of unknown aetiology represents much less of a catastrophe as compared with haemorrhage of aneurysmal origin, it does not preclude cognitive disturbances. Thus, the presence of blood per se anywhere in the subarachnoid spaces appears to affect higher brain function(s).

Adolescent↗

PubMed1992

Changes in cognitive functioning of the oldest old.

Cognitive changes during a 2-year interval in a representative sample of the oldest old were investigated. Respondents were 324 people aged 84 to 90 at baseline who were selected from census records in the Jönköping region of Sweden. Following a 2-year interval, it was possible to reinterview 213 people, or 94% of individuals, still alive. Performance on a battery of five cognitive tests showed a small decline in mean scores, and a 10% increase in the number of people meeting criteria for significant cognitive impairment. Respondents with better functioning at baseline tended to have stable performance over this period.

Aged↗

PubMed1992

Cognitive function in non-demented older adults with hypothyroidism.

PURPOSE: (1) to evaluate objectively changes in cognitive function and electrophysiologic characteristics associated with hypothyroidism of varying severity and duration in primarily older persons; (2) to determine whether these changes are reversible when a euthyroid state has been attained after treatment with thyroid hormone. SUBJECTS AND METHODS: We enrolled 54 non-demented hypothyroid patients (31-99, mean 68.6 +/- 16.4 years) with biochemical evidence of hypothyroidism (38 had overt and 14 had minimal hypothyroidism) and 30 euthyroid controls (31-96, mean 63.7 +/- 18.4 years) screened for good general health. We evaluated attention, orientation, memory, learning, visual-spatial abilities, calculation, language, visual scanning, and motor speed using standardized neuropsychological tests. Electrophysiological measures of neurocognitive function included the P300 latency component of the auditory Event-Related Potentials (ERP) and conduction speed from eye to cortex, the P100 latency component of the Patterned Visual-Evoked Potential (PVEP). All patients were studied when hypothyroid. A subset of patients with minimal initial test abnormalities were available to be retested when euthyroid, 5 and 9 months after onset of thyroid replacement therapy. RESULTS: Hypothyroid patients showed significantly lower scores on the Mini-Mental Status Test (MMS) and on five of 14 neuropsychological tests as compared to controls. The neuropsychological tests affected were copying a cube (visual-spatial function), the Inglis Paired Associates Learning Test-Low and Medium association items (memory and learning), Animal Naming (word fluency/production), and the Trail Making A test (attention, visual scanning and psychomotor function. Hypothyroidism also was associated with longer P100 latencies of PVEPs to 20' checks, but showed no significant differences in PVEP P100 latency to 50' checks, nor in the latency of the auditory ERP component P300. There was a statistically significant correlation between a laboratory index of the severity of hypothyroidism (serum T4) and the Inglis Medium Association items and Animal Naming. There was a statistically significant improvement after 5 months of treatment on three of the timed performance tests that previous studies have shown to be most sensitive to brain dysfunction. CONCLUSION: Hypothyroidism in non-demented older adults is associated with impairments in learning, word fluency, visual-spatial abilities, and some aspect of attention, visual scanning, and motor speed. The MMS by itself was sensitive in differentiating hypothyroid patients with cognitive deficits from controls, while electrophysiological measures did not generally differentiate the hypothyroid patients from normal controls. The MMS was not sensitive to treatment effects, but treatment was associated with significant improvements in three of the most sensitive measures of cognitive dysfunction.

Adult↗

PubMedDate not supplied

[Cognitive function in alcoholics in a double-blind study of piracetam].

The effects of piracetam on cognitive functions have been studied in alcoholic patients. The investigation was carried out on 27 alcoholics who were admitted to hospital with acute withdrawal syndrome. The trial was performed under double-blind condition. Thirteen patients were treated with piracetam and 14 with placebo. The performance of patients treated with piracetam (experimental group) was significantly better at the Block-Design retest, as compared with the control subjects. This was associated with comparatively good perceptual organization, visual motor coordination and abstract reasoning in these patients. Similar kind of performance of these patients has been achieved in the tests used to measure psychomotor speed and attention capacity. Our findings agree well with some observations of the clinicians and may stimulate further research in this field.

Adult↗

PubMed1992

Cognitive function and regional cerebral blood flow in Parkinson's disease.

In order to investigate relationships between cognition and regional brain function, we studied 20 non-demented patients with idiopathic Parkinson's disease (PD), 21 mildly demented patients with Alzheimer's disease (AD) and 24 control subjects using cognitive testing and single photon emission computerized tomographic (SPECT) measurements of relative regional cerebral blood flow (rCBF). Neuropsychological tests were grouped into clusters reflecting frontal lobe executive abilities, perseveration, memory and visuospatial ability, with a summary score summarizing performance in all four of these spheres. SPECT imaging utilized the tracer [123I]N-isopropyl-p-iodoamphetamine with a relative measure of regional tracer uptake normalized to occipital radiotracer uptake (rCBF ratios). Patients with PD performed more poorly than controls in all cognitive domains, and were intermediate to AD patients and controls in tests of memory and overall cognitive functioning. Those PD patients who performed most poorly on neuropsychological testing showed lowest rCBF ratios in left and right temporal lobes. Using a stepwise multiple regression procedure, we examined patterns of correlations between cognitive clusters and predictor variables, including rCBF ratios, in the PD patients. We found that while patient age was a strong determinant of performance on the memory cluster and the summary score, dorsolateral frontal lobe perfusion and scores on a depression inventory accounted for a greater proportion of the variance of the frontal lobe and perseveration clusters than did age. These results imply that different neural mechanisms are responsible for the different aspects of cognitive decline seen in PD patients, with overall cognitive function closely related to age and temporal perfusion, while frontal lobe abilities are more linked to frontal perfusion and the presence of depression.

Aged↗

PubMed1989

Effects of social drinking and familial alcoholism risk on cognitive functioning: null findings.

The effects of both heavy social drinking and high familial alcoholism risk status on the cognitive performance of college men were examined in this study. A two by three factorial design was employed represented by two social drinking groups (heavy/nonheavy) and three familial risk groups (high, middle, and low). The cognitive performance tasks employed--group embedded figures, revised Beta mazes, mirror tracing, and symbol-digit paired associate learning--had all been previously shown to present difficulties to male alcoholics. No evidence was obtained of a relationship between heavy drinking or familial risk and cognitive functioning, nor a meaningful interaction of these two independent variables. Little evidence was revealed for the "hangover hypothesis" as evidenced by a relationship between drinking behavior within the past week and cognitive performance. The findings are discussed in the context of previous findings in these areas and the general difficulties of interpretation posed in nonexperimental research based on subject variables.

Adolescent↗

PubMed1991

Cognitive functioning and positive and negative symptoms in schizophrenia.

The present study examined schizophrenics' performance on a variety of cognitive measures in order to explore the relationship between schizophrenic symptoms and cognitive performance. The Wechsler Adult Intelligence Scale and a battery of neuropsychological tests, developed at the Montreal Neurological Institute, were administered to 38 acutely ill, hospitalized schizophrenics. Patients were diagnosed using DSM III criteria. Negative symptoms were assessed with the SANS and positive symptoms with the SAPS. Both the cognitive tests and the symptom rating scales were re-administered to this sample at a 6 month follow-up period. Analyses revealed that, at both time periods cognitive deficits were more likely to be associated with high negative symptom ratings than with positive symptoms. Only certain tests showed significant improvement at the follow-up period. Furthermore, improved cognitive functioning was related to an improvement in positive, but not negative, symptoms.

Adolescent↗

PubMed1988

[Cognitive function in patients with parkinsonism--in relationship with frontal lobe symptoms].

Whether the basal ganglia have a cognitive function or not is a worldwide dispute. We have examined 13 parkinsonian patients and 12 age-matched non-parkinsonian controls using the Modified Wisconsin Card Sorting Test (MCST). All 12 controls could achieve all 6 sets of categories which were successively changed. On the other hand, in the parkinsonians, 9 patients could achieve all 6 sets, but 4 patients could do only 4 to 0 sets. The difference between the two groups was statistically significant. These 4 patients who showed poor achievement on MCST had tendency showing higher percentage of perseverative errors. Taking the proportion of perseverative error (PE) to total error (TE) revealed that the parkinsonian group had a peak ranged from 55% to 65% which meant higher occurrence of perseverative errors. When the 4 parkinsonians whose proportion of PE/TE on MCST was over 55% were excluded, a comparison of the parkinsonians with the controls showed no significant difference statistically in both groups. There were no clinical differences based upon Yahr's classification between the 4 parkinsonians with poor MCST score and those with the normal score. Among these parkinsonians whose proportion of PE/TE ranged from 55% to 65%, 3 cases showed apparent frontal lobe signs and 3 mild dementia on Wechsler Intelligence Scale for Adults. Two patients with chorea-acanthocytosis and showing a marked atrophy of the caudate nucleus were also examined. They showed excellent results on MCST.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1988

Correlates of cognitive function in an elderly community population.

In 1982 and 1983, brief, structured performance tests of selected areas of cognitive function were administered to 3,682 (82.1 per cent) of the residents aged 65 years and older of the geographically defined community of East Boston, Massachusetts, a center of the Established Populations for Epidemiologic Studies of the Elderly program. There was a strong inverse relation between age and performance on all four cognitive tests in analyses adjusted for sex only as well as in those adjusted for the effects of other variables. Similarly, fewer years of formal education, increasing level of disability on the modified Katz Activities of Daily Living Scale, and less prestigious occupations, as measured by the modified Duncan Socioeconomic Index, were each independently related to lower performance on all four tests.

Activities of Daily Living↗

PubMed1986

Effects of D-Met2, Pro5-enkephalinamide on pain tolerance and some cognitive functions in man.

The effects of D-Met2, Pro5-enkephalinamide (EA) on pain tolerance and some cognitive functions have been examined in healthy male volunteers. Dihydrocodeine (DC) was used as reference substance. Applying the submaximum effort tourniquet technique EA (10 mg SC) was found to elevate the pain threshold similarly to DC (20 mg SC). Neither DC nor EA impaired the performance in the symbol cancellation test, which quantitates the intensity of attention. In this assay rather a slight improvement was detected. in addition the short-term memory performance (Wechsler test) was also improved by EA and DC. No alteration was seen in the word fluency test, an indicator of long-term (semantic) memory. The data show that EA not only improves pain tolerance but some of its mental effects are similar to those of a classical morphine congener DC.

Adult↗

PubMed1987

Reliability and validity of the Disability Rating Scale and the Levels of Cognitive Functioning Scale in monitoring recovery from severe head injury.

The Disability Rating Scale (DRS) and the Levels of Cognitive Functioning Scale (LCFS) are both widely used to monitor recovery from head injury, despite the total lack of published research on the reliability and validity of the LCFS, and the fragmented and incomplete reports on these characteristics of the DRS. Forty head-injured inpatients were evaluated with the DRS and LCFS four times weekly throughout their rehabilitation hospitalization. The DRS and LCFS were compared in terms of how consistently ratings could be made by different raters, how stable those ratings were from day to day, their relative correlation with Stover Zeiger (S-Z) ratings collected concurrently at admission, and with S-Z, Glasgow Outcome Scale (GOS), and Expanded GOS (EGOS) ratings collected concurrently at discharge, and finally in the ability of admission DRS and LCFS scores to predict discharge ratings on the S-Z, GOS, and EGOS. Results suggest that both scales possess significant degrees of test-retest and interrater reliabilities, and of concurrent and predictive validities, but the DRS surpasses the LCFS in nearly every regard. These results offer psychometric justification favoring the use of the DRS for monitoring recovery from head injury.

Adult↗

PubMedDate not supplied

Behavioral toxicology: evaluating cognitive functions.

Behavioral toxicology is concerned with the identification of adverse effects on neural and behavioral functions resulting from exposure to a neurotoxicant. Many substances are known to have effects on cognitive functions such as memory, attention and perception. This paper reviews some of the issues that must be addressed when trying to assess these neurotoxic effects on cognition, and identifies a variety of paradigms that have been explored for use in behavioral toxicology.

Arousal↗

PubMed1992

Cortical localization of cognitive function by regression of performance on event-related potentials.

This paper demonstrates a new method of mapping cortical localization of cognitive function, using electroencephalographic (EEG) data. Cross-subject regression analyses are used to identify cortical sites and post-stimulus latencies where there is a high correlation between subjects' performance and their cognitive event-related potential (ERP) amplitude. The procedure was tested using a mental arithmetic task and was found to identify essentially the same cortical regions that have been associated with such tasks on the basis of research with patients suffering localized cortical lesions. Thus, it appears to offer an inexpensive, noninvasive tool for exploring the dynamics of localization in neurologically normal subjects.

Adult↗

PubMed1985

A psychopharmacological perspective of cognitive functions. II. Specific pharmacologic agents.

In this article we review the effects of specific drugs or neurotransmitter systems on cognitive functions. While much of what we know about drugs' effects on memory is derived from animal experiments, this review focuses on studies relevant to human clinical conditions. We conclude with a speculative analysis or taxonomy of the pharmacology of memory which broadly highlights the utility of viewing memory as being comprised of several differentiated processes.

Adrenal Cortex Hormones↗

PubMed1991

The effects of alcohol and other drugs on psychomotor performance and cognitive function.

The effects of four doses of alcohol (0.25 g/kg-1 g/kg) and placebo on a standard test battery of cognitive and psychomotor performance are described. The tests included critical flicker fusion threshold, choice reaction time, tracking and memory scanning. The results of this experiment are compared with those of a number of similar studies which examined the effects of other psychoactive substances. Using relative effect sizes, the behavioural toxicity of alcohol is compared with the effects of these other drugs on psychomotor performance and cognitive function.

Adult↗