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PubMed1990

Relation of EEG alpha background to cognitive function, brain atrophy, and cerebral metabolism in Down's syndrome. Age-specific changes.

We studied 19 young adults (19 to 37 years old) and 9 older patients (42 to 66 years old) with Down's syndrome (DS) and a control group of 13 healthy adults (22 to 38 years old) to investigate the relation of electroencephalographic (EEG) alpha background to cognitive function and cerebral metabolism. Four of the older patients with DS had a history of mental deterioration, disorientation, and memory loss and were demented. Patients and control subjects had EEGs, psychometric testing, quantitative computed tomography, and positron emission tomography with fludeoxyglucose F 18. A "blinded" reader classified the EEGs into two groups--those with normal alpha background or those with abnormal background. All the control subjects, the 13 young adult patients with DS, and the 5 older patients with DS had normal EEG backgrounds. In comparison with the age-matched patients with DS with normal alpha background, older patients with DS with decreased alpha background had dementia, fewer visuospatial skills, decreased attention span, larger third ventricles, and a global decrease in cerebral glucose utilization with parietal hypometabolism. In the young patients with DS, the EEG background did not correlate with psychometric or positron emission tomographic findings, but the third ventricles were significantly larger in those with abnormal EEG background. The young patients with DS, with or without normal EEG background, had positron emission tomographic findings similar to those of the control subjects. The mechanism underlying the abnormal EEG background may be the neuropathologic changes of Alzheimer's disease in older patients with DS and may be cerebral immaturity in younger patients with DS.

Adult↗

PubMed1996

Influence of moclobemide on cognitive functions of nine depressed patients: pilot trial with neurophysiological and neuropsychological indices.

Quantitative electroencephalogram (QEEG) changes induced by the acute administration of moclobemide (200 mg) in patients with major depression include a transient increase in theta-activity, a slight augmentation of alpha-activity and a sustained increase in beta-activity. This QEEG profile distinguishes moclobemide from sedative antidepressants. A 42-day treatment with 400 mg/day of the drug produces a significant decrease in the late positive-complex peak latency of the event-related potentials, suggesting a positive effect on attention and cognitive functions.

Adult↗

PubMed1992

Cognitive functioning in excessive drinkers: evidence for dissociable impairments.

This article reviews the evidence for neuropsychological impairments in excessive drinkers. The view that the neuropsychological impairments reflect clinically heterogeneous manifestations of a unitary 'Wernicke-Korsakoff complex' resulting from thiamine deficiency is discounted on the basis of a variety of mediating factors which have been demonstrated to affect the pattern of cognitive abilities and deficits in excessive drinkers. In contrast, this article argues that detailed analysis of the apparent clinical heterogeneity in the cognitive status of these patients may provide a means for determining the most appropriate treatment regime and rehabilitation procedures for an individual. These impairments are applied to a theoretical model of information processing identifying dissociable impairments which have been described as the 'frontal-lobe' and the 'right hemisphere' hypotheses of the effects of alcohol on cognitive functioning. Interpretation of research results in terms of functional characteristics rather than localization characteristics is proposed. Two mediating factors, thiamine deficiency and liver dysfunction, are discussed in relation to their differential involvement in these impairments.

Journal Article↗

PubMed2005

Apathy correlates with cognitive function but not CD4 status in patients with human immunodeficiency virus.

Apathy is a prominent neuropsychiatric symptom associated with human immunodeficiency virus (HIV). The increased frequency of apathy in this population may reflect the direct involvement of the virus on the central nervous system (CNS), but the severity of apathy has not been shown to consistently relate to markers of disease activity or other neuropsychiatric complications of the virus. We examined the relationship between ratings of apathy and performance on measures of cognitive function and immune system status in a sample of HIV-infected patients. Apathy was significantly elevated among HIV-infected individuals compared to healthy comparison subjects. Apathy was significantly related to performance on measures of learning efficiency and a measure of cognitive flexibility. Ratings of apathy did not relate to CD4 cell count, but they were associated with disease duration. In addition, ratings of depression were independent of ratings of apathy. These findings suggest that apathy does not co-vary with a proxy measure of active disease status, but apathy does relate to several measures of cognitive dysfunction in patients with HIV. As such, the increased prevalence of apathy among HIV-infected adults may reflect HIV-associated neurologic dysfunction.

Adult↗

PubMed2000

The effect of dopamine depletion from the caudate nucleus of the common marmoset (Callithrix jacchus) on tests of prefrontal cognitive function.

This study examined the effects of depletion of dopamine from the caudate nucleus of the common marmoset (Callithrix jacchus), on tasks sensitive to prefrontal damage (attentional set-shifting and spatial delayed response). There was a marked impairment in performance on the spatial delayed response task, but performance on the attentional set-shifting task was relatively preserved except for an impairment in re-engagement of a previously relevant perceptual dimension. This pattern of impairment is distinct from that seen after excitotoxic lesions of the prefrontal cortex and in patients with Parkinson's disease. Though it is not possible to identify specific cognitive functions that are independent of dopaminergic modulation of the caudate nucleus, due to the partial nature of the lesion, the results do provide insight into those cognitive processes that appear most dependent on caudate dopamine.

Animals↗

PubMed1976

Cognitive functioning under moderate and low dosage methadone maintenance.

The Wechsler Adult Intelligence Scale (WAIS) was administered to two groups of patients in the Santa Clara County Methadone Maintenance Program who were receiving low and moderate daily stabilized dosages of methadone hydrochloride. In the two separate statistical analyses performed, there were no significant differences found between subtest scores or verbal, performance, and full-scale scores of the groups measured. These results, combined with observations regarding the similarities of WAIS profiles of the two groups, indicate that cognitive functioning as measured by the WAIS was not differentially affected by the two dosages.

Administration, Oral↗

PubMed1992

The effects of paroxetine, alone and in combination with alcohol on psychomotor performance and cognitive function in the elderly.

Fifteen healthy male volunteers aged over 60 years received acute and repeated doses of paroxetine 20 mg or placebo, and acute doses of lorazepam 1 mg (as a positive internal control) with or without alcohol (0.6 g/kg of body weight) administered openly in a double blind balanced crossover study in which each subject acted as his own control. Psychomotor performance and cognitive function were assessed using a test battery which included critical flicker fusion, choice reaction time, compensatory tracking, Stroop and memory scanning tests. Subjective ratings of mood and sleep were recorded using line analogue rating scales. The pattern of results indicated that paroxetine had little or no effect on most of the test variables, and in some instances (critical flicker fusion thresholds) improved information processing ability. This was in marked contrast to the lorazepam verum which produced sedation and disruption of performance. Paroxetine had a slight antagonistic effect on alcohol induced sedation whereas impairment of performance with lorazepam was potentiated by co-administration of alcohol. The low behavioural toxicity of paroxetine in elderly volunteers has important implications for the pharmacotherapy of depression.

Aged↗

PubMed1987

Comparisons of the cognitive functioning of familial and nonfamilial alcoholics.

Alcoholic men (N = 81) participating in a Veterans Administration inpatient program were classified using four different strategies to describe the extent of familial alcoholism. These classification schemes included: (1) a comparison of alcoholics with no familial alcoholism, parental alcoholism or alcoholism in other relatives, (2) a unilineal-bilineal approach, (3) a multigenerational approach and (4) an approach that quantified the degree of familial alcoholism. Comparisons were made of the performance of the different familial history groups on a series of neuropsychological tests. No differences in cognitive functioning were found using any of the four classification schemes.

Alcoholism↗

PubMed1996

[Tolerance of neuroleptics, deficit syndrome and cognitive functions].

Neuroleptics have been held responsible for cognitive impairments and negative symptoms in the course of schizophrenia. On the other hand, recent data suggest that alterations in information processing, cognitive and neuro-psychological functions are present at early stages in the developmental course of the illness. Two recent reviews, by D. King and G. Cassens suggest that, although acute administration of neuroleptics may alter performances in some neuro-psychological functions, there is no convincing evidence so far, to support a significant role of chronic neuroleptic treatment in the development of negative symptoms and cognitive dysfunction in schizophrenia. Despite several methodological limitations, which preclude any definitive statement, experimental and clinical data suggest that chronic neuroleptic treatment might improve neuropsychological functioning and the deficit syndrome, in some groups of schizophrenic patients. These results are examined in the framework of recent theoretical developments, which emphasize the role of cognitive dysfunction in the pathophysiology of schizophrenia.

Antipsychotic Agents↗

PubMed1987

Event-related potentials as a tool in the evaluation of cognitive functions in young subjects through the execution of a simple task.

Event-related potentials (ERPs) were recorded in 20 student volunteers. Three recordings were performed using aural stimuli of 4,000 (rare tones) and 250 Hz. In the target recording subjects were asked to count the rare tones. Endogenous and exogenous components of ERP recordings were analyzed. During the target recording N2 and P3 components were observed at 200 ms and approximately 300 ms, respectively, in addition to N1 (100 ms) and P2 (180 ms). The N2 and P3 waves are indicative of analysis at a higher cognitive level and have been termed the 'response set'. The P3 wave appeared to be stable in all subjects and may represent a useful electrophysiological method to explore mnemonic and cognitive functions in man.

Adolescent↗

PubMed2004

Homocysteine and cognitive function in elderly people.

Dementia is highly prevalent among elderly people, and projections show that the number of people affected might triple over the next 50 years, mainly because of a large increase in the oldest-old segment of the population. Because of this and the disease's devastating effects, measures for the prevention and early detection of dementia are crucial. Age and years of education are among the most relevant risk factors for dementia, but in recent years the role of homocysteine has also been investigated. Homocysteine is an amino acid produced in the metabolism of methionine, a process dependent on the B vitamins cobalamin, vitamin B6 and folic acid. There is evidence that increased serum homocysteine levels are associated with declining cognitive function and dementia. We review this evidence in addition to the potential mechanisms through which homocysteine acts on the brain to cause cognitive dysfunction, the metabolism of homocysteine and factors associated with alteration of the normal metabolism.

Aged↗

PubMed1977

Cognitive function and length of survival in elderly subjects living at home.

177 people aged 65 or over, chosen at random from larger representative samples of elderly people living at home in Newcastle upon Tyne, were given the Weschler Adult Intelligence Scale (WAIS) or a shortened form of it, and followed up for 7 years or till death. Discriminated function analysis showed that the power of the test score to predict death occurring within 2 years was not explained away by its correlations with age, sex, social class or physical disability. Exclusion of clinically diagnosed chronic brain syndromes reduced but did not abolish the relationship found to exist between test score and outcome. The ascertainment of impaired cognitive functioning has important applications in the assessment of prognosis and in the planning of care of elderly people.

Aged↗

PubMed2005

Integrative assessment of brain and cognitive function in post-traumatic stress disorder.

The present study combined neuropsychological and electrophysiological measures to obtain a comprehensive profile of the everyday attentional and memory dysfunction reported in PTSD. The event-related potential (ERP) literature has consistently found abnormalities in late components (N2, P3) reflecting working memory (WM) function. However, the neuropsychological profile reported in the literature has considerable variation. The present study examined ERP activity in 33 PTSD participants and matched controls during a standard two-tone auditory oddball task. Neuropsychological assessment was carried out using a task battery assessing a wide range of cognitive functions. Consistent with previous work, the PTSD group showed delayed N2 latency and reduced P3 target amplitude, together with slower and less accurate target detection. Scalp topography provided evidence of widespread abnormality during WM function, but with strongest effects broadly over the left hemisphere. Neuropsychological testing found concomitant difficulties on factorial measures of verbal memory retention/access and sustained attention but enhanced performance on measures of immediate recall. This integrative pattern of effects reflects a specific impairment in the operation of working memory systems that guide ongoing, planned behavior and that facilitate the acquisition and retention of new memories.

Adult↗

PubMed1997

Cognitive function in younger type II diabetes.

OBJECTIVE: To examine central nervous system involvement as a possible complication of diabetes by performing a comprehensive neuropsychological evaluation of relatively young (age < 55 years) NIDDM patients and a group of control subjects. RESEARCH DESIGN AND METHODS: A cross-sectional comparative study of 28 patients, with duration of diabetes 5-18 years (mean +/- SD +/- 3.2 years), screened for acceptable glycemic control and absence of hypoglycemia on the day of examination, compared with 28 demographically similar, nondiabetic control subjects. Neuropsychometric tests performed were Mini-Mental Status Examination (MMSE), Neurobehavioral Cognitive Status Examination (NCSE), and P300 latencies (endogenous evoked potentials). RESULTS: Seven (25.0%) patients reported history suggestive of cognitive impairment during day-to-day activities, and 17 (60.7%) had distal symmetrical polyneuropathy. Average P300 latencies were significantly delayed among the diabetic patients compared with the control subjects (349.5 +/- 28.2 vs. 312.9 +/- 19.3 ms; t = 5.68, P < 0.001). Although there was no significant difference in MMSE scores, compared with control subjects significantly more patients had impairment in NCSE tests of attention (chi 2 = 7.38, P < 0.01), repetition (chi 2 = 4.073, P < 0.05), and memory (chi 2 = 5.83, P < 0.05), while there was no significant difference in tests of comprehension, naming, construction, and calculation. Duration of diabetes, HbA1c levels, and the presence of distal symmetrical polyneuropathy among patients each did not correlate with any of the parameters of cognitive function evaluated. Higher blood glucose levels during the electrophysiological testing were associated with less delay in P300 latencies among the patients. CONCLUSIONS: Central nervous system impairment, manifesting as mild impairments in certain cognitive skills, should be recognized as a possible complication of long-standing NIDDM, even in relatively younger individuals.

Adult↗

PubMed1983

Minimal brain dysfunction symptoms claimed by primary and secondary alcoholics: relation to cognitive functioning.

A group of chronic alcoholics were classified as Primary or Secondary alcoholics according to a self-administering questionnaire. Primary, compared to Secondary, alcoholics claimed a significantly higher number of childhood symptoms associated with the Hyperkinetic and/or the Minimal Brain Dysfunction (Hk/MBD) Syndromes. Primary alcoholics also performed significantly poorer on the Shipley and Raven tests than Secondary alcoholics and had more severe alcoholic dependence scores. High Hk/MBD patients performed more poorly than Low Hk/MBD patients on the Shipley and Raven tests. The results support the hypothesis that a childhood history of Hk/MBD might be a predisposing factor to a more severe type of alcoholism. The results also suggest that certain alcoholics may have premorbid deficits in cognitive functions.

Adult↗

PubMed1994

Cognitive function in old and very old residents of a residential facility: relationship to age, education, and dementia.

OBJECTIVE: To determine if age, education, and dementia status affect neuropsychological performance in old and very old frail residential care subjects. DESIGN: Descriptive study of performance at the time of preadmission assessment. SETTING: Jewish Home for the Aging, Reseda, California. PARTICIPANTS: 201 applicants to the Jewish Home for the Aging residential care setting. Mean age was 84.7 years; SD was 5.6. Ninety-five subjects were 84 years of age or younger, while 106 were age 85 and older. There were 141 nondemented, 21 demented, and 39 were possibly demented applicants. Levels of education were as follows: 0-4 years: n = 25; 5-8: n = 69; 9-12: n = 77; and, 13-20: n = 23. MEASUREMENTS: Independent variables were age, education, and dementia status. Outcome measures were Folstein MMSE, Inglis P-A Learning Test, Digit Span, Cube Copying, selected Boston Diagnostic Aphasia Exam subtests. RESULTS: Subjects with 0 to 4 years of education scored more poorly on cognitive tests than other subjects. The very old tended to score more poorly than the old. Neuropsychological tests discriminated between those with normal cognitive function, possible dementia, and established dementia. About one-third of nondemented elderly scored below the traditional impairment cut-off of 24 points on the Mini-Mental State Exam. CONCLUSIONS: Questions are raised about how to interpret the poorer cognitive performance of very old and often frail subjects, especially in long-term-care settings where there are fewer demands upon residents whose impairments might otherwise cause them more functional difficulty.

Activities of Daily Living↗

PubMed2001

MRI white matter hyperintensities, (1)H-MR spectroscopy and cognitive function in geriatric depression: a comparison of early- and late-onset cases.

UNLABELLED: BACKGROUND AND OBJECTIVES Geriatric depression is often thought to differ from that at other times of adulthood. Recently, several studies have shown that the incidence of white matter hyperintense lesions identified by brain MRI is higher in patients with geriatric depression than in healthy elderly subjects, but a consensus has not yet been reached on the relationship between the severity of white matter lesions and either cognitive impairment or depressive symptoms. METHOD: Forty-seven patients aged 50 to 75 years with major depression were divided into two groups based on age at onset of depression: early-onset (< 50 years) group (20 patients; mean age, 62.7 +/- 6.7) and late-onset (> or =50 years) group (27 patients; mean age, 65.6 +/- 5.4). The severity of hyperintense white matter lesions on MRI was classified by region, then a proton magnetic resonance spectroscopy ((1)H-MRS) focusing on the white matter of the frontal lobes, multidimensional neuropsychological tests and evaluation of depressive symptoms were conducted. RESULTS: The severity of the deep white matter lesions, the deterioration of cognitive function related to subcortical/frontal brain system and clinician-rated depressive symptoms were all more pronounced in the late-onset group compared with those in the early-onset group. It was further observed that the more severe the deep white matter lesions, the lower the levels of N-acetylaspartate/creatine. With the age of onset as the covariate, the patients with moderate deep white matter lesions had more pronounced cognitive impairment and clinician-rated depressive symptoms than those with none and/or mild lesions. CONCLUSION: These results suggest that subcortical/frontal type cognitive impairment and the persistence of depressive symptoms in geriatric depression is related to moderate deep white matter lesions more often complicated in the late-onset group. The (1)H-MRS findings were suggested to be a useful indicator of neuronal/axonal loss in the white matter of the frontal lobes which precedes cognitive impairment.

Aged↗

PubMed1980

Training cognitive functioning in the elderly--inability to replicate previous findings.

This study was designed to replicate Hornblum and Overton's study which trained conservation ability in elderly women [1]. Thirty-four elderly women volunteers were given a pretest battery of area and volume conservation tasks; participants also completed an extensive life history questionnaire. Conservation scores were the highest yet recorded by elderly participants. Thirty-two women received perfect conservation scores; only two were "partial conservers"; no participant was a "nonconserver." Consequently, training was not implemented. These women had high levels of education, good health, adequate income, satisfying leisure activities, and positive attitudes about aging. Advanced chronological age does not guarantee poor conservation performance. The mechanism(s) whereby life history variables influence cognitive functioning needs to be determined.

Aged↗