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Relation of cerebral blood flow to motor and cognitive functions in chronic stroke patients.

BACKGROUND AND PURPOSE: The aim of this study was to examine the levels of cerebral blood flow in relation to motor and cognitive functions in 300 chronic unilateral stroke patients (age, 64 +/- 12 years; mean +/- SD). METHODS: Cerebral blood flow was measured by the 133Xe inhalation method, adjusted for age, sex, and PCO2 level. Motor function was scored according to Brunnstrom hemiplegic staging and cognitive function according to the Hasegawa dementia rating scale tested in Japanese. RESULTS: Asymmetries of blood flow between affected and nonaffected hemispheres increased with lesion size and were highest in 11 embolic strokes (20 +/- 9%) and higher in 80 nonembolic cortical infarctions (11 +/- 11%) and 76 hemorrhages (9 +/- 7%) than in the group of 133 subcortical infarctions (2 +/- 6%) or 16 control subjects (1 +/- 2%). Severity of hemiparesis correlated with decreased cerebral blood flow in the affected hemisphere (P < .01) and increased hemispheric asymmetries of blood flow (P < 001). Cognitive impairments, after adjusting for age, correlated with decreased cerebral blood flow in the nonaffected hemisphere (P < .0001), left hemispheric lesions (P < .0005), and embolic stroke (P < .005) but not with asymmetries of blood flow. Among 67 patients having bilateral reductions of cerebral blood flow, 25 patients with left hemispheric lesions showed more severe cognitive impairments than among 42 patients with right hemispheric lesions (P < .05). CONCLUSIONS: We confirmed that severity of hemiparesis correlated with the degree of asymmetries of cerebral blood flow, reflecting the extent and location of the lesions. Bilateral reductions of cerebral blood flow in patients with left hemispheric lesions may in part contribute to cognitive impairments, indicating reductions of global neuronal activities in the contralateral hemisphere or diffuse cerebrovascular changes. Further studies of cerebral metabolism and follow-up of cerebral circulation are required to reveal the pathophysiology and clinical consequences.

Adolescent↗

Effects of auditory stimulus intensity and hearing threshold on the relationship among P300, age, and cognitive function.

OBJECTIVE: Although P300 is regarded as cognitive or endogenous, studies have demonstrated that stimulus intensity influences the component. To isolate effects of hearing from cognition, two experiments were designed to compare the effects of variation in stimulus intensities with naturally occurring differences in hearing thresholds. METHODS: In experiment 1, 18 participants were tested with 5 auditory oddball event-related potential (ERP) paradigms with different intensities. In experiment 2, an auditory oddball ERP task was completed by 3 groups of participants with different hearing thresholds (n=57). P300 was then correlated with block design and matrices from Wechsler's abbreviated scale of intelligence. RESULTS: At Cz and Pz, manipulation of intensity had less effect on P300 than the observed differences between groups with different hearing thresholds. At Fz, however, the effect of manipulations of stimulus intensity was greater than the effect of naturally occurring differences in hearing thresholds. P300 still correlated in predicted directions with cognitive tests after correcting for the estimated effect of differences in hearing. CONCLUSIONS: The results indicate that P300 is an index of cognitive function even when the relationship is corrected for perceptual differences, at least at posterior scalp areas.

Acoustic Stimulation↗

Cognitive functioning in premenstrual syndrome.

OBJECTIVE: To evaluate cognitive functioning in women with premenstrual syndrome (PMS) and controls during the follicular and luteal phases of the menstrual cycle. METHODS: Thirty women with PMS and 31 controls were selected on the basis of psychiatric interview and prospective daily diary recordings. Subjects were tested on two occasions, follicular (days 8-10) and luteal (days 24-26), using complex tasks consisting of measures validated previously for the assessment of "executive" frontal-lobe functions. Tests were counterbalanced for order across subjects. RESULTS: The Beck Depression Inventory scores were significantly different between the groups and across time (P < .001). Women with PMS had a mean luteal phase Beck score of 13.3 consistent with mild-to-moderate premenstrual depression. There were no statistically significant score differences in tests for attention, memory, cognitive flexibility, and overall mental agility. The evaluation of our preliminary data with 30 PMS subjects and 31 controls indicated a very small effect size (.02). To detect an effect size this small (if in fact one exists) with a power of .8 would require a sample of more than 1000 subjects per group. CONCLUSION: Our sample of women with PMS failed to demonstrate objective evidence of diminished cognitive performance, despite subjective feelings of inadequacy.

Adult↗

Differential effect of desglycinamide9-(Arg8)-vasopressin on cognitive functions of diabetes insipidus and alcoholic patients.

Intranasal treatment with desglycinamide9-(Arg8)-vasopressin (DGAVP) improved certain aspects of cognitive functions of patients with acquired and congenital diabetes insipidus and of alcoholic patients with mild cognitive impairments. Patients with Korsakoff's syndrome, presenting with severe cognitive impairments, were resistent to DGVP treatment. DGAVP treatment did not affect blood pressure and water metabolism. The action of DGAVP on cognitive functions is probably mediated by centrally located target sites and may be expressed only in patients in whom these target sites are unimpaired.

Administration, Intranasal↗

Bipolar I patients with and without a history of psychotic symptoms: do they differ in their cognitive functioning?

Recently, many reports have consistently demonstrated cognitive deficits in patients with bipolar disorder (BD), but their relationship with symptomatology, specifically psychotic symptoms, remains unclear. Our main hypothesis was that a history of hallucinations and/or delusions in the course of BD-I is associated with severe cognitive deficits. We investigated several cognitive functions (memory, attention, verbal fluency and executive functions) in 18 BD-I patients with a history of psychotic symptoms (HPS+), 17 BD-I patients without a history of psychotic symptoms (HPS-), 33 schizophrenic patients and 26 healthy control subjects. Both groups of BD-I patients were more impaired than the normal controls in attention, verbal memory, verbal fluency and executive functions. Only HPS+ BD-I patients showed more difficulties in completing the Stroop test than nonpsychotic bipolar patients. Nevertheless, after adjustment for the effects of current psychopathology, this difference disappeared. Schizophrenic subjects showed worse performance than BD-I subjects in verbal memory and verbal fluency. These results suggest that a history of psychotic symptoms in bipolar I disorder may not be associated with more cognitive deficits. Further research on euthymic bipolar patients with and without HPS is required to confirm these findings.

Adolescent↗

Cognitive functioning in 8- to 18-month-old drug-exposed infants.

This study examined the cognitive functioning in 236 infants at 8 and 18 months of age. Thirty-seven infants were heavily exposed to cocaine in-utero, 30 were lightly exposed, and 169 were not exposed to cocaine. Cognitive functioning was evaluated with the Bayley Scales of Infant Development (2nd ed.; N. Bayley, 1993) at both ages. Infant information processing was also assessed with an infant-controlled habituation procedure. Results indicated that (a) infants of cocaine-abusing women had higher neonatal medical and environmental risk scores; (b) at 8 months, exposure groups did not differ in Psychomotor Development Index, Mental Development Index (MDI) scores, or recovery to a novel stimulus; and (c) infants heavily exposed to cocaine or high environmental risk had a decrease in MDI scores from 8 to 18 months. These results were obtained when neonatal medical and environmental risk, as well as polydrug exposure, were controlled.

Child Development↗

Cognitive function after systemic therapy for breast cancer.

An underinvestigated area of breast cancer survivorship involves the possible impairment of cognitive function following adjuvant chemohormonal therapy. Numerous reports of disturbing and disruptive changes in short- and long-term memory, attention span, concentration, and language skills have been made by breast cancer patients who have received chemotherapy. This article reviews the four published studies that have documented cognitive dysfunction following adjuvant chemohormonal therapies commonly used in breast cancer. The studies describe a subset of approximately one-third of participants who experienced long-term cognitive impairment. Patient- and treatment-related factors that may influence cognitive function are outlined. The impact of these cognitive impairments on the individual breast cancer survivor's quality of life is discussed, as is the potential overall impact of this research on future adjuvant therapy. The need for a prospective longitudinal study documenting the neuropsychological sequelae of adjuvant chemohormonal therapy is emphasized.

Adult↗

Effects of improved glycaemic control maintained for 3 months on cognitive function in patients with Type 2 diabetes.

BACKGROUND AND AIM: In a previous study we failed to find beneficial short-term effects of improved glycaemic control on cognitive functioning in patients with Type 2 diabetes mellitus. A subgroup of the entire sample was tested again to examine the effect of longer-lasting improvement of metabolic control on cognitive functioning. METHODS: The cognitive performance of 26 patients with Type 2 diabetes was assessed at baseline and 3 months after discharge. Thirteen controls were tested at the similar time-points. Attention/concentration, psychomotor speed, verbal fluency, verbal memory and depressive symptoms were assessed. Improved glycaemic control was generally achieved with insulin therapy (20/26). RESULTS: At baseline, there was a trend for diabetic patients to perform worse than controls. Both groups improved significantly over 3 months in several measures. However, diabetic patients did not improve more than controls. CONCLUSIONS: In individuals with long-standing Type 2 diabetes, previous reports of improved cognitive capacity following restoration and maintenance of near-normoglycaemia were not confirmed. This might relate to the type of anti-diabetic therapy.

Blood Glucose↗

[Effects of microgravity on human cognitive function in space flight].

In researches of space flight, studies on the effects of microgravity on cognitive function were relatively few. This paper reviews recent progress on this topic. It was shown that under the condition of microgravity, spatial orientation, motion perception and early process of object recognition were impaired to a certain degree. Capability of muscle movement and coordination was lowered, while higher cognitive functions, such as logic reasoning task, the speed and accuracy of short-term memory retrieval were less affected by microgravity. But long-term memory tasks and performance in which attention processes were needed (e.g., tracking task, selective response task), were impaired during space flight or under simulated weightlessness condition.

Cognition↗

Preliminary assessment of cognitive function in older adults by clock drawing, box copying and narrative writing.

OBJECTIVE: To examine 3 cognitive screening tasks in older adults and determine which demographic, medical and lifestyle variables obtained 13-17 years previously predicted cognitive performance. DESIGN: Population-based longitudinal cohort study begun in 1981. SETTING: Leisure World Laguna Hills, a California retirement community. PARTICIPANTS: The cohort is predominantly white, well educated, upper-middle class; two thirds are women. Data from 1,744 participants (mean age 83 years, range 57-103) were analyzed. MEASUREMENTS: The baseline postal survey (1981-1985) asked demographic information, medical history, selected drug use and personal habits. The 1998 follow-up included 3 tasks to assess cognitive function: (1) clock drawing, (2) copying a box drawing and (3) narrative writing to describe a pictured scene. RESULTS: Within age groups, women tended to have lower scores than men on box copying, similar scores on clock drawing, but higher informational and complexity scores on narrative writing. Performance decreased with increasing age and was poorest in individuals > or = 90 years old. In addition to age, sex and education, significant predictors of performance were: exercise, body mass index and cataract surgery (clock); vitamin E supplements, daily aspirin use and gallbladder surgery (box); vitamin A supplements (narrative writing). Mean scores on all tasks were lower in those later identified as demented compared with nondemented but significantly different only for clock and box drawings. CONCLUSION: Performance on 3 cognitive tests showed significant effects of age, sex and education and was related to later dementia. Better performance by users of antioxidant supplements and aspirin suggests that these drugs may maintain cognitive function in later life.

Aged↗

Cognitive functioning, symptoms, and work in supported employment: a review and heuristic model.

OBJECTIVE: Supported employment has been shown to improve the employment outcomes of clients with severe mental illness (SMI), but many clients who receive this service still fail to achieve their vocational goals. There is a need to better understand how illness-related impairments interfere with work, and how supported employment services deal with those impairments in order to improve the employment outcomes of clients with SMI. METHOD: We conducted a review of research on the relationship between cognitive functioning, symptoms, and competitive employment in clients with SMI. Based on this review, we developed a heuristic model of supported employment that proposes specific interactions between cognitive factors, symptoms, vocational services, and employment outcomes. RESULTS: The review indicated that cognitive functioning and symptoms were strongly related to work in studies of general psychiatric samples. In studies of clients participating in vocational rehabilitation programs, associations between cognitive functioning, symptoms, and work were also present, but were attenuated, suggesting that vocational rehabilitation compensates for the effects of some cognitive impairments and symptoms on work. We describe a heuristic model of supported employment that posits specific and testable effects of cognitive domains and symptoms on vocational services and employment outcomes. CONCLUSIONS: Supported employment appears to work by compensating for the effects of cognitive impairment and symptoms on work. The model may serve as a guide for research aimed at understanding how supported employment works, and for developing supplementary strategies designed to improve the effectiveness and cost-effectiveness of supported employment services.

Cognition Disorders↗

Cognitive functioning in children with sickle cell disease: a meta-analysis.

OBJECTIVE: To establish whether sickle cell disease (SCD) affects cognitive functioning in children with no evidence of cerebral infarction. METHODS: We conducted a meta-analysis of studies of cognition in SCD to determine the size of any statistical difference between children with SCD and controls. Methodological factors were evaluated according to the size and frequency of group differences. RESULTS: There were small but reliable decrements in cognitive functioning on IQ measures (4.3-point difference overall). The most methodologically rigorous studies showed a highly similar pattern. Sampling issues associated with the effect size for IQ were identified. Measures of specific abilities appear more sensitive than IQ scores to cognitive decrements in SCD. CONCLUSIONS: SCD is associated with cognitive effects even in the absence of cerebral infarction. The causes of this cognitive decrement may include direct effects of SCD on brain function or indirect effects of chronic illness.

Adolescent↗

Insight dimensions and cognitive function in psychosis: a longitudinal study.

BACKGROUND: It has been reported that lack of insight is significantly associated with cognitive disturbance in schizophrenia. This study examines the longitudinal relationships between insight dimensions and cognitive performance in psychosis. METHODS: Participants were 75 consecutively admitted inpatients with schizophrenia, affective disorder with psychotic symptoms or schizoaffective disorder. Assessments were conducted at two time points during the study: at the time of hospital discharge after an acute psychotic episode and at a follow-up time that occurred more than 6 months after discharge. A multidimensional approach of insight was chosen and three instruments for its assessment were used: the Scale to Assess Unawareness of Mental Disorder (SUMD), three items concerning insight on the Assessment and Documentation in Psychopathology (AMDP) system and the Insight and Treatment Attitudes Questionnaire. The neuropsychological battery included a wide range of tests that assessed global cognitive function, attention, memory, and executive functions. RESULTS: After conducting adequate statistical correction to avoid Type I bias, insight dimensions and cognitive performance were not found to be significantly associated at cross-sectional and longitudinal assessments. In addition, baseline cognitive performance did not explain changes in insight dimensions at follow-up. Similar results were found in the subset of patients with schizophrenia (n = 37). The possibility of a Type II error might have increased due to sample attrition at follow-up. CONCLUSION: These results suggest that lack of insight dimensions and cognitive functioning may be unrelated phenomena in psychosis.

Adult↗

Micronutrient deficiencies and cognitive functioning.

The relationship between four micronutrient deficiencies (iodine, iron, zinc and vitamin B-12) and children's cognitive functioning is reviewed. Iodine deficiency during pregnancy has negative and irreversible effects on the developing fetus. Although there is some evidence that postnatal iodine deficiency is associated with cognitive deficits, the findings are controversial. Iron deficiency is widespread and has been associated to cognitive deficits, but the results of prevention trials are inconsistent. Zinc deficiency has been linked with low activity and depressed motor development among the most vulnerable children. Associations with cognitive development are less clear and may be limited to specific neuropsychological processes. Vitamin B-12 deficiency has been associated with cognitive problems among the elderly, but little is known about its effect on children's cognitive functioning. Rates of vitamin B-12 deficiency are likely to be high because animal products are the only source of vitamin B-12. Although micronutrient deficiencies often co-occur in the context of poverty, little is known about the impact of multiple micronutrient deficiencies on cognitive development.

Child↗

Pantomime of object use: a challenge to cerebral localization of cognitive function.

The paper illustrates difficulties and insecurities of localizing cognitive functions with the example of pantomime of object use. Numerous studies have established a particular sensitivity of this task to left brain damage (LBD), but there is no agreement as to how components of its cognitive architecture are related to the laterality and intrahemispheric location of responsible lesions. Apraxia and asymbolia have been suspected to be crucial for explaining the vulnerability of pantomime to LBD, but analysis of correlations between impairments of pantomime, imitation of gestures, drawing from memory, and language in patients with LBD and aphasia suggests that neither of these putative deficits can adequately account for the data. It rather appears that pantomime taps a central aspect of left hemisphere function which affects performance on a great number of otherwise widely different tasks and which is not bound to any particular location within the hemisphere. I discuss ways to resolve apparent conflicts between this interpretation and the findings of double dissociations between pantomime and imitation in clinical case studies and of circumscribed left parietal activation during pantomime in functional neuroimaging.

Aphasia↗

Cognitive function, iron status, and hemoglobin concentration in obese dieting women.

OBJECTIVE: To determine the relationships between cognitive function and iron status in dieting obese women. DESIGN: Longitudinal weight loss study (repeated measures within-subject design) with 3 weeks of baseline, 15 weeks of 50% caloric restriction, and 3 weeks of weight stabilization. Dietary iron was fed at twice the US Recommended Dietary Allowance with half of the iron from food sources and half from an oral supplement. SETTING: This was a free-living study with the exception that subjects came to the research center for one meal per day and were provided all other meals and snacks to take home. SUBJECTS: Healthy, premenopausal, obese women (mean BMI=31.5) were recruited through local newspaper, poster and radio advertising. Twenty-four women volunteers were recruited and 14 completed the study. MEASUREMENTS: Cognitive function, iron and hematological status, height, body weights and body composition were measured at baseline; at weeks 5, 10, and 15 of the energy restriction period; and at the end of weight stabilization. Computerized cognitive tests included: Bakan vigilance task, two finger tapping, simple reaction time, immediate word recall, and a focused attention task. Iron status and hematological measures included: serum iron, total iron binding capacity (TIBC), transferrin saturation, serum ferritin, hemoglobin (Hb), hematocrit, red cell count, MCV, MCH, MCHC, and RDW. RESULTS: A significant reduction in Hb, hematocrit, and red blood cell count occurred across the study. Hb at the end of the study was positively correlated (r=0.72, P < 0.01) with mean performance on a measure of sustained attention. Transferrin saturation also correlated positively to sustained attention task performance for those subjects whose Hb declined across the study (r=0.86, P < 0.01). CONCLUSIONS: These findings suggest that dieting diminishes iron status in obese women, even when sufficient dietary iron is available, and that the inability to sustain attention may be an early sign of developing iron deficiency in dieting women.

Adult↗

Cognitive function in nondemented older women who took estrogen after menopause.

Investigations of the effects of estrogen replacement on cognitive function in healthy older women have yielded disparate results. We evaluated the relationship between a history of estrogen use and cognitive test performance in 727 women participating in a large community-based study. Participants were followed longitudinally for an average of 2.5 years. Estrogen use history was obtained at baseline. Standardized tests of memory, language, and abstract reasoning were administered at baseline and at follow-up. Results indicate that women who had used estrogen replacement scored significantly higher on cognitive testing at baseline than nonusers, and their performance on verbal memory improved slightly over time. The effect of estrogen on cognition was independent of age, education, ethnicity, and APOE genotype. Results suggest that estrogen replacement therapy may help to maintain cognitive function in nondemented postmenopausal women.

Aged↗

Effects of long duration exercise on cognitive function, blood glucose, and counterregulatory hormones in male cyclists.

Electrocortical effects of long duration exercise on cognitive function were investigated by analyzing P300 amplitude and latency changes during a 3-h cycling exercise. P300 components were measured in 12 well-trained cyclists and blood glucose, cortisol, insulin, glycerol, and free fatty acids (FFAs) epinephrine and norepinephrine were analyzed. Results indicated that P300 components were affected by exercise with a temporary increase in amplitude between the 1st and the 2nd hour and an increase in latency after 2 h of exercise concomitant with some hormonal changes, including an increase in cortisol and epinephrine and a decrease in blood glucose. These findings suggest a combined effect of arousal and central fatigue on electrocortical indices of cognitive function during acute physical exercise.

Adult↗