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Effects of zinc supplementation on cognitive function in healthy middle-aged and older adults: the ZENITH study.

A randomised double-blind placebo-controlled design was employed to investigate the effects of Zn supplementation on cognitive function in 387 healthy adults aged 55-87 years. Several measures of visual memory, working memory, attention and reaction time were obtained using the Cambridge Automated Neuropsychological Test Battery at baseline and then after 3 and 6 months of 0 (placebo), 15 or 30 mg Zn/d. Younger adults (< 70 years) performed significantly better on all tests than older adults (> 70 years), and performance improved with practice on some measures. For two out of eight dependent variables, there were significant interactions indicating a beneficial effect (at 3 months only) of both 15 and 30 mg/d on one measure of spatial working memory and a detrimental effect of 15 mg/d on one measure of attention. Further work is required to establish whether these findings generalise to older adults in poorer mental and physical health and with less adequate Zn intake and status than the present sample.

Aged↗

[The cerebellum: from motor coordination to cognitive function].

Clinical data in man, as well as experimental results in animals, classically involve the cerebellum in the coordination of ballistic movements and in their accompanying postural adjustment. The cerebellum intervenes in the coding of the order and duration of contraction of the different protagonist muscular groups contributing to the same movement. In normal life, this is an automatic, non conscious procedure. Recent studies seem to indicate that the human neocerebellum (lateral hemispheres and dentate nuclei) plays a role in the regulation of some neocortical cognitive functions. This new functional aspect of cerebellar activity has been inferred from the results obtained by three quite different domains: neuroanatomical data showing the existence of, sometimes reciprocal, pathways between the neocerebellum and associative and limbic areas in primates, neuropsychological data assessing the presence, in some cerebellar patients, of purely cognitive impairments, and data from functional imagery pointing out cerebellar activation in healthy subjects during non motor tasks. II would ensue that, thanks to new cortical targets. The cerebellum could regulate sensorial, procedural, linguistic and emotional activities, so that a cerebellar lesion could be followed by a cognitive and affective syndrome, depending on the importance and on the location of the lesion.

Animals↗

The effects of acute and repeated doses of suriclone on subjective sleep, psychomotor performance and cognitive function in young and elderly volunteers.

Suriclone is a new anxiolytic drug belonging to the family of cyclopyrrolones. The effects of acute and repeated doses of suriclone on subjective sleep, psychomotor performance and cognitive function were compared to those of placebo in young and elderly volunteers. Young volunteers randomly received suriclone 0.2 mg, 0.3 mg, 0.4 mg or placebo tid, and the elderly received suriclone 0.1 mg, 0.2 mg or placebo tid. After the first single dose and after a three-day treatment, subjects completed at 1, 2, 4, 12 and 24 h after drug administration the following battery of psychomotor and cognitive tests: critical flicker fusion threshold, choice reaction time, simulated car tracking test, the stroop test and the Sternberg memory scanning task. Visual analogue scales and the Leeds sleep evaluation questionnaire were also administered during the study. No significant effects of suriclone compared to placebo were seen on the psychomotor tests both in young and elderly volunteers. The only significant result was an improvement of the ease of getting to sleep in the young with 0.4 mg suriclone tid. In conclusion, there is little evidence to suggest that suriclone produces any measurable behavioural toxicity, so often seen with many of the benzodiazepines, in either young or elderly subjects.

Adult↗

Exposure to polybrominated biphenyls. Some effects on personality and cognitive functioning.

Twenty-one persons exposed to polybrominated biphenyls (PBB) were compared with hospital volunteers on a battery of tests measuring memory, motor strength and coordination, cortical-sensory perception, personality, and higher cognitive functioning. Patients exposed to PBB were selected for this study only if they had persistent medical complaints. The PBB adipose levels did not correlate with performance on any test in the battery. The two groups did differ on the Minnesota Multiphasic Personality Inventory, suggesting an adjustment reaction with depressive symptoms and somatizing defenses. Persons exposed to PBB were also impaired relative to control subjects on tests of prose recall, short-term memory, concentration, and cognitive flexibility. However these differences vanished when group differences on education and personality were statistically held constant. The selective admission criteria for this study limit the generalizability of these findings.

Adipose Tissue↗

Cognitive function in young and adult IL (interleukin)-6 deficient mice.

Interleukin-6 (IL-6) is a cytokine shown to affect brain function and to be involved in pathological neurodegenerative disorders such as Alzheimer's disease (AD). In the present study we investigated the cognitive function in transgenic mice not expressing IL-6 (IL-6 KO) and in wild type (WT) genotype at 4 and 12 months of age, using a passive avoidance and an eight-arm radial maze tasks. Motor function was quantified using an Animex apparatus. Hippocampal choline acetyltransferase (ChAT) activity was evaluated in both genotypes. No difference was observed in both genotypes for spontaneous motor activity. The mean latency (s) to re-enter the shock box, was similar in both young mutant and WT mice. However, a decreased sensitivity (50%) to scopolamine (1 mg/kg) in mutant compared to WT mice, was obtained. IL-6 KO mice exhibited a facilitation of radial maze learning over 30 days, in terms of a lower number of working memory errors and a higher percentage of animals reaching the criterion as compared with WT genotype tested at both ages. Furthermore, mutant mice, at the age of 12 months, showed a faster acquisition (22 days versus 30 days to reach the criterion). The pattern of arm entry exhibited by IL-6 KO mice showed a robust tendency to enter an adjacent arm at both ages, while WT only at the age of 4 months. ChAT activity was inversely correlated with memory performance. These findings suggest a possible involvement of IL-6 on memory processes, even if the mechanism remains still unclear.

Age Factors↗

Traumatic brain injury: influence of blood alcohol level on post-acute cognitive function.

Alcohol intoxication frequently contributes to the occurrence of traumatic brain injury. Few studies, however, have examined whether acute pre-injury alcohol intoxication or premorbid history of alcohol abuse exacerbate cognitive impairments that commonly result from traumatic brain injury. This study examined the influence of blood alcohol level at time of hospital admission on cognitive functioning during the post-acute stage of recovery from traumatic brain injury. After controlling for pre-injury history of alcohol abuse, hospital admission blood alcohol level was predictive of poorer delayed verbal memory, greater decrement in verbal memory over time, and poorer visuospatial functioning. Moreover, there were non-significant trends for higher blood alcohol levels to predict poorer performance on measures of immediate verbal memory and perseveration.

Adolescent↗

Disruptive, delinquent and aggressive behavior in female adolescents with a psychoactive substance use disorder: relation to executive cognitive functioning.

OBJECTIVE: This study had four objectives: (1) to determine whether female adolescents with a psychoactive substance use disorder are more impaired than controls on a battery of neuropsychological tests of Executive Cognitive Functioning (ECF); (2) to determine whether these individuals exhibit higher levels of disruptive, delinquent and aggressive behavior compared with controls; (3) to determine whether ECF is related to disruptive, delinquent and aggressive behavior in this population; and (4) to determine whether these relations are moderated by drug use. METHOD: Multiple indicators of ECF, and disruptive, delinquent and aggressive behavior, as well as drug use, were used to test these relations in a sample of 188 female adolescents who qualified for a DSM-III-R diagnosis of a psychoactive substance use disorder (PSUD) and 95 normal controls between the ages of 14-18 years (N = 283). RESULTS: Hierarchical multiple regression equations determined that ECF was related to disruptive, delinquent and aggressive behavior even when chronological age, SES and drug use were accounted for. The final regression models suggested that drug use was more strongly related to disruptive and delinquent behavior, whereas ECF was more strongly related to aggression. Drug use did not moderate any relation between ECF and the dependent measures. CONCLUSIONS: One implication of these results is that violence prevention and treatment outcomes may be ameliorated by incorporating cognitive habilitation of ECF as an integral component of multimodel interventions.

Adolescent↗

Perceptions of teachers and parents on the cognitive functioning of children with severe mental disability and children with congenital deafblindness.

This article reports Phase I results of a questionnaire study on the perceptions of US teachers and parents on the cognitive functioning of children with severe mental disability and children with congenital deafblindness, ages 4-12 years. Teachers were more likely than parents to report emerging skills and to provide examples of how the skill was being taught. Teachers and parents of children with severe mental disability had different perceptions about how children demonstrated understanding of cause-effect, object permanence, memory, incidental cues, reasoning and creativity. Teachers and parents of children with congenital deafblindness differed in their perceptions of how children demonstrate understanding of incidental cues and exhibit reasoning. Both teachers and parents expressed concern about whether choice making was meaningful. Novelty was reported to be a motivating factor for children with severe mental disability, while familiarity was cited as motivating for children with congenital deafblindness. Teachers and parents of all children cited consistency, routine and repetition as important to learning.

Child↗

Cognitive functioning in chronic fatigue syndrome and the role of depression, anxiety, and fatigue.

OBJECTIVE: This study was designed to investigate the role of depression, anxiety, and fatigue in Chronic Fatigue Syndrome (CFS) sufferers' objective and subjective cognitive performance. METHODS: Twenty-three CFS sufferers and 23 healthy control participants were compared on objective and subjective assessments of cognitive performance. Depression, anxiety, and fatigue were also evaluated. RESULTS: CFS sufferers did not demonstrate any impairment in objective cognitive functioning compared to the control group, and objective performance was not related to their higher levels of depression or their level of fatigue. Depression scores only accounted for a small amount of the variance in CFS sufferers' lower subjective assessment of their cognitive performance compared to control participants. There were no differences between the groups on anxiety scores. CONCLUSION: The results are discussed in terms of the heterogeneity of the CFS population and the complex interaction of symptomatological factors that characterise CFS.

Adolescent↗

Cognitive functioning in a population-based sample of very old non-demented and non-depressed persons: the impact of diabetes.

The main objectives of this study were to examine potential effects on cognitive functioning of diabetes and some major cardiovascular signs and diseases in very old age. Analyses were based on data from the Kungsholmen project and involved a population-based sample of non-demented and non-depressed persons aged 75-96 years. Diabetics (n=36) were compared with non-diabetic persons (n=356), and all participants were assessed with an extensive medical examination, specific diagnostic interviews, and laboratory blood analyses. Cognitive ability was indexed by means of the Mini-Mental State Examination (MMSE). The results showed that diabetics perform significantly worse on the MMSE than do non-diabetics, and that the MMSE-performance of elderly with cardiovascular disease (CVD) is significantly worse than in those without CVD. Controlling for cardiovascular signs and diseases did not alter the effects of diabetes. Examination of interaction terms, finally, indicated that, in the examined age range, the effects of diabetes do not vary across age, educational levels or variations in cardiovascular health. The results suggest that cognitive deficits associated with diabetes in very old age may be detected with the MMSE.

Journal Article↗

Once-weekly and 5-days a week iron supplementation differentially affect cognitive function but not school performance in Thai children.

Many studies have reported comparable hemoglobin response in subjects given intermittent and daily iron supplements. However, the effect of intermittent iron supplementation on impaired cognitive function, one of the serious consequences of iron deficiency among children, has not been studied. We investigated the effects of 1 d/wk (weekly) and 5 d/wk (daily) iron supplementation on changes in results of intelligence quotient (IQ), Thai language, and mathematics tests among Thai primary schoolchildren. A double-blind, randomized, placebo-controlled trial was conducted. Primary schoolchildren (n = 397) were randomly assigned to receive iron supplements daily or weekly or placebo. Ferrous sulfate (300 mg) or placebo tablets were given under direct observation by the researcher for 16 wk. Changes in IQ, and Thai language and mathematics scores were then compared. The increases in hemoglobin concentration were comparable in the weekly and daily iron supplementation groups but serum ferritin increased more in the children supplemented daily. Children receiving daily iron supplements, however, had a significantly lower increase in IQ (3 +/- 12 points) than those receiving the supplement weekly (6 +/- 12 points) or placebo (6 +/- 12 points), whereas the last-mentioned two groups did not differ. Z-scores of Thai language and mathematics test results did not differ among the groups. We conclude that weekly iron supplementation is the regimen of choice in this study community.

Child↗

Modafinil, sleep deprivation, and cognitive function in military and medical settings.

Military personnel of many professions, including health care workers, are routinely challenged with performing their duties during hours when the circadian rhythm is at its trough, namely, late night and early morning. Studies have shown that cognitive performance declines significantly during these hours. Although many pharmacologic agents have been studied in an attempt to find a safe medication to enhance alertness and cognitive function, no safe nonaddictive options have been identified. Modafinil is a novel wakefulness-promoting agent that has been shown to improve cognitive performance and promote wakefulness among shift workers. This article reviews the studies on modafinil administration and cognitive performance as they relate to military operations and the provision of health care by sleep-deprived individuals.

Benzhydryl Compounds↗

Assessing cognitive function in cancer patients.

GOALS OF WORK: Some patients with cancer suffer cognitive impairment after chemotherapy. A brief, sensitive instrument is required to screen patients for cognitive impairment. In this study, we compare three possible screening instruments. MATERIALS AND METHODS: Cancer patients (n=31) who had received adjuvant chemotherapy within 2 years underwent cognitive evaluation on three occasions. Fluent English speakers (n=20) completed the High Sensitivity Cognitive Screen (HSCS), the computer-based Headminder and CogHealth, and the Functional Assessment of Cancer Therapy-cognitive function (FACT-COG) questionnaire. Patients not fluent in English (NESB) (n=11) performed CogHealth and Headminder. RESULTS: The patients were aged 31-65 years, and 94% were women with breast cancer. At baseline, 6 of 20 (30%) had moderate-severe cognitive impairment on HSCS, 17 of 31 (55%) had scores greater than one standard deviation (SD) below the mean for normative data in one to two of three domains on Headminder, and on CogHealth, 8 of 31 (26%) were greater than one SD below the mean in at least two of six domains. A large practice effect was seen for the HSCS, with moderate-severe cognitive impairment decreasing from 30 to 5% between the first and second assessment. On FACT-COG, 9 of 19 patients (47%) rated their cognition as greater than one SD below that of a pre-chemotherapy breast cancer control group, with impact on quality of life greater than one SD below for 10 of 19 (53%) patients. No correlation was seen between objective cognitive testing and the FACT-COG. CONCLUSIONS: CogHealth and Headminder were suitable for NESB patients. The HSCS is not recommended for longitudinal studies with short intervals between testing due to practice effect. There is poor correlation between the patients' perception of their cognitive impairment and the objective tests.

Adult↗

Evidence for an improvement in cognitive function following treatment of Schistosoma japonicum infection in Chinese primary schoolchildren.

A double-blind, placebo-controlled, treatment trial was conducted in Sichuan, China to investigate the unique and combined effects on the cognitive function (working memory) of children after treating geohelminth infections with albendazole and treating Schistosoma japonicum infection with praziquantel. One hundred eighty-one children 5-16 years of age participated. At baseline, the praziquantel and placebo groups were similar in all background characteristics. Three months after praziquantel treatment, there was a significant reduction in the prevalence and intensity of S. japonicum infection. There were significant age group by praziquantel treatment interaction effects in three of the five cognitive tests, Fluency, Picture Search, and Free Recall, with effects being strongest in the youngest children (5-7 years old). Exploratory analysis within the youngest children showed a significant positive main effect of treatment on Fluency (P < 0.001), after controlling for sex, anthropometric, and parasitic and iron status. There was also a treatment by height-for-age interaction (P = 0.03) and a treatment by iron status interaction (P = 0.024) on Fluency. There was a treatment by S. japonicum intensity interaction (P < 0.001) on Free Recall, but the main effect of treatment on Picture Search was not significant (P = 0.058). Younger children and those who are physically the most vulnerable are likely to benefit the most from the treatment of S. japonicum infection in terms of improved performance on tests of working memory.

Adolescent↗

Alterations of cognitive functions induced by exogenous application of thyroid hormones in healthy men: a double-blind cross-over study using event-related brain potentials.

The influence of experimentally induced subclinical hyperthyroidism on cognitive functions was tested using exogenous thyroxine or placebo. In a double-blind cross-over design, 24 healthy young men received either 300 microg of levothyroxine or placebo for two consecutive 3-week periods. Determination of thyrotropin (TSH), total triiodothyronine (T3), thyroxine (T4), and sex hormone binding globulin (SHBG) confirmed the induction of subclinical hyperthyroidism. Three weeks after treatment with placebo or T4, subjects were tested in two visual search tasks, one requiring the serial scanning of a stimulus array of eight items in order to detect a missing feature (serial task), while the other task allowed the parallel processing of eight items in order to detect an extra feature. Reaction times varied greatly between the tasks while no effect of T4 medication was revealed on overt search behavior. The late cognitive components of the event-related brain potentials (ERP) were registered during the tasks using a multichannel recording. The late positive component (P300) to target stimuli showed a significant reduction in amplitude in the parallel search task in hyperthyroidism, while for the serial search task a significant frontal negativity was revealed for target stimuli, both suggesting an increased effort to be exerted for the execution of visual search tasks. Thus, short periods of subclinical hyperthyroidism in the range commonly induced in the treatment of thyroid cancer patients induce distinct alterations in brain-electric activity.

Adult↗

[Cognitive function in the obsessive-compulsive disorder associated with cerebral lesions].

INTRODUCTION: Although obsessive-compulsive symptoms are uncommon among patients with neurological diseases, structural neuroimaging (CAT or MRI) disclose focal brain lesions in some patients. However, little is know about the clinical phenomenology of obsessive-compulsive symptoms and the cognitive deficits that occur in neurological conditions. OBJECTIVE: To review the cognitive functioning of patients who develop an obsessive-compulsive disorder (OCD) in association with focal brain lesions. DEVELOPMENT: In the present study, the author review recent studies which suggest that OCD associated with brain lesions is relatively similar to idiopathic or 'functional' OCD (i.e., OCD unassociated with gross brain damage). Idiopathic and acquired forms of OCD are clinically heterogeneous. The content of obsessions and compulsions in acquired OCD depends, at least in part, of the causative lesion, whereas the pattern of cognitive deficits is more homogeneous affecting attention, general intelligence, verbal and visuospatial memory, and executive function. CONCLUSION: It is suggested that the study of different subgroups of patients with acquired OCD would detect differences in the phenomenology of obsessions and compulsions as well as in the pattern of cognitive deficits. Moreover, this approach can improve our understanding about the pathophysiological mechanisms underlying idiopathic OCD.

Brain Diseases↗

A prospective observational study of the effect of night duty on the cognitive function of anaesthetic registrars.

The issue of fatigue in hospital medical staff represents a potential health and safety risk to both staff and patients, and is receiving worldwide interest. We aimed to characterize the cognitive performance of anaesthetic registrars before and after a series of night shifts. We enrolled nine full-time anaesthetic trainees in an Australian adult tertiary-referral hospital. We conducted a cross-over observational study which tested cognitive performance in participants before and after seven consecutive night shifts and compared this with performance before and after seven consecutive day shifts. Cognitive function was measured using a computerized assessment tool. Participants completed a mean of 62.5% of the requested testing (seven participants completed 87%). There was no significant change in performance before or after any day shift, nor at the commencement of each night shift. There was near perfect accuracy in performance in all tests at all times. There was a statistically significant deterioration in speed of performance for detection and identification tasks at the end of night shift as the week progressed. Anaesthetic registrars demonstrate a significant decline in cognitive performance after a series of night shifts.

Anesthesia↗

Cognitive functions after transient topographical amnesia.

Twelve consecutive patients having previously experienced one or more episodes of isolated transient topographical amnesia (TTA) underwent neuropsychological examination 6-12 months after the last episode to detect signs of global cognitive decline and to assess, in particular, cognitive functions deemed critical for topographical orientation. The test scores were compared with those of 12 normal subjects matched for age, sex, educational level and place of residence. Both patients and controls showed normal performances in all tasks. The comparison between the two groups revealed a significantly lower performance of the patient group in a task of geographical orientation, namely 'Map of Italy'. We conclude that isolated episodes of TTA in the elderly per se do not represent a sign of mental deterioration, but can be associated with frailty on survey components of spatial orientation. It remains to be explained whether this feature is a pre-existing condition favouring the occurrence of the episodes of topographical amnesia or represents a sequela.

Activities of Daily Living↗