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PubMed1988

Somatostatin and SMS 201-995 reverse the impairment of cognitive functions induced by cysteamine depletion of brain somatostatin.

The involvement of somatostatin in the organization of cognitive functions was studied. We assessed changes in learning and memory processes by studying the effects of cysteamine, a compound that decreases somatostatin-like immunoreactivity in the brain, somatostatin and the potent somatostatin analogue, SMS 201-995, on active avoidance behaviour, assessed with a shuttle box apparatus, or on passive avoidance behaviour. Cysteamine induced a loss of the conditioned active avoidance response acquired after 3 weeks of daily trials. The effect was observed 2 h (-29%) and 4 h (-51%) after cysteamine treatment (300 mg/kg s.c.) and disappeared after 24 h. Intracerebroventricular administration of somatostatin or SMS 201-995 to cysteamine-treated rats significantly reversed the cysteamine effects on the conditioned avoidance responses. Similar results were obtained on passive avoidance behaviour. We also investigated the effect of cysteamine treatment on brain somatostatin-sensitive adenylate cyclase. We observed that adenylate cyclase activity in the frontal cortex of cysteamine-pretreated animals was more sensitive to inhibition by the SRIF analogue, SMS 201-995, than it was in control animals. This effect was observed at concentrations of SMS 201-995 that were ineffective in control tissue. These results show that disruption of somatostatinergic transmission affects cognitive functions of rats.

Adenylyl Cyclases↗

PubMed1995

Effects of a cold-water stressor on psychomotor and cognitive functioning in humans.

The effects of an acute stressful and painful stimulus, cold water, on psychomotor and cognitive functioning, was assessed in 14 healthy volunteers. Subjects immersed their forearm in ice-cold water (2-3 degrees C) and luke-warm water (37 degrees C) for 3 min, and during this time period a psychomotor or cognitive test was performed. These immersions were done over the course of two experimental sessions, spaced at least 2 days apart, with six trials in each session. Within each session, cold and warm water immersions alternated. Results indicated that flicker-from-fusion threshold from the critical flicker frequency test was higher in the cold-water condition than in the luke-warm-water condition, indicative of increased alertness from the cold stimulus. Short-term memory was attenuated, however, in the cold-water condition. Performance on other tests including those that required speed and/or concentration were not affected by the manipulation. Subjects rated the cold-water stimulus as painful and bothersome, and their blood pressure was significantly elevated by the stimulus. We conclude that a painful stimulus may affect psychomotor and/or cognitive functioning, but the relationship is somewhat complex and depends on the particular tests used.

Adult↗

PubMed2001

Effects of olanzapine and other antipsychotics on cognitive function in chronic schizophrenia: a longitudinal study.

This study aimed to determine the effect of olanzapine and other antipsychotic drugs on cognitive functions after 6months of treatment. Baseline, 3month and 6month psychopathological and cognitive evaluations were made. Thirty-eight partially responsive outpatients with DSM-IV chronic schizophrenia diagnosis were included in the study. On the indication of their attending psychiatrists, 21 patients initiated treatment with olanzapine, and 17 remained on their previous treatment with other antipsychotic drugs. Cognitive assessments were blind to medication and psychopathological status. The olanzapine group presented a significantly greater improvement in negative symptomatology and verbal memory than the comparison group in repeated-measures of MANOVAs between baseline, 3month and 6month assessments. These differences remained statistically significant after covarying out gender, treatment with other atypical antipsychotics, biperidene doses and changes in positive and negative symptoms. In order to match previous differences between groups, cognitive baseline scores for each test were introduced as covariates, resulting in a significant improvement for the olanzapine group in negative symptomatology and the interference task of the Stroop test.We then re-analyzed the data, dividing the comparison group into two groups: risperidone-treated patients (n=9) and patients receiving conventional antipsychotic drugs (n=8). Post-hoc analyses between groups were carried out with baseline cognitive assessment as covariate. The olanzapine group improved significantly more than the risperidone group in negative symptomatology and in the interference task of Stroop test. The improvement in the number of categories of the Wisconsin Card Sorting Test was higher in risperidone patients than in those receiving olanzapine or conventional antipsychotic treatment. Conventional antipsychotic drugs did not present a significant improvement over atypical antipsychotic drugs in any cognitive function. In summary, in patients suffering from chronic schizophrenia, atypical antipsychotic agents were associated with slight differential improvements over time in attentional, verbal memory and executive functions compared with conventional neuroleptic drugs. No differential improvements were found in social functioning, verbal fluency, non-verbal domains of memory or visuo-motor abilities.

Adult↗

PubMed2004

[A study of the effect of donepezil hydrochloride on cognitive function in patients with dementia of Alzheimer's type using WAIS-R].

The present study aimed to assess the initial effects of donepezil hydrochloride (DPZ) on various aspects of cognitive function in patients with dementia of Alzheimer's type (DAT) using the Japanese version of the Wechsler Adult Intelligence Scale-Revised (WAIS-R). DPZ was administered to 47 patients with mild-to-moderate DAT (D group). The control group comprised 61 patients who had been followed up before DPZ was released for use (C group). Both groups underwent WAIS-R testing, before and after 10 months of treatment with DPZ for group D, and at time of diagnosis of DAT and 10 months later for group C. D and C groups did not differ significantly in terms of gender ratio, years of education, age at onset of DAT, age at administration of DPZ or at diagnosis of DAT, severity of dementia, MMSE score, presence of behavioral and psychological symptoms of dementia, concomitant use of psychotropic medication, or initiation of rehabilitation. No significant differences were found between D and C groups in verbal (V), performance (P) or full-scale (F) intelligence quotient (IQ), or in six verbal subtest scores of VIQ and five performance subtest scores of PIQ on WAIS-R, before administration of DPZ or at diagnosis of DAT. For differences between each score on WAIS-R at diagnosis of DAT or before administration of DPZ and 10 months later, DPZ inhibited decreases in FIQ and in VIQ, PIQ, vocabulary, similarities, picture arrangement and object assembly subtest scores on WAIS-R. These indices are related to concept formation and abstract thinking, which form part of executive function. DPZ effectively prevented decline of cognitive function, particularly executive function, in patients with DAT.

Aged↗

PubMed2005

Presurgical evaluation and cognitive functional reorganization in Fishman syndrome.

Fishman syndrome, also known as encephalocraniocutaneous lipomatosis (ECCL), is a rare, congenital neurocutaneous syndrome characterized by unilateral skin, eye, and brain abnormalities. Epileptic seizures and developmental delay are usually present. We report the clinical, radiological, and, for the first time, neurophysiological findings in a 24-year-old woman diagnosed with ECCL who was evaluated for epilepsy surgery. Functional magnetic resonance imaging revealed transfer of memory and language functions to the nonaffected hemisphere, providing evidence that functional reorganization and restoration of cognitive functions may occur in the context of extensive malformations, such as neurocutaneous syndromes.

Adult↗

PubMed1999

Cognitive function and prenatal exposure to ionizing radiation.

It is clear from the many studies of the prenatally exposed survivors of the atomic bombing of Hiroshima and Nagasaki that exposure to ionizing radiation during gestation has harmful effects on the developing human brain, particularly if that exposure occurs at critical stages in the development of the neocortex. Data on a variety of measures of cognitive function, including the occurrence of severe mental retardation as well as variation in the intelligence quotient (IQ) and school performance, show significant effects on those survivors exposed 8-15 weeks and 16-25 weeks after ovulation. Studies of seizures, primarily those without known precipitating cause, also exhibit a radiation effect on those individuals exposed in the first 16 weeks after ovulation. The cellular and molecular events that subtend these abnormalities are still largely unknown although some progress toward an understanding has occurred. For example, magnetic resonance imaging of the brain of some of the mentally retarded survivors has revealed a large region of abnormally situated gray matter, suggesting an abnormality in neuronal migration, but cell killing could also contribute importantly to the effects on cognitive function that have been seen. The retardation of growth in stature observed in individuals exposed in the first and second trimesters of pregnancy suggests that the development of an atypically small head size, without conspicuously impaired cognitive function, may reflect a generalized retardation of growth.

Child↗

PubMed2005

High-fat diets, insulin resistance and declining cognitive function.

Results from our work in rats and others findings from human epidemiologic studies demonstrate deficits in cognitive performance following chronic ingestion of high fat, high saturated fat, diets. Yet, the precise physiologic mechanism underlying these deficits is not well understood. We report that older adults with insulin resistance show remarkably similar deficits in cognitive function and respond to glucose ingestion in a comparable manner to rodents fed a high-fat diet, suggesting that insulin resistance is a probable mediator of these diet-induced deficits. As insulin resistance worsens to overt type 2 diabetes, profound deficits in cognitive functions, especially those dependent on the medial temporal lobes, are apparent in both obese Zucker rats and humans with type 2 diabetes. Unlike the older adult with insulin resistance, glucose ingestion further impairs medial temporal lobe function in adults with type 2 diabetes. Collectively, the human and rodent data point to a role of diet-induced endocrine abnormalities, including the development of insulin resistance, as mediating the cognitive deficits associated with high fat consumption.

Animals↗

PubMedDate not supplied

Socioeconomic position, cognitive function, and clustering of cardiovascular risk factors in adolescence: findings from the Mater University Study of Pregnancy and its outcomes.

OBJECTIVES: The objectives of this study were to examine the extent of clustering of smoking, high levels of television watching, overweight, and high blood pressure among adolescents and whether this clustering varies by socioeconomic position and cognitive function. METHODS: This study was a cross-sectional analysis of 3613 (1742 females) participants of an Australian birth cohort who were examined at age 14. RESULTS: Three hundred fifty-three (9.8%) of the participants had co-occurrence of three or four risk factors. Risk factors clustered in these adolescents with a greater number of participants than would be predicted by assumptions of independence having no risk factors and three or four risk factors. The extent of clustering tended to be greater in those from lower-income families and among those with lower cognitive function. The age-adjusted ratio of observed to expected co-occurrence of three or four risk factors was 2.70 (95% confidence interval [CI], 1.80-4.06) among those from low-income families and 1.70 (95% CI, 1.34-2.16) among those from more affluent families. The ratio among those with low Raven's scores (nonverbal reasoning) was 2.36 (95% CI, 1.69-3.30) and among those with higher scores was 1.51 (95% CI, 1.19-1.92); similar results for the WRAT 3 score (reading ability) were 2.69 (95% CI, 1.85-3.94) and 1.68 (95% CI, 1.34-2.11). Clustering did not differ by sex. CONCLUSION: Among adolescents, coronary heart disease risk factors cluster, and there is some evidence that this clustering is greater among those from families with low income and those who have lower cognitive function.

Adolescent↗

PubMed1991

Improvement in cognitive functioning of alcoholics following orthotopic liver transplantation.

Cognitive functioning in alcoholic cirrhotics before and 1 year following orthotopic liver transplantation was compared with age- and sex-matched normal subjects. The alcoholic group improved significantly following transplantation on tests measuring psychomotor, visuopractic and abstracting abilities whereas the performance of normal controls remained virtually unchanged. In contrast, memory capacity in alcoholics with cirrhosis did not statistically improve following successful transplantation. Further investigation, using more sophisticated measures of memory function, are required to determine whether memory deficits are either associated with alcohol neurotoxicity or an irreversible component of hepatic encephalopathy. These findings suggest that a reversible hepatic encephalopathy underlies many of the neuropsychologic deficits observed in cirrhotic alcoholics and can be ameliorated following successful liver transplantation.

Adult↗

PubMed2002

The domain-specific, stage-limited impact of the apolipoprotein E epsilon-4 allele on cognitive functions in Alzheimer's disease.

To examine the impact of the APOE epsilon4 allele on the cognitive functions of Alzheimer's disease (AD) patients, we administered the eight neuropsychological tests from the Consortium to Establish a Registry for Alzheimer's Disease Neuropsychological Assessment Battery to 118 Korean AD patients. The impact of the APOE epsilon4 allele was significant in the Word List Recall Test (WLRT) and the Word List Recognition Test (WLRcT) only, and its impact was confined to the very mild AD (VMAD) patients (F = 7.65, d.f. = 2, p < 0.01 for WLRT; F = 3.27, d.f. = 2, p = 0.04 for WLRcT). In the VMAD group, the performance on the two tests of the APOE-epsilon4-positive patients was poorer than that of the APOE-epsilon4-negative patients. Our findings suggest that the impact of the APOE epsilon4 allele on cognitive functions in AD may be domain specific and confined to the early stage of AD.

Aged↗

PubMed2001

The acute effects of an extract of Bacopa monniera (Brahmi) on cognitive function in healthy normal subjects.

The Ayurvedic medicine Bacopa monniera (Brahmi) has been shown to exert cognitive enhancing effects in animals. The current study examined the acute effects of an extract of Bacopa monniera on cognitive function in normal healthy human subjects. The study was a double-blind, placebo-controlled independent group design in which subjects were randomly allocated to one of two treatment conditions, Bacopa monniera (300 mg) (n = 18) or placebo (n = 20). Neuropsychological testing was conducted before and 2 h after drug administration. No significant changes were found on any of the tests. The findings suggest that Bacopa monniera, at least for the dose administered, has no acute effects on cognitive functioning in normal healthy subjects. Copyright 2001 John Wiley & Sons, Ltd.

Journal Article↗

PubMed2002

Cognitive functioning in neurologically symptomatic and asymptomatic forms of Wilson's disease.

We sought to determine the pattern of cognitive deficits in patients with Wilson's disease (WD) with different type and degree of neurological involvement, and to interpret the findings in relation to the underlying pathology. A total of 67 WD patients were examined with a neuropsychological test battery assessing different aspects of cognitive processing. The patients were subdivided into three groups: neurologically asymptomatic, neurological with pure basal ganglia lesions, and neurological with more extensive pathology. The results were compared with 50 matched healthy controls. Patients with a neurological form of WD showed a mild but definitive impairment in all cognitive functions. In contrast, the neurologically asymptomatic patients showed no deficits when compared with normal controls. Multifocal pathology was associated with more severe cognitive deficits than selective basal ganglia lesions but did not contribute significantly to memory impairment. A range of cognitive functions, including frontal-executive ability, aspects of memory and visuospatial processing, are affected in the neurologically symptomatic WD patients. In contrast, no subliminal deficits were observed in the asymptomatic patients. The lesions of the basal ganglia seem to be of central importance in explaining the symptomatology.

Adult↗

PubMed1999

1998 Curt P. Richter Award. The effect of hormone replacement therapy on cognitive function in elderly women.

Although evidence seems to indicate favorable effects of hormone replacement therapy (HRT) on cognitive functions and mood in elderly healthy and demented women, some questions remain. For instance, the nature of the long term effect of HRT, e.g. in preventing cognitive decline is still unclear. In this respect, the addition of progestagens in combined HRT has been mentioned to oppose some of the beneficial effects of estrogens. The present paper aims to illuminate these questions and presents two studies. In the first study, the long term effects of combined HRT in healthy postmenopausal women was investigated using a parallel groups (HRT-users vs. controls) design. HRT subjects were always tested during the estrogen-progestagen phase. Results indicated that after 6 and 12 months, women in the HRT-treatment group had higher scores on several indicators of the subjective feeling of well being (sleep, physical and psychological complaints) than matched controls, although at baseline both groups were not severely impaired. Effects of HRT on memory functions were seen when HRT treated subjects were compared with their own baseline functioning, but not when compared with controls. Hence, the addition of progestagen did not oppose the effects of estrogens on subjective feelings of well being or on memory. Our second (case-control) study involved women of middle-age who were unaware of the purpose of the experiment. No positive effects of HRT use on subjective scales of well being or on memory were found. However, women with HRT were faster on basic sensorimotor speed tasks as compared with controls. It should be kept in mind that double blind testing in an experimental study is difficult due to withdrawal bleeding and the reduction of flushes. Expectancy effects may have confounded the results of the first study. However, our findings indicate that the use of a particular design and type of memory test can explain the controversial results of studies into the effect of HRT on cognitive function. Furthermore, it was concluded that HRT has a global activating, instead of specific direct effect on cognitive functions.

Affect↗

PubMed2003

Effects of donepezil on cognitive functioning in Down syndrome.

Our goal in this study was to determine whether donepezil, an acetylcholinesterase inhibitor, would improve cognitive functioning in 19 subjects with Down syndrome and no dementia. They were assigned to either a donepezil or placebo group. Cognitive functioning and caregiver ratings were measured at baseline, 4 weeks, and 12 weeks. With the exception of one area (language), no improvement was noted in any of the cognitive subtests, behavioral scores, or caregiver ratings. Subjects in the donepezil group showed an improvement in language scores compared to subjects in the placebo group. The results suggest that donepezil may improve language performance in subjects with Down syndrome and no dementia, but further studies need to be done on a larger group to confirm this result.

Adolescent↗

PubMed2005

Blood DHEAS concentrations correlate with cognitive function in chronic schizophrenia patients: a pilot study.

There is evidence that neurosteroids such as DHEA and its sulfated form DHEAS can modulate cognitive function. We hypothesize that DHEA/S concentrations may be linked to cognitive impairment in schizophrenia. The aim of this pilot study was to test this hypothesis by examining the relationship between blood levels of DHEAS and cognitive function. The performance of 26 stable medicated chronic schizophrenia patients in a range of neuropsychological domains including verbal memory (Wechsler Memory Scale), executive function (AIM), memory of faces (PFMT), memory for objects (VOLT) and identification of facial emotional expressions (PEAT) was assessed. Single morning blood samples were assayed for levels of DHEAS and cortisol. Significant associations were found between DHEAS levels and DHEAS/Cortisol ratio and verbal memory, executive function and memory for faces. The relationship was independent of the age related reduction in DHEAS levels. These preliminary results suggest that DHEAS may be associated with cognitive impairment in schizophrenia.

Adult↗

PubMed2006

Cognitive functioning in school-aged children with vertically acquired HIV infection being treated with highly active antiretroviral therapy (HAART).

In today's era of highly active antiretroviral therapy (HAART), few children with HIV-1 infection experience severe central nervous system (CNS) manifestations indicative of encephalopathy. However, little is known about the neurocognitive strengths and weaknesses of HIV-infected children treated with HAART. This cross-sectional study is the first to systematically investigate the relation between cognitive functioning and medical markers in HIV-infected children and adolescents treated with HAART with varying levels of computed tomography (CT) brain scan abnormalities. The Wechsler Intelligence Scale for Children-Third Edition was administered to 41 vertically infected children (mean age = 11.2 years) treated with HAART for at least 1 year. Other procedures at the time of testing included CT brain scans and collection of CD4 cell counts and plasma HIV1 RNA PCR. Although global cognitive functioning among participants was in the Average range, children with minimal to moderate CT brain scan abnormalities scored significantly lower than children with normal scans on composite measures of cognitive functioning and five specific subtests, especially tasks involving executive functions. Furthermore, children with worse immune status (CD4+ counts < or = 500) scored lower on subtests measuring processing speed. Viral load was unrelated to cognitive test scores. Thus, children with HIV being treated with HAART remain at risk for developing CNS disease. Findings emphasize the importance of conducting neuropsychological assessments in this population, particularly for children with cortical atrophy and absolute CD4+ cell counts < or = 500.

Adolescent↗

PubMed1984

The Minnesota Diabetes Complications Clinical Trial cognitive functions under long-term maximized and standard metabolic controls.

We have studied memory (Wechsler Memory Scale) and mood states in 20 insulin dependent diabetics under maximized metabolic control (treated with multiple insulin injections daily or insulin pumps) and 12 patients under standard control (treated with one or more injections of insulin daily). Both groups of patients have been enrolled in the Minnesota Diabetes Complications Clinical Trial for two years or longer. The patients in the maximized control group (mean +/- SD) blood glucose 130 +/- 9 mg/dl) had hypoglycemic episodes much more frequently than the patients in the standard control group (mean +/- SD blood glucose 242 +/- 22 mg/dl). Both groups of patients had normal cognitive functions, including a few patients with numerous hypoglycemic episodes. Only one patient who developed a hypoglycemic coma for several weeks has had lasting abnormal cognitive functions including a few patients with numerous hypoglycemic episodes. We conclude that long-term maximized diabetic control (at least 2 years), although not devoid of danger, does not seem to affect cognitive functions in the patients tested according to the parameters used.

Adult↗

PubMed1999

Volumetric analysis of frontal lobe regions in schizophrenia: relation to cognitive function and symptomatology.

BACKGROUND: The purpose of this study was to examine the structure of dorsolateral, medial, and orbital regions of the frontal lobe in schizophrenia, and to determine whether their volumetric measurements were related to cognitive function and symptomatology. METHODS: High resolution magnetic resonance imaging scans of the brains of 14 schizophrenic patients and 14 closely matched healthy controls were acquired. Volumes of gray and white matter of the left and right dorsolateral, medial, and orbital prefrontal brain regions were measured. Tests of verbal and visual memory and executive functions were used to assess cognitive function. The SANS and SAPS were used to obtain symptom ratings in patients. RESULTS: Data of 13 schizophrenic patients were analyzed. Patients showed a general, though not significant, decrease in volumes of frontal regions as compared to controls. In patients, but not in controls, smaller left and right prefrontal gray matter volumes were significantly correlated with impaired performance on immediate recall in verbal and visual memory and semantic fluency. Furthermore, in patients, smaller total orbitofrontal gray matter volume was significantly correlated with more severe negative symptomatology (rs = -.76, p = .006). CONCLUSIONS: These findings suggest that in schizophrenia, deficits in verbal and visual memory and semantic fluency and negative symptoms may be related to (subtle) abnormalities in frontal lobe structure.

Adolescent↗