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PubMed2004

Effects of levodopa on cognitive functioning in moderate-to-severe Parkinson's disease (MSPD).

Although improved cognition has been reported in patients with mild Parkinson's disease (PD) following the administration of levodopa, mixed results have been found in moderately-to-severely affected PD patients (MSPD), particularly in studies conducted since 1980. In the present study, 16 MSPD patients were tested on separate days, once following overnight levodopa withdrawal and once while optimally treated. A battery of neuropsychological tests that assess a range of cognitive functions (i.e., attention, language, visuospatial, memory, and executive), as well as a measure of depression, were used. Although patients performed better on a measure of confrontation naming in the untreated than in the treated condition, there were no significant differences for any of the other cognitive variables or for the depression scale variable. Thus, these data suggest that there are generally no adverse or beneficial effects of levodopa therapy on cognition in MSPD patients.

Aged↗

PubMed2003

Effects of sertraline on autonomic and cognitive functions in healthy volunteers.

RATIONALE: Though sertraline, a selective serotonin reuptake inhibitor (SSRI), causes autonomic and cognitive adverse events such as dry mouth and somnolence, there is a paucity of appropriately designed studies on the cognitive and autonomic effects of the drug in the literature. OBJECTIVE: To compare the effects of sertraline on cognitive and autonomic functions with those of placebo in healthy humans. METHOD: A randomized, double blind, cross over study of 12 healthy male volunteers aged 24 (21- 32; median; range) years. Subjects orally received 50 mg sertraline and placebo once daily for periods of 14 days each with at least 14 days in between. Heart rate variability (HRV), skin conductance level (SCL) and skin conductance response (SCR) following sudden deep respiration were employed as parameters for autonomic function. Quantitative EEG (qEEG) and psychometric tests served as parameters for cognitive function. Measurements were performed repeatedly before the start of drug administration and on the last treatment day. RESULTS: Sertraline caused a significant reduction of heart rate and SCL ( P<0.05), whereas HRV and SCR were not changed. Cognitive functions such as flicker fusion frequency, memory, choice reaction time and psychomotor performance were not influenced by sertraline but slow and fast beta power density in the qEEG was increased. CONCLUSION: Cognitive and psychomotor performance are not altered in healthy humans receiving multiple dosing with sertraline. The observed decreases in heart rate and SCL may be due to a sympatho-inhibitory effect of sertraline.

Adult↗

PubMed2000

Recovery of cognitive function after remifentanil-propofol anesthesia: a comparison with desflurane and sevoflurane anesthesia.

UNLABELLED: We compared the recovery characteristics of remifentanil, desflurane, and sevoflurane when used for anesthesia in elective operative procedures. Sixty ASA physical status I and II patients, aged 18-65 yr, were randomly assigned to receive remifentanil-propofol, desflurane-N2O, or sevoflurane-N2O anesthesia. Before the induction of anesthesia, the patients of the desflurane and sevoflurane groups received fentanyl 2 microg/kg. In all groups, anesthesia was induced with propofol and maintained either with remifentanil 0.25 microg x kg(-1) x min(-1), desflurane, or sevoflurane 0.85 MAC with 65% nitrous oxide in oxygen. Anesthetics were titrated to achieve an adequate level of surgical anesthesia and to maintain mean arterial pressure within 20% of baseline values. Early recovery times and a modified Aldrete Recovery Score > 9 were recorded. Trieger Dot Test and Digit Substitution Test (DSST) were performed the day before surgery and in the postanesthesia care unit to evaluate intermediate recovery. The remifentanil-propofol group had a significantly faster emergence than desflurane or sevoflurane, with no difference between both inhaled anesthetics. Thirty min after anesthesia administration, patients in the remifentanil-propofol and in the desflurane groups gave significantly more correct responses in the DSST compared with sevoflurane (remifentanil 87%, desflurane 83%, sevoflurane 56%), the impairment in the sevoflurane patients corresponding to the effects of a blood alcohol level of approximately 0.1% and, thus, being of clinical importance. Ninety minutes after anesthesia administration, no significant difference could be demonstrated among the groups in the DSST scores. Emergence and return of cognitive function was significantly faster after remifentanil-propofol compared with desflurane and sevoflurane up to 60 min after anesthesia administration. IMPLICATIONS: We compared awakening and intermediate recovery times after remifentanil-propofol anesthesia to desflurane-N2O and sevoflurane-N2O anesthesia. Emergence and return of cognitive function was significantly faster after remifentanil-propofol compared with desflurane and sevoflurane up to 60 min after anesthesia administration.

Adult↗

PubMedDate not supplied

Relationship between psychopathology and cognitive functioning in schizophrenia.

The purpose of this study was to delineate the relationship between positive, negative, cognitive, depressive, and excitement symptom dimensions of schizophrenia and cognitive functioning. Fifty-eight patients with schizophrenia (DSM-IV criteria) were assessed using the Positive and Negative Syndrome Scale (PANSS) and a battery of neuropsychological tests (executive function/abstraction, verbal and spatial working memory, verbal and nonverbal memory/learning, attention, visuospatial ability, and psychomotor speed). The cognitive symptom dimension correlated with executive functions, attention, verbal memory, and spatial ability. Severity of the negative symptom dimension was related to impairment in the structure of the semantic knowledge system, verbal memory, and auditory attention. In contrast, severity of the positive symptom dimension correlated only with impairment in the structure of the semantic knowledge system, and psychomotor speed. Finally, severity of the depressive and excitement symptom dimension was not associated with cognition. Correlations between symptom dimensions and cognitive measures were at best modest. Severity of cognitive and negative symptoms was mainly correlated with deficits on executive functions, semantic memory, and verbal memory, while positive symptoms only with semantic memory. These correlations were modest, suggesting that psychopathology and cognitive deficits in schizophrenia are caused, at least partially, by distinct pathophysiological processes.

Adult↗

PubMed2002

Effects of glucagon-like peptide 1 on counterregulatory hormone responses, cognitive functions, and insulin secretion during hyperinsulinemic, stepped hypoglycemic clamp experiments in healthy volunteers.

Glucagon-like peptide 1 (GLP-1) and analogues are being evaluated as a new therapeutic principle for the treatment of type 2 diabetes. GLP-1 suppresses glucagon secretion, which could lead to disturbances of hypoglycemia counterregulation. This has, however, not been tested. Nine healthy volunteers with normal oral glucose tolerance received infusions of regular insulin (1 mU x kg(-1) x min(-1)) over 360 min on two occasions in the fasting state. Capillary glucose concentrations were clamped at plateaus of 4.3, 3.7, 3.0, and 2.3 mmol/liter for 90 min each (stepwise hypoglycemic clamp); on one occasion, GLP-1 (1.2 pmol x kg(-1) x min(-1)) was administered i.v. (steady-state concentration, approximately 125 pmol/liter); on the other occasion, NaCl was administered as placebo. Glucagon, cortisol, GH (immunoassays), and catecholamines (radioenzymatic assay) were determined, autonomous and neuroglucopenic symptoms were assessed, and cognitive function was tested at each plateau. Insulin secretion rates were estimated by deconvolution (two-compartment model of C-peptide kinetics). At insulin concentrations of approximately 45 mU/liter, glucose infusion rates were similar with and without GLP-1 (P = 0.26). Only during the euglycemic plateau (4.3 mmol/liter), GLP-1 suppressed glucagon concentrations (4.1 +/- 0.4 vs. 6.5 +/- 0.7 pmol/liter; P = 0.012); at all hypoglycemic plateaus, glucagon increased similarly with GLP-1 or placebo, to maximum values greater than 20 pmol/liter (P = 0.97). The other counterregulatory hormones and autonomic or neuroglucopenic symptom scores increased, and cognitive functions decreased with decreasing glucose concentrations, but there were no significant differences comparing experiments with GLP-1 or placebo, except for a significant reduction of GH responses during hypoglycemia with GLP-1 (P = 0.04). GLP-1 stimulated insulin secretion only at plasma glucose concentrations of at least 4.3 mmol/liter. In conclusion, the suppression of glucagon by GLP-1 does occur at euglycemia, but not at hypoglycemic plasma glucose concentrations (< or = 3.7 mmol/liter). GLP-1 does not impair overall hypoglycemia counterregulation except for a reduction in GH responses, which is in line with other findings demonstrating pituitary actions of GLP-1. Below plasma glucose concentrations of 4.3 mmol/liter, the insulinotropic action of GLP-1 is negligible.

Adult↗

PubMed1996

Cognitive function in schizophrenic patients.

Cognitive impairment is a relatively frequent aspect of schizophrenia. Deficits are most prominent in tasks involving attention, memory, and executive function. Although some research suggests that deterioration is progressive, these deficits appear to be relatively stable over time. Imaging and biochemical studies show that schizophrenia is characterized by a number of morphological, hemodynamic, and neurochemical abnormalities within systems integrating the cortex, temporal lobes, and various limbic structures. Neurochemical assays suggest that the neurotransmitters serotonin, dopamine, and glutamate play a significant role in the disease-associated decrement. Cognitive impairment in schizophrenia impedes psychosocial performance and eventual reintegration into society and is therefore an especially relevant target in the development of new therapeutic modalities. Atypical agents, such as clozapine and olanzapine, hold special promise in this area.

Antipsychotic Agents↗

PubMed2003

Does brain tumor histology influence cognitive function?

This retrospective study investigated the relationship between tumor histology and postsurgical cognitive function in patients diagnosed with malignant brain tumors. The neuropsychological functioning of 24 adult patients diagnosed with glioblastoma multiforme (GBM) was compared with the neuropsychological functioning of 24 adult patients diagnosed with anaplastic astrocytoma (AA). The groups were matched with respect to patient age, gender, and education, as well as tumor location and tumor volume. The mean raw test scores of the AA patient group were superior to the mean scores of the GBM patient group on nearly all measures administered. However, significant performance differences were not detected for any of 5 neuropsychological domain scores (Intellectual, Language, Memory, Executive, and Motor Function). Analysis of covariance (ANCOVA) revealed that tumor histology was not a significant predictor of domain score after controlling for tumor volume. Multiple regression and correlation analyses supported the results of the ANCOVA by offering further evidence of weak relationships between tumor type, tumor volume, and neuropsychological test scores. We conclude that tumor histology is not clearly predictive of cognitive performance in adults with AA and GBM.

Adult↗

PubMed1994

The Maudsley rat strains as a probe to investigate noradrenergic-cholinergic interaction in cognitive function.

Central noradrenergic function in relation to cognitive performance was studied in the Maudsley rat strains. Neurochemical studies revealed a higher response to acute stress in the locus coeruleus (LC) in the Maudsley reactives (MR) than in the Maudsley non-reactives (MNRA). Autoradiographic studies showed that MNRAs had greater 125I clonidine binding to alpha 2 receptors in LC, which was accompanied by a higher behavioral sensitivity to clonidine. MRs had a deficit in working memory, but were superior to MNRAs in two reference memory tasks. MRs displayed a stronger preference for novel objects, with no strain differences in general exploratory activity. The behavioral profile of the MRs is similar to rats treated with drugs which enhance noradrenergic function. Furthermore, MNRA rats had greater availability of muscarinic receptors, which correlated with behavioral performance in the spatial working memory task. The differences in noradrenergic and cholinergic systems and their relationship to the behavioral profile make the Maudsley strains a useful tool to probe the interaction between two neurotransmitter systems in cognitive function.

Age Factors↗

PubMed2005

Perceived cognitive function and emotional distress following coronary artery bypass surgery.

Many patients experience decrements in cognitive function and emotional adjustment following coronary artery bypass graft (CABG) surgery. Moreover, cognitive decline and emotional distress are often positively related. This study evaluated the cross-sectional and prospective associations of emotional and subjective cognitive complaints, to assess the hypothesis that they would be mutually reinforcing. Participants were 76 CABG patients recruited from Akron General Medical Center. Depression and anxiety symptoms and perceived cognitive difficulties were evaluated at a baseline postsurgical visit and re-assessed 5 months later. Emotional symptoms and perceived cognitive difficulties were significantly related both within and across time. After controlling for numerous potential confounds, baseline perceived cognitive difficulties predicted a more negative course of emotional symptoms during follow-up. Baseline emotional symptoms did not predict the course of perceived cognitive difficulties. Perceptions of cognitive decline may contribute to emotional distress in patients post-CABG.

Aged↗

PubMed2006

[Hormone replacement therapy and cognitive function].

Observational studies have suggested that postmenopausal hormone replacement therapy (HRT) may improve cognitive function, but data from randomized clinical trials have been sparse and inconclusive. The effects of HRT on dementia and mild cognitive impairment were assessed in a subgroup of participants in the Women's Health Initiative Memory Study (WHIMS) (a multicenter, randomized, double-blind, placebo-controlled clinical trial). There were two study arms, one involved 4,532 postmenopausal women who received continuous combined estrogen (conjugated equine estrogens [CEE] plus medroxyprogesterone acetate [MPA]) or placebo, and the other involved 2,947 hysterectomized women randomized to continuous unopposed CEE or placebo. All participants were aged 65 years or older. CEE with or without MPA did not protect against (but substantially increased the risk of) dementia of any cause or cognitive decline. Incidence of probable dementia in the estrogen-alone trial was statistically similar to that in the estrogen plus progestin trial. When data from both trials were pooled, the overall risk for probable dementia was increased by 76% (HR, 1.76; 95% CI, 1.19 to 2.60; P = 0.005). A second report from WHIMS suggested that cognitive decline in women aged 65 years and older was greater in those receiving hormone therapy than in those receiving placebo (HR, 1.25; 95% CI, 0.97-1.60). The WHIMS results clearly indicate that CEE with or without MPA should not be used to prevent dementia or enhance cognition in women older than 65 years.

Alzheimer Disease↗

PubMed2006

Metabolic brain networks associated with cognitive function in Parkinson's disease.

The motor manifestations of Parkinson's disease (PD) have been linked to an abnormal spatial covariance pattern involving basal ganglia thalamocortical pathways. By contrast, little is known about the functional networks that underlie cognitive dysfunction in this disorder. To identify such patterns, we studied 15 non-demented PD patients using FDG PET and a voxel-based network modeling approach. We detected a significant covariance pattern that correlated (p<0.01) with performance on tests of memory and executive functioning. This PD-related cognitive pattern (PDCP) was characterized by metabolic reductions in frontal and parietal association areas and relative increases in the cerebellar vermis and dentate nuclei. To validate this pattern, we analyzed data from 32 subsequent PD patients of similar age, disease duration and severity. Prospective measurements of PDCP activity predicted memory performance (p<0.005), visuospatial function (p<0.01), and perceptual motor speed (p<0.005) in this validation sample. PDCP scores additionally exhibited an excellent degree of test-retest reliability (intraclass correlation coefficient, ICC=0.89) in patients undergoing repeat FDG PET at an 8-week interval. Unlike the PD-related motor pattern, PDCP expression was not significantly altered by antiparkinsonian treatment with either intravenous levodopa or deep brain stimulation (DBS). These findings substantiate the PDCP as a reproducible imaging marker of cognitive function in PD. Because PDCP expression is not altered by routine antiparkinsonian treatment, this measure of network activity may prove useful in clinical trials targeting the progression of non-motor manifestations of this disorder.

Brain↗

PubMed1993

Methylphenidate and desipramine in hospitalized children: I. Separate and combined effects on cognitive function.

OBJECTIVE: The separate and combined effects of methylphenidate and desipramine on cognitive function were investigated in 16 psychiatrically hospitalized children with primary, secondary, and mixed features of attention-deficit hyperactivity disorder and mood disorder. METHOD: A double-blind, placebo controlled, crossover design was used to investigate drug effects on vigilance, short-term memory, visual problem solving, and higher-order learning. RESULTS: Methylphenidate alone improved vigilance, both drugs positively affected short-term memory and visual problem solving, and combined drugs affected learning of higher-order relationships. CONCLUSIONS: Separate and combined drug effects are related to the specific cognitive domain assessed and have implications for neurotransmitter models of action.

Arousal↗

PubMed2000

Polymorphisms of genes controlling homocysteine/folate metabolism and cognitive function.

Elevated concentrations of the amino acid homocysteine and/or folate deficiency have been reported to affect neural development/function in both human patients and animal models. We have investigated the distribution of functional polymorphisms in genes involved in homocysteine/folate metabolism in children with high IQ and in children with average IQ. No differences in the frequencies of genetic variants in the methionine synthase or methylenetetrahydrofolate reductase genes were found. However, the cystathionine beta-synthase (CBS) 844ins68 allele was significantly underrepresented in children with high IQ. The mechanism by which a functional genetic variant in the CBS gene may influence cognitive function remains to be determined.

Adolescent↗

PubMed1990

Why worry? The cognitive function of anxiety.

The phenomenon of worry is considered to arise from cognitive processes involved in anxiety, that serve to maintain high levels of vigilance for personal danger. Rather than rely on self-report alone, the research described here draws on information processing methodology, to investigate this hypothesized cognitive function. Evidence is summarized to show that anxious subjects selectively attend to threatening information, and interpret ambiguous events in a relatively threatening way. However, the evidence on memory suggests that although such information may be easily activated, it is not necessarily more accessible. The allocation of attentional priority to threatening information is seen as a characteristic of anxious (rather than depressed) mood, while the ease with which this processing mode is adopted may underlie trait anxiety and vulnerability to anxiety disorders.

Anxiety↗

PubMed1996

Effects of some psychotropic agents on cognitive functions in rats.

The effects of some psychotropic agents were evaluated on cognitive function in rats. Acute administration of antipsychotic agents chlorpromazine, haloperidol or pimozide-all inhibited the active avoidance response as elicited by pole climbing test-the least effect being seen with pimozide. The antianxiety benzodiazepines, lorazepam and alprazolam, also attenuated active avoidance learning with the latter showing lesser effects. Maze task performance was differentially affected by these psychotropic drugs with maze traversing time being increased significantly after all drug treatment, except alprazolam.

Animals↗

PubMed2001

[Locating the impairment of human cognitive function during hypoxia].

Objective. To find the location where the human brain cognitive function impairs under hypoxia. Method. 14 healthy males, aged 18-20 years, performed auditory Oddball test of two different intensities (55 dB, 80 dB) during exposure to 5000 m by breathing low oxygen mixture. EEG and Reaction Time (RT) were recorded. P3, the component of ERP, was extracted from EEG. P3 latency and RT were used as indices of the experiment. Additive Factors Method was used to analyse the result of the experiment. Result. Interaction between hypoxia and stimulus intensity was found for P3 latency and RT. Conclusion. Acute hypoxia influences the preprocessing stage of information processing.

Acoustic Stimulation↗

PubMed2026

Role of Polygenic Risk Scores in Predicting Cognitive Functioning after Mild Traumatic Brain Injury: A TRACK-TBI Study.

Patients with traumatic brain injury (TBI) and Glasgow Coma Scale scores of 13-15 (historically called mild TBI [mTBI]) commonly experience changes in cognitive functioning, including processing speed, memory, and executive functioning. In a prospective sample (N = 523) of individuals of European descent who had been treated in a U.S. level 1 trauma center for mTBI, we examined the prognostic value of four polygenic risk scores (PRS) for cognitive outcomes at 6-months postinjury. To estimate the impact of mTBI on cognition, primary cognitive outcomes were scaled as z-scores reflecting changes in performance relative to predicted preinjury performance. The PRS examined were previously developed and validated to predict cognition-related outcomes of educational attainment (Education-PRS), intelligence (Intelligence-PRS), and Alzheimer's disease (AD-mild traumatic brain injury (APOE)-PRS and AD + APOE-PRS). Both the Education-PRS and Intelligence-PRS displayed bivariate associations with all four cognitive outcomes (β = 0.19-0.32), whereas neither Alzheimer's disease PRS was significantly associated with any outcome. After controlling for other factors known to predict cognitive outcomes of TBI (e.g., sex, education, mTBI severity defined by a combination of Glasgow Coma Scale scores and the presence/absence of acute intracranial findings on clinical neuroimaging), the Education-PRS and Intelligence-PRS remained independently predictive of verbal episodic memory (β = 0.10-0.16), whereas their associations with processing speed and executive functioning were mostly nonsignificant and were mediated through educational attainment. Looking across primary z-score and secondary raw score outcomes, cognitive outcomes 6 months post-mTBI were good on average, and PRS made small independent contributions to outcome prediction. The mediation model findings may support theories of cognitive reserve, which propose that individuals with stronger preinjury cognitive processing abilities (often estimated by educational history) can better compensate for TBI. Moreover, findings indicate that PRS may contribute modestly to multivariable models predicting cognitive function after TBI.

Humans↗

PubMed2005

Disparities among older adults in measures of cognitive function by race or ethnicity.

This study examined racial or ethnic differences in cognitive function, cross-sectionally and longitudinally, using survey data from the Asset and Health Dynamics Among the Oldest Old. A version of the Telephone Interview for Cognitive Status (TICS), proxy assessments of cognition, and difficulties in performing daily tasks were assessed. Blacks performed below Whites on the TICS at baseline and on proxy assessments of cognition. TICS score declined with age for Whites and Blacks, with some relative gains for Blacks. At baseline, Blacks more often had difficulties in performing daily tasks, with some increase in difficulties relative to Whites with age. Differences between other groups and Whites were smaller than those between Blacks and Whites.

Activities of Daily Living↗