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PubMed2003

Evaluating the interdependence of aging-related changes in visual and auditory acuity, balance, and cognitive functioning.

High proportions of shared age-related variance are found among measures of perceptual acuity, balance, muscle strength, and cognitive capabilities in age-heterogeneous, cross-sectional studies. Reliance on cross-sectional studies is problematic, however, because associations may arise from age-related mean trends. Narrow age-cohort samples provide an alternative basis for testing hypotheses regarding associations among rates of change. Cross-domain associations were evaluated in combined 75-year-old cohort samples from Denmark, Finland, and Sweden. In general, no consistent associations were found across sensory, balance, strength, and cognitive domains. These findings indicate that the effects of aging on sensory acuity, balance, and cognitive functioning are likely to be largely independent, multidimensional, and complex at the level of the individual.

Age Factors↗

PubMed1999

Effect of selegiline on cognitive functions in Parkinson's disease.

BACKGROUND: Selegiline hydrochloride, a selective MAO-B inhibitor is known to improve motor functions in Parkinson's disease (PD). The present study was undertaken to study the effect of selegiline on memory and intelligence of PD patients. MATERIAL AND METHOD: Thirty two patients of PD were divided in two groups: selegiline group (n = 17) received 10 mg selegiline per day and control group (n = 15) did not receive selegiline. Patients receiving trihexyphenidyl and selegiline were excluded. All other treatment remained unchanged. All patients were examined at baseline and after three months for change in UPDRS score, WAIS score, memory test and P300. RESULTS: Patients in selegiline group had less severe disease (UPDRS score 24.11 +/- 14.07) as compared to controls (UPDRS score 40.53 +/- 18.52). There was significant improvement in UPDRS score (p < 0.05), WAIS (p < 0.001) and memory (p < 0.001) in selegiline group. In the control group there was a significant prolongation of P300 latency (p < 0.05). CONCLUSION: The study suggests that selegiline improves memory functions and intelligence in PD patients in addition to motor functions. It also prevents prolongation of P300 latency which is a marker of cognitive function.

Adult↗

PubMed2003

Epilepsy in low-grade gliomas: the impact on cognitive function and quality of life.

Low-grade gliomas frequently are associated with epilepsy. The purpose of this study is to determine the impact of epilepsy and antiepileptic drug (AED) treatment on cognitive functioning and health-related quality of life (HRQOL) in these patients. One hundred fifty-six patients without clinical or radiological signs of tumor recurrence for at least 1 year after histological diagnosis and with an epilepsy burden (based on seizure frequency and AED use) ranging from none to severe were compared with healthy controls. The association between epilepsy burden and cognition/HRQOL was also investigated. Eighty-six percent of the patients had epilepsy and 50% of those using AEDs actually were seizure-free. Compared with healthy controls, glioma patients had significant reductions in information processing speed, psychomotor function, attentional functioning, verbal and working memory, executive functioning, and HRQOL. The increase in epilepsy burden that was associated with significant reductions in all cognitive domains except for attentional and memory functioning could primarily be attributed to the use of AEDs, whereas the decline in HRQOL could be ascribed to the lack of complete seizure control. In conclusion, low-grade glioma patients suffer from a number of neuropsychological and psychological problems that are aggravated by the severity of epilepsy and by the intensity of the treatment.

Adult↗

PubMed2005

Participating in social activities helps preserve cognitive function: an analysis of a longitudinal, population-based study of the elderly.

BACKGROUND: This study examines how changes in cognition over time are related to participation in social activities and the extent of social networks. METHODS: Data are drawn from a population-based, longitudinal study that began in 1989 among elderly Taiwanese. An over-dispersed Poisson model is used to regress the number of failed cognitive tasks (0-5) in 1996, 1999, and 2000 on prior measures of cognitive impairment, social activities, social networks, health status, and sociodemographic characteristics. The analysis sample comprises 2387 individuals, who contribute a total of 4603 observations across three survey intervals (1993-96, 1996-99, 1999-2000). RESULTS: After adjusting for prior cognitive impairment, baseline health status, and sociodemographic factors, respondents who participated in one or two social activities failed 13% fewer cognitive tasks (P < 0.01) than those with no social activities; those who engaged in three or more activities failed 33% fewer cognitive tasks (P < 0.001). In contrast, none of the social network measures was related to cognitive impairment. CONCLUSIONS: Despite a social structure where elderly persons often live with their children and social interaction is likely to be more family-centered than in western countries, data from Taiwan suggest that participation in social activities outside the family may have a bigger impact on cognitive function than social contacts with family or non-relatives.

Aged↗

PubMed2004

11Beta-hydroxysteroid dehydrogenase inhibition improves cognitive function in healthy elderly men and type 2 diabetics.

In aging humans and rodents, inter-individual differences in cognitive function have been ascribed to variations in long-term glucocorticoid exposure. 11beta-Hydroxysteroid dehydrogenase type 1 (11beta-HSD1) regenerates the active glucocorticoid cortisol from circulating inert cortisone, thus amplifying intracellular glucocorticoid levels in some tissues. We show that 11beta-HSD1, but not 11beta-HSD2, mRNA is expressed in the human hippocampus, frontal cortex, and cerebellum. In two randomized, double-blind, placebo-controlled crossover studies, administration of the 11beta-HSD inhibitor carbenoxolone (100 mg three times per day) improved verbal fluency (P < 0.01) after 4 weeks in 10 healthy elderly men (aged 55-75 y) and improved verbal memory (P < 0.01) after 6 weeks in 12 patients with type 2 diabetes (52-70 y). Although carbenoxolone has been reported to enhance hepatic insulin sensitivity in short-term studies, there were no changes in glycemic control or serum lipid profile, nor was plasma cortisol altered. 11beta-HSD1 inhibition may be a new approach to prevent/ameliorate cognitive decline.

11-beta-Hydroxysteroid Dehydrogenases↗

PubMed1999

[Roles of alpha-2 adrenoceptor in prefrontal cortical cognitive functions].

Studies in non-human primates have demonstrated that norepinephrine can improve, through actions at postsynaptical alpha-2A adrenoceptors, cognitive functions of the prefrontal cortex, such as attentional regulation, working memory and response inhibition. Several psychiatric disorders, including attention-deficit hyperactivity disorder (ADHD), show prominent syndromes seen in cognitive deficits of the prefrontal cortex. These basic studies help develop novel pharmacotherapies for psychiatric disorders such as ADHD.

Adrenergic alpha-Agonists↗

PubMed2004

Effects of quetiapine on cognitive functions in schizophrenia.

OBJECTIVE: All atypical antipsychotic drugs with complex pharmacology have been shown to improve some, but not all, domains of cognitive function, including quetiapine, i.e., the agent with the most rapid dissociation from dopamine receptors and a relatively weak serotonin antagonism. The present study was to evaluate which, if any, areas of cognition improve in patients with schizophrenia, following a brief treatment with quetiapine. METHODS: Effects of quetiapine on cognition were investigated in a group of patients with schizophrenia (n=14). Neuropsychological tests in cognitive areas previously shown as impaired in schizophrenia were administered at baseline and after 8 weeks of treatment with quetiapine. Administered at these two times were also the Positive and Negative Syndrome Scale, Hamilton Depression Rating Scale, and scales to assess motor side effects (Abnormal Involuntary Movement Scale, Simpson-Angus Scale, and Barnes Akathisia Scale). RESULTS: Wilcoxon Signed Ranks Test indicated a statistically significant improvement in scores on Digit Span Test, Trail Making Test, Stroop Test, Finger Tapping Test, and on the Positive and Negative Syndrome Scale. No significant change was noted in motor side effects. CONCLUSION: The patients improved in their attentional, motor, and visuo-motor skills, and in executive functions as well as with respect to psychopathology, without an increase in motor side effects.

Adult↗

PubMed1993

The cerebellum and cognitive functions in humans.

Recent neuropsychological studies have given rise to the hypothesis that the cerebellum is involved in nonmotor cognitive functions. The interpretation of these findings is, however, restricted by methodological problems, such as heterogenous patient samples. The present study compared patients with pathology confined to the cerebellum and patients with combined cerebellar and brainstem lesions to matched normal controls on a range of memory and learning tasks. Two procedural learning tasks were also conducted, involving perceptual (mirror reading) and conceptual skill acquisition (the Tower of Hanoi task). Patients with damage to both cerebellum and brainstem, but not patients with cerebellar pathology alone, showed impairments on memory and visuoconstructive tasks and evidence of frontal lobe dysfunction. Cerebellar damage had no effect on skill acquisition. These results do not support the hypothesis of cerebellar involvement in procedural learning per se.

Adult↗

PubMed2002

Longitudinal assessment of premorbid cognitive functioning in patients with schizophrenia through examination of standardized scholastic test performance.

OBJECTIVE: Studies suggest the presence of premorbid cognitive impairment in patients with schizophrenia, yet the onset and course of these deficits remain unclear. The purpose of this study was to investigate the longitudinal course of premorbid cognitive functioning in individuals with schizophrenia by using prospective data obtained from scholastic test results. METHOD: Scores from grades 4, 8, and 11 on the Iowa Tests of Basic Skills and the Iowa Tests of Educational Development were obtained for 70 subjects who later developed schizophrenia. The mean percentile rank of the subjects' scores in the areas of vocabulary, reading comprehension, language, mathematics, sources of information, and an overall composite category were compared with state norms. RESULTS: The subjects scored below the 50th percentile for each category in all three grades, but only language, reading, sources of information, and composite scores from grade 11 were significantly below state norms. With regard to longitudinal course, there was a significant linear decrease in language scores over time. Scores from grade 11 were positively correlated with WAIS-R IQ, verbal fluency, and Rey Auditory Verbal Learning scores at first illness episode. Scores from grade 11 were not significantly correlated with age at illness onset or ratings of disorganized, psychotic, or negative symptoms. CONCLUSIONS: Scholastic test scores at grades 4 and 8 were nonsignificantly below average in this group of children who later developed schizophrenia. However, test scores dropped significantly between grades 8 and 11. This corresponds to ages 13-16 years, or the onset of puberty. Poor or declining scholastic performance may be a precursor to the cognitive impairment seen during the first episode of illness.

Adolescent↗

PubMedDate not supplied

Behavioral toxicology: evaluating cognitive functions.

Behavioral toxicology is concerned with the identification of adverse effects on neural and behavioral functions resulting from exposure to a neurotoxicant. Many substances are known to have effects on cognitive functions such as memory, attention and perception. This paper reviews some of the issues that must be addressed when trying to assess these neurotoxic effects on cognition, and identifies a variety of paradigms that have been explored for use in behavioral toxicology.

Arousal↗

PubMed1992

Cortical localization of cognitive function by regression of performance on event-related potentials.

This paper demonstrates a new method of mapping cortical localization of cognitive function, using electroencephalographic (EEG) data. Cross-subject regression analyses are used to identify cortical sites and post-stimulus latencies where there is a high correlation between subjects' performance and their cognitive event-related potential (ERP) amplitude. The procedure was tested using a mental arithmetic task and was found to identify essentially the same cortical regions that have been associated with such tasks on the basis of research with patients suffering localized cortical lesions. Thus, it appears to offer an inexpensive, noninvasive tool for exploring the dynamics of localization in neurologically normal subjects.

Adult↗

PubMed2003

Blood pressure and cognitive functioning among independent elderly.

BACKGROUND: The morbidity and mortality benefits of blood pressure (BP) control for the elderly is well documented. The cognitive consequences of hypertension control in this population, however, are still under debate. We aim to study the association between BP and cognitive performance in the elderly. Specifically, we explore 1) the possibility that BP is differentially associated with various cognitive domains; and 2) the utility of analyzing both BP and cognitive scores as continuous variables to unravel possible nonlinear associations. METHODS: Four hundred ninety-five community living 70 to 85 year olds completed eight cognitive tests that measured memory, concentration, visual retention, verbal fluency, and the mini-mental state examination (MMSE). The performance of each test was analyzed first by comparing four groups (normotensives, normalized hypertensives, untreated hypertensives, and treated but uncontrolled hypertensives). Then, using BP values as continuous variables, linear, U-curve, and J-curve associations were estimated. RESULTS: On all cognitive tests, except for verbal fluency, normotensives performed poorest, treated but uncontrolled hypertensives achieved the highest scores. The MMSE scores and the lighter concentration task were linearly related to BP; J-curve association was observed between memory and visual retention; prolonged concentration was related to pulse pressure alone. CONCLUSIONS: Low BP, as observed among the normotensive subjects, was associated with poor cognitive performance. Mild hypertension appeared to enhance cognitive functioning among the subjects of this study. Moreover, we found support for the hypothesis that the association between BP and different dimensions of cognition take on different patterns.

Activities of Daily Living↗

PubMed2005

Cognitive functions correlate with white matter architecture in a normal pediatric population: a diffusion tensor MRI study.

A possible relationship between cognitive abilities and white matter structure as assessed by magnetic resonance diffusion tensor imaging (DTI) was investigated in the pediatric population. DTI was performed on 47 normal children ages 5-18. Using a voxelwise analysis technique, the fractional anisotropy (FA) and mean diffusivity (MD) were tested for significant correlations with Wechsler full-scale IQ scores, with subject age and gender used as covariates. Regions displaying significant positive correlations of IQ scores with FA were found bilaterally in white matter association areas, including frontal and occipito-parietal areas. No regions were found exhibiting correlations of IQ with MD except for one frontal area significantly overlapping a region containing a significant correlation with FA. The positive direction of the correlation with FA is the same as that found previously with age, and indicates a positive relationship between fiber organization and/or density with cognitive function. The results are consistent with the hypothesis that regionally specific increased fiber organization is a mechanism responsible for the normal development of white matter tracts.

Adolescent↗

PubMed1985

A psychopharmacological perspective of cognitive functions. II. Specific pharmacologic agents.

In this article we review the effects of specific drugs or neurotransmitter systems on cognitive functions. While much of what we know about drugs' effects on memory is derived from animal experiments, this review focuses on studies relevant to human clinical conditions. We conclude with a speculative analysis or taxonomy of the pharmacology of memory which broadly highlights the utility of viewing memory as being comprised of several differentiated processes.

Adrenal Cortex Hormones↗

PubMed1991

The effects of alcohol and other drugs on psychomotor performance and cognitive function.

The effects of four doses of alcohol (0.25 g/kg-1 g/kg) and placebo on a standard test battery of cognitive and psychomotor performance are described. The tests included critical flicker fusion threshold, choice reaction time, tracking and memory scanning. The results of this experiment are compared with those of a number of similar studies which examined the effects of other psychoactive substances. Using relative effect sizes, the behavioural toxicity of alcohol is compared with the effects of these other drugs on psychomotor performance and cognitive function.

Adult↗

PubMedDate not supplied

[Relation of the cerebellum with cognitive function: neuroanatomical, clinical and neuroimaging evidence].

INTRODUCTION: Published studies in the last decades, employing a variety of methodologies, suggest that the cerebellum function is not only limited to motor control but also has an important role in cognition and emotion. DEVELOPMENT: In the present paper we review the main neuroanatomical and functional neuroimaging studies supporting the idea that the cerebellum has a role in non motor behavior. On the other hand, we expound the results of the neuropsychological studies of patients with cerebellar lesions. The deficits showed after cerebellar lesions include disturbances in executive functions, learning, memory, attention, visuo-spatial functions, language and personality change. Some studies propose that the cerebellum, through its afferent and efferent circuits with the cerebrum, perform a global function capable to influencing motor behavior, in cognitive functions and in emotion. A fault in this function would cause the behavioral deficits shown in patients with cerebellar lesions. CONCLUSION: The evidence available in the anatomical, functional and clinical studies support the conclusion that the cerebellum participates not only in motor functions, but also in cognitive functions and in emotion.

Brain↗

PubMed2004

Self-awareness of cognitive functioning in schizophrenia.

Poor awareness of psychiatric symptoms is associated with schizophrenia. It is unclear whether this lack of insight extends to the cognitive impairment that affects at least 85% of people with schizophrenia. Given the increasing efforts to develop treatments for cognitive impairment, and the link between awareness of disability and treatment compliance, it is important to understand whether people with schizophrenia have awareness of their cognitive deficits. Ratings of cognitive functioning from 185 outpatients diagnosed with schizophrenia, their clinicians' ratings and objective neuropsychological test results were compared in the following cognitive domains: attention, nonverbal memory, and verbal memory. The results indicated that there was poor concordance among the three assessments. Patients did not agree with their clinician's assessments and did a very poor job of accurately classifying their cognitive status. However, clinicians were also poor at classifying cognitive status consistent with neuropsychological test results. The implications of these findings for understanding insight in schizophrenia are discussed.

Adult↗

PubMed2005

Amyloid mediates the association of apolipoprotein E e4 allele to cognitive function in older people.

BACKGROUND: The neurobiological changes underlying the association of the apolipoprotein E (APOE) e4 allele with level of cognition are poorly understood. OBJECTIVE: To test the hypothesis that amyloid load can account for (mediate) the association of the APOE e4 allele with level of cognition assessed proximate to death. METHODS: There were 44 subjects with clinically diagnosed Alzheimer's disease and 50 without dementia, who had participated in the Religious Orders Study. They underwent determination of APOE allele status, had comprehensive cognitive testing in the last year of life, and brain autopsy at death. The percentage area of cortex occupied by amyloid beta and the density of tau positive neurofibrillary tangles were quantified from six brain regions and averaged to yield summary measures of amyloid load and neurofibrillary tangles. Multiple regression analyses were used to examine whether amyloid load could account for the effect of allele status on level of cognition, controlling for age, sex, and education. RESULTS: Possession of at least one APOE e4 allele was associated with lower level of cognitive function proximate to death (p = 0.04). The effect of the e4 allele was reduced by nearly 60% and was no longer significant after controlling for the effect of amyloid load, whereas there was a robust inverse association between amyloid and cognition (p = 0.001). Because prior work had suggested that neurofibrillary tangles could account for the association of amyloid on cognition, we next examined whether amyloid could account for the effect of allele status on tangles. In a series of regression analyses, e4 was associated with density of tangles (p = 0.002), but the effect of the e4 allele was reduced by more than 50% and was no longer significant after controlling for the effect of amyloid load. CONCLUSION: These findings are consistent with a sequence of events whereby the e4 allele works through amyloid deposition and subsequent tangle formation to cause cognitive impairment.

Aged↗