SEARCH · PubMed Health

Results for “Cognitive Dysfunction”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,243 records · Page 69Linked to original sources

PubMed1997

Neurometabolism of active neuropsychiatric lupus determined with proton MR spectroscopy.

PURPOSE: To determine the neurometabolism of patients with active neuropsychiatric systemic lupus erythematosus (NPSLE) by using proton MR spectroscopy. METHODS: Thirty-six patients with SLE and eight control subjects were studied with proton MR spectroscopy to measure brain metabolites. Peaks from N-acetylaspartate (NAA), creatine (Cr), choline (Cho), and at 1.3 parts per million (ppm) lipid, macromolecules, and lactate were measured. Patients were classified as having major NPSLE (seizures, psychosis, major cognitive dysfunction, delirium, stroke, or coma) (n = 15) or minor NPSLE (headache, minor affective disorder, or minor cognitive disorder) (n = 21). Patients with major NPSLE were severely ill and hospitalized. RESULTS: SLE patients had lower NAA and increased metabolites at 1.3 ppm than did control subjects (NAA/Cr(SLE) = 1.90 +/- 0.35, NAA/Cr(Control) = 2.16 +/- 0.26; 1.3 ppm/Cr(SLE) = 0.49 +/- 0.41, 1.3 ppm/Cr(Control) = 0.27 +/- 0.05). NAA/Cr in patients with current or prior major NPSLE was lower than in patients without major NPSLE. Increased peaks at 1.3 ppm were present in all SLE subgroups, but particularly in patients with major NPSLE. These resonances were not evident at an echo time of 136, indicating that these signals were not lactate. CONCLUSION: Major NPSLE, past or present, is associated with decreased levels of NAA. Elevated peaks around 1.3 ppm do not represent lactate even in severely ill patients, indicating that global ischemia is not characteristic of NPSLE. Neurochemical markers determined by MR spectroscopy may be useful for determining activity and degree of brain injury in NPSLE.

Adult↗

PubMed2006

Neuropsychology of multiple sclerosis--an overview.

Neuropsychological dysfunctions have been well documented in patients with multiple sclerosis. We herein give an overview of the main findings of recent decades. The pros and cons of considering the cognitive deficits of multiple sclerosis patients as a form of 'subcortical dementia' are discussed. By comparing the neuropsychological descriptions of multiple sclerosis patients as given in the literature to other neurological diseases which are also associated with neuropsychological deficiencies, we propose the term 'multiple disconnection syndrome' to describe the variety of neuropsychological deficits encountered in this demyelinating disease. Furthermore, a ' threshold of cerebral tolerance' is assumed which must be crossed before cognitive dysfunctions are manifested clinically.

Cognition↗

PubMed2006

The neurobiology of cognition in schizophrenia.

Currently, no drugs exist that effectively treat cognition in people with schizophrenia. What is known about the neurobiology of cognition in schizophrenia is derived from the animal literature; it is inadequate and superficial. Despite this lack, pharmacologic research into potential molecular targets has uncovered several viable possibilities from animal studies. A subcommittee of the Measurement and Treatment Research to Improve Cognition in Schizophrenia (MATRICS) program investigated the range of putative molecular targets for treating cognition. Those targets that show promise for pharmacologic focus include the dopamine receptors (especially D1) in the prefrontal cortex (PFC), the serotonin receptors in the PFC and anterior cingulate cortex, the glutamatergic excitatory synapse, the acetylcholine nicotinic receptors in the hippocampus, the acetylcholine muscarinic receptors, and the brain gamma-aminobutyric acid (GABA) system. Once developed and tested, the effective compounds will be valuable for the treatment of the symptom domains of cognitive dysfunction and negative symptoms.

Animals↗

PubMed1983

Cluster analysis of the WAIS on brain-damaged patients.

In recognition of increased usage of cluster analytic techniques, the current study attempted to examine sampling bounds for tests and subjects on one cluster-analytic procedure. Specifically, the WAIS subtest scores from a heterogeneous group of subjects with CNS involvement were first, factor analyzed and then clustered by means of Ward's hierarchical procedure. This methodology had been previously applied to two different samples of aphasics and aphasia batteries. In both these aphasic studies, an underlying severity dimension of language dysfunction was found. In contrast, in the current study, salient feature groups were found. Moreover, these groups were distributed in a sequential or hierarchical model in terms of specific cognitive deficits. From these data, it is argued that two major parameters in determining the resulting cluster structures are the homogeneity/heterogeneity of the sample and test battery employed. Although such a statement is obvious, the theoretical ramifications are large, in that the cluster structure may be a function of test weighting or sample diversity, not the phenomenon of interest. However, the cluster structures found in the current study were consistent with historical models of cognitive dysfunction and also lend support to hierarchical models of sequential cognitive impairment. These findings are discussed in terms of their clinical and experimental ramifications with respect to grouping subjects in terms of WAIS profiles.

Adult↗

PubMed1998

Cortical dysfunction in schizophrenia during auditory word and tone working memory demonstrated by functional magnetic resonance imaging.

BACKGROUND: Verbal learning and memory deficits are among the most severe cognitive deficits observed in schizophrenia. We have demonstrated that such deficits do not extend to working memory for tones in a substantial number of patients even when verbal working memory is impaired. In this study we used functional magnetic resonance imaging to study the neural basis of this dissociation of auditory verbal and nonverbal working memory in individuals with schizophrenia. METHODS: While undergoing functional magnetic resonance imaging, 12 schizophrenic patients and 12 matched control subjects performed auditory Word Serial Position Task and Tone Serial Position Task. RESULTS: Both tasks produced activation in frontal cortex and temporal and parietal lobes of the cerebrum in both groups. While robust activation was observed in the left inferior frontal gyrus (areas 6, 44, and 45) in the control group during the Word Serial Position Task, activation in the patient group was much reduced in these areas and failed to show the same task-specific activation as in controls. Reduced activation in patients was not confined to the inferior frontal gyrus, but also extended to a medial area during the Tone Serial Position Task and to premotor and anterior temporal lobe areas during both tasks. CONCLUSIONS: These findings support the hypothesis that abnormalities in cortical hemodynamic response in the inferior frontal gyrus underlie the verbal working memory deficit in schizophrenia. The relationship of verbal working memory deficits to other cognitive functions suggests that abnormal functioning in the speech-related areas may reflect a critical substrate of a broad range of cognitive dysfunctions associated with schizophrenia.

Adult↗

PubMed2002

Cognitive functioning of long-term heavy cannabis users seeking treatment.

CONTEXT: Cognitive impairments are associated with long-term cannabis use, but the parameters of use that contribute to impairments and the nature and endurance of cognitive dysfunction remain uncertain. OBJECTIVE: To examine the effects of duration of cannabis use on specific areas of cognitive functioning among users seeking treatment for cannabis dependence. DESIGN, SETTING, AND PARTICIPANTS: Multisite retrospective cross-sectional neuropsychological study conducted in the United States (Seattle, Wash; Farmington, Conn; and Miami, Fla) between 1997 and 2000 among 102 near-daily cannabis users (51 long-term users: mean, 23.9 years of use; 51 shorter-term users: mean, 10.2 years of use) compared with 33 nonuser controls. MAIN OUTCOME MEASURES: Measures from 9 standard neuropsychological tests that assessed attention, memory, and executive functioning, and were administered prior to entry to a treatment program and following a median 17-hour abstinence. RESULTS: Long-term cannabis users performed significantly less well than shorter-term users and controls on tests of memory and attention. On the Rey Auditory Verbal Learning Test, long-term users recalled significantly fewer words than either shorter-term users (P =.001) or controls (P =.005); there was no difference between shorter-term users and controls. Long-term users showed impaired learning (P =.007), retention (P =.003), and retrieval (P =.002) compared with controls. Both user groups performed poorly on a time estimation task (P<.001 vs controls). Performance measures often correlated significantly with the duration of cannabis use, being worse with increasing years of use, but were unrelated to withdrawal symptoms and persisted after controlling for recent cannabis use and other drug use. CONCLUSIONS: These results confirm that long-term heavy cannabis users show impairments in memory and attention that endure beyond the period of intoxication and worsen with increasing years of regular cannabis use.

Adult↗

PubMed1996

Chronic developmental lead exposure increases the threshold for long-term potentiation in rat dentate gyrus in vivo.

Chronic developmental lead (Pb) exposure has been long associated with cognitive dysfunction in children and animals. In an attempt to more directly relate the behavioral observations of impaired cognitive ability to Pb-induced effects on neuronal activity, we utilized the long-term potentiation (LTP) model of neural plasticity to assess synaptic function. Male rats were chronically exposed to 0.2% Pb(2+)-acetate through the drinking water of the pregnant dam, and directly through their own water supply at weaning. As adults, field potentials evoked by perforant path stimulation were recorded in the dentate gyrus under urethane anesthesia. LTP threshold was determined by applying a series of stimulus trains of increasing intensities. Baseline testing of dentate gyrus field potentials indicated that input/output functions, maximal response amplitudes, and threshold currents required to evoke a population spike (PS) did not differ for control and Pb-exposed animals. Despite similarities in baseline synaptic transmission, Pb-exposed animals required a higher train intensity to evoke LTP than controls. With maximal train stimulation, however, control and Pb animals exhibited comparable levels of potentiation. These findings suggest that the mechanisms of LTP induction are preferentially impaired by Pb exposure. Although baseline synaptic transmission was not altered in Pb-exposed animals, decreases in glutamate release following high K+ perfusion and reductions in paired pulse facilitation have been reported in the intact animal. Pb-induced reductions in calcium influx through voltage-sensitive or N-methyl-D-aspartate (NMDA) receptor-dependent channels may mediate increases in LTP threshold. It is possible that the threshold changes in the induction of LTP reported here contribute to cognitive impairments associated with Pb exposure.

Analysis of Variance↗

PubMed2006

The relationship between psychological dimensions of depressive symptoms and cognitive functioning in the elderly - the MEMO-Study.

Aim of this study was to examine the association of symptom dimensions of depressive symptoms and cognitive functioning in the elderly. In a population-based study with 365 participants 65-83 years of age, dimensions of depressive symptoms were assessed with the four subscales of the CES-D-score and standardized cognitive tests assessing attention, memory, cognitive speed, and motor speed were performed. Compared to men, women scored significantly higher on the subscales for depressed affect and somatic complaints. Older participants had a significantly higher score for interpersonal difficulties. Participants with lower education had higher scores on all four psychological dimensions of depressive symptoms than those with high education (only significant for depressive affect). Individuals scoring high on CES-D subscales for depressive affect and somatic complaints had statistically significant (after Bonferroni adjustment) lower scores in attention and motor function in multivariate analyses. No significant associations between the symptom dimensions of positive affect and interpersonal difficulties with any of the cognitive tests were found in univariate and multivariate analyses (after Bonferroni adjustment). Our findings suggest specific patterns in the relationships between symptom dimensions of depressive symptoms and cognitive dysfunction in the general elderly population. This novel approach might be useful in addressing the heterogeneity of cognitive impairment in depression and in predicting cognitive outcome in depression.

Age Factors↗

PubMed1999

Neuropsychological and behavioral status of children with complex partial seizures.

Neuropsychological and behavioral status were examined in 57 children aged 7 to 16 years with complex partial seizures (CPS) and compared with 27 sibling control children of the same age. Epilepsy had a significant effect on both cognitive and behavioral adjustment measures. Children with CPS had significant impairment across all seven cognitive domains assessed, reflective of a profile of relatively diffuse and generalized cognitive dysfunction. Age at onset of recurrent seizures was the strongest and most consistent predictor of adequacy of cognitive functioning; earlier age at onset was associated with poorer cognitive status. Children with CPS also had more problems compared with sibling control children on measures of social and school competence and internalizing behavior problems, but not externalizing behaviors. Further, frequency of seizure activity in the past year, rather than age at seizure onset, emerged as the strongest predictor of these behavioral difficulties. These findings are discussed in the context of understanding the impact of CPS on cognition and behavioral adjustment, and identifying the contribution of various aspects of the neurodevelopmental course of CPS to these issues.

Achievement↗

PubMed2006

Human lupus autoantibodies against NMDA receptors mediate cognitive impairment.

Neuropsychiatric systemic lupus erythematosus, which often entails cognitive disturbances and memory loss, has become a major complication for lupus patients. Previously, we developed a murine model of neuropsychiatric lupus based on Abs that cross-react with dsDNA and the NMDA receptor (NMDAR). We showed that these murine Abs impair cognition when they access the CNS through a breach in the blood-brain barrier (BBB) triggered by lipopolysaccharide. Because studies show that lupus patients possess anti-NMDAR Abs in their serum and cerebrospinal fluid, we decided to investigate whether these human Abs contribute to cognitive dysfunction. Here, we show that serum with reactivity to DNA and NMDAR extracted from lupus patients elicited cognitive impairment in mice receiving the serum intravenously and given lipopolysaccharide to compromise the BBB integrity. Brain histopathology showed hippocampal neuron damage, and behavioral testing revealed hippocampus-dependent memory impairment. To determine whether anti-NMDAR Abs exist in the brains of systemic lupus erythematosus patients, we eluted IgG from a patient's brain. The IgG bound DNA and NMDAR and caused neuronal apoptosis when injected into mouse brains. We examined four more brains of patients with neuropsychiatric lupus and found that they displayed endogenous IgG colocalizing with anti-NMDAR Abs. Our results indicate that lupus patients have circulating anti-NMDAR Abs capable of causing neuronal damage and memory deficit, if they breach the BBB, and that the Abs exist within patients' brains. Which aspects of neuropsychiatric lupus may be mediated by anti-NMDAR Abs, how often, and in which patients are now important clinical questions.

Animals↗

PubMed1995

Falls and major injuries are risk factors for thoracolumbar fractures: cognitive impairment and multiple injuries impede the detection of back pain and tenderness.

Risk factors for thoracolumbar fracture (TLF) and occurrence of back pain/tenderness detection (BPTD) in TLF patients have not been fully evaluated. Of 4142 blunt trauma patients directly admitted to a level I trauma center, 183 (4.4%) had a TLF. Risk factors for TLF (p < or = 0.05) were major non-TLF injuries (Abbreviated Injury Scale score > or = 3) and a fall mechanism of injury. Of 110 with TLF, Glasgow Coma Scale score (GCS) of 13 to 15, and no myelopathy, 34 (30.9%) had no BPTD; 7 of 34 (20.6%) required operative spinal stabilization. BPTD was lacking in 63% of patients with GCS scores of 13 to 14 compared to 22% of patients with GCS scores of 15 (p = 0.001). BPTD was decreased when major non-TLF injuries were present (63 vs. 91%) in the GCS score of 15 group (0.003), but similar in GCS score of 13 to 14 patients. In patients with GCS scores of 13 to 15, decreased BPTD is simultaneously related to both cognitive dysfunction and major injuries (p = 0.005). In conclusion, major injuries and falls are risks for TLF and cognitive deficit and major injury impedes BPTD in TLF. Thoracolumbar x-ray films should be carefully considered in patients with altered mentation or major injury.

Accidental Falls↗

PubMed1993

The relationship between age, gender and cognitive performance in the very old: the effect of selective survival.

OBJECTIVE: To determine the prevalence of cognitive disability as a function of advanced age and gender in elderly nursing home and community-dwelling populations. Since cognitive dysfunction is associated with increased mortality, we hypothesized that selective survival results in a decreased prevalence of cognitive disability in the oldest old. DESIGN: Cohort study. An analysis of 6-month longitudinal data obtained from a national probability sample of older persons in 260 nursing homes (n = 1951) and 2-year-longitudinal data obtained from a sample of community-dwelling older persons (n = 2947). MEASURES: In the nursing home sample, the primary outcome measure was cognitive performance score. In the community sample, cognitive performance was determined using the results of three orientation questions and assessment of decision-making ability. Cognitive performance and subsequent survival, controlling for various disease states and demographic factors, were examined in three age cohorts of men and women (ages 65-79, 80-89, 90-99). RESULTS: In the nursing home sample, the cognitive performance of very old men (> or = 90 years) was better than that of younger men (aged 80-89 years, P < 0.05) and very old women (age > or = 90 years, P = 0.001). Among 80-89-year-olds with poor cognitive performance, the 6-month mortality rate was higher in men than in women (38% vs 19%, P = 0.001). However, the mortality rates of men and women with good cognitive performance were not statistically different in any age group. Proportional-hazards regression analysis demonstrated that poor cognitive performance remained a powerful predictor of death among men aged 80-89 years with a relative risk of 2.7 (95% Cl, 1.19-3.17; P = 0.0006) after controlling for covariates. Results from the community sample lent support to our findings: within each age group, mortality rates for men and women with intact cognitive performance were not statistically different. However, in the two older age groups, the mortality rates of subjects with impaired cognitive performance were significantly greater for men than for women (P < 0.01 for both age groups). CONCLUSIONS: Decreased cognitive performance is significantly associated with mortality among elderly men. Survival by men who have relatively intact cognitive function results in a population of oldest men, those aged 90-99 years, with cognitive performance scores better than younger men or similarly-aged women. The same selective survival phenomenon was not observed among women. Thus, there may be less cognitive disability among very old men than previously expected.

Age Factors↗

PubMed1994

Brain reactive autoantibodies and cognitive impairment in systemic lupus erythematosus.

Nervous system involvement in SLE encompasses a wide array of clinical manifestations which may reflect multiple etiologic factors including autoantibodies to nervous tissue antigens. The aim of the present study was to examine the association between autoantibodies to a wide range of brain antigens and cognitive abnormalities in an unselected population of 70 SLE patients. Using a battery of standardized neuropsychological tests, cognitive impairment was identified in 15/70 (21%) SLE patients compared with 1/25 (4%) patients with rheumatoid arthritis and 1/23 (4%) healthy subjects (P = 0.04). Integral membrane proteins were isolated from dissociated brain cells by temperature-induced phase separation with Triton X-114. Synaptosomes were isolated by differential centrifugation and membrane enriched fractions were prepared by lectin affinity chromatography. Western blotting identified IgG reactivity to a wide range of proteins (MW 22-52 K) in SLE patients. The proteins identified were distinct from well-characterized intracellular antigens including ribosomal P proteins. There was no significant difference in the prevalence of anti-brain antibodies between SLE patients who were cognitively impaired and those who were not impaired. Furthermore, there was no association between the presence of autoantibodies and subsets of cognitive dysfunction. These results suggest that circulating autoantibodies to brain antigens are not responsible for the abnormalities in cognitive function in SLE patients.

Adolescent↗

PubMed2006

Cognitive evaluation of traumatically brain-injured rats using serial testing in the Morris water maze.

PURPOSE: As deficits in memory and cognition are commonly observed in survivors of traumatic brain injury (TBI), causing reduced quality of life for the patient, a major goal in experimental TBI research is to identify and evaluate cognitive dysfunction. The present study assessed the applicability of the serial Morris water maze (MWM) test to determine cognitive function following experimental TBI in the same group of rats which is particularly important for long-term studies and increasingly valuable for the evaluation of novel treatment strategies. METHODS: Male Sprague-Dawley rats (n = 27) were anesthetized and subjected to either sham injury (n = 9) or lateral fluid percussion (FP) brain injury of moderate severity (n = 18). At 4 weeks post-injury, animals were trained in a water maze over 3 days (acquisition/learning phase) to find a submerged platform. At 8 weeks post-injury the hidden platform was then moved to the opposite quadrant, and animals were trained to find the new position of the platform over 3 days. Forty-eight hours later, animals were tested for memory retention in a probe trial in which the platform was not present. RESULTS: Brain-injured animals had significant learning impairment (p < 0.0001), shifted-learning impairment (p < 0.001) and memory retention deficits (p < 0.01) in comparison to their sham-injured counterparts over the 8 week testing period. Swim speed and distance were not significantly altered by brain injury at any time point. CONCLUSION: The validation of this testing paradigm using a clinically relevant experimental brain injury model is an important addition to behavioral outcome testing.

Animals↗

PubMed2005

Cognitive performance of hypertensive elderly Nigerians: a case control study.

The importance and contribution of optimal blood pressure control to improvement in quality of life, cognitive abilities inclusive, have been established and accepted by all and sundry. In the elderly population, however, hypertension and cognitive dysfunction are commonly encountered disorders. The objective is to determine the role of blood pressure on the cognitive performances of Nigerian elderly hypertensive patients. A total of 327 randomly selected elderly subjects above 60 years of age comprising 153 hypertensive: 53 males (34.64%) and 100 females (65.36%) with a mean age of 66.65 +/- 6.64 years; and 174 normotensive healthy controls: 63 males (36.21%) and 111 females (63.79%) with a mean age of 67.29 +/- 6.45 years were studied. The mean blood pressure for the hypertensive was 160/110mmHg (range 150/94 - 190/130mmHg) while it was 120/74mmHg (range 110/50 - 139/89mmHg) for the normotensives. The cognitive testing was done with the Community Screening Instrument for Dementia (CSI'D'). The main outcome measures were cognitive test scores (CSI'D' scores) and blood pressure readings. The CSI'D' scores correlated significantly with higher educational level (P < 0.05; P = 0.0372) but the mean CSI'D' scores of hypertensives was not significantly different from that of normotensives (P>0.05). The diastolic blood pressure was the strongest predictor of the presence of cognitive impairment with a statistically significant linear relationship (P = 0.013). This study assessed the effect of blood pressure on cognitive performance. The evidence from the study showed that blood pressure has no effect on cognitive performance of subjects generally but among hypertensive subjects, diastolic blood pressure negatively correlates with cognitive performance.

Age Factors↗

PubMed2006

Obesity and ADHD may represent different manifestations of a common environmental oversampling syndrome: a model for revealing mechanistic overlap among cognitive, metabolic, and inflammatory disorders.

Obesity and attention-deficit hyperactivity disorder (ADHD) are both increasing in prevalence. Childhood exposure to television has shown linkage to both ADHD and obesity with the former ascribed to dysfunctional cognitive hyperstimulation and the latter to altered patterns of diet and exercise. Empirical evidence has contradicted prior presumptions that the hyperactivity of ADHD would decrease the risk of obesity. Instead, obesity and ADHD demonstrate significant comorbidity. We propose that obesity and ADHD represent different manifestations of the same underlying dysfunction, a phenomenon we term environmental oversampling syndrome. Oversupply of information in the form of nutritional content and sensory content may independently predispose to both obesity and ADHD. Moreover, the pathogenic mechanisms of these conditions may overlap such that nutritional excess contributes to ADHD and cognitive hyperstimulation contributes to obesity. The overlapping effects of medications provide further evidence towards the existence of shared etiologic pathways. Metabolism and cognition may represent parallel systems of intelligence, and oversampling of content may constitute the source of parallel dysfunctions. The emerging association between psychiatric and metabolic disorders suggests a fundamental biologic link between these two systems. In addition, the immune system may represent yet another form of intelligence. The designation of syndrome X subsumes seemingly unrelated metabolic and inflammatory entities. Environmental oversampling syndrome may represent an even more inclusive concept that encompasses various metabolic, inflammatory, and behavioral conditions. Apparently disparate conditions such as insulin resistance, diabetes, hypertension, syndrome X, obesity, ADHD, depression, psychosis, sleep apnea, inflammation, autism, and schizophrenia may operate through common pathways, and treatments used exclusively for one of these conditions may prove beneficial for the others.

Attention Deficit Disorder with Hyperactivity↗

PubMed1995

Modifiability of neuropsychological dysfunction in schizophrenia.

Schizophrenia is often characterized by compromised neuropsychological functioning, especially on tasks sensitive to frontal and temporohippocampal functions but the extent to which cognitive dysfunction can be modified in schizophrenics remains unclear. Twenty-four inpatient schizophrenics and 24 intellectually and demographically matched, inpatient mood-disordered controls were randomly assigned to one of two conditions. Subjects assigned to the cued condition received instructional cues on measures of visual and semantic memory, executive function, and constructional ability. Subjects in the standard condition performed the same neuropsychological measures without cues. The present study revealed some degree of plasticity of neurobehavioral function in schizophrenia.

Adult↗

PubMed1984

Coping with transient intellectual dysfunction after coronary bypass surgery.

In summary, we believe that the impact of our findings on the patient and clinician includes recognition and acknowledgment that transient cognitive dysfunction frequently follows coronary bypass surgery. With this recognition comes the reassurance to the patient and his family that it is a temporary phenomenon that should resolve in time. To help the patient comply with his postoperative instructions during this difficult time period, there should be individual, slow-paced presentation of material with intentional repetition of information to help him remember the specific details of his postoperative instruction; the individual most involved with assisting in the patient's postoperative recovery should be included in all teaching sessions; and instructive audiovisual material should be used in postoperative home care.

Adaptation, Psychological↗