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 847 records · Page 47Linked to original sources

PubMed2002

Memory impairment following status epilepticus in immature rats: time-course and environmental effects.

Status epilepticus (SE) has a high mortality and morbidity rate in children. Disturbances in learning and memory are frequently associated with SE although it is not clear when the cognitive deficits occur. If cognitive dysfunction occurs immediately following the seizure, the window of opportunity for therapeutic intervention is limited. The first goal of this study was to determine the timing of cognitive dysfunction following SE in weanling rats. As there is evidence that enriching the environment can improve cognitive and motor deficits following brain injury, our second goal was to determine whether environmental enrichment improves cognitive function following SE. Rats underwent lithium-pilocarpine-induced SE at postnatal (P) day 20 and were then tested for visual-spatial memory in the water maze at P22, P25, P30, or P50. Rats with SE performed significantly worse in the water maze than control rats at all time points. Once the time-courses of visual-spatial memory deficits were determined, a second group of P20 rats were subjected to SE and were then placed in an enriched environment (enriched group) or remained in standard cages in the vivarium (nonenriched group) for 28 days. Following environmental manipulation, the animals were tested in the water maze. Rats housed in an enriched environment following the SE performed substantially better in the water maze than rats housed in standard cages. However, no differences were found between the enriched and nonenriched groups in EEG or histological evaluation. Although SE results in cognitive impairment within days of the seizure, housing in an enriched environment after SE has a beneficial effect on cognitive performance in rats.

Action Potentials↗

PubMed2001

Distribution of m1 muscarinic acetylcholine receptors in the hippocampus of patients with Alzheimer's disease and dementia with Lewy bodies-an immunohistochemical study.

Of the five subtypes (m1-m5) of muscarinic acetylcholine receptors (mAChR), the m1 subtype is the most abundant in the human cerebral cortex and hippocampus. Impairment of the muscarinic cholinergic system in the brain may cause cognitive dysfunction in patients with Alzheimer's disease (AD), and choline esterase inhibitors (ChE-I) are used to improve cognitive dysfunction. Severe impairment of the cholinergic system has also been reported in the brains of subjects with dementia with Lewy bodies (DLB). There have been a few reports about the distribution of mAChR subtypes in the human brain. In the present study, we investigated the distribution of m1 mAChR in the human hippocampus using an antibody against the m1 subtype. In the control brains, m1 immunoreactivity was observed in the apical dendrites and cell bodies of granular neurons of the dentate gyrus and pyramidal neurons of CA1-3 and the subiculum. The dendrites and the cell bodies of the pyramidal neurons in layers III and V of the parahippocampal cortex and other temporal cortices were also positive for m1 immunoreactivity. This m1 immunoreactivity was markedly reduced in AD and DLB brains.

Acetylcholine↗

PubMed2005

Diet rich in alpha-lactalbumin improves memory in unmedicated recovered depressed patients and matched controls.

Depression is associated with reduced brain serotonin (5-hydroxytryptamine; 5-HT) function and with cognitive dysfunctions. A diet rich in alpha-lactalbumin protein has been found to increase the ratio tryptophan /large neutral amino acids (Trp/SigmaLNAA), and to improve cognitive functioning in individuals with high neuroticism scores. Since cognitive dysfunctions sometimes persist after remission of depression, the present study investigated the effects of alpha-lactalbumin-enriched diet on cognition in recovered depressed patients. Twenty-three recovered depressed patients and 20 healthy matched controls without a history of depression consumed meals rich in alpha-lactalbumin or casein protein in a double-blind crossover design. Mood, cognitive function and plasma amino acids were assessed at both sessions before and after dietary intake. Alpha-lactalbumin protein had no effect on mood, but improved abstract visual memory and impaired simple motor performance. These effects were independent of history of depression. Supplements of lactalbumin may be useful for nutrition research in relation to age- or disease-related memory decline. The present findings should be further examined in different (e.g. medicated) samples. The long-term effects of alpha-lactalbumin should also be investigated.

Adult↗

PubMed2006

Subjective memory complaints and clinical characteristics in elderly Koreans: a questionnaire survey.

OBJECTIVES: The overall objectives of the Ajou-Bundang Study for the Elderly (AB study) were to describe the current geriatric diseases and health behaviors, and to improve the visiting health service in South Korea. The particular objectives of the current study were to describe the AB study and to investigate the associations between subjective memory complaints (SMCs) and objective cognitive function, to assess the clinical characteristics of SMCs, and to measure possible differences between elderly people with and without cognitive dysfunction. METHODS: A cross-sectional study of a sample of people from the AB study was constructed to study the association between SMCs and demographic variables. SMCs, cognitive function, and demographic characteristics were ascertained. A total of 9,477 subjects aged 65 years or over were recruited from the residents of Bundang, Korea. RESULTS: SMCs were reported by 57.3% of the study participants. SMCs were correlated with advanced age and with being female. Further analyses of cognitive functions revealed that associated factor profiles differed between the participants with and without cognitive dysfunction. CONCLUSIONS: These results show that age is associated with SMCs, irrespective of the level of cognitive function. Longitudinal SMC studies should be undertaken to investigate potentially associated clinical parameters.

Age Distribution↗

PubMed2004

Stepped-care approach to treating MS: a managed care treatment algorithm.

OBJECTIVE: To introduce a model treatment algorithm for use in the managed care setting as a strategy to provide ongoing disease management and long-term care for patients with multiple sclerosis (MS), with the goal of delaying disease progression and the associated disability and cognitive dysfunction. SUMMARY: MS is a chronic inflammatory disorder of the central nervous system that is associated with progressive disability and cognitive dysfunction. Currently, management of MS involves planning an effective long-term treatment strategy that can delay the progression of the disease. This article reviews a typical stepped-care approach to treating MS that is based on the concept of a platform drug, which is an agent that provides baseline immunomodulatory action throughout the course of the disease. Considerations for selecting a platform therapy include the effect on the full spectrum of MS (disability, relapses, lesion load, and atrophy as well as patient compliance and the potential impact of neutralizing antibodies [NAbs]). Currently, 4 first-line therapies are approved for relapsing MS: the 3 interferon beta (IFNbeta) products and glatiramer acetate. Of these, the IFNbetas are generally recommended as platform therapy because all have shown significant effects on relapses, magnetic resonance imaging parameters of the disease, and because intramuscular (i.m.) IFNbeta-1a (Avonex) and subcutaneous (s.c.) IFNbeta-1a (Rebif) have been shown to slow the progression of sustained disability. Patients being treated with IFNbetas can develop NAbs to the drug, which can lead to a loss of efficacy and subsequent occurrence of breakthrough disease. The 3 different formulations of IFNbeta are associated with a varying incidence of NAbs (i.m. IFNbeta-1a, 5%; s.c. IFNbeta-1a, 24%; IFNbeta-1b [Betaseron], 45%). Antibodies also form against glatiramer acetate, although their clinical significance needs to be elucidated. As the disease progresses or has periods of aggressive activity, the stepped-care approach is to add other agents onto the platform therapy to improve control of the disease. CONCLUSION: Stepped care, as outlined in this model treatment algorithm for the managed care setting, is an effective method to achieve the fundamental goal of MS treatment, that is, to delay disease progression and the associated disability and cognitive impairment.

Adjuvants, Immunologic↗

PubMed2004

Nicotinic receptors and cognition in Parkinson's Disease: the importance of neuronal synchrony.

Parkinson's Disease (PD) is associated with cognitive deficits. The earliest impairment is evident for executive abilities, visuospatial orientation and memory. Dopamine deficiency is unlikely to be singly responsible for all cognitive changes in PD. Acetyl-choline has an essential role in cognition, thus cholinergic transmission may have an important role in non-dopaminergic cognitive changes. If so, some cognitive defects could possibly be treated with choline-esterase inhibitors. A concern is the potential negative motor effect of cholinergic medication in PD. Surprisingly, these are reported only in a few patients studied. Establishing the relationship between select cognitive deficits and nicotinic neurotransmission may lay the foundation for rational pharmacotherapy of cognitive dysfunction in PD. We summarize anatomical, physiological and pharmacological aspects of nicotinic receptor function. The focus is on those nicotine receptor dependent cognitive dysfunctions which are likely to contribute to motor impairment. Lastly, we discuss hypotheses concerning cholinergic involvement in neuronal synchrony and sensorimotor integration in PD.

Cholinergic Agents↗

PubMed1999

Diagnostic criteria for malingered neurocognitive dysfunction: proposed standards for clinical practice and research.

Over the past 10 years, widespread and concerted research efforts have led to increasingly sophisticated and efficient methods and instruments for detecting exaggeration or fabrication of cognitive dysfunction. Despite these psychometric advances, the process of diagnosing malingering remains difficult and largely idiosyncratic. This article presents a proposed set of diagnostic criteria that define psychometric, behavioral, and collateral data indicative of possible, probable, and definite malingering of cognitive dysfunction, for use in clinical practice and for defining populations for clinical research. Relevant literature is reviewed, and limitations and benefits of the proposed criteria are discussed.

Cognition Disorders↗

PubMed2006

Transient versus prolonged hyperlocomotion following lateral fluid percussion injury in mongolian gerbils.

Posttraumatic hyperactivity is a neurobehavioral symptom commonly seen in patients after traumatic brain injury (TBI). No useful animal model has yet been established for evaluation of this important symptom. We induced either mild (MILD, 0.7-0.9 atm) or moderate (MOD, 1.3-1.6 atm) lateral fluid percussion injury (LFPI) in Mongolian gerbils. Open-field and T-maze tests were used during a 7-day period after the trauma. All animals were perfusion fixed for histopathological examinations. Transient locomotor hyperactivity was found with a peak at 6 hr after injury in the MILD animals, whereas MOD animals showed prolonged and severe hyperlocomotion throughout the 7-day posttrauma period (P < 0.0001). Interestingly, the temporal profile of the posttraumatic hyperactivity was similar to that of the working memory deficit in both injury groups. Histological examination revealed significant neural tissue damages, including cortical necrosis, white matter rarefaction, and neuronal loss in the hippocampus in the ipsilateral hemisphere of the MOD animals, vs. only negligible changes in the MILD animals. Correlation analysis revealed that the volume of white matter lesions was significantly correlated with both posttraumatic hyperactivity (r = 0.591, P < 0.01) and working memory deficit (r = -0.859, P < 0.0001). Taken together, our findings confirm the successful reproduction of posttraumatic hyperactivity following experimental TBI. The posttraumatic hyperlocomotion probably shared pathomechanisms common to those of cognitive dysfunction caused by LFPI, supporting the speculation from previous studies that some neurobehavioral abnormities intimately correlate with TBI-induced cognitive dysfunction. Histopathologically, significant involvement of white matter damage in the posttraumatic functional deficits was indicated.

Analysis of Variance↗

PubMed2005

Temporal lobe epileptic activity mimicking dementia: a case report.

Epileptic activity is an underdiagnosed cause that can determine a disruption of memory and cognitive performance, leading an incorrect diagnosis of dementia. We report a 68-year-old man, referred with a 5-year history of subtle behavioral changes and a subjective memory impairment, who was admitted to our department because of recurrent episodes of confusional state lasting from 1 week. Neuropsychological evaluation demonstrated a marked impairment of all cognitive domains examined. Electroencephalogram (EEG) recording showed frequent almost continuous sharp waves localized on the bilateral posterior temporal regions with mild right side predominance. Treatment with phenytoin reversed his cognitive dysfunction and behavioral disturbances. We presume that ictal temporal lobe epileptiform activity is the cause of his confusional episodes and cognitive dysfunction, showing an electroclinical picture of complex partial status epilepticus. However, we hypothesize that the interictal discharges and ictal and postictal effects of subclinical seizures could be involved in the behavioral changes and memory impairment complained by our patient in the last years.

Aged↗

PubMed1996

Learning disabilities and central auditory dysfunction.

Hearing loss, whether peripheral or central, compounds the communication and educational problems of the learning disabled student. A central auditory processing disorder uniquely interferes with both the input and integration of verbal information, further resulting in a potentially permanent cognitive dysfunction during the developmental period of acquisition of language. Illustrative cases are presented that indicate the panorama of cognitive dysfunction associated with the learning disabled status. Methods of evaluation and identification and diagnostic criteria are correlated with auditory, visual, and academic performance. Comments regarding clinical awareness, prompt recognition, and ensuing individualized remediation are submitted.

Adult↗

PubMed2001

Prevalence of behavioral changes associated with age-related cognitive impairment in dogs.

OBJECTIVE: To determine the prevalence of age-related behavioral changes, namely impairment, in a randomly chosen population of dogs. DESIGN: Age-stratified cohort study. ANIMALS: 97 spayed female and 83 castrated male dogs that were 11 to 16 years old. PROCEDURE: Data on possible impairment in 4 behavioral categories (ie, orientation in the home and yard, social interaction, house training, and sleep-wake cycle) linked to cognitive dysfunction were obtained from dog owners, using a structured telephone interview. Hospital records of dogs had been screened to exclude dogs with dysfunction in organ systems that may cause behavioral changes. Dogs with behavioral impairment were those with > or = 2 signs of dysfunction within a category. Dogs with impairment in 1 category were considered mildly impaired and those with impairment in > or =2 categories were considered severely impaired. RESULTS: Age by sex interactions for dogs with impairment in any category were not significant, and, therefore, data on castrated males and spayed females were pooled for analyses across ages. The prevalence of age-related progressive impairment was significant in all categories. The percentage of 11- to 12-year-old dogs with impairment in > or = 1 category was 28% (22/80), of which 10% (8/80) had impairment in > or = 2 behavioral categories. Of 15- to 16-year-old dogs, 68% (23/34) had impairment in > or =1 category, of which 35% (12/34) had impairments in > or = 2 categories. There were no significant effects of body weight on the prevalence of signs of dysfunction in the behavioral categories. CONCLUSIONS AND CLINICAL RELEVANCE: Data collected provide estimates of the prevalence of various degrees of age-related behavioral changes associated with cognitive dysfunction in dogs. Age-related behavioral changes may be useful indicators for medical intervention for dogs with signs of cognitive impairment.

Age Factors↗

PubMed2003

Cognitive effects of atypical antipsychotics: focus on bipolar spectrum disorders.

Studies examining cognitive dysfunction in bipolar disorder have documented neuropsychologic impairment in some patients. Recollection memory, attention, and visual information processing may be particularly impaired in patients with bipolar illness. Cognitive impairment appears to worsen with illness progression, and may have a significant impact on function. Pharmacotherapy to treat bipolar disorder including lithium, anticonvulsants, antidepressants, and atypical antipsychotics may have varying effects on cognitive functioning. Treatment with atypical antipsychotics has been associated with improvement in various cognitive measures in patients with schizophrenia, and the little data available in patients with bipolar disorder suggest the potential for similar benefits. Studies to determine if current treatments for bipolar disorder can prevent, delay, or even improve cognitive dysfunction are needed.

Anticonvulsants↗

PubMed2001

Clinical trials in Alzheimer's disease. Calculating Alzheimer's Disease Assessment Scale-cognitive subsection with the data from the consortium to establish a registry for Alzheimer's disease.

The database of the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) is a seminal work in the field of cognitive dysfunction and Alzheimer's disease. This 24-center study of 1,094 patients with Alzheimer's disease who received no treatment for their cognitive dysfunction and 463 normal control subjects is rich in neurobehavioral data and contains extensive imaging and neuropathologic findings. However, the Alzheimer's Disease Assessment Scale (ADAS) was not administered as part of the CERAD study, which limits the study's applicability to modern drug trials, in which the ADAS-cognitive subsection (ADAS-cog) is a popular end point. The purpose of this investigation was to develop a derived ADAS-cog score from the neurobehavioral data obtained from subjects during their evaluation in the CERAD study. Two calculated ADAS-cog scores were developed. The first was based on clinically mapping the items on the ADAS-cog to assessments that were performed in the CERAD study. The second was based on rescaling the Mini-Mental Status Exam (MMSE), using published results correlating the ADAS-cog to the MMSE. Standard characteristics of both calculated ADAS-cog scores were calculated and compared with each other and with the literature. Both calculated ADAS-cog scores performed comparably to published characteristics of the ADAS-cog. The clinically based calculated ADAS-cog outperformed the rescaled MMSE. Using the CERAD database, it is now possible to model the progression of an untreated (placebo) population of patients with Alzheimer's disease and correlate it to a study using ADAS-cog.

Aged↗

PubMed2005

Neuropsychological deficits after mechanical aortic valve replacement.

BACKGROUND AND AIM OF THE STUDY: Studies using transcranial Doppler monitoring have identified high-intensity transient signals (HITS) after mechanical valve replacement. Although cognitive dysfunction in relation to HITS was reported in some studies, the current data basis is inconsistent. The study aim was to investigate the long-term effects of HITS on cognitive function. METHODS: Forty patients who had undergone mechanical valve replacement (mean 5.3 years previously) participated in the study. HITS-measurements were performed on the day of neuropsychological assessment. Patients were allocated to HITS-high and HITS-low groups on the basis of the median HITS-rate. Both patient groups completed a neuropsychological test battery and were compared to healthy controls. RESULTS: Both patient groups showed verbal and visual memory deficits in comparison with controls. The HITS-high group scored lower on verbal memory compared to the HITS-low group. In addition, the HITS-high group showed executive deficits when compared to the HITS-low group and controls. The significant effects with respect to verbal memory and executive functions remained after extracorporeal circulation time differences were controlled for. CONCLUSION: The study results imply that heart valve replacement with mechanical prostheses may be associated with mild cognitive impairment. The differential impairment pattern of the high- and low-HITS groups further suggests that the number of HITS may be of critical importance. The observed memory impairments were consistent with the view that cognitive dysfunction after valve replacement may be due to temporal lobe dysfunction. However, future studies are required to investigate the association of number of HITS, cerebral changes and cognitive function in further detail.

Aged↗

PubMed2005

The effects of type 1 diabetes on cognitive performance: a meta-analysis.

OBJECTIVE: To investigate the exact nature and magnitude of cognitive impairments in patients with type 1 diabetes and the possible association with other disease variables, such as recurrent episodes of hypoglycemia and metabolic control. RESEARCH DESIGN AND METHODS: MedLine and PsycLit search engines were used to identify studies on cognitive performance in patients with type 1 diabetes. Effect sizes (Cohen's d), which are the standardized differences between the experimental and the control group, were calculated. In the meta-analysis, a combined d value was calculated, expressing the magnitude of associations across studies. RESULTS: A total of 33 studies were identified that met the inclusion criteria. Compared with nondiabetic control subjects, the type 1 diabetic group demonstrated a significantly lowered performance on the following cognitive domains: intelligence (d = -0.7), speed of information processing (d = -0.3), psychomotor efficiency (d = -0.6), visual (d = -0.4) and sustained attention (d = -0.3), cognitive flexibility (d = -0.5), and visual perception (d = -0.4). Lowered cognitive performance in diabetic patients appeared to be associated with the presence of microvascular complications but not with the occurrence of severe hypoglycemic episodes or with poor metabolic control. CONCLUSIONS: In patients with type 1 diabetes, cognitive dysfunction is characterized by a slowing of mental speed and a diminished mental flexibility, whereas learning and memory are spared.The magnitude of the cognitive deficits is mild to moderate, but even mild forms of cognitive dysfunction might hamper everyday activities since they can be expected to present problems in more demanding situations.

Attention↗

PubMed2006

Amphetamine sensitization alters dendritic morphology in prefrontal cortical pyramidal neurons in the non-human primate.

Amphetamine (AMPH) sensitization in the nonhuman primate induces persistent aberrant behaviors reminiscent of the hallmark symptoms of schizophrenia, including hallucinatory-like behaviors, psychomotor depression, and profound cognitive impairment. The present study examined whether AMPH sensitization induces similarly long-lasting morphologic alterations in prefrontal cortical pyramidal neurons. Three to 3(1/2) years postsensitization, sensitized, and AMPH-naïve control monkeys were killed. Blocks of prefrontal cortex were Golgi-impregnated for elucidation of pyramidal dendritic morphology in layers II/superficial III (II/IIIs), deep III, and V/VI. In AMPH-sensitized animals as compared to AMPH-naïve controls, pyramidal dendrites in layer II/IIIs exhibited reduced overall dendritic branching and reduced peak spine density (22%) on the apical trunk. Across all layers, the distance from soma to peak spine density along the apical trunk was decreased (126.38+/-7.65 mum in AMPH-sensitized compared to 162.98+/-7.26 microm in AMPH-naïve controls), and basilar dendritic length was reduced (32%). These findings indicate that chronic dopamine dysregulation, consequent to AMPH sensitization, results in enduring, atrophic changes in prefrontal pyramidal dendrites that resemble the pathologic alterations described in patients with schizophrenia and may contribute to the persistence of schizophrenia-like behavioral changes and cognitive dysfunction associated with sensitization. These findings may also provide key insights into the etiologic origin of the pronounced behavioral disturbances and cognitive dysfunction associated with schizophrenia.

Amphetamine↗

PubMed2004

The international classification of functioning, disability and health and its application to cognitive disorders.

PURPOSE: This paper describes the conceptual foundation and systematic framework of the International Classification of Functioning, Disability, and Health (ICF) as a mechanism for understanding the course and consequences of various health related states. The specific application of the ICF with persons with cognitive dysfunction is also presented. METHOD: A comprehensive literature review related to the conceptualization of the ICF, its classification scheme and coding process is presented. Information on cognitive disorders including prevalence, functional manifestations and the assessment of a person's cognitive functioning and the applicability of the ICF's holistic classification and coding of cognitive dysfunction within the components of body structure and function, activity and participation, and environmental attributes is also reviewed. CONCLUSION: The ICF has the potential to classify and interpret cognitive deficits on a global level and thereby reflects upon the overall health and functioning of the individual in major life activities. The coding system systematically organizes measures related to the person's cognitive status and the resulting functional outcomes. The ICF focuses on individuals' performance of activities in all aspects of life and validates the independence and well-being of persons with disabilities making it an important instrument to be used by rehabilitation professionals.

Activities of Daily Living↗

PubMed2006

Use of computerized assessment to predict neuropsychological functioning and emotional distress in patients with systemic lupus erythematosus.

OBJECTIVE: Cognitive dysfunction and neuropsychiatric disturbance are common in systemic lupus erythematosus (SLE). This study addressed the ability of the Automated Neuropsychological Assessment Metrics (ANAM), a computerized cognitive testing battery consisting of cognitive subtests, a sleepiness rating scale, and a mood scale, to predict neuropsychological status in patients with SLE. METHODS: Sixty individuals with SLE and no overt neuropsychiatric symptoms were administered ANAM to determine its validity as a screening measure of cognitive dysfunction and emotional distress in SLE. RESULTS: Performance on ANAM was compared with results of a consecutively administered, 2-hour battery of traditional neuropsychological tests and the Beck Depression Inventory II (BDI-II). Individual ANAM cognitive test scores were significantly correlated with most neuropsychological tests, particularly those measuring psychomotor processing speed and executive functioning. Using logistic regression, ANAM cognitive subtests successfully predicted individuals with SLE who had probable versus no impairment after controlling for premorbid levels of cognitive ability. Sensitivity of group classification was 76.2% and specificity was 82.8%, with 80% correct classification overall. ANAM's ability to predict neuropsychological functioning remained even after controlling for subjective reports of depressed mood and current sleepiness. Further, the ANAM mood scale was significantly correlated with the BDI-II (r = 0.67, P < 0.001), indicating its potential future use as a screening tool for emotional distress. CONCLUSION: ANAM shows promise as a time- and cost-efficient tool for screening and monitoring cognitive and emotional functioning in SLE, and can indicate when a more thorough neuropsychological investigation is warranted.

Adult↗