Reduction In Cognitive Function Research Articles

Radiation-induced cognitive impairment-from bench to bedside

Approximately 100,000 patients per year in the United States with primary and metastatic brain tumor survive long enough (>6 months) to develop radiation-induced brain injury. Before 1970, the human brain was thought to be radioresistant; the acute central nervous system (CNS) syndrome occurs after single doses of ≥ 30 Gy, and white matter necrosis can occur at fractionated doses of ≥ 60 Gy. Although white matter necrosis is uncommon with modern radiation therapy techniques, functional deficits, including progressive impairments in memory, attention, and executive function have become increasingly important, having profound effects on quality of life. Preclinical studies have provided valuable insights into the pathogenic mechanisms involved in radiation-induced cognitive impairment. Although reductions in hippocampal neurogenesis and hippocampal-dependent cognitive function have been observed in rodent models, it is important to recognize that other brain regions are affected; non-hippocampal-dependent reductions in cognitive function occur. Neuroinflammation is viewed as playing a major role in radiation-induced cognitive impairment. During the past 5 years, several preclinical studies have demonstrated that interventional therapies aimed at modulating neuroinflammation can prevent/ameliorate radiation-induced cognitive impairment independent of changes in neurogenesis. Translating these exciting preclinical findings to the clinic offers the promise of improving the quality of life in patients with brain tumors who receive radiation therapy.

Is cognitive impairment following early life stress in severe mental disorders based on specific or general cognitive functioning?

Schizophrenia spectrum and bipolar disorder are characterized by high levels of childhood trauma as well as of cognitive dysfunction. Our aim is to investigate the association between these two factors in the largest study in the literature so far.A total of 406 patients with schizophrenia spectrum- or bipolar disorders were recruited from a catchment area based organization in Oslo, Norway. Information about early life stress was obtained using the Childhood Trauma Questionnaire (CTQ). Cognitive function was assessed through a comprehensive and standardized neuropsychological test battery.Physical abuse, sexual abuse and physical neglect were significantly associated with reduced scores on working memory and executive function scales (p=0.04 to p<0.001), and verbal and performance tasks from the Wechsler Abbreviated Scale of Intelligence (WASI) (p=0.059 to p<0.001). When verbal and performance tasks from the WASI were added into a multivariate regression model, the association between CTQ and the specific cognitive domains decreased, and only WASI scores remained statistically significant.Our results indicate that childhood trauma is associated with a reduction in cognitive function across cognitive domains in patients with schizophrenia spectrum- and bipolar disorders, in particular working memory and executive function as well as general cognition. Moreover, these dysfunctions seem to be driven by underlying deficits in general cognitive tasks as measured by the WASI.

Neuropsychological and cognitive performance of homeless adults.

Many homeless people may have been exposed to events and situations that could potentially produce neuropsychological impairments. In the current study, 80 homeless participants underwent a battery of tests designed to 1) estimate long-standing established memory and intelligence, which was assumed to indicate prehomeless function and 2) measure current memory and intelligence function. Mental health screening and substance misuse data were also obtained. Results indicated that current memory and IQ were significantly lower than the estimated normal population means and also their prehomeless estimates. The memory score change was from 100.5 to 90.3 (p .001) and IQ change from 98.8 to 95.6 (p .038). The interaction between task type (memory or IQ) and measure (prehomeless or current) was also significant (p .003), signifying that there was a greater change in the domain of memory function than in IQ. Many participants reported substance misuse and clinically significant mental health concerns. We conclude that the homeless individuals in our sample appear to have suffered a reduction in cognitive function, which may have occurred either during homelessness or prior to it.

Neural network modeling of central auditory dysfunction in Alzheimer’s disease

Many reports have described that individuals with Alzheimer's disease show neural breakdown in the brainstem nuclei, hippocampus and auditory cortex in the temporal lobe of the brain. However, it is still unclear whether auditory skills mediated by these areas differ across individuals with and without Alzheimer's disease and how these auditory skills are further confounded by reduction in cognitive function in individuals with AD. The aim of this study is to discover the hidden and nonlinear associations among higher-order auditory and cognitive processes in individuals with and without Alzheimer's disease through artificial neural network analysis. The analyses were based on auditory test data obtained from nine clinically confirmed Alzheimer's disease cases and nine age-matched controls. Hearing threshold sensitivity was equivalent across groups, indicating similar peripheral auditory function. Auditory function was evaluated by standardized tests of auditory closure, auditory attention, and auditory figure ground in listeners with and without Alzheimer's disease. The inputs used for analyses were cognitive status and auditory function. The dependent variables were RAU scores computed from scores of auditory tests. Artificial neural networks showed a complex relationship between the input variables (cognitive status and auditory function) that cannot be predicted simply on the basis of cognition differences between individuals with and without Alzheimer's disease. The results of this study suggest that central auditory function declines with age, regardless of changes in cognitive function.

Factors affecting and strategies to improve pain management in emergency departments: a comprehensive systematic review.

Factors affecting and strategies to improve pain management in emergency departments: a comprehensive systematic review.

Cerebroprotective Effect of Piracetam in Patients Undergoing Open Heart Surgery

Reduction of cognitive function is a possible side effect after the use of cardiopulmonary bypass (CPB) during cardiac surgery. Since it has been proven that piracetam is cerebroprotective in patients undergoing coronary bypass surgery, we investigated the effects of piracetam on the cognitive performance of patients undergoing open heart surgery. Patients scheduled for elective open heart surgery were randomized to the piracetam or placebo group in a double-blind study. Patients received 12 g of piracetam or placebo at the beginning of the operation. Six neuropsychological subtests from the Syndrom Kurz Test and the Alzheimer's Disease Assessment Scale were performed preoperatively and on day 3, postoperatively. To assess the overall cognitive function and the degree of cognitive decline across all tests after the surgery, we combined the six test-scores by principal component analysis. A total of 88 patients with a mean age of 67 years were enrolled into the study. The mean duration of CPB was 110 minutes. Preoperative clinical parameters and overall cognitive functions were not significantly different between the groups. The postoperative combined score of the neuropsychological tests showed deterioration of cognitive function in both groups (piracetam: preoperative 0.19 ± 0.97 vs. postoperative -0.97 ± 1.38, p <0.0005 and placebo: preoperative -0.14 ± 0.98 vs. postoperative -1.35 ± 1.23, p <0.0005). Patients taking piracetam did not perform better than those taking placebo, and both groups had the same decline of overall cognitive function (p = 0.955). Piracetam had no cerebroprotective effect in patients undergoing open heart surgery. Unlike the patients who underwent coronary surgery, piracetam did not reduce the early postoperative decline of neuropsychological abilities in heart valve patients.

K03 A multidisciplinary intensive rehabilitation programme for individuals with Huntington's disease: preliminary results from the pilot project

BackgroundStudies suggest that persons with Huntington's disease (HD) benefit from intensive rehabilitation.AimsTo assess preliminary results of a multidisciplinary rehabilitation programme on quality of life, cognitive and motor function.Methods12 patients with...

Cognitive function after endurance exercise: a comparison between Gatorade® and a placebo

Since Gatorade® (G) is a glucose formulation that improves exogenous glucose availability; we propose ingestion prior to exercise will improve the expected impaired cognitive function commonly associated with prolonged exercise.12 highly trained cyclists (3 females, 9 males; 19–44 yrs; average VO2 peak 60.4L/kg*min) exercised at 65% VO2 peak for 2 hours on a cycle ergometer while heart rate, core body temperature, expired O2/CO2, RER, RPE, glucose and lactate were collected every 30 minutes beginning at 30 minutes prior to exercise when G or a placebo (P) was ingested (500 ml). An Automated Neuropsychological Assessment Metrics (ANAM) computerized cognitive function test was given prior to and post exercise.Blood glucose averages were significantly different at the start of exercise for G and P (133.1 mg/dL ± 23.2 and 86.2 mg/dL ± 10.1; p=.0001) while after exercise there was no difference (95.3 mg/dL ±13.9 and 81.2 mg/dL ± 17.3) respectively. While both median (p=.002) and mean (p=.01) reaction time for spatial processing decreased after exercise for G, there was no difference when compared to P. No other improvements in cognitive ability were found compared to P, as well as core body temperature, heart rate, RPE, lactate, and RER were not different. Overall, there was no reduction in cognitive function after exercising at 65% VO2 peak for 2 hours.

Longitudinal Assessment of Intellectual Achievement in Patients With Classical Galactosemia

To conduct a longitudinal assessment of long-term cognitive outcome in patients with classical galactosemia. Inclusion criteria were (1) previous assessment of IQ dating back >10 years with tests being comparable with the recent German tests HAWIK-III and HAWIE-R, (2) absence of illnesses other than galactosemia, (3) absence of foreign language problems, (4) enzymatic-metabolic proof of classical galactosemia, (5) compliance with dietary therapy, and (6) written informed consent. Twenty-three patients who fulfilled these criteria were found. They underwent the first IQ test at a mean age of 11 +/- 5 years and the second 13.6 to 15.5 years later at a mean age of 26 +/- 5 years. Results were corrected for the obsolescence of test norms (Flynn effect). Mean total IQ scores on the first and second tests were 78 +/- 14 and 73 +/- 15, respectively, and not significantly different. IQ scores in the average range were observed for 7 patients on the first test and for 5 patients on the second test. For 17 patients, the intraindividual IQ scores remained essentially unchanged. Five patients showed a decrease and 1 an increase of the IQ score over time. No consistent pattern of change was found with respect to performance or verbal IQ subscores or in achievements in the individual subtest. The results confirm the presence of reduced cognitive ability in classical galactosemia and present evidence for an absence of substantial galactosemia-induced aggravation of this impairment with increasing age, at least in patients from 4 to 40 years of age. It remains to be clarified whether a reduction of cognitive function in galactosemia may be initiated by an in utero toxicity of endogenously formed galactose and which role such a process may play in the development of intellectual deficiencies that are later maintained throughout life.

Update on Neonatal Anesthetic Neurotoxicity

A fundamental premise of general anesthesia is that anesthetics produce a reversible state of unconsciousness and unresponsiveness. Implicit in this premise is that the brain and spinal cord are neurophysiologically the same before and after anesthesia. Recent experimental data has questioned the complete reversibility of anesthesia. In certain circumstances, anesthetic exposure in neonatal animals leads to neuronal death. Given the large number of neonates and infants that undergo surgery and anesthesia, the implications of these data for anesthesia in humans are readily apparent. Although the relevance of these findings to humans is a subject of heated debate, the unequivocal demonstration of neuronal death in animals exposed to clinically relevant concentrations of anesthetics has provoked significant concern amongst anesthesia care providers and patients. This editorial reviews new laboratory and clinical research presented at the Anesthesiology/Foundation for Anesthesia Education and Research Session at the Annual Meeting of the American Society of Anesthesiologists, Oct 21, 2008 which advances our understanding in this area.

Single and Combined Effects of Cerebral White Matter Lesions and Lacunar Infarctions on Cognitive Function in an Elderly Population

This study is to investigate the association between single and combined vascular brain changes (white matter lesions [WMLs], lacunar infarctions) and the cognitive domains of memory, processing speed, and motor function in the elderly adults. In a sample of 268 participants aged 65-83 years of the MEMO (Memory and Morbidity in Augsburg Elderly) population-based study in Augsburg, Germany, cerebral magnetic resonance imaging (MRI) was performed and a detailed neuropsychological test battery applied. Analysis of covariance determined the effects of vascular brain changes on domains of cognitive functioning. Strong associations of large WMLs and of MRI-defined lacunar infarction with three different domains of cognitive function even after adjustment for age, gender, and education were found. The combined occurrence of both lesions affected about one in 10 participants and was associated with a strong decrease in cognitive function in all domains. The difference between the groups with only one lesion type (either large WMLs or MRI-defined infarction) and participants affected by both was significant in the domains of processing speed and memory, even after adjustment for important confounders such as age, gender, education, and comorbidities. The effects of both lesion types on cognitive function were not more than additive. Our study shows that both large WMLs and MRI-defined lacunar infarction contribute to impairments in different cognitive domains. The results suggest that their combined occurrence is associated with stronger reductions in cognitive function than each of the two brain lesion types alone.

Cognitive Neuroscience of Aging

The number of reports on the cognitive neuroscience of aging has increased in recent years, and most of these studies have found many similarities in the patterns of activity in young and old adults, indicating that basic neural mechanisms are maintained into older age. Despite these overall similarities, older adults often have less activity in some regions, such as medial temporal areas during memory processing and visual regions across a variety of cognitive domains. It seems clear that age reductions in cognitive function can be tied, at least in part, to these reductions in brain activity. On the other hand, older adults typically also overrecruit some brain areas, mainly the ventral or dorsal prefrontal cortex during memory tasks, as well as both the frontal and parietal regions during tasks engaging cognitive control processes, such as attention. Sometimes this overrecruitment appears to be in response to altered function in other brain regions and is often seen in those older adults who perform better on the task at hand. These findings have provided rather convincing support for the idea that overrecruitment can be compensatory in the elderly. Nevertheless, not all age increases can be interpreted as compensatory, and some are more indicative of neural inefficiency. The challenge facing future research will be to understand the task conditions that promote compensation in older adults, the role of the various brain areas in aiding cognitive function, and how these compensatory mechanisms can be elicited to enhance quality of life in the elderly.

Increased Glucose Levels Are Associated With Episodic Memory in Nondiabetic Women

Patients with type 2 diabetes have an increased risk of a reduction in cognitive function. We investigated the hypothesis that plasma glucose is associated with a reduction in episodic and/or semantic memory already in nondiabetic subjects. We linked two large population-based datasets in Sweden: the Betula study, in which a random sample from the population aged 35-85 years was investigated for cognitive function, including episodic and semantic memory; and the Västerbotten Intervention Program, a health survey with subjects aged 40, 50, and 60 years, that includes measuring of fasting and 2-h plasma glucose, along with other risk factors for diabetes and cardiovascular disease. We identified 411 (179 men and 232 women, mean age 50.6 +/- 8.0 years) nondiabetic subjects, free from dementia, who had participated in the two surveys within 6 months. Women had better episodic (score 7.37 +/- 1.42) and semantic memory (score 16.05 +/- 2.76) than men (score 6.59 +/- 1.29 and 15.15 +/- 2.92, respectively, P < 0.001 for both). In an adjusted multivariate model, fasting plasma glucose (fPG) and 2-h plasma glucose (2hPG) were significantly negatively associated with episodic memory (fPG: B -0.198, SE 0.068, beta -0.209, P = 0.004; and 2hPG: B -0.061, SE 0.031, beta -0.148, P = 0.048, respectively) in women but not in men. The association was not found in relation to semantic memory. We conclude that an increase in plasma glucose is associated with impairment in episodic memory in women. This could be explained by a negative effect on the hippocampus caused by raised plasma glucose levels.

Dietary Influences on Cognitive Function with Aging

Human epidemiologic studies provide convincing evidence that dietary patterns practiced during adulthood are important contributors to age-related cognitive decline and dementia risk. Diets high in fat, especially trans and saturated fats, adversely affect cognition, while those high in fruits, vegetables, cereals, and fish are associated with better cognitive function and lower risk of dementia. While the precise physiologic mechanisms underlying these dietary influences are not completely understood, modulation of brain insulin activity and neuroinflammation likely contribute. Not surprisingly, deficits in cognitive functions, especially those dependent on the medial temporal lobes, are apparent in type 2 diabetes mellitus (T2DM). Special care in food selection at meals should be exercised by those with T2DM since ingestion of rapidly absorbed, high-glycemic index carbohydrate foods further impairs medial temporal lobe function, with food-induced increases in oxidative stress and cytokine release likely explaining the association between food ingestion and reduction in cognitive function in those with T2DM.

Cognitive function in childhood and early adulthood and hospital admission for schizophrenia and bipolar disorders in Danish men born in 1953

Objective This study examines the influence of cognitive function and change in cognitive function during adolescence on schizophrenia and bipolar disorders in adulthood and explores possible mechanisms for any associations. Method A cohort of 6923 men born in Copenhagen, Denmark in 1953, who had completed assessments of cognitive performance (measured by a total test score that combines verbal, arithmetic and spatial functions) at ages 12 and 18, were followed from 1972 until 2002. Psychiatric outcomes (hospital admissions for schizophrenia and bipolar disorders) were obtained from the Danish Psychiatric Register. Results During the follow-up period 133 of the men had a discharge diagnosis of schizophrenia or schizophrenia spectrum disorder. Cognitive function measured at both ages 12 and 18 years was inversely associated with these disorders (unadjusted hazard ratio (HR) per SD of cognitive function at age 12: 0.87 (95% CI: 0.75,1.05) and at age 18: 0.72 (95% CI: 0.60,0.86)). Adjustment for birth weight, social circumstances during childhood, indicators of social integration and educational attainment at age 18 years changed these associations only slightly. When cognitive function measured at ages 12 and 18 were entered in the same model only the latter was inversely associated with risk of schizophrenia or spectrum disorder. Decline in cognitive function between ages 12 and 18 was associated with an increased risk of schizophrenia spectrum disorder (HR: 1.32 (95% CI: 1.01,1.75)). Cognitive function at both ages also showed an inverse association with bipolar disorders, though the association was imprecisely estimated due to small numbers ( N = 16). Conclusions Low cognitive function at ages 12 and 18 years and cognitive decline between these two ages were associated with increased risk of schizophrenic disorders. This suggests that reduction in cognitive function during childhood may be an early symptom of these outcomes.

Trials in Sickle Cell Disease

Children with sickle cell disease are at risk of developing neurologic complications, including stroke, transient ischemic attack, seizures, coma, and a progressive reduction in cognitive function. Transcranial Doppler ultrasound, magnetic resonance imaging, and overnight pulse oximetry appear to predict, making prevention an achievable goal so that there is now a focus on randomized controlled trials. The Stroke Prevention Trial in Sickle Cell Anemia (STOP) reported a reduction in the number of overt clinical strokes experienced by those children with critically high transcranial Doppler velocities (>200 centimeters per second) who were chronically transfused. Two additional Phase III studies and two pilot trials have been funded. STOP II focused on whether it is safe to discontinue blood in prophylactically transfused children when their velocities had remained normal for at least 30 months. The Silent Infarct Transfusion trial is designed to determine whether children with sickle cell anemia and silent cerebral infarcts, approximately 20% of the population, will have a decrease in the progressive neurologic complications after receiving regular blood transfusion therapy. Pilot safety and feasibility trials of low-dose aspirin and overnight respiratory support are also beginning. The collaboration provides an infrastructure for future clinical trials in this vulnerable group of children.

The early recovery of cognitive function after total-hip replacement under hypotensive epidural anesthesia

Recovery of cognitive function immediately after major surgery has not been previously reported, partly because of residual drug effects and pain. Changes in cognitive function were assessed using the Stroop Color and Word Test (SCWT), which was performed preoperatively, and 1 and 2 hours after total-hip replacement performed under hypotensive epidural anesthesia. In this case series, patients were sedated with propofol alone and had a lumbar plexus block performed at the end of surgery. The SCWT was completed in 52 of 55 patients at either 1 or 2 hours after surgery. A significant reduction in cognitive function was noted 1 hour after surgery but a return toward baseline occured 2 hours after surgery. Age older than 70 years adversely affected recovery of cognitive function, but neither the preoperative diagnosis of hypertension nor the degree or duration of intraoperative hypotension (mean arterial pressure less than 45 mmHg) influenced cognitive function. The Stroop Color and Word Test can be used to assess change in cognitive function immediately after surgery. Total-hip replacement performed under regional anesthesia with propofol sedation enables recovery of cognitive function (as assessed by SCWT) 2 hours after surgery.

PSYCHOLOGICAL FUNCTIONING IN WOMEN WITH FIBROMYALGIA: A GROUNDED THEORY STUDY

The aim of this study was to elucidate psychological functioning and psychological processes in women with fibromyalgia. Twenty-one females with fibromyalgia (aged 26–72 years) were interviewed in-depth. The interviews were analysed in line with grounded theory. A core concept, “unprotected self,” mirroring childhood conditions and adult psychological functioning, was identified. Intense activity or hypomanic helpfulness often was used as self-regulation in adult life. Later an increased exposure to mental load is accompanied by reduction of cognitive functioning and generalised pain. The phase of persistence of fibromyalgia is marked by reduction of cognitive functions, unprotected psychological functioning, and increased mental load as from crisis and somatic symptoms.

Cognitive changes and sleep disordered breathing in elderly: Differences in race

Objectives Sleep disordered breathing (SDB) is a highly prevalent sleep disorder in older persons. It is known to be associated with reductions in cognitive function. As part of a larger study examining SDB in African-Americans and Caucasians, it became possible to examine whether racial background may differentially affect the relationship between SDB and cognitive performance. Methods Community-dwelling African-American and Caucasian elderly (ages 65+) at high risk for SDB were tested at two time points. During each visit, subjects were interviewed in their homes about their sleep and medical condition. The Mini-Mental Status Examination (MMSE) was used to assess cognitive function. Objective sleep studies were recorded in the subjects' homes and scored for sleep, apneic events, and oxygen saturation levels. Results Increases in respiratory disturbance index (RDI) were associated with decreases in cognitive performance over time, after controlling for gender and education level. There were no differential effects of race on this relationship. There was no relationship between declining cognitive function and hypoxemia. Conclusions Analyses of the data confirm that declining cognitive function in older persons with mild to moderate SDB is related to the amount of respiratory disturbances occurring at night, and suggest that the effect of SDB on cognitive decline is unrelated to race and measured hypoxemia. The large number of community-dwelling elderly with mild to moderate SDB may accrue considerable benefits (both cognitively and medically) from the treatment of SDB, even if they are not markedly hypoxemic.

Relationship between allergic rhinitis, disturbed cognitive functions and psychological well-being.

Symptomatic allergic rhinitis reduces quality of life as a result of the symptoms experienced and possibly as a result of impaired psychological well-being and cognitive functioning. Few investigations have measured cognitive functions objectively and it remains uncertain whether allergic rhinitis leads to an objective reduction in cognitive functions. To evaluate the relationship between symptomatic allergic rhinitis, cognitive functions and psychological well-being. Differences between subjective and objective cognitive impairments were evaluated. The cognitive functions (working memory, memory retrieval, speed of information processing and flexibility of information processing) and psychological well-being of 26 patients with symptomatic allergic rhinitis and 36 healthy controls matched for intelligence, education, age and sex were compared. The influence of education, intelligence, sex and age was considered. Overall, psychological well-being was significantly impaired in the patient group, as shown by higher scores in feelings of insufficiency, complaints of somatization, sleep disturbances and depressive feelings, whereas cognitive function was not. Allergic rhinitis was related to significantly impaired psychological well-being and to perceived impaired cognitive functioning. However, no significant objective impairment of cognitive functioning was found. Allergic patients may temporarily put more effort into sustaining performance, resulting in earlier exhaustion, which is not noticed during assessment but which impairs psychological well-being.