oalib
Search Results: 1 - 10 of 100 matches for " "
All listed articles are free for downloading (OA Articles)
Page 1 /100
Display every page Item
Cognitive impairment after cerebrovascular stroke: Relationship to vascular risk factors
Eman M Khedr, Sherifa A Hamed, Hala K El-Shereef, Ola A Shawky, Khalid A Mohamed, et al
Neuropsychiatric Disease and Treatment , 2009, DOI: http://dx.doi.org/10.2147/NDT.S4184
Abstract: gnitive impairment after cerebrovascular stroke: Relationship to vascular risk factors Original Research (5931) Total Article Views Authors: Eman M Khedr, Sherifa A Hamed, Hala K El-Shereef, Ola A Shawky, Khalid A Mohamed, et al Published Date February 2009 Volume 2009:5 Pages 103 - 116 DOI: http://dx.doi.org/10.2147/NDT.S4184 Eman M Khedr1, Sherifa A Hamed1, Hala K El-Shereef2, Ola A Shawky1, Khalid A Mohamed1, Effat M Awad3, Mohamed A Ahmed2, Ghaydaa A Shehata1, Mahmoud A Eltahtawy4 1Department of Neurology and Psychiatry, 2Department of Internal Medicine, 3Department of Physiology, 4Department of Clinical Pathology, Assiut University, Faculty of Medicine, Assiut, Egypt Background: Cognitive decline after cerebrovascular stroke has adverse outcome consequences. Since some vascular causes can be prevented and treated, the identification of stroke-related cognitive impairment is a challenge. Patients with cognitive impairment and vascular diseases exhibit higher homocysteine (Hcy) concentrations. Whether Hcy is an independent risk factor for cognitive impairment after stoke is still in question. The objectives of this study were to determine: 1) the relative frequency of first-ever post-stroke dementia (PSD) (three months after onset) in a consecutive sample of our population, 2) the risk factors associated with PSD, and 3) the relationship between Hcy levels and PSD. Methods: Eighty-one inpatients with first-ever stroke were prospectively evaluated with a neuropsychological battery and event-related evoked potentials (P300) at onset and then after three months. A wide range of demographic, clinical, radiological and laboratory variables were examined. PSD was diagnosed if the clinical presentation fulfilled DSM-IV criteria of vascular dementia, the patient scored ≤21 on Mini Mental State Examination (MMSE) and ≤67 points on Cognitive Abilities Screening Instruments (CASI). Results: PSD was diagnosed in 21%. PSD was significantly associated with increasing age, low levels of education, large sized and lacunar infarctions, severity of stroke, prolonged P300 latency, smoking, hypertension, and elevated Hcy levels. High Hcy levels increased the odds ratio of PSD after adjustment of significantly relevant variables including age, smoking, size of infarction, and carotid stenosis. Conclusions: Cognitive decline is common after stroke. The results of this study indicate that PSD may result from stroke and its related risk factors including possible direct association with high Hcy levels. Better knowledge of the risk factors for PSD should increase the effectiveness of preventive strategies in patients with this condition.
Cognitive impairment after cerebrovascular stroke: Relationship to vascular risk factors  [cached]
Eman M Khedr,Sherifa A Hamed,Hala K El-Shereef,Ola A Shawky
Neuropsychiatric Disease and Treatment , 2009,
Abstract: Eman M Khedr1, Sherifa A Hamed1, Hala K El-Shereef2, Ola A Shawky1, Khalid A Mohamed1, Effat M Awad3, Mohamed A Ahmed2, Ghaydaa A Shehata1, Mahmoud A Eltahtawy41Department of Neurology and Psychiatry, 2Department of Internal Medicine, 3Department of Physiology, 4Department of Clinical Pathology, Assiut University, Faculty of Medicine, Assiut, EgyptBackground: Cognitive decline after cerebrovascular stroke has adverse outcome consequences. Since some vascular causes can be prevented and treated, the identification of stroke-related cognitive impairment is a challenge. Patients with cognitive impairment and vascular diseases exhibit higher homocysteine (Hcy) concentrations. Whether Hcy is an independent risk factor for cognitive impairment after stoke is still in question. The objectives of this study were to determine: 1) the relative frequency of first-ever post-stroke dementia (PSD) (three months after onset) in a consecutive sample of our population, 2) the risk factors associated with PSD, and 3) the relationship between Hcy levels and PSD.Methods: Eighty-one inpatients with first-ever stroke were prospectively evaluated with a neuropsychological battery and event-related evoked potentials (P300) at onset and then after three months. A wide range of demographic, clinical, radiological and laboratory variables were examined. PSD was diagnosed if the clinical presentation fulfilled DSM-IV criteria of vascular dementia, the patient scored ≤21 on Mini Mental State Examination (MMSE) and ≤67 points on Cognitive Abilities Screening Instruments (CASI).Results: PSD was diagnosed in 21%. PSD was significantly associated with increasing age, low levels of education, large sized and lacunar infarctions, severity of stroke, prolonged P300 latency, smoking, hypertension, and elevated Hcy levels. High Hcy levels increased the odds ratio of PSD after adjustment of significantly relevant variables including age, smoking, size of infarction, and carotid stenosis.Conclusions: Cognitive decline is common after stroke. The results of this study indicate that PSD may result from stroke and its related risk factors including possible direct association with high Hcy levels. Better knowledge of the risk factors for PSD should increase the effectiveness of preventive strategies in patients with this condition.Keywords: post-stroke dementia, vascular risk factors, homocysteine
Advanced Asymptomatic Carotid Disease and Cognitive Impairment: An Understated Link?  [PDF]
Irena Martini?-Popovi?,Arijana Lovren?i?-Huzjan,Vida Demarin
Stroke Research and Treatment , 2012, DOI: 10.1155/2012/981416
Abstract: Advanced carotid disease is known to be associated with symptomatic cerebrovascular diseases, such as stroke or transient ischemic attack (TIA), as well as with poststroke cognitive impairment. However, cognitive decline often occurs in patients with advanced carotid stenosis without clinically evident stroke or TIA, so it is also suspected to be an independent risk factor for dementia. Neurosonological methods enable simple and noninvasive assessment of carotid stenosis in patients at risk of advanced atherosclerosis. Cognitive status in patients diagnosed with advanced carotid stenosis is routinely not taken into consideration, although if cognitive impairment is present, such patients should probably be called symptomatic. In this paper, we discuss results of some most important studies that investigated cognitive status of patients with asymptomatic advanced carotid disease and possible mechanisms involved in the causal relationship between asymptomatic advanced carotid disease and cognitive decline. 1. Introduction While detrimental effects of stroke on cognitive functions have been well documented in the literature, the mechanisms linking advanced carotid disease and impaired cognitive status in patients without symptomatic cerebrovascular incidents are less clear. Advanced carotid disease is associated with the presence of multiple vascular risk factors, which most often include arterial hypertension, dyslipidemia, cigarette smoking, diabetes, and older age [1–3]. The same risk factors were shown to be associated not only with vascular dementia, but also with neurodegenerative dementia, importantly with Alzheimer’s disease [4]. The vascular hypothesis of Alzheimer’s disease provides substantial evidence that vascular risk factors play a critical role in the development of cognitive impairment and clinically evident dementia during aging [4]. Vascular dementia and Alzheimer’s disease in their pure forms are two ends of a pathologic continuum [5]. However, many studies during the last decade implicated the overlap of their pathologies. It was shown that a substantial proportion of brains who meet neuropathological criteria for Alzheimer’s disease also demonstrate lesions typical for vascular pathology, such as cerebral amyloid angiopathy, microvascular degeneration, and periventricular white matter lesions [6, 7]. Results of the seminal “Nun Study” that followed 102 elderly nuns until postmortem showed higher prevalence of clinically expressed dementia in those who met neuropathological criteria for Alzheimer’s disease and simultaneously had brain
Non-Audit Services and the Impairment of Auditors Independence: A Further Examination
Appah Ebimobowei
Pakistan Journal of Social Sciences , 2012, DOI: 10.3923/pjssci.2011.100.107
Abstract: This study discuses the provision of non-audit services and the impairment of researcher s independence. The researcher examines the adequacy of independence of auditors and determines whether or not the provision of non-audit services affect the independence of researcher s. To achieve the objective of this study, data was collected from documentary sources in a descriptive manner. The study examines: the concept of independence; factors affecting independence; non-audit services; non-audit service and regulatory framework of some selected countries; non-audit services and regulatory framework in Nigeria; some selected empirical studies on non-audit services and researcher s independence. A few suggestions are finally put forward which if accepted would improve researcher s independence on the provision of non-audit services.
Vascular cognitive impairment: Current concepts and Indian perspective
Alladi Suvarna,Kaul Subhash,Mekala Shailaja
Annals of Indian Academy of Neurology , 2010,
Abstract: Cognitive impairment due to cerebrovascular disease is termed "Vascular Cognitive Impairment" (VCI) and forms a spectrum that includes Vascular Dementia (VaD) and milder forms of cognitive impairment referred to as Vascular Mild Cognitive Impairment (VaMCI). VCI represents a complex neurological disorder that occurs as a result of interaction between vascular risk factors such as hypertension, diabetes, obesity, dyslipidemia, and brain parenchymal changes such as macro and micro infarcts, haemorrhages, white matter changes, and brain atrophy occurring in an ageing brain. Mixed degenerative and vascular pathologies are increasingly being recognised and an interaction between the AD pathology, vascular risk factors, and strokes is now proposed. The high cardiovascular disease burden in India, increasing stroke incidence, and ageing population have contributed to large numbers of patients with VCI in India. Inadequate resources coupled with low awareness make it a problem that needs urgent attention, it is important identify patients at early stages of cognitive impairment, to treat appropriately and prevent progression to frank dementia.
An Examination of Psychopathology and Daily Impairment in Adolescents with Social Anxiety Disorder  [PDF]
Franklin Mesa, Deborah C. Beidel, Brian E. Bunnell
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0093668
Abstract: Although social anxiety disorder (SAD) is most often diagnosed during adolescence, few investigations have examined the clinical presentation and daily functional impairment of this disorder exclusively in adolescents. Prior studies have demonstrated that some clinical features of SAD in adolescents are unique relative to younger children with the condition. Furthermore, quality of sleep, a robust predictor of anxiety problems and daily stress, has not been examined in socially anxious adolescents. In this investigation, social behavior and sleep were closely examined in adolescents with SAD (n = 16) and normal control adolescents (NC; n = 14). Participants completed a self-report measure and an actigraphy assessment of sleep. Social functioning was assessed via a brief speech and a social interaction task, during which heart rate and skin conductance were measured. Additionally, participants completed a daily social activity journal for 1 week. No differences were observed in objective or subjective quality of sleep. Adolescents with SAD reported greater distress during the analogue social tasks relative to NC adolescents. During the speech task, adolescents with SAD exhibited a trend toward greater speech latency and spoke significantly less than NC adolescents. Additionally, SAD participants manifested greater skin conductance during the speech task. During the social interaction, adolescents with SAD required significantly more confederate prompts to stimulate interaction. Finally, adolescents with SAD reported more frequent anxiety-provoking situations in their daily lives, including answering questions in class, assertive communication, and interacting with a group. The findings suggest that, although adolescents with SAD may not exhibit daily impaired sleep, the group does experience specific behavioral and physiological difficulties in social contexts regularly. Social skills training may be a critical component in therapeutic approaches for this group.
A combined electrophysiological and morphological examination of episodic memory decline in amnestic mild cognitive impairment  [PDF]
Michael Hoppst?dter,Lutz Fr?lich,Michèle Wessa,Herta Flor,Patric Meyer
Frontiers in Aging Neuroscience , 2013, DOI: 10.3389/fnagi.2013.00051
Abstract: Early stages of Alzheimer’s disease (AD) are characterized by neuropathological changes within the medial temporal lobe cortex (MTLC), which lead to characteristic impairments in episodic memory, i.e., amnestic mild cognitive impairment (aMCI). Here, we tested the neural correlates of this memory impairment using event-related potentials (ERPs) and voxel-based morphometry. Twenty-four participants were instructed to encode lists of words and were tested in a yes/no recognition memory task. The dual-process model of recognition memory dissociates between acontextual familiarity and recollection of contextual details. The early frontal ERP old/new effect, which is thought to represent a neural correlate of familiarity-based memory, was absent in aMCI, whereas the control group showed a significant early old/new effect at frontal electrodes. This effect was positively correlated with behavioral episodic memory performance. Analyses of brain morphology revealed a focused gray matter loss in the inferior and medial temporal lobes in aMCI versus healthy controls. Moreover, the positive correlation between gray matter volume in the MTLC and the familiarity-related early frontal old/new effect supports the notion that this effect relies upon the integrity of the MTLC. Thus, the present findings might provide a further functional marker for prodromal AD.
Resorufin analogs preferentially bind cerebrovascular amyloid: potential use as imaging ligands for cerebral amyloid angiopathy
Byung Han, Meng-liang Zhou, Ananth K Vellimana, Eric Milner, David H Kim, Jacob K Greenberg, Wenhua Chu, Robert H Mach, Gregory J Zipfel
Molecular Neurodegeneration , 2011, DOI: 10.1186/1750-1326-6-86
Abstract: We found that the phenoxazine derivative resorufin preferentially bound cerebrovascular amyloid deposits over neuritic plaques in the aged Tg2576 transgenic mouse model of AD/CAA, whereas the congophilic amyloid dye methoxy-X34 bound both cerebrovascular amyloid deposits and neuritic plaques. Similarly, resorufin-positive staining was predominantly noted in fibrillar Aβ-laden vessels in postmortem AD brain tissues. Fluorescent labeling and multi-photon microscopy further revealed that both resorufin- and methoxy-X34-positive staining is colocalized to the vascular smooth muscle (VSMC) layer of vessel segments that have severe disruption of VSMC arrangement, a characteristic feature of CAA. Resorufin also selectively visualized vascular amyloid deposits in live Tg2576 mice when administered topically, though not systemically. Resorufin derivatives with chemical modification at the 7-OH position of resorufin also displayed a marked preferential binding affinity for CAA, but with enhanced lipid solubility that indicates their use as a non-invasive imaging tracer for CAA is feasible.To our knowledge, resorufin analogs are the fist class of amyloid dye that can discriminate between cerebrovascular and neuritic forms of amyloid. This unique binding selectivity suggests that this class of dye has great potential as a CAA-specific amyloid tracer that will permit non-invasive detection and quantification of CAA in live patients.Cerebral amyloid angiopathy (CAA) is characterized by amyloid deposition within the walls of leptomeningeal and cortical arterioles. Among the several types of amyloid proteins causing CAA, amyloid β (Aβ) is by far the most common. Aβ comprises several species of 39-43-residue peptides (including Aβ1-40 and Aβ1-42) that are produced from amyloid precursor protein (APP) via sequential proteolytic cleavage by β- and γ-secretases [1-3]. Soluble Aβ monomers are produced throughout life; in certain individuals, these aggregate to form insoluble amyloid fib
Cardiac Impairment Evaluated by Transesophageal Echocardiography and Invasive Measurements in Rats Undergoing Sinoaortic Denervation  [PDF]
Raquel A. Sirvente, Maria C. Irigoyen, Leandro E. Souza, Cristiano Mostarda, Raquel N. La Fuente, Georgia O. Candido, Pamella R. M. Souza, Alessandra Medeiros, Charles Mady, Vera M. C. Salemi
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0087935
Abstract: Background Sympathetic hyperactivity may be related to left ventricular (LV) dysfunction and baro- and chemoreflex impairment in hypertension. However, cardiac function, regarding the association of hypertension and baroreflex dysfunction, has not been previously evaluated by transesophageal echocardiography (TEE) using intracardiac echocardiographic catheter. Methods and Results We evaluated exercise tests, baroreflex sensitivity and cardiovascular autonomic control, cardiac function, and biventricular invasive pressures in rats 10 weeks after sinoaortic denervation (SAD). The rats (n = 32) were divided into 4 groups: 16 Wistar (W) with (n = 8) or without SAD (n = 8) and 16 spontaneously hypertensive rats (SHR) with (n = 8) or without SAD (SHRSAD) (n = 8). Blood pressure (BP) and heart rate (HR) did not change between the groups with or without SAD; however, compared to W, SHR groups had higher BP levels and BP variability was increased. Exercise testing showed that SHR had better functional capacity compared to SAD and SHRSAD. Echocardiography showed left ventricular (LV) concentric hypertrophy; segmental systolic and diastolic biventricular dysfunction; indirect signals of pulmonary arterial hypertension, mostly evident in SHRSAD. The end-diastolic right ventricular (RV) pressure increased in all groups compared to W, and the end-diastolic LV pressure increased in SHR and SHRSAD groups compared to W, and in SHRSAD compared to SAD. Conclusions Our results suggest that baroreflex dysfunction impairs cardiac function, and increases pulmonary artery pressure, supporting a role for baroreflex dysfunction in the pathogenesis of hypertensive cardiac disease. Moreover, TEE is a useful and feasible noninvasive technique that allows the assessment of cardiac function, particularly RV indices in this model of cardiac disease.
Pathology and pathogenesis of vascular cognitive impairment—a critical update  [PDF]
Kurt A. Jellinger
Frontiers in Aging Neuroscience , 2013, DOI: 10.3389/fnagi.2013.00017
Abstract: Vascular cognitive impairment (VCI) [vascular cognitive disorder (VCD), vascular dementia] describes a continuum of cognitive disorders ranging from mild cognitive impairment (MCI) to dementia, in which vascular brain injury involving regions important for memory, cognition and behavior plays an important role. Clinical diagnostic criteria show moderate sensitivity (ca 50%) and variable specificity (range 64–98%). In Western clinical series, VaD is suggested in 8–10% of cognitively impaired elderly subjects. Its prevalence in autopsy series varies from 0.03 to 58%, with means of 8 to 15% (in Japan 22–35%). Major types of sporadic VaD are multi-infarct encephalopathy, small vessel and strategic infarct type dementias, subcortical arteriosclerotic leukoencephalopathy (SAE) (Binswanger), multilacunar state, mixed cortico-subcortical type, granular cortical atrophy (rare), postischemic encephalopathy, and a mixture of cerebrovascular lesions (CVLs). They result from systemic, cardiac and local large or small vessel disease (SVD); their pathogenesis is multifactorial. Hereditary forms of VaD caused by gene mutations are rare. Cognitive decline is commonly associated with widespread small ischemic vascular lesions involving subcortical brain areas (basal ganglia and hemispheral white matter). The lesions affect neuronal networks involved in cognition, memory, and behavior (thalamo-cortical, striato-subfrontal, cortico-subcortical, limbic systems). CVLs often coexist with Alzheimer-type lesions and other pathologies; 25–80% of elderly demented show mixed pathologies. The lesion pattern of “pure” VaD differs from that in mixed dementia (AD + CVLs) suggesting different pathogenesis of both phenotypes. Minor CVLs, except for severe amyloid angiopathy, appear not essential for cognitive impairment in full-blown AD, while both mild AD-type pathology and SVD may interact synergistically in promoting dementia. However, in a large percentage of non-demented elderly individuals, both AD-related and vascular brain pathologies have been reported. Despite recent suggestions for staging and grading CVLs in specific brain areas, due to the high variability of CVLs associated with cognitive impairment, no validated neuropathological criteria are currently available for VaD and mixed dementia. Further clinico-pathological studies and harmonization of neuropathological procedures are needed to validate the diagnostic criteria for VaD and mixed dementia in order to clarify the impact of CVLs and other coexistent pathologies on cognitive impairment as a basis for further
Page 1 /100
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.