944 resultados para Impaired visuospatial working memory


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Background: The Rivermead Behavioural Memory Test (RBMT) assesses everyday memory by means of tasks which mimic daily challenges. The objective was to examine the validity of the Brazilian version of the RBMT to detect cognitive decline. Methods: 195 older adults were diagnosed as normal controls (NC) or with mild cognitive impairment (MCI) or Alzheimer`s disease (AD) by a multidisciplinary team, after participants completed clinical and neuropsychological protocols. Results: Cronbach`s alpha was high for the total sample for the RBMT profile (PS) and screening scores (SS) (PS=0.91, SS=0.87) and for the AD group (PS=0.84, SS=0.85), and moderate for the MCI (PS=0.62, SS=0.55)and NC (PS=0.62, SS=0.60) groups. RBMT total scores, Appointment, Pictures, Immediate and Delayed Story, Immediate and Delayed Route, Delayed Message and Date contributed to differentiate NC from MCI. ROC curve analyses indicated high accuracy to differentiate NC from AD patients, and, moderate accuracy to differentiate NC from MCI. Conclusions: The Brazilian version of the RBMT seems to be an appropriate instrument to identify memory decline in Brazilian older adults.

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Objective: To compare the volume of the hippocampus and parahippocampal gyrus in elderly individuals with and without depressive disorders, and to determine whether the volumes of these regions correlate with scores on memory tests. Method: Clinical and demographic differences, as well as differences in regional gray matter volumes, were assessed in 48 elderly patients with depressive disorders and 31 control subjects. Brain (structural MRI) scans were processed using statistical parametric mapping and voxel-based morphometry. Cognitive tests were administered to subjects in both groups. Results: There were no between-group gray matter volume differences in the hippocampus or parahippocampal gyrus. In the elderly depressed group only, the volume of the left parahippocampal gyrus correlated with scores on the delayed naming portion of the visual verbal learning test. There were also significant direct correlations in depressed subjects between the volumes of the left hippocampus, right and left parahippocampal gyrus and immediate recall scores on verbal episodic memory tests and visual learning tests. In the control group, there were direct correlations only between overall cognitive performance (as assessed with the MMSE) and the volume of right hippocampus, and between the total score on the visual verbal learning test and the volume of the right and left parahippocampal gyrus. Conclusions: These findings highlight different patterns of relationship between cognitive performance and volumes of medial temporal structures in depressed individuals and healthy elderly subjects. The direct correlation between delayed visual verbal memory recall scores with left parahippocampal volumes specifically in elderly depressed individuals provides support to the view that depression in elderly populations may be a risk factor for dementia. (C) 2009 Elsevier Inc. All rights reserved.

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Objectives: Neurocysticercosis (NCYST) is the most frequent CNS parasitic disease worldwide, affecting more than 50 million people. However, some of its clinical findings, such as cognitive impairment and dementia, remain poorly characterized, with no controlled studies conducted so far. We investigated the frequency and the clinical profile of cognitive impairment and dementia in a sample of patients with NCYST in comparison with cognitively healthy controls (HC) and patients with cryptogenic epilepsy (CE). Methods: Forty treatment-naive patients with NCYST, aged 39.25 +/- 10.50 years and fulfilling absolute criteria for definitive active NCYST on MRI, were submitted to a comprehensive cognitive and functional evaluation and were compared with 49 HC and 28 patients with CE of similar age, educational level, and seizure frequency. Results: Patients with NCYST displayed significant impairment in executive functions, verbal and nonverbal memory, constructive praxis, and verbal fluency when compared with HC (p < 0.05). Dementia was diagnosed in 12.5% patients with NCYST according to DSM-IV criteria. When compared with patients with CE, patients with NCYST presented altered working and episodic verbal memory, executive functions, naming, verbal fluency, constructive praxis, and visual-spatial orientation. No correlation emerged between cognitive scores and number, localization, or type of NCYST lesions on MRI. Conclusions: Cognitive impairment was ubiquitous in this sample of patients with active neurocysticercosis (NCYST). Antiepileptic drug use and seizure frequency could not account for these features. Dementia was present in a significant proportion of patients. These data broaden our knowledge on the clinical presentations of NCYST and its impact in world public health. Neurology (R) 2010;74:1288-1295

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P>Background The evolution and therapeutic outcome of American tegumentary leishmaniasis (ATL) depend upon many factors, including the balance between Th1 and Th2 cytokines to control parasite multiplication and lesion extension. Other cytokines known for their role in inflammatory processes such as interleukin IL-17 or IL-18 as well as factors controlling keratinocyte differentiation and the inflammatory process in the skin, like the Notch system, could also be involved in the disease outcome. Notch receptors are a group of transmembrane proteins that regulate cell fate decisions during development and adulthood in many tissues, including keratinocyte differentiation and T-cell lineage commitment, depending on their activation by specific groups of ligands (Delta-like or Jagged). Objectives To compare the in situ expression of Notch system proteins (receptors, ligands and transcriptional factors) and cytokines possibly involved in the disease outcome (IL-17, IL-18, IL-23 and transforming growth factor-beta) in ATL cutaneous and mucosal lesions, according to the response to therapy with N-methyl glucamine. Methods Cutaneous and mucosal biopsies obtained from patients prior to therapy with N-methyl glucamine were analysed by immunohistochemistry and real-time polymerase chain reaction. Results Notch receptors and Delta-like ligands were found increased in patients with ATL, particularly those with poor response to therapy or with mucosal lesions. Conclusions The increase of Notch receptors and Delta-like ligands in patients with a poor response to treatment suggests that these patients would require a more aggressive therapeutic approach or at least a more thorough and rigorous follow-up.

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Previous studies have shown that patients with major depression have an interhemispheric imbalance between right and left prefrontal and motor cortex. We aimed to investigate the interhemispheric interactions in patients with major depression using repetitive transcranial magnetic stimulation (rTMS). Thirteen patients with major depression and 14 age-matched healthy subjects participated in this study. Corticospinal excitability before and after 1 Hz rTMS (applied to the left primary motor cortex) was assessed in the left and right motor cortex and these results were compared with those in healthy subjects. There was a significant difference in the interhemispheric effects between patients with depression and healthy subjects. In healthy subjects, 1 Hz rTMS significantly decreased corticospinal excitability in the stimulated, left hemisphere and increased it in the contralateral, right hemisphere. In depressed subjects, 1 Hz rTMS also decreased corticospinal excitability in the left hemisphere; however, it induced no significant changes in corticospinal excitability in the contralateral, right hemisphere. In addition, there was a significant correlation between the degree of interhemispheric modulation and the severity of the depression as indexed by the Beck Depression Inventory scores. Our findings showing a decreased interhemispheric modulation in patients with major depression are consistent with the notion that mood disorders are associated with slow interhemispheric switching mechanisms.

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Objective: To describe the findings of proton magnetic resonance spectroscopy (H-1-MRS) in Alzheimer`s disease (AD) and cognitive impairment, no dementia (CIND) elderly from a community-based sample. Methods: Thirteen patients with AD, 12 with CIND and 15 normal individuals were evaluated. The H-1-MRS was performed in the right temporal, left parietal and medial occipital regions studying the metabolites N-acetylaspartate (NAA), creatine (Cr), choline (Cho) and myoinositol (ml). The clinical diagnosis was based on standardized cognitive tests - MMSE and CAMDEX - and the results correlated with the H-1-MRS. Results: Parietal Cho was higher in control individuals and lower in CIND subjects. AD and control groups were better identified by temporal and parietal ml combined with the temporal NAA/Cr ratio. CIND was better identified by parietal Cho. Conclusion: The H-1-MRS findings confirmed the hypothesis that metabolic alterations are present since the first symptoms of cognitively impaired elderly subjects. These results suggest that combining MRS from different cerebral regions can help in the diagnosis and follow-up of community elderly individuals with memory complaints and AD. Copyright (C) 2008 S. Karger AG, Basel.

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Endothelial dysfunction has been linked to a decrease in nitric oxide (NO) bioavailability and attenuated endothelium-derived hyperpolarizing factor (EDHF)-mediated relaxation. The small (SK(Ca)) and intermediate (IK(Ca)) calcium-activated potassium channels play a key role in endothelium-dependent relaxation. Because the repressor element 1-silencing transcription factor (REST) negatively regulates IK(Ca) expression, we hypothesized that augmented REST and decreased IK(Ca) expression contributes to impaired endothelium-dependent vasodilation associated with hypertension. Acetylcholine (ACh) responses were slightly decreased in small mesenteric arteries from male stroke-prone spontaneously hypertensive rats (SHRSPs) versus arteries from Wistar Kyoto (WKY) rats. Incubation with N-nitro-L-arginine methyl ester (L-NAME; 100 mu mol/L) and indomethacin (100 mu mol/L) greatly impaired ACh responses in vessels from SHRSP. lberiotoxin (0.1 mu mol/L), which is a selective inhibitor of large-conductance K(Ca) (BK(Ca)) channels, did not modify EDHF-mediated vasodilation in SHRSP or WKY. UCL-1684 (0.1 mu mol/L.), which is a selective inhibitor of SKCa channels, almost abolished EDHF-mediated vasodilation in WKY and decreased relaxation in SHRSP. 1-((2-chlorophenyl)diphenylmethyl)-1H-pyrazole (TRAM-34; 10 mu mol/L) and charybdotoxin (0.1 mu mol/L), which are both IKCa inhibitors, produced a small decrease of EDHF relaxation in WKY but completely abrogated EDHF vasodilation in SHRSP. EDHF-mediated relaxant responses were completely abolished in both groups by simultaneous treatment with UCL-1684 and TRAM-34 or charybdotoxin. Relaxation to SK(Ca)/IK(Ca) channels agonist NS-309 was decreased in SHRSP arteries. The expression of SK(Ca) was decreased, whereas IK(Ca) was increased in SHRSP mesenteric arteries. REST expression was reduced in arteries from SHRSP. Vessels incubated with TRAM-34 (10 mu mol/L) for 24h displayed reduced REST expression and demonstrated no differences in IK(Ca). In conclusion, IK(Ca) channel upregulation, via decreased REST, seems to compensate deficient activity of SK(Ca) channels in the vasculature of spontaneously hypertensive rats. (Translational Research 2009; 154:183-193)

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Objectives: We compared nitrite, B-type natriuretic peptide (BNP), and cGMP levels in preeclamptic with those found in healthy pregnant. Methods: We studied 21 healthy pregnant and 27 preeclamptic. Plasma cGMP and BNP levels were determined by ELISA. Nitrite levels were determined by chemiluminescence. Results: Higher cGMP and BNP, and lower nitrite levels were found in preeclamptic versus healthy pregnant Conclusions: Altered cGMP levels reflect increased BNP levels and not impaired nitric oxide activity in preeclampsia. (C) 2011 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.