984 resultados para Cognitive Functions


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Introduction: Cognitive impairment affects 40-65% of multiple sclerosis (MS) patients, often since early stages of the disease (relapsing remitting MS, RRMS). Frequently affected functions are memory, attention or executive abilities but the most sensitive measure of cognitive deficits in early MS is the information processing speed (Amato, 2008). MRI has been extensively exploited to investigate the substrate of cognitive dysfunction in MS but the underlying physiopathological mechanisms remain unclear. White matter lesion load, whole-brain atrophy and cortical lesions' number play a role but correlations are in some cases modest (Rovaris, 2006; Calabrese, 2009). In this study, we aimed at characterizing and correlating the T1 relaxation times of cortical and sub-cortical lesions with cognitive deficits detected by neuropsychological tests in a group of very early RR MS patients. Methods: Ten female patients with very early RRMS (age: 31.6 ±4.7y; disease duration: 3.8 ±1.9y; EDSS disability score: 1.8 ±0.4) and 10 age- and gender-matched healthy volunteers (mean age: 31.2 ±5.8y) were included in the study. All participants underwent the following neuropsychological tests: Rao's Brief Repeatable Battery of Neuropsychological tests (BRB-N), Stockings of Cambridge, Trail Making Test (TMT, part A and B), Boston Naming Test, Hooper Visual Organization Test and copy of the Rey-Osterrieth Complex Figure. Within 2 weeks from neuropsychological assessment, participants underwent brain MRI at 3T (Magnetom Trio a Tim System, Siemens, Germany) using a 32-channel head coil. The imaging protocol included 3D sequences with 1x1x1.2 mm3 resolution and 256x256x160 matrix, except for axial 2D-FLAIR: -DIR (T2-weighted, suppressing both WM and CSF; Pouwels, 2006) -MPRAGE (T1-weighted; Mugler, 1991) -MP2RAGE (T1-weighted with T1 maps; Marques, 2010) -FLAIR SPACE (only for patient 4-10, T2-weighted; Mugler, 2001) -2D Axial FLAIR (0.9x0.9x2.5 mm3, 256x256x44 matrix). Lesions were identified by one experienced neurologist and radiologist using all contrasts, manually contoured and assigned to regional locations (cortical or sub-cortical). Lesion number, volume and T1 relaxation time were calculated for lesions in each contrast and in a merged mask representing the union of the lesions from all contrasts. T1 relaxation times of lesions were normalized with the mean T1 value in corresponding control regions of the healthy subjects. Statistical analysis was performed using GraphPad InStat software. Cognitive scores were compared between patients and controls with paired t-tests; p values ≤ 0.05 were considered significant. Spearmann correlation tests were performed between the cognitive tests, which differed significantly between patients and controls, and lesions' i) number ii) volume iii) T1 relaxation time iv) disease duration and v) years of study. Results: Cortical and sub-cortical lesions count, T1 values and volume are reported in Table 1 (A and B). All early RRMS patients showed cortical lesions (CLs) and the majority consisted of CLs type I (lesions with a cortical component extending to the sub-cortical tissue). The rest of cortical lesions were characterized as type II (intra-cortical lesions). No type III/IV lesions (large sub-pial lesions) were detected. RRMS patients were slightly less educated (13.5±2.5y vs. 16.3±1.8y of study, p=0.02) than the controls. Signs of cortical dysfunction (i.e. impaired learning, language, visuo-spatial skills or gnosis) were rare in all patients. However, patients showed on average lower scores on measures of visual attention and information processing speed (TMT-part A: p=0.01; TMT-part B: p=0.006; PASAT-included in the BRB-N: p=0.04). The T1 relaxation values of CLs type I negatively correlated with the TMT-part A score (r=0.78, p<0.01). The correlations of TMT-part B score and PASAT score with T1 relaxation time of lesions as well and the correlation between TMT-part A, TMT-part B and PASAT score with lesions' i) number ii) volume iii) disease duration and iv) years of study did not reach significance. In order to preclude possible influences from partial volume effects on the T1 values, the correlation between lesion volume and T1 value of CLs type I was calculated; no correlation was found, suggesting that partial volume effects did not affect the statistics. Conclusions: The present pilot study reports for the first time the presence and the T1 characteristics at 3 T of cortical lesions in very early RRMS (< 6 y disease duration). It also shows that CLS type I represents the most frequent cortical lesion type in this cohort of RRMS patients. In addition, it reveals a negative correlation between the attentional test TMT-part A and the T1 properties of cortical lesions type I. In other words, lower attention deficits are concomitant with longer T1-relaxation time in cortical lesions. In respect to this last finding, it could be speculated that long relaxation time correspond to a certain degree of tissue loss that is enough to stimulate compensatory mechanisms. This hypothesis is in line with previous fMRI studies showing functional compensatory mechanisms to help maintaining normal or sub-normal attention performances in RR MS patients (Penner, 2003).

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For a quasilinear operator on the semiaxis a reduction theorem is proved on the cones of monotone functions in Lp - Lq setting for 0 < q < ∞, 1<= p < ∞. The case 0 < p < 1 is also studied for operators with additional properties. In particular, we obtain critera for three-weight inequalities for the Hardy-type operators with Oinarov' kernel on monotone functions in the case 0 < q < p <= 1.

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The Government Decision1 on the Structural, Organisational, Financial Management and Systems Reform of the Health Sector of June, 2003 acknowledged that in order to increase the effectiveness of the health service generally, and its capacity to deliver the reform agenda, it was important that the service was fully concentrated on addressing its core health objectives. The Minister for Health and Children and Minister for Finance felt that there could be scope to transfer certain functions out of the health service and locate them more appropriately within other functional areas of Government. As part of the overall decision, it was agreed that a working group would be established, to include the Departments of Health and Children, Finance and An Taoiseach, to examine the scope for transfer of certain activities to other, more appropriate, Departments and agencies and that on completion of this review, the Minister for Health and Children would bring proposals to Government. Read the Report (PDF, 70kb)  

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In case Krein's strings with spectral functions of polynomial growth a necessary and su fficient condition for the Krein's correspondence to be continuous is given.

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The costs of coping with stressful situations are traded-off against other functions such as immune responses. This trade-off may explain why corticosterone secretion reduces immune reactions. Corticosterone differentially affects various immunity components. However, which component is suppressed varies between studies. It remains unclear whether the trade-off in energy, nutrition, autoimmunity or oxidative stress accounts for differential immunosuppression. In this study, we investigated whether corticosterone differentially affects the constitutive innate and humoral acquired immunity. We used barn owl nestlings, implanting 50% with a corticosterone-releasing pellet and the other 50% with a placebo pellet. To measure the effect on humoral immunity we vaccinated 50% of the corticosterone-nestlings and 50% of the placebo-nestlings with the antigens 'Tetravac' and the other 50% were injected with PBS. To assess the costs of elevated corticosterone, we measured body mass and resistance to oxidative stress. Administration of corticosterone increased corticosterone levels whereas vaccination induced the production of antibodies. Corticosterone reduced the production of antibodies, but it did not significantly affect the constitutive innate immunity. Corticosterone reduced body growth and resistance to oxidative stress. Under stressful conditions barn owl nestlings seem to keep the constitutive innate immunity, whereas elevated corticosterone levels negatively affected inducible immune responses. We found evidence that mounting a humoral immune reaction is not costly in terms of growth, but reduces the resistance to oxidative stress independently of corticosterone administration. We suggest that humoral immunity is suppressed because the risk of immunopathologies may be disproportionately high when mounting an antibody response under stressful situations.

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We introduce an algebraic operator framework to study discounted penalty functions in renewal risk models. For inter-arrival and claim size distributions with rational Laplace transform, the usual integral equation is transformed into a boundary value problem, which is solved by symbolic techniques. The factorization of the differential operator can be lifted to the level of boundary value problems, amounting to iteratively solving first-order problems. This leads to an explicit expression for the Gerber-Shiu function in terms of the penalty function.

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Background: Inadequate intraoperative cerebral perfusion and increased serum anticholinergic activity (SAA) have been suggested as possible causes of postoperative cognitive dysfunction (POCD). Methods: 53 patients aged >65 yrs undergoing elective major surgical procedures under standardized general anaesthesia. Cerebral perfusion was monitored with transcranial Doppler and near-infrared spectroscopy. Mx, an index of cerebral autoregulation was calculated based on the correlation of spontaneous changes inmean arterial blood pressure (MAP) and cerebral blood flow velocity. Cognitive function was measured preoperatively and 7 days postoperatively using the CERAD-Neuropsychological Battery. A postoperative decline >1 z-score in at least 2 cognitive variables was defined as POCD. SAA was measured preoperatively and 7 days postoperatively (data available for 38 patients). CRP was measured at the same time points and 2 days postoperatively. Results: Age was 75_7 yrs (mean_SD). 23 patients (43%) developed POCD. There were no statistical significant differences between patients with POCD and without POCD in age (77_7 vs 73_6 yrs), MAP (74_12 vs 78_11 mmHg), cerebral tissue oxygenation indices (67_6 vs 69_4 %) SAA preoperatively (1.74_1.52 vs 1.74_1.21) and 7 days postoperatively (1.90_1.63 vs 1.84_1.39) and CRP preoperatively (32_72 vs 7_9), 2 days postoperatively (176_129 vs 111_69) and 7days postoperatively (53_43 vs 48_25). Patients with POCD had less efficient autoregulation than patients without POCD (Mx 0.55_0.15 vs 0.45_0.20, p = 0.046). However, the percentage of patients with clearly impaired autoregulation (ie, Mx>0.5) was statistically not different between groups (with POCD: 65%; without POCD: 38%; p = 0.06) but there seems to be a trend. Conclusions: Our data on the association between cerebral perfusion and POCD in elderly patients are inconclusive and more patients need to be investigated. In this small group of patients SAA seems not to be associated with POCD.

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Non-pathological or normal ageing is accompanied by brain alterations that are the result of natural changes occurring with age and our ability to compensate for them. Compared to younger adults, older adults have reduced vision, more difficulties in detecting relevant information they are not intending to and require more time to process sensorial information. Little is known on how these changes affect behaviour in a natural environment. Relying on a translational approach at the frontiers between neurobiology, psychophysics, neuropsychology and epidemiology, we were able to: explore the needs for innovative instrumentations to detect cerebral decline in clinical settings; develop and validate a new computed neuropsychological instrument designed to measure cerebral decline in healthy older adults; explore the link between processing speed and on-road driving performance; and investigate the effects of being able to anticipate on visual processing speed.

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Cognitive impairment has been identified in the early phase of schizophrenia spectrum disorders, and is a major contributor to disease-related disability. While screening tools assessing cognitive impairment have been validated for adult schizophrenic populations, there is a need for brief, easily administered, standardized instruments that provide clinically relevant information for adolescents. This study examines the utility of the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) in identifying and quantifying neurocognitive impairment in adolescents with schizophrenia spectrum disorders and other serious psychiatric illnesses. 112 adolescents, including 32 healthy subjects and 80 patients, were administered the RBANS. Patients with psychotic disorders demonstrated significant impairment on the RBANS total score compared to patients with other disorders and healthy controls, but this impairment appeared somewhat less severe than is typically reported for in adult patients with schizophrenia on this measure. The RBANS appears to be sensitive in the detection of neurocognitive impairment in a psychiatric population of adolescents with psychotic symptomatology, and may therefore have utility as a clinical screening instrument and/or neurocognitive outcome measure in this population.

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Vaginal delivery can cause lesions of the various pelvic structures responsible for the mechanisms of continence. These lesions may perhaps be prevented in the future by measuring pressure generated during childbirth. Tear of the anal sphincter during childbirth is a marker of a global impairment of the urinary, ano-rectal and sexual pelvic functions in the short and medium term. Persistence of a defect of the anal sphincter is frequent in spite of immediate suture. The correlation between these defects and ano-rectal incontinence are not established in our experience. The quality of the contraction of the sphincter complex and pubo-rectal sling seems to play a more important role in ano-rectal continence after a traumatic childbirth.

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Glutamate was previously shown to enhance aerobic glycolysis i.e. increase glucose utilization and lactate production with no change in oxygen levels, in mouse cortical astrocytes by a mechanism involving glutamate uptake. It is reported here that a similar response is produced in both hippocampal and cerebellar astrocytes. Application of the cognitive-enhancing drug CX546 promoted further enhancement of glucose utilization by astrocytes from each brain area following glutamate exposure. alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors represent the purported molecular target of cognitive-enhancing drugs such as CX546, and the presence of AMPA receptor subunits GluR1-4 was evidenced in astrocytes from all three regions by immunocytochemistry. AMPA itself did not stimulate aerobic glycolysis, but in the presence of CX546, a strong enhancement of glucose utilization and lactate production was obtained in cortical, hippocampal and cerebellar astrocytes. The effect of CX546 was concentration-dependent, with an EC(50) of 93.2 microm in cortical astrocytes. AMPA-induced glucose utilization in the presence of CX546 was prevented by the AMPA receptor antagonist 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) and the negative modulator GYKI 52466. In addition, the metabolic effect of CX546 in the presence of AMPA was mimicked by the AMPA receptor modulator cyclothiazide. Our data suggest that astrocyte energetics represents a novel target for cognitive-enhancing drugs acting as AMPA receptor modulators.

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Cognitive errors (CE) and coping strategies (CS) are the focus of most cognitive-behavioral treatments for incarcerated child molesters. Several studies have reported differences in CEs and CSs between child molesters and controls. However, the vast majority of these studies assessed cognitive errors and coping using questionnaires, which are known to present a number of important limitations. This pilot study aimed to compare the CEs and CSs of N = 17 incarcerated child abusers and N = 12 controls using observer-rated methods, namely the Cognitive Error Rating Scale (CERS; Drapeau et al., 2005) and the Coping Action Pattern Rating Scale (CAPRS; Perry, Drapeau, & Dunkley, 2005). Results showed that child molesters presented more cognitive errors, in particular positive selective abstraction, and lower coping functioning, such as escape strategies. Treatment and research implications, including the use of observer-rated methods, are discussed.

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The prevalence of unhealthy drinking at all levels in Irish society poses serious issues in terms of the consequence to individuals concerned, as well as to society as a whole. The workplace offers a useful setting for early identification and intervention with new employees who may have pre-existing alcohol use disorder issues. This pilot study aimed to evaluate the effectiveness within the workplace of a brief Cognitive Behavioural Therapy (CBT) intervention in reducing participants binge and risky drinking behaviours. Twenty-six Irish Naval recruits volunteered to participate in this randomised controlled trial. The intervention was conducted over four consecutive one and a half hour weekly sessions. Participants completed four principle outcome measures at intake, termination of the intervention and at the two-month follow-up assessment. The Alcohol Use Disorders Identification Test (Babor, Higginis-Biddle, Saunders & Monterio, 2001) was used to measures participants’ consumption levels and frequency of binge or risky drinking. A Readiness Ruler (Miller, Zweben, Diclemente, & Rychtarik, 1992) was used to measure participants’ readiness to change drinking, while the Drinking Expectancy Questionnaire (Young & Oei, 1996) was used to measure participants’ beliefs pertaining to alcohol, and their ability to refuse alcohol in high-risk social surroundings. There were preliminary data in support of the intervention. There were interaction effects that approached statistical significance for both a reduction in participants’ binge drinking (p =. 064) and an increase in participants’ ability to refuse alcohol in high-risk social settings (p = .059). There was also a significant interaction effect (pThis resource was contributed by The National Documentation Centre on Drug Use.

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OBJECTIVE: Cognitive change over the course of psychodynamic psychotherapy has been postulated by several models, but has rarely been studied. Based on the adaptive skills model (Badgio, Halperin, & Barber, 1999), it is reasonable to expect that very brief dynamic psychotherapy may be associated with change in coping patterns and cognitive errors (also known as cognitive distortions) y. METHOD: N = 50 outpatients presenting with various psychiatric disorders and undergoing 4 sessions of Brief Psychodynamic Intervention (BPI; Despland, Drapeau, & de Roten, 2005; Despland, Michel, & de Roten, 2010) were included in this naturalistic study (mean age: 31 years; 56% female; all Caucasian). Cognitive errors and coping strategies were assessed using the Cognitive Errors Rating Scale (Drapeau et al., 2008) and Coping Patterns Rating Scale (Perry et al., 2005). These observer rated methods were applied to the verbatim transcriptions of all 4 therapy sessions completed by each patient. RESULTS: Results indicate change in both cognitive errors and coping patterns over the course of BPI, including an increase in the Overall Coping Functioning and a decrease in unhelpful coping processes, such as isolation, which reflects a shift in participant appraisal towards stress appraised as a challenge at the end of treatment. These changes predicted symptom change at the end of treatment. While cognitive errors also changed over the course of BPI, no predictive effect was found with regard to symptom change. CONCLUSIONS: These results are interpreted within the framework of common change principles in psychotherapy. Implications and future research are discussed.