283 research outputs found

    Functional outcome is tied to dynamic brain states after mild to moderate traumatic brain injury

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    The current study set out to investigate the dynamic functional connectome in relation to long-term recovery after mild to moderate traumatic brain injury (TBI). Longitudinal resting-state functional MRI data were collected (at 1 and 3 months postinjury) from a prospectively enrolled cohort consisting of 68 patients with TBI (92% mild TBI) and 20 healthy subjects. Patients underwent a neuropsychological assessment at 3 months postinjury. Outcome was measured using the Glasgow Outcome Scale Extended (GOS-E) at 6 months postinjury. The 57 patients who completed the GOS-E were classified as recovered completely (GOS-E = 8; n = 37) or incompletely (GOS-E < 8; n = 20). Neuropsychological test scores were similar for all groups. Patients with incomplete recovery spent less time in a segregated brain state compared to recovered patients during the second visit. Also, these patients moved less frequently from one meta-state to another as compared to healthy controls and recovered patients. Furthermore, incomplete recovery was associated with disruptions in cyclic state transition patterns, called attractors, during both visits. This study demonstrates that poor long-term functional recovery is associated with alterations in dynamics between brain networks, which becomes more marked as a function of time. These results could be related to psychological processes rather than injury-effects, which is an interesting area for further work. Another natural progression of the current study is to examine whether these dynamic measures can be used to monitor treatment effects

    Comparison between Spanish young and elderly people evaluated using Rivermead Behavioural Memory Test

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    The first objective of this work was to compare scores obtained in the daily memory function between young and elderly people, and to check whether there are differences between the groups for each of the profile scores obtained in the memory test. A second aim of this paper is to study the relationship between everyday memory and age, while controlling for gender and educational level. The total and profile scores obtained in the Rivermead Behavioural Memory Test were compared in a sample of 60 young and 120 elderly people from Valencia (Spain). Results showed significant differences between the two groups: those between 18 and 30 years obtained a higher average than those over 65. Once the group comparison was controlled for gender and educational level, the statistical effect of age group disappeared. The non-significant effect of group can not be explained by the introduction of gender, because both its main effect and the interaction were not statistically significant. However, educational level had a statistically significant effect which may explain the non-significant effect of group in this new analysis. The main conclusion is the need to carefully control for educational level in all studies related with everyday memory and ageing, as the differences found could be due to generational differences more than to biological deterioratio

    Comparative Long-term Adverse Effects Elicited by Invasive Group B and C Meningococcal Infections

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    No vaccine is universally active against serogroup B meningococci. A theoretical concern that serogroup B capsular polysaccharide may induce autoimmunity hampers vaccine development. We studied long-term complications in 120 survivors of meningococcal disease. No evidence of increased autoimmune, neurological, or psychiatric disease was noted

    Executive Functioning in Daily Life in Parkinson's Disease: Initiative, Planning and Multi-Task Performance

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    Impairments in executive functioning are frequently observed in Parkinson's disease (PD). However, executive functioning needed in daily life is difficult to measure. Considering this difficulty the Cognitive Effort Test (CET) was recently developed. In this multi-task test the goals are specified but participants are free in their approach. This study applies the CET in PD patients and investigates whether initiative, planning and multi-tasking are associated with aspects of executive functions and psychomotor speed. Thirty-six PD patients with a mild to moderate disease severity and thirty-four healthy participants were included in this study. PD patients planned and demonstrated more sequential task execution, which was associated with a decreased psychomotor speed. Furthermore, patients with a moderate PD planned to execute fewer tasks at the same time than patients with a mild PD. No differences were found between these groups for multi-tasking. In conclusion, PD patients planned and executed the tasks of the CET sequentially rather than in parallel presumably reflecting a compensation strategy for a decreased psychomotor speed. Furthermore, patients with moderate PD appeared to take their impairments into consideration when planning how to engage the tasks of the test. This compensation could not be detected in patients with mild PD

    Decision making as a predictor of first ecstasy use: a prospective study

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    Ecstasy (+/- 3,4-methylenedioxymethamphetamine) is a widely used recreational drug that may damage the serotonin system and may entail neuropsychological dysfunctions. Few studies investigated predictors for ecstasy use. Self-reported impulsivity does not predict the initiation of ecstasy use; the question is if neuropsychological indicators of impulsivity can predict first ecstasy use. This study tested the hypothesis that a neuropsychological indicator of impulsivity predicts initiation of ecstasy use. Decision-making strategy and decision-making reaction times were examined with the Iowa Gambling Task in 149 ecstasy-naive subjects. The performance of 59 subjects who initiated ecstasy use during a mean follow-up period of 18 months (range, 11-26) was compared with the performance of 90 subjects that remained ecstasy-naive. Significant differences in decision-making strategy between female future ecstasy users and female persistent ecstasy-naive subjects were found. In addition, the gap between decision-making reaction time after advantageous choices and reaction time after disadvantageous choices was smaller in future ecstasy users than in persistent ecstasy-naives. Decision-making strategy on a gambling task was predictive for future use of ecstasy in female subjects. Differences in decision-making time between future ecstasy users and persistent ecstasy-naives may point to lower punishment sensitivity or higher impulsivity in future ecstasy users. Because differences were small, the clinical relevance is questionabl

    The use of Bayesian latent class cluster models to classify patterns of cognitive performance in healthy ageing

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    The main focus of this study is to illustrate the applicability of latent class analysis in the assessment of cognitive performance profiles during ageing. Principal component analysis (PCA) was used to detect main cognitive dimensions (based on the neurocognitive test variables) and Bayesian latent class analysis (LCA) models (without constraints) were used to explore patterns of cognitive performance among community-dwelling older individuals. Gender, age and number of school years were explored as variables. Three cognitive dimensions were identified: general cognition (MMSE), memory (MEM) and executive (EXEC) function. Based on these, three latent classes of cognitive performance profiles (LC1 to LC3) were identified among the older adults. These classes corresponded to stronger to weaker performance patterns (LC1>LC2>LC3) across all dimensions; each latent class denoted the same hierarchy in the proportion of males, age and number of school years. Bayesian LCA provided a powerful tool to explore cognitive typologies among healthy cognitive agers.The study is integrated in the "Maintaining health in old age through homeostasis (SWITCHBOX)" collaborative project funded by the European Commission FP7 initiative (grant HEALTH-F2-2010-259772). NS and JAP are main team members of the European consortium SWITCHBOX (http://www.switchbox-online.eu/). NCS is supported by a SwitchBox post-doctoral fellowship. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

    Case-finding of dementia in general practice and effects of subsequent collaborative care; design of a cluster RCT

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    <p>Abstract</p> <p>Background</p> <p>In the primary care setting, dementia is often diagnosed relatively late in the disease process. Case finding and proactive collaborative care may have beneficial effects on both patient and informal caregiver by clarifying the cause of cognitive decline and changed behaviour and by enabling support, care planning and access to services.</p> <p>We aim to improve the recognition and diagnosis of individuals with dementia in general practice. In addition to this diagnostic aim, the effects of case finding and subsequent care on the mental health of individuals with dementia and the mental health of their informal carers are explored.</p> <p>Methods and design</p> <p>Design: cluster randomised controlled trial with process evaluation.</p> <p>Participants: 162 individuals ≥ 65 years, in 15 primary care practices, in whom GPs suspect cognitive impairment, but without a dementia diagnosis.</p> <p>Intervention; case finding and collaborative care: 2 trained practice nurses (PNs) invite all patients with suspected cognitive impairment for a brief functional and cognitive screening. If the cognitive tests are supportive of cognitive impairment, individuals are referred to their GP for further evaluation. If dementia is diagnosed, a comprehensive geriatric assessment takes place to identify other relevant geriatric problems that need to be addressed. Furthermore, the team of GP and PN provide information and support.</p> <p>Control: GPs provide care and diagnosis as usual.</p> <p>Main study parameters: after 12 months both groups are compared on: 1) incident dementia (and MCI) diagnoses and 2) patient and caregiver quality of life (QoL-AD; EQ5D) and mental health (MH5; GHQ 12) and caregiver competence to care (SSCQ). The process evaluation concerns facilitating and impeding factors to the implementation of this intervention. These factors are assessed on the care provider level, the care recipient level and on the organisational level.</p> <p>Discussion</p> <p>This study will provide insight into the diagnostic yield and the clinical effects of case finding and collaborative care for individuals with suspected cognitive impairment, compared to usual care. A process evaluation will give insight into the feasibility of this intervention.</p> <p>The first results are expected in the course of 2013.</p> <p>Trial registration</p> <p>NTR3389</p

    Exploratory 7-Tesla magnetic resonance spectroscopy in Huntington’s disease provides in vivo evidence for impaired energy metabolism

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    Huntington’s disease (HD) is a neurodegenerative genetic disorder that affects the brain. Atrophy of deep grey matter structures has been reported and it is likely that underlying pathologic processes occur before, or in concurrence with, volumetric changes. Measurement of metabolite concentrations in these brain structures has the potential to provide insight into pathological processes. We aim to gain understanding of metabolite changes with respect to the disease stage and pathophysiological changes. We studied five brain regions using magnetic resonance spectroscopy (MRS) using a 7-Tesla MRI scanner. Localized proton spectra were acquired to obtain six metabolite concentrations. MRS was performed in the caudate nucleus, putamen, thalamus, hypothalamus, and frontal lobe in 44 control subjects, premanifest gene carriers and manifest HD. In the caudate nucleus, HD patients display lower NAA (p = 0.009) and lower creatine concentration (p = 0.001) as compared to controls. In the putamen, manifest HD patients show lower NAA (p = 0.024), lower creatine concentration (p = 0.027), and lower glutamate (p = 0.013). Although absolute values of NAA, creatine, and glutamate were lower, no significant differences to controls were found in the premanifest gene carriers. The lower concentrations of NAA and creatine in the caudate nucleus and putamen of early manifest HD suggest deficits in neuronal integrity and energy metabolism. The changes in glutamate could support the excitotoxicity theory. These findings not only give insight into neuropathological changes in HD but also indicate that MRS can possibly be applied in future clinical trails to evaluate medication targeted at specific metabolic processes

    Brief cognitive assessment in a UK population sample – distributional properties and the relationship between the MMSE and an extended mental state examination

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    BACKGROUND: Despite the MMSE's known flaws, it is still used extensively as both a screening instrument for dementia and a population measure of cognitive ability. The aim of this paper is to provide data on the distribution of MMSE scores in a representative sample from the UK population and to compare it with an extended cognitive assessment (EMSE) which covers a wider range of cognitive domains and provides a wider range of difficulty levels. METHODS: The MMSE and the EMSE were administered to over 12,000 participants at the screening stage of the MRC Cognitive Function and Ageing Study (MRC CFAS). MRC CFAS is a multi-centre population-based study in England and Wales with respondents aged 65 years and older. RESULTS: Normative values on the MMSE and EMSE are presented by age group, sex and level of education. There are very large differences between age groups, with smaller differences seen between the sexes and by level of education. The EMSE extends the scores at the high end of the ability range, but is no better than the MMSE at differentiating between dementia and non-dementia. CONCLUSION: Population-derived norms are valuable for comparing an individual's score to the score that would be expected among the general population, given the individual's specific demographic characteristics
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