疲劳引起的轻度认知功能障碍的诊疗研究进展

疲劳引起的包括易受到无关信息的干扰、工作错误率增加,任务检测能力和策略性行为调整的能力下降等表现,属轻度认知功能障碍(MCI)范畴。本文对疲劳引起的轻度认知功能障碍的中西医研究进展进行整理。从其涉及的神经生理学机制、中医对其病因病机的认识、中西医特色治疗方面进行了总结,并结合高新技术发展趋势对其生理学机制研究及诊疗的发展进行展望,为今后的研究提供新思路。     

肿瘤专业护士疲劳综合征浅析

近年来,国内护士身心健康问题日益受到关注。护士易患疲劳综合征。疲劳综合征是一个发展的过程,它与长期过重的工作压力有关,这种压力导致心理紧张,产生躯体、情绪和心理的症状及体征,最终出现逃避工作的行为。     

长航人员心理疲劳与GABA机制相关性探讨

心理疲劳指由于长期从事某项工作而出现的心理耗竭感,以及对任务的不能胜任感,并伴有情绪,认知,学习记忆力等方面的功能减退。长航人员作为一种特殊群体,其面对和承担的问题和压力都更加严峻,其心理疲劳的发病更具针对性,严重影响了我国海军整体实力。本文对长航人员心理疲劳从概念,表现等方面深入讨论,并进一步分析心理疲劳发病机制与GABA的相关性。心理疲劳的发生可能和中枢神经系统内抑制作用密切相关,而GABA作为脑内的经典抑制性神经递质在整个反应过程中起到关键和标志性作用。然而该结论还有待进一步分子生物学实验研究的证明。     

中枢疲劳研究与思考

中枢疲劳既可以作为独立疾病影响人们的日常工作和学习,又可以作为症状出现于多种慢性疾病,其定义和机制国内外说法不尽相同。中枢疲劳是由于中枢神经系统发生退行性或其他不良变化,从而导致躯体、神经、包括心理一系列的疲劳样反应。其机制涉及到中枢神经系统和外周传导系统等多个维度、多个节点的变化,充分把握中枢疲劳的概念本质及潜在生物学机制对其临床防治有着重要理论和实践意义。此外,动物模型作为基础研究的前提和必要工具是中枢疲劳研究过程中又一重要问题。本文在文献整理的基础上,先从定义的角度出发由疲劳引申到中枢疲劳,将现阶段对中枢疲劳的不同概念阐述做一分析,并从机制和动物模型两个方面展开对国外研究进展进行综述。     

基于质谱技术的神经肽研究进展

神经肽是一类重要的内源活性物质,在神经系统中发挥重要的作用,并连接大脑和其他神经器官。基于质谱技术的神经肽组学研究旨在对神经肽进行大规模研究,在分子水平上得到重要信息,进一步加深对神经系统调控机制以及神经疾病致病机理的理解。文中综述了利用质谱技术进行神经肽研究的基本策略,包括样品处理、定性定量方法以及质谱成像等研究进展。     

多巴胺神经系统显像分子探针研究

多巴胺神经系统在神经退行性疾病和精神紊乱中充当了主要角色,比如帕金森病、亨廷顿病、迟发性运动障碍、精神分裂症。以多巴胺能神经系统为靶点的PET显像可以了解多巴胺合成、受体密度和状态改变,为神经系统疾病的早期诊断、疗效监测、发病机制以及脑认知功能的研究等方面提供客观、科学的观察手段。本文综述了以多巴胺受体、多巴胺转运体及囊泡单胺转运体为靶点的PET显像剂的研究进展。     

肠道菌群与神经系统疾病

人类肠道菌群是数以万亿的细菌组成的高度多样化的生态系统,菌群失调与多个系统疾病有关联。肠道菌群通过菌群-肠-脑轴与神经系统多途径双向互作,能引起神经免疫炎症反应、肠黏膜和血脑屏障功能改变、直接刺激迷走神经和肠道神经系统脊神经、神经内分泌-下丘脑-垂体-肾上腺轴,造成神经系统疾病。肠道菌群的代谢产物也有一定的作用。文中综述自闭症谱系障碍、多发性硬化、帕金森病、癫痫、吉兰巴雷综合征、阿尔茨海默病、视神经脊髓炎、肝性脑病、肌萎缩侧索硬化、精神分裂症、抑郁症、慢性疲劳综合征、亨廷顿病、脑卒中等肠道菌群改变特征及其干预措施的研究进展。目前肠道菌群的研究还处在初级阶段,因果关系和机制方面的研究比较少,这对精准实施菌群临床干预措施具有重要意义,期待将来有所突破成为一些神经系统疾病治疗的新路径。     

精神疲劳评价方法研究进展

长时间飞行活动所致的精神疲劳一直是航空航天医学中一个重要的课题。尤其随着我军航空技术的发展,精神疲劳已经成为影响飞行安全的重要原因之一。研究发现,精神疲劳发生时,机体的生理、心理、生化和工作绩效等功能会发生变化。例如,精神疲劳时,脑电图的theta波、delta波和alpha波发生变化、瞳孔直径增大、心率变异性的低频谱功率升高和高频谱功率降低、姿势控制能力下降、反应时延长、临界融合频率降低、血浆中氨基酸等功能性分子水平改变和认知能力的下降等。精神疲劳的客观评定方法就是研究者借助于某些设备来监测到这些变化,并根据这些变化对疲劳状态进行判断。本文将从生理、心理、生化和作业绩效等方面阐述了精神疲劳客观的评定方法,并指出了这些方法的优缺点。最后,本文对精神疲劳评价方法发展趋势做出了初步的判断,即我们应对精神疲劳进行综合量化评定,这样才能更全面准确地评估精神疲劳。     

朊粒蛋白正常生理功能研究进展

作为多种神经退行性疾病致病源的朊粒蛋白（PrP^c）是机体内一种正常表达蛋白,其生理功能在神经系统、铜代谢、抗氧化机制、细胞信号转导、细胞凋亡,以及核酸代谢等诸多方面都得到不同形式的表现,本文分类介绍其各种相关功能的研究进展以及研究的思路与方法。     

光学神经成像研究进展

大脑功能的成像检测在认知神经科学领域具有极其重要的意义。现代光子学技术的发展为认知脑成像提供了新的研究手段,在神经系统信息处理机制研究中发挥重要作用。文章介绍了在神经元、神经元网络、特定脑皮层功能构筑以及系统与行为等不同层次开展神经系统信息处理机制研究的各种光学成像技术,包括多光子激发荧光显微成像、内源信号光学成像、激光散斑成像和近红外光学成像等,并评述了这些有特色的光学成像技术在多层次获取和分析神经信息中的研究进展。     

Mental Fatigue Affects Visual Selective Attention

Mental fatigue is a form of fatigue, induced by continuous task performance. Mentally fatigued people often report having a hard time keeping their attention focussed and being easily distracted. In this study, we examined the relation between mental fatigue, as induced by time on task, and attention-related changes in event-related potentials (ERPs). EEG, reaction times and response accuracies were obtained from 17 healthy volunteers during two hours of task performance on an adapted Eriksen flanker task. In this task, the size of targets and flankers was manipulated to discern neuronal processes that are related to processing of relevant information from processes related to the processing of irrelevant information. The ERP data showed that effects induced by target size manipulation were not affected by time on task, while an initial effect of flanker size manipulation decreased gradually with increasing time on task. We conclude that attention was affected by mental fatigue, in the form of a decrease in the ability to suppress irrelevant information. In behavioural results, this was reflected by a tendency of participants to increasingly base their response decision on irrelevant information, resulting in decreased response accuracies.     

Indices of mental working ability in school students learning some subjects by advanced educational programs

The study enrolled 390 schoolchildren attending classes of general, humanitarian, and mathematical education profiles. Mental working ability, memory, and speed and level of cognitive processes were examined. Lower indices were revealed in pupils attending mathematical classes which may be a manifestation of greater fatigue characteristic of this group of pupils. The education in classes of humanitarian profile was associated with significantly higher volume of the operative memory. This finding suggests that the advanced learning of humanities promotes the development of memory. Higher speed of cognitive processes and accuracy of solution of mental tasks were shown to be characteristic of the pupils of mathematical classes.     

Aggregated mental models predict observed outcomes following Eurasian Beaver (Castor fiber) reintroduction

Outcome prediction is important for conservation; however, analysis may be hampered by specialist resource deficiencies. Mental modelling techniques offer a potential solution, drawing on accessible sources of knowledge held informally by local stakeholders. Mental models show linked social and ecological variables from the perspectives of community members, whose insights may otherwise be neglected. Currently, an important weakness in conservation mental modelling is inadequate attention paid to real-time model predictive validity. To address this knowledge gap, baseline mental model predictions concerning Beaver (Castor fiber) reintroduction in Southwest England were followed up at three years. Participants were invited to submit outcome observations for concept variables identified in their original models, blind to inferences based on model dynamic analysis, so that the two sets of data could be compared. Individual concept values and models were found to show weak and highly inconsistent predictive validity, however, multi-stakeholder aggregated mental models showed consistently strong predictive performance. This finding was enhanced by setting tighter thresholds for inclusion of individual model items in aggregation procedures. Threshold effects can be interpreted as a reflection of greater agreement: tighter thresholds retain more highly shared model components. It is proposed that enhanced real-time predictive validity for aggregated models is explained by a ‘wisdom of the crowd’ statistical effect, analogous to well-recognised crowd judgement effects observed in relation to much simpler questions. The findings show the scope for stakeholder mental modelling methods as an investigative tool, to supplement more conventional ecosystem assessments in predicting data-poor conservation outcomes.     

Trial history effects in stroop task performance are independent of top-down control

In this study we sought to elucidate what mechanisms underlie the effects of trial history on information processing. We explicitly focused on the contribution of conflict control and S-R binding to sequential trial effects. Performance and brain activity were measured during two hours of continuous Stroop task performance. Mental fatigue, known to influence top-down processing, was used to elucidate separate effects via top-down and bottom-up mechanisms. Here we confirm that performance in the Stroop task is indeed strongly modulated by stimulus history. Performance was affected by the kind of advance information available; dependent on this information adjustments were made, resulting in differential effects of cognitive conflict, and S-R binding on subsequent performance. The influence of mental fatigue on information processing was mainly related to general effects on attention.     

A conceptual framework for the revision of the ICD-10 classification of mental and behavioural disorders

The World Health Organization (WHO) is revising the ICD-10 classification of mental and behavioural disorders, under the leadership of the Department of Mental Health and Substance Abuse and within the framework of the overall revision framework as directed by the World Health Assembly. This article describes WHO’s perspective and priorities for mental and behavioural disorders classification in ICD-11, based on the recommendations of the International Advisory Group for the Revision of ICD-10 Mental and Behavioural Disorders. The WHO considers that the classification should be developed in consultation with stakeholders, which include WHO member countries, multidisciplinary health professionals, and users of mental health services and their families. Attention to the cultural framework must be a key element in defining future classification concepts. Uses of the ICD that must be considered include clinical applications, research, teaching and training, health statistics, and public health. The Advisory Group has determined that the current revision represents a particular opportunity to improve the classification’s clinical utility, particularly in global primary care settings where there is the greatest opportunity to identify people who need mental health treatment. Based on WHO’s mission and constitution, the usefulness of the classification in helping WHO member countries, particularly low- and middle-income countries, to reduce the disease burden associated with mental disorders is among the highest priorities for the revision. This article describes the foundation provided by the recommendations of the Advisory Group for the current phase of work.     

Amino acids and central fatigue

Summary. There is an increasing interest in the mechanisms behind central fatigue, particularly in relation to changes in brain monoamine metabolism and the influence of specific amino acids on fatigue. Several studies in experimental animals have shown that physical exercise increases the synthesis and metabolism of brain 5-hydroxytryptamine (5-HT). Support for the involvement of 5-HT in fatigue can be found in studies where the brain concentration of 5-HT has been altered by means of pharmacological agents. When the 5-HT level was elevated in this way the performance was impaired in both rats and human subjects, and in accordance with this a decrease in the 5-HT level caused an improvement in running performance in rats. The precursor of 5-HT is the amino acid tryptophan and the synthesis of 5-HT in the brain is thought to be regulated by the blood supply of free tryptophan in relation to other large neutral amino acids (including the branched-chain amino acids, BCAA) since these compete with tryptophan for transport into the brain. Studies in human subjects have shown that the plasma ratio of free tryptophan/BCAA increases during and, particularly, after sustained exercise. This would favour the transport of tryptophan into the brain and also the synthesis and release of 5-HT which may lead to central fatigue. Attempts have been made to influence the 5-HT level by giving BCAA to human subjects during different types of sustained heavy exercise. The results indicate that ingestion of BCAA reduces the perceived exertion and mental fatigue during exercise and improves cognitive performance after the exercise. In addition, in some situations ingestion of BCAA might also improve physical performance; during exercise in the heat or in a competitive race when the central component of fatigue is assumed to be more pronounced than in a laboratory experiment. However, more experiments are needed to further clarify the effect of BCAA and also of tryptophan ingestion on physical performance and mental fatigue. Received January 3, 2000 / Accepted February 1, 2000     

Can Cognitive Activities during Breaks in Repetitive Manual Work Accelerate Recovery from Fatigue? A Controlled Experiment

Neurophysiologic theory and some empirical evidence suggest that fatigue caused by physical work may be more effectively recovered during “diverting” periods of cognitive activity than during passive rest; a phenomenon of great interest in working life. We investigated the extent to which development and recovery of fatigue during repeated bouts of an occupationally relevant reaching task was influenced by the difficulty of a cognitive activity between these bouts. Eighteen male volunteers performed three experimental sessions, consisting of six 7-min bouts of reaching alternating with 3 minutes of a memory test differing in difficulty between sessions. Throughout each session, recordings were made of upper trapezius muscle activity using electromyography (EMG), heart rate and heart rate variability (HRV) using electrocardiography, arterial blood pressure, and perceived fatigue (Borg CR10 scale and SOFI). A test battery before, immediately after and 1 hour after the work period included measurements of maximal shoulder elevation strength (MVC), pressure pain threshold (PPT) over the trapezius muscles, and a submaximal isometric contraction. As expected, perceived fatigue and EMG amplitude increased during the physical work bouts. Recovery did occur between the bouts, but fatigue accumulated throughout the work period. Neither EMG changes nor recovery of perceived fatigue during breaks were influenced by cognitive task difficulty, while heart rate and HRV recovered the most during breaks with the most difficult task. Recovery of perceived fatigue after the 1 hour work period was also most pronounced for the most difficult cognitive condition, while MVC and PPT showed ambiguous patterns, and EMG recovered similarly after all three cognitive protocols. Thus, we could confirm that cognitive tasks between bouts of fatiguing physical work can, indeed, accelerate recovery of some factors associated with fatigue, even if benefits may be moderate and some responses may be equivocal. Our results encourage further research into combinations of physical and mental tasks in an occupational context.     

Detecting mental disorders in primary care

Managing mental health problems of people around the world is a major challenge for health workers as well as for policy makers. It is a particular problem for low- and middle-income countries for many reasons, especially due to lack of recourses.A computer-assisted interview, the GMHAT/PC (Global Mental Health Assessment Tool - Primary Care) has been developed to assist general practitioners and other health professionals to make a quick, convenient, and comprehensive, standardised mental health assessment. It has proved to be a reliable and valid tool in various studies. Its use by other health professionals may help in detecting and managing mental disorders in primary care and general health settings more effectively. The article outlines the development and potential use of the GMHAT/PC.