三种抗运动病药物对前庭-听觉认知和自主神经反应活动影响分析

目的 空间运动病是载人航天飞行不可规避的医学问题之一,目前服用抗运动病药物是较为有效的预防方法.但大多数抗运动病药物均对认知功能有一定影响,且其影响在前庭刺激下会有所改变.为良好地指导航天医学实践,本试验比较了口服3种抗运动病药物(盐酸地芬尼多、茶苯海明、盐酸异丙嗪)对前庭刺激下听觉认知和自主神经反应活动的影响. 方法 采用拉丁方试验设计、严格双盲给药,对8名受试者进行了定最前庭刺激,前庭刺激的同时要求受试者完成听觉认知任务.记录受试者完成认知任务的脑电信号,采用事件相关电位技术提取完成认知任务的P3成分.对口服安慰剂和不同抗运动病药物下P3成分潜伏期和峰值波幅进行了比较. 结果 抑制前庭自主神经反应的顺序为盐酸异丙嗪、茶苯海明、盐酸地芬尼多、安慰剂;对前庭刺激下脑认知过程的影响从强到弱为盐酸异丙嗪、茶苯海明、安慰剂、盐酸地芬尼多. 结论 在同样前庭刺激下盐酸地芬尼多对自主神经系统反应有调节作用,对前庭刺激下脑认知过程影响较弱,是温和作用药物,也是在非严重运动病爆发下的首选药物.     

前庭性错觉对认知能力的影响及其评估技术研究进展

前庭性错觉在飞行员飞行过程中的发生频率极高,发生前庭性错觉会对飞行人员认知能力造成严重危害,并进一步威胁飞行安全,故研究前庭性错觉对认知能力的影响具有重要意义。既往研究中,关于前庭性错觉对认知能力直接影响的研究较少,笔者介绍了与之密切相关的两类研究——空间定向障碍及前庭功能分别对认知能力的影响,影响主要存在于视觉空间、记忆、注意与执行4个领域,笔者据此分析了前庭性错觉发生时可能影响的认知能力,并重点分析了影响较大的大尺度空间、视觉工作记忆、注意、执行能力及对应的评估技术,以期为后续研究方向及评估技术选用提供参考。     

随意头旋转时动态视敏度试验中视觉前庭的相互作用

前言 纵然为了维持空间定向作用必需有完整的前庭功能,但航空界还没有好的可用的前庭功能筛选试验。高频随意头旋转被选来作为一种前庭刺激,而将视觉影响从前庭眼球反射(VOR)中分离出。对随意头旋转时的动态视敏度试验,进行了评定,以考虑将这个试验用作前庭功能普查的可行性。方法 24名正常的受试者,在三种不同的视觉条件下(强化视觉的前庭眼球反射,前庭眼球反射,抑制视觉的前庭眼球反射),从     

秋千摆动和倒视刺激对动态姿态平衡的影响

目的 观察秋千摆动和倒视刺激对动态姿态平衡的影响,探讨视觉、本体觉和前庭觉在姿态平衡中的贡献。方法 １６名受试者进行秋千摆动测试,秋千测试前后进行动态姿态平衡测试（感觉整合测试,３６种测试状态）;另外１０名受被者进行上下倒视刺激,倒视刺激前后进行动态姿态平衡测试。结果 秋千摆动刺激后运动病症状明显,综合平衡分降低有显著性意义,测试状态４对应的平衡分、策略分和视觉贡献降低有显著性意义。倒视刺激后运动     

采用眼球反转检测耳石功能

航天初期发生的空间运动病与人的前庭功能有关，航天生产的微重力主要影响耳石感受器。绎耳石功能的检测有重要意义。在耳石功能检测的多种方法中，眼球反转检测是较为单纯反映耳石功能的一项生理指标，它提供了一种可以较为有效地预测空间运动病易感性的手段，且在空间运动病机理研究以及航天飞行后前庭功能的重适应研究上有很好的应用前景，同时对临床上前庭功能障碍的诊断可提供重要参考。     

不同运动形式光点对前庭知觉和前庭眼动反射的影响

笔者以32名健康飞行员为对象,在角加减速度为±6°/s~2、角速度为90°/s梯形运行方式前庭刺激下,实验观察了随人体同步移动光点和相对移动光点对人体前庭知觉和前庭眼动反射的影响。结果表明,同步移动光点起着视觉固视作用,使前庭眼动反射受抑制,但对前庭知觉影响不明显;相对移动光点诱发出视眼动反射,在视前庭功能相互作用中呈优势反应。     

载人航天中微重力环境对认知功能的影响

目前在载人航天的研究中，对于在微重力条件下认知功能变化的研究还较少。本文综述了近年来这方面的一些进展。研究表明，在微重力条件下，空间定向、运动知觉出现障碍，早期物体识别受影响的程度也较大，肌肉运动和协调功能有所减弱。微重力条件对高级认知功能，如逻辑推理、短时记忆提取的速度和准确性等的影响较小，但是一些需要注意参与的认知任务(如跟踪任务、视觉选择反应)和长时记忆任务，在航天环境或模拟失重条件下会受到影响。     

抛物线飞行与航天运动病

抛物线飞行与航天运动病王林杰童伯伦航天初期航天员发生运动病比例较大，航天运动病症状的程度、表现形式因人而异，会给航天员的工作和健康造成一定程度的影响。种种假说都认为，其发生与对前庭的刺激有关，因此研究失重对前庭功能的影响、对航天运动病易感性的预测、防...     

急性缺氧对经不同感觉通道引发的脑事件相关电位和反应时的影响

目的研究经不同感觉通道输入信息时脑认知能力的差异，观察急性缺氧时经不同感觉通道输入信息时脑认知能力的改变。方法１０名受试者在地面和４３００ｍ模拟高度（吸入低氧混合气）分别进行视觉、听觉和视－听（视觉和听觉刺激同时呈现）Ｏｄｄｂａｌ任务测试，记录脑电图（ＥＥＧ）和反应时（ＲＴ），ＥＥＧ经叠加平均处理提取出脑事件相关电位（ＥＲＰ），并测量其Ｐ３波的潜时和波幅。以Ｐ３潜时和ＲＴ为主要指标评定脑认知能力。采用两因素析因设计及统计学处理。结果不同感觉通道间比较，视觉通道的Ｐ３潜时和ＲＴ均长于听觉和视－听通道，ＲＴ以视－听通道最快。急性缺氧对视觉通道和听觉通道均可明显减慢其Ｐ３潜时和ＲＴ。结论对听觉刺激的脑认知反应速度较视觉为快，而用视听联合刺激可加快反应速度。缺氧会减慢脑信息加工过程，听觉刺激的认知反应和视觉一样对缺氧敏感。     

某些体训项目对人体前庭功能的影响

目的：探讨采用某些体训项目进行的主动前庭功能训练对人体前庭功能的影响。方法：１０名健康被试人员进行了为期２ｗｋ的滚轮、悬梯、浪木、四柱秋千以及旋转秋千５种主动训练,训练前后进行前庭功能实验室检测。结果：体训后,被试人员对线性加速度刺激的耐受时间明显延长,训练前后动态姿态平衡检测反映体训后被试人员在用前庭觉和视觉共同维持身体平衡时,重心的晃动显著降低。结论：本实验所设计的直线加刺激体训方法取得了一定效果,角加速度训练的方法和刺激强度有待进一步研究。     

Visual acuty after trabeculectomy

BACKGROUND/AIM: In this study we compared the two groups of glaucoma patients who had underwent trabeculectomy, with or without intraoperative application of antimetabolite 5-Fluorouracile (5 FU). METHODS: We followed up 50 glaucoma patients (group I) in a four-years period after trabeculectomy alone (antimetabolites were not applied), and 50 patients in whom antimetabolite 5 FU was applied (group II). We followed up intraocular pressure (IOP), visual acuity (VA), lens transparency, optic disc changes, visual fields (VF perimetry).The IOP at the time of the surgery, and the period of the treatment before the surgery were the important data for the follow-up. RESULTS: The results that we got in the first group were: in 8 patients (16%) there was no change of VA, and of optic disc with a mild VF deterioration; in 18 patients (33%) the worsening of VA by 1 Snellen line (3 years after the surgery) with no change of the disc and a mild VF progressing; in 10 patients (20%) VA decreased by 2 Snellen lines with the progressive VF changes and cataract appearance, (cataract and VA worsening appeared mainly 3 years after the surgery); in 6 patients (12%) by 3 Snellen lines, and in 4 patients (8%) by 4 Snellen lines. In 4 patients (8%), the highest worsening of VA--(0.2) and the best (0.9) at the time of the surgery were observed. The VA ranging from 0.4-0.6 at the time of the surgery yielded the longest preservation of vision. In the group II (5 FU applied intra-operatively): in 5 patients (10%) there was no change of VA and of optic disc with a mild VF deterioration; in 20 patients (40%) the worsening of VA by 1 Snellen line, with no change of the disc and a mild VF progressing. In 14 patients (28%) VA decreased by 2 Snellen lines with the progressive VF changes and cataract appearance; in 7 patients (14%) by 3 Snellen lines, and in 4 patints (8%) by 4 Snellen lines. CONCLUSION: All of the checked parameters were better in the group II of the patients, (5 FU applied intraoperatively). Also, in the group of the patients with the longest treatment before the surgery and with the good VA, and in the patients with the shorter treatment and with the bad VA, the quickest progression of the vision losts was observed. The best preservation of VA was recordered in the patients with a mild IOP, and in those who had not been treated more than 1 or 2 years with the drops before the surgery. The VA ranging from 0.4-0.6 at the time of the surgery allowed the longest preservation of vision.     

Altered Processing of Complex Visual Stimuli in Patients with Postconcussive Visual Motion Sensitivity

BACKGROUND AND PURPOSE:Vestibular symptoms are common after concussion. Vestibular Ocular Motor Screening identifies vestibular impairment, including postconcussive visual motion sensitivity, though the underlying functional brain alterations are not defined. We hypothesized that alterations in multisensory processing are responsible for postconcussive visual motion sensitivity, are detectable on fMRI, and correlate with symptom severity.MATERIALS AND METHODS:Twelve patients with subacute postconcussive visual motion sensitivity and 10 healthy control subjects underwent vestibular testing and a novel fMRI visual-vestibular paradigm including 30-second “neutral” or “provocative” videos. The presence of symptoms/intensity was rated immediately after each video. fMRI group-level analysis was performed for a “provocative-neutral” condition. Z-statistic images were nonparametrically thresholded using clusters determined by Z > 2.3 and a corrected cluster significance threshold of P = .05. Symptoms assessed on Vestibular Ocular Motor Screening were correlated with fMRI mean parameter estimates using Pearson correlation coefficients.RESULTS:Subjects with postconcussive visual motion sensitivity had significantly more Vestibular Ocular Motor Screening abnormalities and increased symptoms while viewing provocative videos. While robust mean activation in the primary and secondary visual areas, the parietal lobe, parietoinsular vestibular cortex, and cingulate gyrus was seen in both groups, selective increased activation was seen in subjects with postconcussive visual motion sensitivity in the primary vestibular/adjacent cortex and inferior frontal gyrus, which are putative multisensory visual-vestibular processing centers. Moderate-to-strong correlations were found between Vestibular Ocular Motor Screening scores and fMRI activation in the left frontal eye field, left middle temporal visual area, and right posterior hippocampus.CONCLUSIONS:Increased fMRI brain activation in visual-vestibular multisensory processing regions is selectively seen in patients with postconcussive visual motion sensitivity and is correlated with Vestibular Ocular Motor Screening symptom severity, suggesting that increased visual input weighting into the vestibular network may underlie postconcussive visual motion sensitivity.

Up to 3.8 million concussions occur annually in the United States, with estimated direct and indirect costs totaling more than $12 billion.^1,2 Vestibular symptoms occur in up to 80% of patients in the first few days following injury.^3-5 Persistent dizziness has been reported to occur in up to one-third of postconcussive patients reporting acute vestibular symptoms, and a positive Vestibular Ocular Motor Screening (VOMS) outcome is associated with protracted recovery.^3,6,7 The link between visual and vestibular motion-processing is critical for spatial orientation and balance control, and oculomotor dysfunction, balance, and vestibular networks share multisensory integration pathways implicated as the primary deficits in postconcussive dizziness and imbalance.^8-11Similar to patients with other vestibular disorders, patients with postconcussive vestibular impairment may compensate through an increased reliance on other somatosensory input, leading to the re-weighting of sensory data including visual and vestibular cues.^5,12-14 We hypothesized that while these changes may be beneficial in the acute phase, persistent overreliance on a specific sensory system may become pathologic and maladaptive during recovery. This may lead to persistent and debilitating dizziness syndromes such as “visual motion sensitivity,” which are characterized by inappropriate responses including disorientation, dizziness, imbalance, and headaches triggered by visual environmental motion.^5,12The alterations in multisensory processing that likely underlie visual motion sensitivity are currently largely theoretic and represent an important knowledge gap in our understanding of these symptoms.¹⁵ We hypothesized that alterations in multisensory processing involving the primary vestibular cortex and associated input are responsible for postconcussive visual motion sensitivity (PCVMS). The purpose of this study was to define functional brain activation in patients with PCVMS compared with control subjects and to correlate these changes with clinical symptom severity. To this end, we have developed a novel visual-vestibular task-based fMRI paradigm, which is presented here for the first time.     

舱外航天服视野设计中的虚拟视域仿真建模

目的探讨一种用于舱外航天服视野设计和分析的虚拟视域仿真建模方法。方法利用Solidworks软件建立三维人体模型,在对软件进行二次开发的基础上,充分利用软件提供的聚光源特性,建立了模拟人眼视锥及人眼运动的仿真算法,从而在Solidworks软件中实现人穿着舱外服后的虚拟视域仿真分析。结果将所建立的模型用于舱外服视野分析,其结果与人-服试验过程视野工效测试结果相一致。结论该模型可应用于舱外航天服设计过程中,对于其它具有工效要求的产品设计具有参考意义。     

连续视觉显示终端作业过程中视疲劳指标变化规律的研究

在阴极射线管（ＣＲＴ）显著器屏幕上按四种方式（固定，滚动，变动，混合）显示排列成一行的２５个白色阿拉伯数字，每行由０～９十个数字中的９个组成，要求被试者找出所缺的１个数字，８位被试参加４次实验，每次只接受一种方式的作业，连续３ｈ。对实验前和连续工作３０、６０、８０、１００、１２０、１５０和１８０ｍｉｎ以及休息５、１０和１５ｍｉｎ时的纵向动态视力进行测试。结果表明，在四种显示方式中，随着工作时间和延