脑卒中患者偏侧忽略线分法试验中线段位置对结果的影响

目的研究线分法试验中线段位置对不同程度偏侧忽略脑卒中患者线分结果的影响，探讨线段位置对线分结果影响的机制。方法根据凯瑟林一波哥量表（CatherineBergegoScale，CBS）检出26例首发脑卒中致左侧偏侧忽略的患者，分为轻度忽略组（15例）和重度忽略组（11例），20例年龄匹配的健康成人作为对照组。进行线分法检查时，让患者中分在Ag纸的左侧、中央和右侧的长度为10cm的水平线段。然后在另外一张同样的Ag纸上，先让患者标出他所看到的线段两端，然后再在标出的线段中央划一条垂直分隔线。计算分隔线右侧长度占所分隔线段长度的百分比。结果轻度忽略组与对照组在上述线分试验中所有结果的差异均无统计学意义。在标出线段两端前，重度忽略组患者分隔左侧及中央线段时分隔线较实际中点出现明显右移。重度忽略患者标记后的3条线段长度均明显短于对照组和轻度忽略组，缩短的原因是标记左侧端点时标记点明显右移。结论线段位置主要对重度偏侧忽略患者的线分结果有影响，其主要机制是重度偏侧忽略患者所看到的线段均较实际线段短，忽略了所有位置线段的左侧端，这种忽略程度白左向右逐渐减轻。     

线分法试验中反转效应机制的探讨

目的探讨线分法试验中反转效应的可能机制。 方法首先根据偏侧忽略行为量表筛选出存在左侧偏侧忽略的脑卒中患者25例,另外选取20例年龄与之相匹配的正常人纳入对照组。所有入选者均进行以下线分作业：在2张A4纸的左侧、中央及右侧各画3条水平直线,直线的长度分别为100 mm和20 mm,让受检者用右手执笔在每条线段中央划一条垂直短线;然后在另外2张A4纸上同样画3条水平直线,让受检者标出所看到线段的两端点。 结果偏侧忽略(左侧)患者在进行线分法试验时出现了长度反转效应,对线段两端均有忽略,不仅低估了100 mm线段长度,也低估了20 mm线段长度。 结论偏侧忽略患者在进行线分法试验时,进入中心视野的线段不被忽略,即所谓的“中心凹忽略回避”理论,该理论可用于解释线分法试验中的反转效应。     

智能助行康复机器人训练结合偏侧注意提醒对脑卒中后偏侧忽略患者下肢功能的影响

目的:通过智能助行康复机器人训练结合偏侧注意提醒的康复治疗,观察1例右侧半球脑梗死后左侧忽略患者的偏侧忽略恢复和下肢功能改善情况。方法:采用智能助行康复机器人训练为主的综合训练(即下肢康复机器人训练+偏侧注意提醒+常规康复治疗)治疗脑卒中偏侧忽略患者,共治疗3周,每周5次。在治疗前后分别通过删除字母试验、星星删除试验、Albert线段划消试验、高声朗读试验、Schenkenberg二等分线段测验、绘图试验评价患者的视觉空间忽略症状,通过听觉测试及触觉测试评价患者的听觉和触觉忽略症状。通过Fugl-Meyer运动功能量表(FMA)评价患者的下肢运动功能,Berg平衡量表(BBS)评价患者的平衡功能,功能性步行分级(FAC)评价患者的步行功能,Barthel指数评价患者的日常生活活动能力。结果:经过3周的治疗,患者的下肢FMA、BBS评分、FAC评级、Barthel指数较治疗前明显提高。患者的删除字母试验、Albert线段划消试验评定中左侧划消数量仍然少于右侧,但较治疗前明显增多,Schenkenberg二等分线段测验评定中的中点偏移率较前明显降低;高声朗读试验评定中左侧文字朗读数量仍然少于右侧,但较治疗前明显增加,绘图试验评定中左侧图形完整性与右侧相当,较治疗前亦有好转;听觉及触觉测试评定中左侧听觉及触觉的探查能力与右侧相当,较前明显好转。结论:在常规康复治疗的基础上,通过智能助行康复机器人训练结合偏侧注意提醒治疗后,患者的下肢运动功能、平衡功能及步行能力较前明显好转,患者偏侧忽略症状亦得到缓解。     

偏侧空间忽略发生的相关解剖位点研究

目的:探讨右侧半球脑卒中后左侧偏侧空间忽略的临床及相关的大脑解剖位点。方法:本研究收集了120例右侧脑卒中患者,其中60例左侧空间忽略患者(忽略组)及60例右侧半球卒中后无忽略的患者(对照组),进行病例对照研究,分析两组的临床特征,并运用MRIcro软件对两组研究对象的头颅影像结果进行分析,分别将两组患者的颅内病灶进行叠加,继后相减,并进行基于体素的卡方分析,进而探讨哪些脑区的损伤几率在忽略组高于对照组。结果:忽略组与对照组相比,性别构成、年龄、偏盲几率、受教育年数、病程、接受影像检查时间差异无显著性意义(P0.05);忽略组的病灶体积显著大于对照组(P0.05),MMSE得分显著低于对照组(P0.05);两组的头颅病灶分析显示:额下回、中央前回、中央后回、颞上回、颞中回、脑岛及其周围白质、顶下小叶白质的损伤的发生率,忽略组显著高于对照组。结论:右侧脑卒中患者中,发生忽略的患者病灶体积更大,MMSE得分更低。忽略的发生与额下回、中央前回、中央后回、颞上回、颞中回、脑岛及其周围白质及其顶下小叶白质的损伤相关。     

右侧脑损伤后左侧空间忽略的临床分型研究

目的:对右侧脑损伤后左侧空间忽略按表现的参考框架不同进行分型研究,并分析其临床特征。方法:对于首次发生右侧半球脑损伤的患者176例,运用线段划消、星型划消、线段二等分、画钟测验及句子阅读进行忽略的筛查测验,并运用缺口探查和场景临摹测试对忽略患者进行不同参考框架下分型研究,进一步比较不同参考框架下忽略组间的一般状况、临床特征及忽略程度。结果:在176例患者中,29例表现为左侧空间忽略,其中16例为单纯的自我为中心的忽略,13例合并存在自我为中心的忽略及刺激物为中心的忽略。单纯的自我为中心的忽略组与合并存在刺激物为中心的忽略组间的一般状况(年龄、性别构成比、MMSE),忽略程度(线段划消、星形划消、线段二等分、画钟及场景临摹)及临床特征(左侧肢体肌力、面瘫有无、偏盲有无、左侧躯体感觉异常、病理征有无)无显著的差异;合并刺激物为中心的忽略组的患者受教育年数明显高于单纯的自我为中心的忽略组。两组间的病灶分布无显著性差异。结论:按参考框架的不同对左侧空间忽略进行分型,单纯的自我为中心的忽略最常见,但是近一半的自我为中心的忽略合并刺激物为中心的忽略。忽略的严重程度及躯体功能障碍的严重程度对忽略的分型无提示意义。受教育年限越长的右侧半球损伤的患者越容易存在非自我为中心的空间忽略。     

右侧丘脑出血后合并Pusher综合征及偏侧空间忽略1例患者的疗效观察

目的 观察1例右侧丘脑出血后合并Pusher综合征及偏侧空间忽略患者的临床疗效.万法 收集右侧丘脑出血后合并Pusher综合征及偏侧空间忽略患者1例.采用康复治疗技术(如视觉反馈训练、重心转移训练、下肢机器人训练等)纠正患者Pusher综合征,采用常规行为学治疗、作业治疗、阅读训练及传统中医方法对患者偏侧空间忽略进行干预.观察患者治疗前、后临床表现及行为特点.结果 患者经治疗后其运动功能明显提高,各体位下均无明显向患侧倾斜的表现,在他人监视下可独立步行.出院3个月后复诊发现,患者可独立步行,左手精细运动功能较差,Pusher综合征完全纠正,偏侧空间忽略症状也得到明显缓解.结论 右侧丘脑出血可发生Pusher综合征及偏侧空间忽略,早期康复治疗可纠正Pusher综合征,缓解偏侧空间忽略症状,促进患者运动功能恢复.     

急性脑梗死患者吞咽相关中枢功能重组及其偏侧性分析

目的 利用血氧水平依赖功能磁共振技术观察急性脑梗死患者吞咽相关中枢功能重组及其偏侧性特征。 方法 选取健康志愿者10例组成正常对照组，选取首次出现吞咽困难主诉的急性期脑梗死患者10例组成患者组，患者组再根据新发梗死部位分为左侧脑梗死亚组（5例）和右侧脑梗死亚组（5例）。采集正常对照组、患者组在吞咽状态和非吞咽状态下BOLD-fMRI扫描原始数据，应用SPM5软件进行数据处理，获得激活脑功能区坐标、体积等参数，通过公式计算吞咽中枢偏侧性指数，同时利用SPSS 13.0版软件对脑功能区激活体积等数据进行统计分析。 结果 患者组除了与正常对照组相似的激活区之外，还可见BA36、BA9、BA23/31、BA7、BA18/19区等更为广泛的激活；同时左侧脑梗死亚组表现出右侧偏侧性，右侧脑梗死亚组表现出左侧偏侧性。 结论 中枢性吞咽障碍患者吞咽决策启动中枢的激活反应受损比较明显；梗死侧别不同对吞咽中枢偏侧性产生一定影响，提示健侧大脑半球功能重组在吞咽康复过程中可能具有重要作用。     

视动刺激治疗视空间偏侧忽略的临床研究

摘要 目的：探讨视动刺激对视空间偏侧忽略患者的治疗效果及长期疗效。 方法：将16例首次脑卒中后出现左侧视空间偏侧忽略的患者随机分为2组,治疗组（n=8）和对照组（n=8）,治疗组应用视动刺激技术（optokinetic stimulation,OKS）及传统视空间偏侧忽略的针对性训练。对照组患者仅进行传统视空间偏侧忽略的针对性训练,治疗周期均为2周。分别在基线期、治疗前、治疗后及随访末4个阶段对两组患者进行偏侧忽略纸笔测试及行为学评定。 结果：OKS组患者治疗后纸笔测试和CBS评定明显优于治疗前(P<0.01),且效果比对照组明显(P<0.01),治疗后2周的随访,发现治疗组效果改善持续保持(P>0.05)。 结论：视动刺激可显著改善卒中后忽略患者的忽略症状及日常行为能力。     

重复经颅磁刺激的累积效应在治疗偏侧忽略中的作用研究

目的:观察连续数天的低频重复经颅磁刺激在对偏侧忽略患者的治疗中是否产生了累积效应,探讨累积效应是否是低频重复经颅磁刺激治疗偏侧忽略的重要机制。方法:将12例偏侧忽略患者随机分为治疗组和对照组,并对治疗组进行为期10天的低频重复经颅磁刺激治疗,每两天对这12例患者用线段划消和直线二等分测试进行评估,观察治疗组和对照组忽略症状的变化趋势。结果:rTMS的治疗效果和治疗时间之间存在相关关系,治疗组线段划消测试的评估结果和治疗时间之间的相关系数r=-0.659;直线二等分测试中r=-0.606。对照组线段划消测试评估结果和治疗时间之间无相关关系,P0.05;直线二等分测试结果和治疗时间之间也无相关关系,P0.05。结论:低频重复经颅磁刺激对偏侧忽略患者症状的改善是一个渐进的过程,具有累积效应,低频重复经颅磁刺激的累积效应在对偏侧忽略患者症状的改善中起到了关键作用。     

镜像治疗对脑卒中偏侧忽略症改善的疗效观察

目的:探讨镜像治疗对于脑卒中偏侧忽略患者功能的影响。方法:脑卒中偏侧忽略患者24例,随机分为对照组12例和镜像组12例,2组患者均接受常规的针对偏侧忽略的康复训练,镜像组在此基础上增加镜像治疗。治疗前和治疗3周后采用中国行为性忽略测试-香港版(CBIT-HK)量表进行评估,并分别比较常规测试评分、行为测试评分及总评分。结果:治疗3周后,2组患者CBIT-HK常规测试评分、行为测试评分及总评分均较治疗前有显著提高(均P0.01),且观察组3项评分均更高于对照组(均P0.01)。结论:镜像治疗结合常规康复训练短期可以明显改善脑卒中偏侧忽略症状。     

Eye patching biases spatial attention after thalamic hemorrhage in a patient without spatial neglect: a case report

Monocular patching has been advocated as a treatment for spatial neglect. Eye patching, however, is also reported to increase spatial bias. Thus, patching brain injury patients for ocular conditions may also impair their attention. To learn if an eye patch may induce asymmetric attention in a patient without spatial neglect, we tested a woman with diplopia after a left thalamic-intraventricular hemorrhage. She had no spatial neglect on bedside attention tasks. Using a laser pointer, she bisected a blank space at near (279 mm) and far (914 mm) distances under 3 conditions: unpatched and wearing a right or left eye patch. Unpatched, she showed no bias. She erred further leftward with right patching at both distances. Right eye patching appeared to induce neglect of right space when the patient performed this task. With left patching, leftward error tended to increase in near space only. Clinicians prescribing eye patches to patients with brain injury even for purely ocular indications, should evaluate them for spatial neglect once the patch is in place.     

Monocular patching in subjects with right-hemisphere stroke affects perceptual-attentional bias

Monocular patching is a possible inexpensive treatment for spatial neglect. Previous studies were unpromising, but since neglect symptoms are heterogeneous, fractionating spatial bias may detect significant effects of patching. Poststroke, perceptual-attentional (PA) spatial bias, motor-intentional (MI) spatial bias, or both may occur. In this study, six poststroke subjects bisected lines while self-monitoring their performance via a camera/video apparatus. We dissociated PA and MI spatial bias by right-left reversing visual feedback in some trials. Subjects were tested with and without right and left eye patches. Patching did not affect group line-bisection error, but both right and left patches decreased individual subject PA spatial bias (p < 0.05). We detected no patching effect on individual subject MI spatial bias (significant patch side by bias interaction, p = 0.03). When we examined each subject's results separately, patching improved performance in subjects who had greater PA and MI spatial biases. We conclude that monocular patching may primarily affect poststroke PA spatial bias. Further studies on this intervention are needed.     

Stimulus symmetry affects the bisection of figures but not lines: evidence from event-related fMRI

Many geometric shapes retain their symmetry when bisected, but appear asymmetrical when misbisected. We have previously shown that this correspondence can guide the accuracy and speed of perceptual bisection (Landmark) judgments. Using event-related fMRI, here we examined whether the behavioural effects of symmetry are also evident at the neural level. The data showed that the presence/absence of symmetry modulates the activity of right anterior cingulate gyrus, an area associated with a variety of higher level attentional functions. A previous visual half-field study also showed that bisected lines are apprehended more quickly and accurately than misbisected lines in right, but not left, visual field. We were able to localise this advantage to right superior temporal gyrus. Significantly, we found no evidence that symmetry played a role in apprehending the midpoint of the line stimuli traditionally used to assess visual neglect. The data clarify the effects of visual symmetry on bisection behaviour, and highlight novel dissociations within the neural systems thought to underline Landmark performance.     

Effects of lateralized light flash and color on unilateral neglect

Abstract

Purpose: Bottom-up-based sensory stimulation has been useful in promoting recovery from post-stroke neglect. Light and color are salient stimuli for guiding our orienting behaviors and influence the degree of spatial bias. This study evaluated the effects of lateralized light flash and color on spatial bias in unilateral neglect (UN). Method: We enrolled 15 individuals with UN as a consequence of a right hemispheric stroke of less than 65?d. This was a 3?×?3 design study with three conditions of lens color (colorless, red, and blue) and three conditions of flash light locations (no flash, left, and right). Results: All participants showed a decrease in ipsilesional spatial bias under left-side light flash and a red lens. Right-side light flash and a blue lens induced more rightward bias than other conditions. Conclusions: This evidence confirms the use of sensory stimulation to complement post-stroke UN remediation. Lateralized light flash to the contralesional space and red-colored lenses have beneficial effects on amelioration of UN, whereas ipsilesional light flash and the color blue may exacerbate ipsilesional spatial bias in stroke survivors with UN.

• Implications for Rehabilitation

• Contralesional light flash and the color red may ameliorate ipsilesional spatial bias in stroke survivors with unilateral neglect (UN).

• Ipsilesional flash of light and the color blue may worsen ipsilesional spatial bias in stroke survivors with UN.

     

Representation of time intervals in the right posterior parietal cortex: Implications for a mental time line

Space and time interact with each other in the cognitive system. Recent studies indicate the posterior parietal cortex (PPC) as the neural correlate of spatial–temporal interactions. We studied whether the contribution of the PPC becomes critical in tasks requiring the performance of spatial computations on time intervals. We adopted an integrated neuropsychological and transcranial magnetic stimulation (rTMS) approach, presenting behavioural timing tasks to both healthy subjects and right-brain-damaged patients with and without evidence of spatial neglect. rTMS of the right PPC of healthy subjects induced a lateralised bias during a task requiring setting the midpoint of a time interval. This bias mimicked the rightward bias observed in tasks requiring setting the midpoint of line intervals. These effects were selectively encountered when rTMS was applied during the retrieval phase of the task, while no effects were observed during the initial encoding phase of the time interval. Similar effects were also observed during bisection of time intervals by right-brain-damaged patients with spatial neglect. The specific role of the right PPC in bisection of physical intervals was confirmed by an experiment in which line segments were used.These findings document the neural correlates of spatial–temporal interactions and argue for a linear metric representation of time intervals.     

Effects of hand and spatial conditions on visual line bisection

This study examined the effects of hand and spatial conditions on a visual line bisection task with normal right-handers and proposed a normal range of deviation for this task in middle and advanced age. Twenty-four normal dextrals in their fifties and sixties performed a visual line bisection task using either the left or right hand under three spatial conditions: at the midline and in the left and right hemispaces. Our results revealed that performance was significantly affected by the hand used but not spatial conditions: Left hand performance was significantly further leftward than right hand performance. There was no significant interaction between the hand and spatial conditions. The mean deviation of the right hand was 2.2% of the half line length to the right of the true center. The possibility of left unilateral spatial neglect should be considered if a patient bisects a line with a deviation greater than 10% of the half line length to the right.     

Hypnotizability and the Peripersonal Space

High hypnotizability is associated with left-sided cerebral asymmetry, which could influence measurement of the Peripersonal Space (PPS). Right-handed participants with high (highs, n = 20), medium (mediums, n = 9), and low hypnotizability scores (lows, n = 20) performed the line bisection test on a computer screen automatically displaced at distances of 30, 60, and 90 cm from the subjects’ eyes. Highs’ results showed rightward bias of the bisection (Relative Error, RE) for all presentation distances. In contrast, in lows RE was displaced leftward at 30 cm and exhibited a progressive rightward shift at 60 and 90 cm, as occurs in the general population. Mediums’ RE values were intermediate between highs’ and lows’ values. Bisection Times (BT) were significantly longer in highs/mediums than in lows. Findings indicate that the highs’ bisection identifies PPS as if it was extrapersonal, but further studies should assess its functional characteristics. The highs/mediums longer BT suggest less efficient sensorimotor performance.     

Exploring the Relationship between Semantics and Space

The asymmetric distribution of human spatial attention has been repeatedly documented in both patients and healthy controls. Biases in the distribution of attention and/or in the mental representation of space may also affect some aspects of language processing. We investigated whether biases in attention and/or mental representation of space affect semantic representations. In particular, we investigated whether semantic judgments could be modulated by the location in space where the semantic information was presented and the role of the left and right parietal cortices in this task. Healthy subjects were presented with three pictures arranged horizontally (one middle and two outer pictures) of items belonging to the same semantic category. Subjects were asked to indicate the spatial position in which the semantic distance between the outer and middle pictures was smaller. Subjects systematically overestimated the semantic distance of items presented in the right side of space. We explored the neural correlates underpinning this bias using rTMS over the left and right parietal cortex. rTMS of the left parietal cortex selectively reduced this rightward bias. Our findings suggest the existence of an attentional and/or mental representational bias in semantic judgments, similar to that observed for the processing of space and numbers. Spatial manipulation of semantic material results in the activation of specialised attentional resources located in the left hemisphere.     

经颅直流电刺激对脑卒中后视觉空间忽略不同参考框架成分的影响

目的：探究右后顶叶皮层经颅直流电刺激对脑卒中后视觉空间忽略患者以自身为中心参考框架成分和非自身为中心参考框架成分的影响。方法：20名右侧半球脑卒中后左侧视觉空间忽略患者随机分为观察组和对照组各10例，观察组行经颅直流电刺激联合常规康复治疗，对照组只进行常规康复治疗。治疗前和治疗2周后对2组患者进行自身为中心成分（线段二等分）、非自身为中心成分（缺口探查）行为学评估。结果：治疗2周后，观察组线段二等分偏侧化评分和左侧缺口圆标记错误评分治疗前后差值和治疗后与对照组差值比较差异均有统计学意义(均P＜0.05)，但对照组以上评分治疗前后差值比较均无统计学意义。结论：右后顶叶皮层经颅直流电刺激对视觉空间忽略患者不同参考框架下成分均有促进恢复作用。