No strong evidence for lateralisation of word reading and face recognition deficits following posterior brain injury

Face recognition and word reading are thought to be mediated by relatively independent cognitive systems lateralised to the right and left hemispheres, respectively. In this case, we should expect a higher incidence of face recognition problems in patients with right hemisphere injury and a higher incidence of reading problems in patients with left hemisphere injury. We tested this hypothesis in a group of 31 patients with unilateral right or left hemisphere infarcts in the territory of the posterior cerebral arteries. In most domains tested (e.g., visual attention, object recognition, visuo-construction, motion perception), we found that both patient groups performed significantly worse than a matched control group. In particular, we found a significant number of face recognition deficits in patients with left hemisphere injury and a significant number of patients with word reading deficits following right hemisphere injury. This suggests that face recognition and word reading may be mediated by more bilaterally distributed neural systems than is commonly assumed.     

Ankle Intrinsic Stiffness in Subcortical Poststroke Subjects

The authors' purpose was to evaluate bilateral ankle intrinsic stiffness in subcortical poststroke subjects. Ten subcortical poststroke subjects and 10 healthy controls participated in this study. The ankle passive stiffness at 3 different speeds and the electromyographic activity of the soleus, the gastrocnemius, and the tibialis anterior muscles of poststroke contralesional (CONTRA) and ipsilesional (IPSI) limbs and of one limb of healthy subjects were assessed. Ankle electromyographic activity was collected to ensure that reflexive or voluntary muscle activity was not being elicited during the passive movements. A significant interaction was observed between the effects of the limb (IPSI vs. CONTRA vs. control) and ankle position, F(4, 28) = 3.285, p = .025, and between the effects of the limb and the velocity of stretch, F(2, 14) = 4.209, p = .037. While increased intrinsic stiffness was observed in the CONTRA limb of poststroke subjects at ankle neutral position when the passive stretch was applied with a velocity of 1°/s (p = .021), the IPSI limb of poststroke subjects presented increased stiffness at 20º of plantar flexion when the stretch was applied with a velocity of 5°/s (p = .009) when compared to healthy group. Subcortical poststroke subjects present increased intrinsic stiffness in both the CONTRA and IPSI limbs in specific ankle amplitudes.     

我对卒中单元的体会

卒中单元作为卒中治疗的最佳模式,逐渐被临床医生所接受,就卒中单元的概念、特点及我国卒中的现状等多数人所关心的问题进行了分析和探讨,以助于更好的理解。     

建立有中国特色的卒中单元

卒中单元是一种医疗管理模式,它将治疗脑卒中的有效手段集中在一起,让病人在有效治疗时间窗内的到他所需要的最佳治疗,尽可能地使卒中病人恢复神经功能,恢复自我,回归社会。但我国的卒中单元还存在许多问题,需共同努力建立有中国特色的卒中单元。     

社区医师应成为脑卒中治疗的重要环节

我国现代医疗技术对脑卒中的诊断和治疗手段越来越完善,但对于脑卒中的急救和预防水平却不尽人意,应当重视社区医院、社区医生在脑卒中急救、预防、治疗、康复中的重要作用,建立符合我国国情的“卒中单元”,使社区医生成为脑卒中治疗体系的起始点和终结点。     

Contribution of temporal preparation and processing speed to simple reaction time in persons with Alzheimer’s disease and mild cognitive impairment

Temporal preparation was assessed in 15 Alzheimer’s disease (AD) patients, 20 persons with mild cognitive impairment (MCI) and 28 healthy older adults. Participants completed a simple reaction time task in which the preparatory interval duration varied randomly within two blocks (short versus long temporal window). Results indicated that AD and MCI patients had difficulty preparing for the shortest preparatory interval of the short temporal window. AD and MCI patients also had difficulty maintaining an optimal level of preparation up to 5 s within the short temporal window. These results suggest that AD and MCI patients might show difficulty preparing for rapidly occurring events and maintaining preparation over time. This phenomenon should be considered when using reaction time measures with such patients.     

从指南看TIA概念的演变及临床意义

短暂性脑缺血发作(TIA)的概念从20世纪50年代提出至今已有50余年,随着临床研究的深入和神经影像学技术的进步,人们对TIA的认识发生了深刻的变化。美国心脏协会(AHA)、美国卒中协会(ASA)在2009年6月发表最新指南提出TIA是由脑、脊髓或视网膜局灶性缺血引起的短暂性神经功能障碍,且无急性脑梗死证据。本文对新指南进行了解读,并对TIA概念的演变进行了简单回顾,同时探讨这种演变的临床意义。     

3-6岁儿童汉字字形认知的发展

以汉字、一般线条图、似字线条图和笔画组合为材料,采用字典判断任务考察3-6岁儿童汉字字形认知的发展特点。结果发现儿童辨别汉字与似字符号的能力随年龄增长显著提高。3岁儿童较难区分汉字与各类似字符号。4-5岁儿童对汉字笔画特征有了一定意识。6岁儿童对汉字组合模式的认识显著提高。笔画意识出现较早且发展速度较快,组合模式意识出现较晚且发展速度较慢。5岁和6岁是汉字字形认知发展的重要时期。     

Clock drawing performance and brain morphology in mild cognitive impairment and Alzheimer's disease

The Clock Drawing Test (CDT) is a widely used instrument in the neuropsychological assessment of Alzheimer's disease (AD). As CDT performance necessitates several cognitive functions (e.g., visuospatial and constructional abilities, executive functioning), an interaction of multiple brain regions is likely. Fifty-one subjects with mild cognitive impairment, 23 with AD and 15 healthy controls underwent high-resolution magnetic resonance imaging. Optimized voxel-based morphometry (VBM) was performed to investigate the putative association between CDT performance and gray matter (GM) density throughout the entire brain. In the first step of analysis (p<.001, uncorrected), VBM revealed a reduced GM density in numerous cortical (temporal lobe, frontal lobe, parietal lobe, cerebellum) and subcortical (thalamus, basal ganglia) brain regions to be associated with poorer CDT performance. When corrected for multiple comparisons (p<.01), the associations remained significant predominantly in the left temporal and--less pronounced--the right temporal lobe. VBM demonstrated CDT performance to depend on the integrity of widely distributed cortical and subcortical areas in both brain hemispheres with accentuation in the left-sided temporal lobe region.     

缺血性卒中治疗中的若干启示

脑卒中具有高发病率、高病死率、高度致残的临床特点。目前对缺血性卒中的治疗已取得了重大进展,但它仍是内科临床工作中最具挑战性的任务之一。哲学反思对科学的发展具有指导作用,本文从哲学的角度对缺血性卒中的治疗策略和措施进行综合分析,以把握其最新的发展趋势。