Social participation following right hemisphere stroke: influence of a cognitive-communication disorder

Background: The ability to return to social activities and roles is an important focus of rehabilitation for people affected by stroke. Rehabilitation professionals currently have limited evidence on the impact of a cognitive-communication disorder (CCD) following right hemispheric (RH) stroke on social participation, and how to support return to social activities and roles.

Aims: This study describes (1) social participation change as reported by people with RH stroke; (2) compares social participation change across two groups based on the presence or absence of CCD following RH stroke; and (3) compares self and proxy reports of changes in participation.

Methods & Procedures: A telephone survey was conducted with randomly selected people with first onset, unilateral RH stroke, and with matched significant others (proxies). The Sydney Psychosocial Reintegration Scale (SPRS-2) was utilised to explore change associated with stroke across Occupational Activities (OA), Interpersonal Relationships (IR) and Independent Living Skills (LS). Survey responses were compared utilising independent t-tests across two groups based on the presence or absence of CCD. Participant-proxy agreement was established using inter-rater correlation coefficient.

Outcomes & Results: Change in social participation was reported for thirty-six participants with an average age of 65.95 years (SD = 13.09), of whom 58.3% were male and 38.9% employed at the time of the stroke. Time post-stroke to completion of the SPRS-2 ranged from six to 33 months. Most participants (94.4%, n = 34) reported change in at least one of the SPRS-2 domains. The presence of CCD had an impact on social participation as measured on the SPRS-2, which was significantly different to what was reported by participants without a communication impairment post-RH stroke (p = 0.02.) Inter-rater agreement statistic (Kappa) indicated a fair participant-proxy dyad agreement in the group with CCD, and a moderate agreement in the group without CCD across the SPRS-2 domains.

Conclusions: Changes in social participation following RH stroke occur across Occupational Activities, Interpersonal Relationships and Independent Living Skills for the majority of people and occur with greater frequency and degree where a CCD is present. This exploratory study highlights the importance of rehabilitation goals that address social participation to reduce potential social isolation in people with CCD post-RH stroke. Further identification of risk factors for social participation restriction in this population is required to better inform rehabilitation timing and focus.     

患侧大脑半球多脑叶离断术治疗难治性癫痫

目的应用患侧大脑半球多脑叶离断术治疗该侧半球性病变导致的难治性癫痫,目的是对保留病变半球基本功能的癫痫患者提出一个有效而实用的术式。方法①大脑半球多脑叶离断术的创新:对患侧大脑半球我们分步骤离断额叶,颞叶、和顶枕叶与丘脑、基底节的联系;通过侧脑室额角和枕角离断胼胝体前后部,只保留中央前后回皮层及其与丘脑、基底节和内囊的联系;通过外侧裂切除岛叶皮层;通过颞角切除海马杏仁核。②利用这一术式我们治疗了5例大脑半球病变引发的难治性癫痫患者。结果该术式在5例患者成功实施。结果证实,该手术创伤小,并发症少,术后病人没有任何加重对侧肢体功能障碍的并发症,癫痫得到有效控制。随访13～20个月,Engel I级3例;II级2例。结论大脑半球多脑叶离断术,是对那些保留运动、感觉和语言功能的半球性病变所致的难治性癫痫患者有效、可靠的治疗选择。     

Regional and hemispheric determinants of language laterality: Implications for preoperative fMRI

Language is typically a function of the left hemisphere but the right hemisphere is also essential in some healthy individuals and patients. This inter‐subject variability necessitates the localization of language function, at the individual level, prior to neurosurgical intervention. Such assessments are typically made by comparing left and right hemisphere language function to determine “language lateralization” using clinical tests or fMRI. Here, we show that language function needs to be assessed at the region and hemisphere specific level, because laterality measures can be misleading. Using fMRI data from 82 healthy participants, we investigated the degree to which activation for a semantic word matching task was lateralized in 50 different brain regions and across the entire cortex. This revealed two novel findings. First, the degree to which language is lateralized across brain regions and between subjects was primarily driven by differences in right hemisphere activation rather than differences in left hemisphere activation. Second, we found that healthy subjects who have relatively high left lateralization in the angular gyrus also have relatively low left lateralization in the ventral precentral gyrus. These findings illustrate spatial heterogeneity in language lateralization that is lost when global laterality measures are considered. It is likely that the complex spatial variability we observed in healthy controls is more exaggerated in patients with brain damage. We therefore highlight the importance of investigating within hemisphere regional variations in fMRI activation, prior to neuro‐surgical intervention, to determine how each hemisphere and each region contributes to language processing. Hum Brain Mapp, 2010. © 2010 Wiley‐Liss, Inc.     

Clinical functional MRI of the language domain in children with epilepsy

Functional MRI (fMRI) for the assessment of language functions is increasingly used in the diagnostic workup of patients with epilepsy. Termed "clinical fMRI," such an approach is also feasible in children who may display specific patterns of language reorganization. This study was aimed at assessing language reorganization in pediatric epilepsy patients, using fMRI. We studied 26 pediatric epilepsy patients (median age, 13.05 years; range, 5.6-18.7 years) and 23 healthy control children (median age, 9.37 years; range, 6.2-15.4 years), using two child-friendly fMRI tasks and adapted data-processing streams. Overall, 81 functional series could be analyzed. Reorganization seemed to occur primarily in homotopic regions in the contralateral hemisphere, but lateralization in the frontal as well as in the temporal lobes was significantly different between patients and controls. The likelihood to find atypical language organization was significantly higher in patients. Additionally, we found significantly stronger activation in the healthy controls in a primarily passive task, suggesting a systematic confounding influence of antiepileptic medication. The presence of a focal cortical dysplasia was significantly associated with atypical language lateralization. We conclude that important confounds need to be considered and that the pattern of language reorganization may be distinct from the patterns seen in later-onset epilepsy.     

反射性注意线索范式下眼球指向加工引起事件相关电位成分及时序性变化

摘要： 背景：眼球指向可以引起相关大脑区域的激活,这种激活在一定程度上具有特异性、视野优势和时间进程上的差异。 目的：探讨眼球指向的有效性对视觉反射性注意的脑电活动规律的影响。 设计、时间及地点：被试内实验设计,于2009-07/20~2009-08/01在北京师范大学心理学院脑电实验室完成。 对象：被试采取自愿报名的方式,按纳入和排除标准,共募集14名年龄为18~23岁（Mean age=21）的健康的北京师范大学本科生,男7人,女7人。纳入标准：选取视力或者矫正视力正常（裸眼或矫正视力国标1.0以上）的本科生,被试在实验过程中无显著的脑电漂移。排除标准：视觉和矫正视觉异常的被试,被试在实验过程中出现显著的脑电漂移。 方法：采用事件相关电位的脑电记录方法对14名大学生进行眼球指向的视觉注意加工实验。根据其脑电图记录的分析结果,找出视野和眼球指向有效性引起的注意加工的大脑神经细胞脑电活动差异,并探讨在时间进程上诱发的脑电成分的活动规律。 主要观察指标：用事件时间相关电位的方法记录分布在大脑的各功能区电极在时间进程上（0~800ms）的诱发电位,来观察左右视野、眼球朝向有效性的视觉注意加工规律。 结果：左右视野和眼球朝向引起早期波N1、P1、P2的峰值和潜伏期,眼球朝向有效性诱发了早期波和晚期波电极点（P7、P8、F7、F8、PO3、PO4）的半球优势,且差异有统计学意义（P<0.05）。结果发现在眼球指向的注意线索任务中,发现了早期反射性注意的EDAN和ADAN,没有发现晚期的LDAP成分。 结论：眼球指向的反射性注意转移存在半球优势;且诱发了早期的EDAN（200~400 ms）和ADAN(400-500ms)脑电成分,没有引起晚期的LDAP(500~800ms)成分。这说明视觉反射性注意发生在视觉刺激呈现的很短时间内,存在明显的注意加工优势。 关键词：眼球朝向;提示有效性;事件相关电位;半球优势;反射性注意     

Musical brains: a study of spontaneous and evoked musical sensations without external auditory stimuli

Conclusions. Our observations confirm that musical sensations with no external stimuli, either spontaneous or evoked, occur in normal individuals and that a biological substrate can be demonstrated by brain single photon emission computed tomography (SPECT). Objectives. There are individuals, usually musicians, who are seemingly able to evoke and/or have spontaneous musical sensations without external auditory stimuli. However, to date there is no available evidence to determine if it is feasible to have musical sensations without using external sensory receptors, or if there is a biological substrate for these sensations. Subjects and methods. A group of 100 musicians and another of 150 otolaryngologists were asked if they had spontaneous musical auditory sensations and/or were capable of evoking them. SPECT evaluations with Tc^99m-HMPAO were conducted in six female musicians while they were evoking these sensations or, in one case, while she was having them spontaneously. In three of them an additional SPECT was conducted in basal conditions (having been asked to avoid evoking music).Results. In all, 97 of 100 musicians had spontaneous musical sensations; all 100 could evoke and modify them. Of the 150 otolaryngologists, 18 (12%) were musicians. Of the 132 nonmusicians, spontaneous musical sensations occurred in 52 (39.4%), 72 (54.5%) could evoke and 23 (17.4%) were able to modify them, 58 (43.9%) did not have spontaneous musical sensations nor could they evoke them. The musical sensations of the 72 otolaryngologists that could evoke were less elaborated than those of musicians. NeuroSPECT during voluntary musical autoevocation demonstrated significant (>2 SD) increased activation of executive frontal cortex in Brodmann areas 9 and 10, secondary visual cortex (area 17), and paracingulate (areas 31 and 32). There was also activation in the para-executive frontal cortex (areas 45 and 46). In the basal ganglia there was activation in thalamus and lentiform nucleus. Deactivation below 2 SD was demonstrated by mean values in the cingulate gyrus, Brodmann areas 23 and 24, and subgenual area 25. Deactivation was also demonstrated when minimal values were analyzed in the same areas plus area 4 and areas 36 and 38, the latter in the pole of the temporal lobes. In three patients comparison of basal state with autoevocation demonstrated activation in executive frontal cortex (areas 8 and 9), para-executive cortex (area 45), primary auditory cortex (area 40), the right thalamus, and lentiform nucleus.     

Neural substrates for functionally discriminating self-face from personally familiar faces

Understanding the neurobiological substrates of self-recognition yields important insight into socially and clinically critical cognitive functions such as theory of mind. Experimental evidence suggests that right frontal and parietal lobes preferentially process self-referent information. Recognition of one's own face is an important parameter of self-recognition, but well-controlled experimental data on the brain substrates of self-face recognition is limited. The goal of this study was to characterize the activation specific to self-face in comparison with control conditions of two levels of familiarity: unknown unfamiliar face and the more stringent control of a personally familiar face. We studied 12 healthy volunteers who made "unknown," "familiar," and "self" judgments about photographs of three types of faces: six different novel faces, a personally familiar face (participant's fraternity brother), and their own face during an event-related functional MRI (fMRI) experiment. Contrasting unknown faces with baseline showed activation of the inferior occipital lobe, which supports previous findings suggesting the presence of a generalized face-processing area within the inferior occipital-temporal region. Activation in response to a familiar face, when contrasted with an unknown face, invoked insula, middle temporal, inferior parietal, and medial frontal lobe activation, which is consistent with an existing hypothesis suggesting familiar face recognition taps neural substrates that are different from those involved in general facial processing. Brain response to self-face, when contrasted with familiar face, revealed activation in the right superior frontal gyrus, medial frontal and inferior parietal lobes, and left middle temporal gyrus. The contrast familiar vs. self produced activation only in the anterior cingulate gyrus. Our results support the existence of a bilateral network for both perceptual and executive aspects of self-face processing that cannot be accounted for by a simple hemispheric dominance model. This network is similar to those implicated in social cognition, mirror neuron matching, and face-name matching. Our findings also show that some regions of the medial frontal and parietal lobes are specifically activated by familiar faces but not unknown or self-faces, indicating that these regions may serve as markers of face familiarity and that the differences between activation associated with self-face recognition and familiar face recognition are subtle and appear to be localized to lateral frontal, parietal, and temporal regions.     

rTMS to the right inferior parietal lobule disrupts self-other discrimination

Self–other discrimination is fundamental to social interaction,however, little is known about the neural systems underlyingthis ability. In a previous functional magnetic resonance imagingstudy, we demonstrated that a right fronto-parietal networkis activated during viewing of self-faces as compared with thefaces of familiar others. Here we used image-guided repetitivetranscranial magnetic stimulation (rTMS) to create a ‘virtuallesion’ over the parietal component of this network totest whether this region is necessary for discriminating self-facesfrom other familiar faces. The current results indeed show that1 Hz rTMS to the right inferior parietal lobule (IPL) selectivelydisrupts performance on a self–other discrimination task.Applying 1 Hz rTMS to the left IPL had no effect. It appearsthat activity in the right IPL is essential to the task, thusproviding for the first time evidence for a causal relationbetween a human brain area and this high-level cognitive capacity.     

From novel to familiar: tuning the brain for metaphors

Metaphors are fundamental to creative thought and expression. Newly coined metaphors regularly infiltrate our collective vocabulary and gradually become familiar, but it is unclear how this shift from novel to conventionalized meaning happens in the brain. We investigated the neural career of metaphors in a functional magnetic resonance imaging study using extensively normed new metaphors and simulated the ordinary, gradual experience of metaphor conventionalization by manipulating participants' exposure to these metaphors. Results showed that the conventionalization of novel metaphors specifically tunes activity within bilateral inferior prefrontal cortex, left posterior middle temporal gyrus, and right postero-lateral occipital cortex. These results support theoretical accounts attributing a role for the right hemisphere in processing novel, low salience figurative meanings, but also show that conventionalization of metaphoric meaning is a bilaterally-mediated process. Metaphor conventionalization entails a decreased neural load within semantic networks rather than a hemispheric or regional shift across brain areas.