Left Hemisphere Damage Research Articles

Lesion characteristics driving right-hemispheric language reorganization in congenital left-hemispheric brain damage

Pre- or perinatally acquired (“congenital”) left-hemispheric brain lesions can be compensated for by reorganizing language into homotopic brain regions in the right hemisphere. Language comprehension may be hemispherically dissociated from language production. We investigated the lesion characteristics driving inter-hemispheric reorganization of language comprehension and language production in 19 patients (7–32years; eight females) with congenital left-hemispheric brain lesions (periventricular lesions [n=11] and middle cerebral artery infarctions [n=8]) by fMRI. 16/17 patients demonstrated reorganized language production, while 7/19 patients had reorganized language comprehension. Lesions to the insular cortex and the temporo-parietal junction (predominantly supramarginal gyrus) were significantly more common in patients in whom both, language production and comprehension were reorganized. These areas belong to the dorsal stream of the language network, participating in the auditory-motor integration of language. Our data suggest that the integrity of this stream might be crucial for a normal left-lateralized language development.

Narratives of focal brain injured individuals: A macro-level analysis

Focal brain injury can have detrimental effects on the pragmatics of communication. This study examined narrative production by unilateral brain damaged people (n=36) and healthy controls and focused on the complexity (content and coherence) and the evaluative aspect of their narratives to test the general hypothesis that the left hemisphere is biased to process microlinguistic information and the right hemisphere is biased to process macrolinguistic information. We found that people with left hemisphere damage's (LHD) narratives were less likely to maintain the overall theme of the story and produced fewer evaluative comments in their narratives. These deficits correlated with their performances on microlinguistic linguistic tasks. People with the right hemisphere damage (RHD) seemed to be preserved in expressing narrative complexity and evaluations as a group. Yet, single case analyses revealed that particular regions in the right hemisphere such as damage to the dorsolateral prefrontal cortex (DLPFC), the anterior and superior temporal gyrus, the middle temporal gyrus, and the supramarginal gyrus lead to problems in creating narratives. Our findings demonstrate that both hemispheres are necessary to produce competent narrative production. LHD people's poor production is related to their microlinguistic language problems whereas RHD people's impaired abilities can be associated with planning and working memory abilities required to relate events in a narrative.

The Study Trends of the Right Hemisphere Damage Cognitive-Communication Disorders - Focused of Recent 10 Years -

우반구 손상(Right Hemisphere Damage, RHD)에 따른 의사소통장애는 좌반구 손상 환자군과는 다른 양상을 보이며, 좌반구 손상 환자 대상의 실어증 평가에서는 그 장애 정도가 잘 감별되지 않기 때문에 이들에 대한 언어 평가와 중재연구가 적극적으로 이루어지지 않고 있다. 본 연구에서는 최근 10년간 국내외 관련 학술지에서 다루어진 RHD 환자에 대한 연구논문을 분석하여 RHD 환자의 의사소통장애 평가와 중재 방향에 대한 동향을 파악하고, 향후 임상과 연구 영역에서의 시사점을 얻고자 하였다. 국내외 논문 총 75편(국내 논문 13편, 국외 논문 62편)을 대상으로 연구유형과 연구영역으로 나누어 분석을 실시하였다. 연구유형 및 연구영역에서 국내외 동일하게 RHD 환자의 인지-의사소통장애 특성을 비교하고, 언어외적 능력을 가장 많이 살펴본 것으로 나타났다. 그러나 평가도구 개발 연구 및 인지-의사소통 외 능력(예: 일상생활능력, 우울)과 같이 다양한 주제에 대한 연구가 빈번히 이루어져 있는 국외 연구와는 달리 국내 연구는 아직까지 제한적인 범위 내에서만 이루어져 있었다. 본 논문을 통해 파악된 RHD 환자군의 국내외 연구 동향을 통해 향후 국내 RHD 환자를 대상으로 한 임상장면과 연구에서 다양하고 심도 높은 연구가 이루어질 것으로 기대한다.Communication disorders caused by Right Hemisphere Damage manifests different symptom with that of left, and studies concerning language evaluation and intervention have not been actively investigated because they are either mild or difficult to discern through the aphasic assessment targeted to left hemisphere damage patients. This study analyzes domestic and international RHD group study trends in last 10 years for the purpose of examining the trends regarding directions of RHD group communication disorders and intervention. 75 thesis were analyzed(13 domestic and 62 international) after classifying them into two categories, study type and research area. Regarding research type, both domestic and international studies primarily comprised characteristic comparison. As for the research area, both studies mainly investigated on extra-linguistic ability. While international studies frequently investigated the development and suitability of evaluation instrument as well as RHD group s activities of daily life. Domestic studies have shown limited scopes of research. Therefore, it seems that more attention should henceforth be payed to RHD patients in domestic level, and in-depth studies of diverse subjects should be conducted as well.

Affective speech prosody perception and production in stroke patients with left-hemispheric damage and healthy controls

Purpose‘Affective prosody’ defines the supra-segmental features of speech that, when manipulated, can change the type and intensity of emotion conveyed by the speaker. Although the right hemisphere is predominantly linked to the processing of affective prosodic cues, existing literature also suggests that damage to the left hemisphere can result in similar deficits. This study aims to demonstrate, and add to the evidence, that patients with left-hemisphere injury experience difficulties with affective prosodic perception and production, measured via a new combination of assessments and analyses. It is also hypothesised that aphasia severity will be correlated with impaired processing of affective prosody. ResultsStroke and control participants differed significantly on prosody perception tests of matching auditory affective cues to visual images. Prosodic production was measured by participants vocalising different affective expressions of words and monosyllables – from which significant differences were found in perceptual judgements of emotion accuracy and intensity, and acoustic analyses of pitch range and variance. There were significant correlations between participants’ Western Aphasia Battery (WAB) scores, quality of life, and prosody production. ConclusionIndividuals with left-hemisphere damage after stroke have impaired affective prosodic perception and production that may be associated with reduced quality of life.

The canonical semantic network supports residual language function in chronic post-stroke aphasia.

Current theories of language recovery after stroke are limited by a reliance on small studies. Here, we aimed to test predictions of current theory and resolve inconsistencies regarding right hemispheric contributions to long-term recovery. We first defined the canonical semantic network in 43 healthy controls. Then, in a group of 43 patients with chronic post-stroke aphasia, we tested whether activity in this network predicted performance on measures of semantic comprehension, naming, and fluency while controlling for lesion volume effects. Canonical network activation accounted for 22%-33% of the variance in language test scores. Whole-brain analyses corroborated these findings, and revealed a core set of regions showing positive relationships to all language measures. We next evaluated the relationship between activation magnitudes in left and right hemispheric portions of the network, and characterized how right hemispheric activation related to the extent of left hemispheric damage. Activation magnitudes in each hemispheric network were strongly correlated, but four right frontal regions showed heightened activity in patients with large lesions. Activity in two of these regions (inferior frontal gyrus pars opercularis and supplementary motor area) was associated with better language abilities in patients with larger lesions, but poorer language abilities in patients with smaller lesions. Our results indicate that bilateral language networks support language processing after stroke, and that right hemispheric activations related to extensive left hemispheric damage occur outside of the canonical semantic network and differentially relate to behavior depending on the extent of left hemispheric damage. Hum Brain Mapp 38:1636-1658, 2017. © 2016 Wiley Periodicals, Inc.

Differences between left- and right-sided neglect revisited: A large cohort study across multiple domains

ABSTRACTUnilateral spatial neglect (USN) is a syndrome that can occur after right- and left-hemisphere damage. It is generally accepted that left-sided USN is more severe than right-sided USN. Evidence for such a difference in other domains is lacking. Primary aims were to compare frequency, severity, region specificity, cognition, physical functioning, and physical independence between left and right USN. Secondary aims were to compare lesion characteristics. A total of 335 stroke patients admitted for inpatient rehabilitation were included. The severity of the lateralized attentional deficit was measured with a shape cancellation and line bisection test (in peripersonal and extrapersonal space) and the Catherine Bergego scale. The Mini-Mental State Examination, Stichting Afasie Nederland score, search organization (i.e., best R and intersections rate), Motricity Index, balance, mobility, and self-care were assessed. Measures were statistically compared between left, right, and no USN patients. Lesion overlay plots were compared with lesion subtraction analyses. Results: Left USN (15.82%) was more frequent than right USN (9.25%). Demographic and stroke characteristics were comparable between groups. The lateralized attentional deficit was most severe in left USN. USN in both peripersonal and extrapersonal space was more frequently left-sided in nature. Search efficiency was lower in left USN. Balance was poorer in right USN. No differences between left and right USN were found for cognitive ability, communication, motor strength, mobility, and self-care. Most patients with left USN had right-hemispheric lesions, whereas patients with right USN could have lesions in either the left or the right hemisphere. To conclude, left and right USN are both common after stroke. Although the lateralized attention deficit is worse in left than in right USN, consequences at the level of physical functioning and physical independence are largely comparable. From a clinical perspective, it is important to systematically screen for USN, both after right- and after left-hemisphere damage.

Co-speech hand movements during narrations: What is the impact of right vs. left hemisphere brain damage?

Persons with brain damage show deviant patterns of co-speech hand movement behaviour in comparison to healthy speakers. It has been claimed by several authors that gesture and speech rely on a single production mechanism that depends on the same neurological substrate while others claim that both modalities are closely related but separate production channels. Thus, findings so far are contradictory and there is a lack of studies that systematically analyse the full range of hand movements that accompany speech in the condition of brain damage. In the present study, we aimed to fill this gap by comparing hand movement behaviour in persons with unilateral brain damage to the left and the right hemisphere and a matched control group of healthy persons. For hand movement coding, we applied Module I of NEUROGES, an objective and reliable analysis system that enables to analyse the full repertoire of hand movements independent of speech, which makes it specifically suited for the examination of persons with aphasia.The main results of our study show a decreased use of communicative conceptual gestures in persons with damage to the right hemisphere and an increased use of these gestures in persons with left brain damage and aphasia. These results not only suggest that the production of gesture and speech do not rely on the same neurological substrate but also underline the important role of right hemisphere functioning for gesture production.

A linguistic comparison between auditory verbal hallucinations in patients with a psychotic disorder and in nonpsychotic individuals: Not just what the voices say, but how they say it

BackgroundAuditory verbal hallucinations (AVH) in psychotic patients are associated with activation of right hemisphere language areas, although this hemisphere is non-dominant in most people. Language generated in the right hemisphere can be observed in aphasia patients with left hemisphere damage. It is called “automatic speech”, characterized by low syntactic complexity and negative emotional valence. AVH in nonpsychotic individuals, by contrast, predominantly have a neutral or positive emotional content and may be less dependent on right hemisphere activity. We hypothesize that right hemisphere language characteristics can be observed in the language of AVH, differentiating psychotic from nonpsychotic individuals. Method17 patients with a psychotic disorder and 19 nonpsychotic individuals were instructed to repeat their AVH verbatim directly upon hearing them. Responses were recorded, transcribed and analyzed for total words, mean length of utterance, proportion of grammatical utterances, proportion of negations, literal and thematic perseverations, abuses, type-token ratio, embeddings, verb complexity, noun-verb ratio, and open-closed class ratio. ResultsLinguistic features of AVH overall differed between groups F(13,24)=3.920, p=0.002; Pillai’s Trace 0.680. AVH of psychotic patients compared with AVH of nonpsychotic individuals had a shorter mean length of utterance, lower verb complexity, and more verbal abuses and perseverations (all p<0.05). Other features were similar between groups. ConclusionAVH of psychotic patients showed lower syntactic complexity and higher levels of repetition and abuses than AVH of nonpsychotic individuals. These differences are in line with a stronger involvement of the right hemisphere in the origination of AVH in patients than in nonpsychotic voice hearers.

Lateralized motor control processes determine asymmetry of interlimb transfer

This experiment tested the hypothesis that interlimb transfer of motor performance depends on recruitment of motor control processes that are specialized to the hemisphere contralateral to the arm that is initially trained. Right-handed participants performed a single-joint task, in which reaches were targeted to 4 different distances. While the speed and accuracy was similar for both hands, the underlying control mechanisms used to vary movement speed with distance were systematically different between the arms: the amplitude of the initial acceleration profiles scaled greater with movement speed for the right-dominant arm, while the duration of the initial acceleration profile scaled greater with movement speed for the left-non-dominant arm. These two processes were previously shown to be differentially disrupted by left and right hemisphere damage, respectively. We now hypothesize that task practice with the right arm might reinforce left-hemisphere mechanisms that vary acceleration amplitude with distance, while practice with the left arm might reinforce right-hemisphere mechanisms that vary acceleration duration with distance. We thus predict that following right arm practice, the left arm should show increased contributions of acceleration amplitude to peak velocities, and following left arm practice, the right arm should show increased contributions of acceleration duration to peak velocities. Our findings support these predictions, indicating that asymmetry in interlimb transfer of motor performance, at least in the task used here, depends on recruitment of lateralized motor control processes.

Formulaic language performance in left- and right-hemisphere damaged patients: structured testing

ABSTRACTBackground: Formulaic expressions—conversational speech formulas, idioms, pause fillers, conventional phrases, proverbs, expletives, and so on—constitute on average about 25% proportionally of everyday communication. While some clinical and experimental studies have implicated a right hemisphere involvement, controversy remains surrounding cerebral processing with respect to comprehension and production of formulaic expressions.Aims: The purpose of this study was to further investigate hemispheric specialisation for production and comprehension of formulaic and matched literal expressions by examining performance of individuals with unilateral brain damage compared with matched healthy controls (HCs) utilising structured tasks involving repetition, elicited speech, and comprehension.Methods & Procedures: Individuals with unilateral brain damage (right hemisphere damage (RHD) or left hemisphere damage (LHD)) due to cerebrovascular accident and matched HC participants completed five different tasks (Repetition, Multiple Choice Sentence Completion, Free-form Sentence Completion, Picture-matching Completion, and Written Multiple Choice) involving formulaic and literal expressions.Outcomes & Results: The LHD and RHD groups showed significant differences between two types of sentences (formulaic versus literal expressions) in the free-form sentence completion and picture-matching tasks, respectively, but not in the repetition or multiple choice (spoken or written) tasks.Conclusions: The findings lend support to the dual process model of formulaic and literal expressions, implying a right hemisphere involvement in processing of formulaic expressions when elicitation tasks are utilised. Because repetition and multiple choice tasks did not reflect differential processing, the results also indicate that task may differentially manifest speech characteristics of brain-damaged individuals.

Dysfunction of the Human Mirror Neuron System in Ideomotor Apraxia: Evidence from Mu Suppression.

Stroke patients with ideomotor apraxia (IMA) have difficulties controlling voluntary motor actions, as clearly seen when asked to imitate simple gestures performed by the examiner. Despite extensive research, the neurophysiological mechanisms underlying failure to imitate gestures in IMA remain controversial. The aim of the current study was to explore the relationship between imitation failure in IMA and mirror neuron system (MNS) functioning. Mirror neurons were found to play a crucial role in movement imitation and in imitation-based motor learning. Their recruitment during movement observation and execution is signaled in EEG recordings by suppression of the lower (8-10 Hz) mu range. We examined the modulation of EEG in this range in stroke patients with left (n = 21) and right (n = 15) hemisphere damage during observation of video clips showing different manual movements. IMA severity was assessed by the DeRenzi standardized diagnostic test. Results showed that failure to imitate observed manual movements correlated with diminished mu suppression in patients with damage to the right inferior parietal lobule and in patients with damage to the right inferior frontal gyrus pars opercularis-areas where major components of the human MNS are assumed to reside. Voxel-based lesion symptom mapping revealed a significant impact on imitation capacity for the left inferior and superior parietal lobules and the left post central gyrus. Both left and right hemisphere damages were associated with imitation failure typical of IMA, yet a clear demonstration of relationship to the MNS was obtained only in the right hemisphere damage group. Suppression of the 8-10 Hz range was stronger in central compared with occipital sites, pointing to a dominant implication of mu rather than alpha rhythms. However, the suppression correlated with De Renzi's apraxia test scores not only in central but also in occipital sites, suggesting a multifactorial mechanism for IMA, with a possible impact for deranged visual attention (alpha suppression) beyond the effect of MNS damage (mu suppression).

Multi-tasking uncovers right spatial neglect and extinction in chronic left-hemisphere stroke patients

Unilateral Spatial Neglect, the most dramatic manifestation of contralesional space unawareness, is a highly heterogeneous syndrome. The presence of neglect is related to core spatially lateralized deficits, but its severity is also modulated by several domain-general factors (such as alertness or sustained attention) and by task demands. We previously showed that a computer-based dual-task paradigm exploiting both lateralized and non-lateralized factors (i.e., attentional load/multitasking) better captures this complex scenario and exacerbates deficits for the contralesional space after right hemisphere damage. Here we asked whether multitasking would reveal contralesional spatial disorders in chronic left-hemisphere damaged (LHD) stroke patients, a population in which impaired spatial processing is thought to be uncommon. Ten consecutive LHD patients with no signs of right-sided neglect at standard neuropsychological testing performed a computerized spatial monitoring task with and without concurrent secondary tasks (i.e., multitasking). Severe contralesional (right) space unawareness emerged in most patients under attentional load in both the visual and auditory modalities. Multitasking affected the detection of contralesional stimuli both when presented concurrently with an ipsilesional one (i.e., extinction for bilateral targets) and when presented in isolation (i.e., left neglect for right-sided targets). No spatial bias emerged in a control group of healthy elderly participants, who performed at ceiling, as well as in a second control group composed of patients with Mild Cognitive Impairment. We conclude that the pathological spatial asymmetry in LHD patients cannot be attributed to a global reduction of cognitive resources but it is the consequence of unilateral brain damage. Clinical and theoretical implications of the load-dependent lack of awareness for contralesional hemispace following LHD are discussed.

Predictability effect reflects different contributions from each hemisphere: data from left and right hemisphere damage patients

Predictability effect reflects different contributions from each hemisphere: data from left and right hemisphere damage patients

Outcomes of a multicomponent intervention on occupational performance in persons with unilateral acquired brain injury

Complications after unilateral acquired brain injury (ABI) can affect various areas of expertise causing (depending on the location of the lesion) impairment in occupational performance. The aim of this study was to analyze and compare the concepts of occupational performance and functional independence, both before and after a multicomponent intervention including occupational therapy, in persons with unilateral brain damage. This was a longitudinal quasi-experimental pretest post-test study in a sample of 58 patients with unilateral brain injury (28 with traumatic brain injury and 30 with ischemic stroke). The patients' level of independence was measured using the short version of the International Classification of Functioning, Disability and Health. We also measured quality of performance using the Assessment of Motor and Process Skills. The findings of this study showed that patients with injury in the right hemisphere improved more than those with left hemisphere damage (p<0.001). All the patients with ABI, especially those with right-sided injury, derived benefit from the multicomponent intervention, except in the area of motor skills. More research is needed on the specific techniques that might address such skills.

Exploring the impact of laterality and polarity of tDCS on therapy for chronic post-stroke anomia

Event Abstract Back to Event Exploring the impact of laterality and polarity of tDCS on therapy for chronic post-stroke anomia Margaret Sandars1*, Lauren L. Cloutman1 and Anna M. Woollams1 1 University of Manchester, School of Psychological Sciences, United Kingdom Introduction: Anomia is a frequent and persistent symptom of post-stroke aphasia. Transcranial Direct Current Stimulation (tDCS) is a non-invasive neurostimulation technique that can be used to enhance the effects of behavioural speech and language therapy. Previous studies have suggested that applying anodal (excitatory) tDCS to perilesional areas in the damaged left hemisphere and/or cathodal (inhibitory) tDCS to homologous areas in the intact right hemisphere may be particularly beneficial (e.g. Baker et al., 2010; Rosso et al., 2014). However, the effects of varying both polarity and laterality of tDCS have yet to be systematically investigated within participants. The aim of the current study was to determine the optimal tDCS parameters to increase naming ability in two stroke survivors with chronic anomia: JSc, with Broca’s aphasia, and JSo, with Anomic aphasia. Methods: Six individualised 20-item treated sets were created from a pool of those incorrectly named prior to therapy. Participants completed six therapy cycles, each involving a different stimulation condition: left perilesional anodal, cathodal and sham and right contralesional anodal, cathodal and sham. Perilesional sites were determined on the basis of MRI structural scans: JSc=inferior frontal gryus (IFG), JSo=posterior superior temporal gyrus (STG). In each cycle, participants received 20 minutes of 1mA tDCS (electrodes 5cm x 7cm) on three consecutive days alongside computerised naming therapy. In the sham conditions, anodal stimulation was applied for one minute before being slowly turned off. Results: For JSc, there were significant immediate gains following left anodal, left cathodal and right sham stimulation, one week after left cathodal stimulation, and three weeks after left anodal and left cathodal stimulation. The effect of left anodal stimulation was significantly greater than that for sham immediately post-therapy (χ2=4.57, p<0.05), and three weeks later (χ2=6.99, p<0.01). JSo named significantly more items correctly immediately in all conditions, one week after left cathodal, right anodal, right cathodal and right sham stimulation, and three weeks after left cathodal, right cathodal and right sham stimulation. None of the active stimulation conditions resulted in significantly greater item gains than sham. Conclusion: Although there were clear therapeutic gains across the majority of conditions for both patients, the additional benefits for neurostimulation were more selective. For JSc, the beneficial effect of behavioural therapy for anomia was enhanced by anodal tDCS applied to left frontal perilesional regions, consistent with Baker et al. (2010) and Vestito et al. (2014), and neuroimaging of recovery and therapeutic gains in patients with chronic anomia (e.g. Fridriksson, 2010; Fridriksson et al., 2012; Meinzer et al., 2008). There was no benefit associated with cathodal stimulation of right contralesional sites, inconsistent with Rosso et al. (2014). In contrast, active tDCS did not increase JSo’s therapy gains above those observed for sham, irrespective of laterality and polarity. Overall, our results highlight variability of chronic stroke aphasic patients with differing behavioural and lesion profiles in their response to tDCS. Figure 1 Acknowledgements This research was funded by a Stroke Association Junior Research Training Fellowship awarded to the lead author (Award number TSA JRTF 2013/01) References

顔を構成するパーツを配置する課題で著明な異常を認めた 左半球損傷患者 2 例

顔を構成するパーツを配置する課題で著明な異常を認めた 左半球損傷患者 2 例

The Effects of Semantic Constraint and Cloze Probability in Left and Right Hemisphere Damaged Individuals

The Effects of Semantic Constraint and Cloze Probability in Left and Right Hemisphere Damaged Individuals

You may now kiss the bride: Interpretation of social situations by individuals with right or left hemisphere injury

While left hemisphere damage (LHD) has been clearly shown to cause a range of language impairments, patients with right hemisphere damage (RHD) also exhibit communication deficits, such as difficulties processing prosody, discourse, and social contexts. In the current study, individuals with RHD and LHD were directly compared on their ability to interpret what a character in a cartoon might be saying or thinking, in order to better understand the relative role of the right and left hemisphere in social communication. The cartoon stimuli were manipulated so as to elicit more or less formulaic responses (e.g., a scene of a couple being married by a priest vs. a scene of two people talking, respectively). Participants' responses were scored by blind raters on how appropriately they captured the gist of the social situation, as well as how formulaic and typical their responses were. Results showed that RHD individuals' responses were rated as significantly less appropriate than controls and were also significantly less typical than controls and individuals with LHD. Individuals with RHD produced a numerically lower proportion of formulaic expressions than controls, but this difference was only a trend. Counter to prediction, the pattern of performance across participant groups was not affected by how constrained/formulaic the social situation was. The current findings expand our understanding of the roles that the right and left hemispheres play in social processing and communication and have implications for the potential treatment of social communication deficits in individuals with RHD.

Cerebral asymmetry for language: Comparing production with comprehension

Although left-hemispheric damage can impair both the production and comprehension of language, it has been claimed that comprehension is more bilaterally represented than is production. A variant of this theme is based on the theory that different aspects of language are processed by a dorsal stream, responsible for mapping words to articulation, and a ventral stream for processing input for meaning. Some have claimed that the dorsal stream is left-hemispheric, while the ventral stream is bilaterally organized. We used fMRI to record activation while left- and right-handed participants performed covert word-generation task and judged whether word pairs were synonyms. Regions of interest were Broca's area as part of the dorsal stream and the superior and middle temporal gyri as part of the ventral stream. Laterality indices showed equal left-hemispheric lateralization in Broca's area for word generation and both Broca's area and temporal lobe for the synonym judgments. Handedness influenced laterality equally in each area and task, with right-handers showing stronger left-hemispheric dominance than left-handers. Although our findings provide no evidence that asymmetry is more pronounced for production than for comprehension, correlations between the tasks and regions of interest support the view that lateralization in the temporal lobe depends on feedback influences from frontal regions.

Hemispheric specificity for proprioception: Postural control of standing following right or left hemisphere damage during ankle tendon vibration

Right brain damage (RBD) following stroke often causes significant postural instability. In standing (without vision), patients with RBD are more unstable than those with left brain damage (LBD). We hypothesised that this postural instability would relate to the cortical integration of proprioceptive afferents. The aim of this study was to use tendon vibration to investigate whether these changes were specific to the paretic or non-paretic limbs.14 LBD, 12 RBD patients and 20 healthy subjects were included. Displacement of the Centre of Pressure (CoP) was recorded during quiet standing, then during 3 vibration conditions (80Hz – 20s): paretic limb, non-paretic limb (left and right limbs for control subjects) and bilateral. Vibration was applied separately to the peroneal and Achilles tendons. Mean antero-posterior position of the CoP, variability and velocity were calculated before (4s), during and after (24s) vibration.For all parameters, the strongest perturbation was during Achilles vibrations. The Achilles non-paretic condition induced a larger backward displacement than the Achilles paretic condition. This condition caused specific behaviour on the velocity: the LBD group was perturbed at the onset of the vibrations, but gradually recovered their stability; the RBD group was significantly perturbed thereafter. After bilateral Achilles vibration, RBD patients required the most time to restore initial posture.The reduction in use of information from the paretic limb may be a central strategy to deal with risk-of-fall situations such as during Achilles vibration. The postural behaviour is profoundly altered by lesions of the right hemisphere when proprioception is perturbed.