Right Brain Damaged Patients Research Articles

Time bisection and reproduction: Evidence for a slowdown of the internal clock in right brain damaged patients

Previous studies show that the right hemisphere is involved in time processing, and that damage to the right hemisphere is associated with a tendency to perceive time intervals as shorter than they are, and to reproduce time intervals as longer than they are. Whether time processing deficits following right hemisphere damage are related and what is their neurocognitive basis is unclear. In this study, right brain damaged (RBD) patients, left brain damaged (LBD) patients, and healthy controls underwent a time bisection task and a time reproduction task involving time intervals varying between each other by milliseconds (short durations) or seconds (long durations). The results show that in the time bisection task RBD patients underestimated time intervals compared to LBD patients and healthy controls, while they reproduced time intervals as longer than they are. Time underestimation and over-reproduction in RBD patients applied to short but not long time intervals, and were correlated. Voxel-based lesion-symptom mapping (VLSM) showed that time underestimation was associated with lesions to a right cortico-subcortical network involving the insula and inferior frontal gyrus. A small portion of this network was also associated with time over-reproduction. Our findings are consistent with a slowdown of an ‘internal clock’ timing mechanism following right brain damage, which likely underlies both the underestimation and the over-reproduction of time intervals, and their (overlapping) neural bases.

Sensitivity and Specificity of the Brentano Illusion Test in the Detection of Visual Hemi-Field Deficits in Patients with Unilateral Spatial Neglect.

Stroke survivors with right-brain damage (RBD) often present with attentional deficits such as left unilateral spatial neglect. Some patients also present with contralesional visual hemi-field deficits. A late detection of visual hemi-field deficits (VHFD) contributes to hampering neurorehabilitation and functional outcome of patients with neglect. The Brentano Illusion Test (BRIT) may be used for an early detection of VHFD during the neuropsychological assessment. In the present study, we determined the sensitivity and specificity of the BRIT for screening VHFD in patients with neglect. Sixty-four consecutive RBD patients were examined. Forty-five presented with neglect. Of these, 23 presented with VHFD (hemianopia or quadrantanopia) as detected by the Humphrey automated static visual field testing (reference standard). Consecutive patients also included 19 participants without neglect, who did not have any VHFD. The sensitivity and specificity of the BRIT for neglect patients were 78.3% (95% CI: 61.4-95.1) and 90.9 (95% CI: 78.9-100.0), respectively. Positive predictive value (PPV) was 89.6% (95% CI: 76.4-100.0); negative predictive value (NPV) 80.7% (95% CI: 65.2-96.2). No false positives in the group without neglect were identified. We conclude that the BRIT is an effective tool for clinical neuropsychologists to screen for possible VHFD in neglect patients during the neuropsychological assessment, allowing the refinement of the clinical picture in the neuropsychological report. An early detection of VHFD also allows referring the patient to standard diagnostics for a formal visual field examination, right from the first neuropsychological assessment.

Facial emotion perception and recognition deficits in acute ischemic stroke

BackgroundFacial emotion perception and recognition (FEPR) deficits are the sources of disability, impaired social relationship, and reduced quality of life. Studies of unilateral acute ischemic stroke (AIS) remain controversial about FEPR deficits. MethodsClinical and neurocognitive data were collected and analyzed among normal controls (NC) and AIS patients with left brain damage (LBD), right brain damage (RBD), and infratentorial brain damage (IBD). To assess FEPR, all participants completed a localization test (the Southeastern China Brief Affect Recognition Test). Correlation analyses were conducted between the FEPR deficits and cognitive functions. ResultsCompared with NC, all three groups of AIS patients reported significant FEPR deficits. Although no statistical difference in FEPR deficits were observed among the LBD, RBD and IBD patients, the deficit patterns were markedly different. FEPR deficits were positively correlated with cognitive impairment. ConclusionsFEPR deficits may occur in AIS patients and are associated with impaired cognitive functions, where the cerebral hemispheres and the infratentorial brain are jointly involved. Early recognition and early intervention of FEPR deficits in AIS patients are critical for post-stroke rehabilitation, reconstruction of social function and improvement in life quality.

Reliability and minimal detectable change of body-weight distribution and body sway between right and left brain-damaged patients at a chronic stage

Purpose To assess the reliability and minimal detectable change (MDC) of weight-bearing asymmetry (WBA) and body sway (BS) during “eyes open” (EO) and “eyes closed” (EC) conditions for those with right brain damage (RBD) and left brain damage (LBD) at a chronic stage. Methods Sixteen RBD and 16 LBD patients participated in two sessions within 15 days, composed of two trials of 30 s using a double force platform. Intraclass correlation coefficient (ICC2,1), the standard error of measurement (SEM), and MDC were calculated for WBA and BS (area and velocity of sway). Results Reliability of WBA was excellent (>0.75) except for EC for LBD patients (low SEM was found). The condition of EC was similar to or less reliable than that of EO. The MDC of WBA was 5.4 and 7.3% for LBD and RBD patients, respectively. Velocity of sway should be favored over the area of sway due to better reliability, with an MDC of 9 and 13 mm/s for RBD and LBD patients, respectively. Conclusions Parameters related to WBA and BS were highly reliable, without a difference between RBD and LBD patients, but less so in the condition of EC, and could be used for clinical rehabilitation and/or research. Implications for rehabilitation Weight-bearing asymmetry (WBA) and body sway (BS) are highly reliable posturography parameters. Reliability of WBA/BS is similar among right brain damaged (RBD) and left brain damaged (LBD) patients. A change of 5–7% can be interpreted as significant for WBA for chronic stroke. The minimal detectable change in measures is slightly higher for RBD patients.

Individual EEG profiling of attention deficits in left spatial neglect: A pilot study

Electrophysiological group studies in brain-damaged patients can be run to capture the EEG correlates of specific cognitive impairments. Nonetheless, this procedure is not adequate to characterize the inter-individual variability present in major neuropsychological syndromes. We tested the possibility of getting a reliable individual EEG characterization of deficits of endogenous orienting of spatial attention in right-brain damaged (RBD) patients with left spatial neglect (N+). We used a single-trial topographical analysis (STTA; [39] of individual scalp EEG topographies recorded during leftward and rightward orienting of attention with central cues in RBD patients with and without (N−) neglect and in healthy controls (HC). We found that the STTA successfully decoded EEG signals related to leftward and rightward orienting in five out of the six N+, five out of the six N− patients and in all the six HC. In agreement with findings from conventional average-group studies, successful classifications of EEG signals in N+ were observed during the 400–800 ms period post-cue-onset, which reflects preserved voluntary engagement of attention resources (ADAN component). These results suggest the possibility of acquiring reliable individual EEG profiles of neglect patients.

Visual working memory deficits following right brain damage

Visual working memory (VWM) involves the encoding and maintenance of visual information over time, with the requirement that object features be accurately bound to spatial locations. We and others have shown that damage to the right hemisphere leads to impaired spatial working memory. Here, we test the notion that right brain damage (RBD) may have consequences for domain general VWM. We had eight RBD patients and a group of healthy control participants perform a VWM task under different loads (1 to 3 items to recall) and spatial competition (high vs. low). All participants were asked to remember the colour of target items presented on the right side of space. Patients showed impaired encoding of information evident in poor precision of memory representations and increased guessing rates even at a set size of only one item. Our data suggests that VWM capacity is severely limited following RBD. Although five of the eight patients presented with neglect, it is not clear whether this deficit in VWM is unique to the syndrome. We suggest that future work should directly pit attention and VWM demands against one another in the same patients to determine whether the confluence of deficits in these domains is the critical determinant of the neglect syndrome. Regardless of the implications for the neglect syndrome, however, our data show that VWM deficits in RBD patients extend into non-spatial feature space.

Rightward exogenous attentional shifts impair perceptual memory of spatial locations in patients with left unilateral spatial neglect

Spatial remapping implies the updating and maintaining of the spatial position of objects in successive visual images across time, despite their displacement on the retina due to eye movements. In the parietal cortex, the representation of spatial locations appears to be partly centered on gaze direction, and thus modulated by current eye-gaze position. It has been suggested that short-term memory for spatial locations across delays might be impaired in right brain-injured patients with left spatial neglect, but more so after rightward than leftward gaze shifts – an asymmetry attributed to a loss of spatial representations normally transferred from left to right hemisphere during remapping. Because several studies point to a strong link between attentional and oculomotor circuits in the brain, we hypothesized that similar remapping effects might result from attentional displacements without overt eye movements. We tested this hypothesis in right-brain damaged patients with and without left neglect in a visuo-spatial memory task. As predicted, neglect patients showed a selective deficit in location memory following an exogenous attentional shift caused by a brief flash in the periphery of their right (but not left) visual field. We conclude that an attentional displacement without eye movements is sufficient to remap spatial representations across hemifields, and that this process is impaired in neglect patients when a location has to be transferred to the neglected/left side relative to current gaze or attention focus. More generally, these results support the notion of neural overlap between oculomotor and attentional mechanisms, and confirm a role for impaired remapping in the neglect syndrome, wherein spatial representations of contralesional locations may fail to be maintained during active attentional behavior.

Over- and underestimation of motor ability after a stroke: Implications for anosognosia

We administered a discrepancy-based measure of anosognosia for hemiplegia (AHP) to a group of 42 right-brain-damaged (RBD) and left-brain-damaged (LBD) stroke patients with varying levels of functional motor ability. In addition to the expected (anosognosic) pattern of overestimation of motor function in some RBD patients, we found an equal and opposite underestimation in some others, both RBD and LBD. We also found that around a quarter of self-estimation error could be predicted directly from actual ability, such that patients with poorer motor function tended to overestimate, and vice versa. This pattern suggests that some misestimation is attributable simply to statistical regression. However, even after adjusting for this regression effect, levels of overestimation were significantly greater in RBD patients, while LBD patients were more likely to underestimate their motor ability.

Rey-Osterrieth complex figure (ROCF) tracing task for evaluating unilateral spatial neglect

Unilateral spatial neglect (USN) is often observed in right brain-damaged (RBD) patients but it is a poor prognostic factor for predicting recovery of activities of daily living. In this study, we devised a convenient and quantitative test for evaluating USN, the Rey-Osterrieth Complex Figure (ROCF) tracing task, and examined its usefulness. The subjects were 40 healthy volunteers (21 males; mean age 58.9 years, SD 15.6) and 21 RBD patients (15 males; mean age 54.3 years, SD 10.1). After carrying out the task of copying ROCF, subjects underwent the task of tracing ROCF laid over carbon paper by using a chopstick so as not to leave lines directly on the ROCF. The RBD patients also carried out traditional tests for evaluating USN: the line bisection test, the line cancellation test, and a star cancellation test from the Japanese version of the Behavioral Inattention Test (BIT). We quantified results of both the copying and tracing tasks with the total score (Osterrieth, 1944) and the Laterality index (LI) (Jeffrey S 1995, 2001). We set the cut-off values for total score and LI to 2 SD below their averages in the healthy group. Of the 21 RBD patients, 5 had USN as judged with the traditional tests. However, with the ROCF tracing task, the total scores of 6 patients and the LIs of 9 patients were below the cut-off values. Furthermore, with the ROCF tracing task, in one RBD patient USN was revealed that had not appeared in the ROCF copying task, and in another patient USN was revealed more clearly than with copying because of a decrease of constructive apraxia. The ROCF tracing task might quantify certain aspects of movement memory in the neglect syndrome and detect USN with greater sensitivity than the traditional tests.

Ipsilesional deficit of selective attention in left homonymous hemianopia and left unilateral spatial neglect

AimsPatients with homonymous hemianopia may present a subtle ipsilesional deficit, recently referred to as ‘sightblindness’ in addition to the contralesional visual field defect. We recently demonstrated that this deficit could be worse in right brain-damaged patients with left hemianopia than in left brain-damaged patients with right hemianopia, confirming right hemisphere dominance for visuo-spatial and attentional capacities. In the present study we investigate whether this ipsilesional deficit could be attentional in nature and to what extent it is comparable in right brain-damaged (RBD) patients with left hemianopia and in RBD patients with left neglect. The study was also conducted in RBD patients with neither left hemianopia nor left neglect signs in order to test if a right hemisphere lesion per se could be responsible for subtle ipsilesional attentional deficit. To reach this aim, we tested selective attentional capacities in both visual fields of 10 right brain-damaged patients with left neglect (LN), 8 right brain-damaged patients with left homonymous hemianopia (LHH), 8 right brain-damaged patients with no signs of left neglect or left hemianopia (RBD controls), and 17 healthy age-matched participants (Normal controls). MethodA lateralized letter-detection task was used to test if right-brain damaged patients with LN or LH may present a deficit of selective attention in their right, ipsilesional visual field, in comparison to Normal and RBD controls. Participants were asked to detect a target letter in either a single large stimulus (low attentional load) or a small stimulus surrounded by flankers (high attentional load). Stimuli were displayed either in the left or in the right visual field. Accuracy and reaction times were recorded. ResultsResults on accuracy showed that both LN and LH patients exhibited lower correct responses than Normal controls in their ipsilesional right visual field, suggesting an attentional deficit in their ipsilesional, supposed healthy visual field. More specifically, LH patients exhibited a specific deficit for processing single large stimuli, but not for processing flanked stimuli, relative to normal controls. LN patients exhibited lower correct responses for processing all types of stimulus than normal controls, but also than right brain damaged controls, in both visual fields suggesting a non-lateralized deficit not only due to the right hemisphere lesion. Furthermore, this deficit is more pronounced for flanked small stimuli, requiring higher attentional load. ConclusionsThe present results bring further evidence that patients with left homonymous hemianopia or left unilateral neglect both present a weaker but significant ipsilesional deficit in addition to their well-known massive contralesional deficit. The presence of a specific attentional deficit in the right ipsilesional visual field of left hemianopic and left neglect patients is discussed regarding the hypothesis of hemispheric specialization for selective spatial attention and may have clinical implications for both conditions.

The way to "left" Piazza del Popolo: damage to white matter tracts in representational neglect for places.

The ability of seeing with the mind's eye, the visual mental imagery, is peculiarly compromised in patients with representational neglect. Representational neglect affects the processing of the left side of a mental image and may selectively concern the ability to imagine places and/or objects. Right-brain damaged patients with representational neglect for places (RN+) lose the ability to imagine themselves within a familiar place and fail in transforming an egocentric representation of the environment into an allocentric one and vice-versa. A peak region located at the posterior junction between the parietal and temporal lobes has emerged as pivotal in determining representational neglect for places. Here we aimed at verifying whether white matter disconnections affecting parietal lobe, by preventing the integration of egocentric information with the allocentric one, play a role in representational neglect for places. A track-wise statistical analysis on 58 right brain damaged patients, with and without extrapersonal perceptual neglect and/or representational neglect for places, suggests that the disconnection of the superior longitudinal fasciculus and that of the posterior arcuate segment, together with the disconnection of a fronto-parietal u-shaped tract, may be crucial in determining the representational neglect for places. These results suggest that representational neglect for places emerges from a complex pattern of lesion location and disconnection that involves parietal, temporal and frontal lobes.

Weight and see: Line bisection in neglect reliably measures the allocation of attention, but not the perception of length

Line bisection has long been a routine test for unilateral neglect, along with a range of tests requiring cancellation, copying or drawing. However, several studies have reported that line bisection, as classically administered, correlates relatively poorly with the other tests of neglect, to the extent that some authors have questioned its status as a valid test of neglect. In this article, we re-examine this issue, employing a novel method for administering and analysing line bisection proposed by McIntosh et al. (2005). We report that the measure of attentional bias yielded by this new method (EWB) correlates significantly more highly with cancellation, copying and drawing measures than the classical line bisection error measure in a sample of 50 right-brain damaged patients. Furthermore when EWB was combined with a second measure that emerges from the new analysis (EWS), even higher correlations were obtained. A Principal Components Analysis found that EWB loaded highly on a major factor representing neglect asymmetry, while EWS loaded on a second factor which we propose may measure overall attentional investment. Finally, we found that tests of horizontal length and size perception were related poorly to other measures of neglect in our group. We conclude that this novel approach to interpreting line bisection behaviour provides a promising way forward for understanding the nature of neglect.

Unawareness for Motor Impairment and Distorted Perception of Task Difficulty.

Anosognosia for motor impairment is a complex syndrome that can manifest itself under different forms, guiding patients' behavior and task decisions. However, current diagnostic tools tend to evaluate only more explicit aspects of anosognosia (asking the patients about their motor abilities) and fail to address more subtle features of awareness. We have developed a new assessment measure, the ECT (Errand Choice Test), where patients are asked to judge task difficulty rather than estimate their own impairment. We assessed awareness in a group of 73 unilateral left- and right-brain damaged (30 LBD and 43 RBD, respectively) patients by means of the VATAm, which explicitly requires them to evaluate their own motor abilities, and the ECT. A control group of 65 healthy volunteers was asked to perform the ECT under two conditions: Current condition (i.e., using both hands) and Simulated conditions (i.e., simulating hemiplegia). A total of 27% of the patients showed different performance on the VATAm and ECT, 21% of the patients showing lack of awareness only on VATAm and 6% only on ECT. Moreover, despite the ECT identified a higher frequency of anosognosia after RBD (33.3%) than LBD (27.6%), this hemispheric asymmetry was not significant. Remarkably, anosognosic patients performed very similarly to controls in the "current condition", suggesting that anosognosic patients' ability to perceive the complexity of each task per se is not altered. Different methods may be able to tackle different aspects of awareness and the ECT proved to be able to detect less evident forms of awareness. (JINS, 2018, 24, 45-56).

Visual feedback explains why propointing is better than antipointing in spatial neglect

Rossit et al. (2011) showed that neglect patients perform normally in a propointing task but not in an antipointing task which requires pointing towards the mirrored position of a target. It is assumed that antipointing relies on information from the perceptual pathway of our visual brain. Therefore, this finding supports the notion that neglect is a disorder that primarily affects perceptual spatial representations within the brain leaving spatial maps used for visuomotor guidance intact. Alternatively, performance of patients might be compromised in both tasks, but only obviously so in tasks in which online corrections are made more difficult. It can be argued that online-corrections via visual feedback are less effective in antipointing because a direct comparison between hand and target is not possible in this condition. Secondly, it is also known that neglect patients have a pronounced egocentric bias which is assumed to be associated with a deviation of the perceived body midline. Since the midline is used to compute the end-position in the antipointing task this could also explain why patients are worse in antipointing. We investigated the influence of visual feedback on pro- and antipointing and the effect of providing a visual reference line for the antipointing task in right-brain damaged patients with neglect (n = 20), right-brain damaged patients without neglect (n = 23) and in a group of healthy participants (n = 22). The withdrawal of visual feedback had a stronger effect on propointing compared to antipointing. This effect was stronger in neglect patients than in patients without neglect or healthy controls. The introduction of a reference line reduced errors in antipointing performance, particularly in neglect patients with a strong egocentric bias. The results support our alternative account and challenge the hypothesis that the spatial disorder in neglect affects primarily perceptual maps within the visual system.

Contribution of visuospatial attention, short-term memory and executive functions to performance in number interval bisection

Number interval bisection consists of estimating the mid-number within a pair (1–9=>5). Healthy adults and right-brain damage patients can show biased performance in this task, underestimating and overestimating the mid-number, respectively. The role of visuospatial attention during this task, and its interplay with other cognitive abilities (e.g., working memory) is still object of debate. In this study we explored the relation between visuospatial attention and individual differences in working memory and executive functions during number interval bisection. To manipulate the deployment of visuospatial attention, healthy participants tracked a dot moving to the left or moving to the right while bisecting numerical intervals. We also collected information concerning verbal and visuospatial short-term memory span, and concerning verbal and visuospatial fluency scores. Beside replicating what is typically observed in this task (e.g., underestimation bias), a correlation was observed between verbal short-term memory and bisection bias, and an interesting relation between performance in the number interval bisection, verbal short-term memory, and visuospatial attention. Specifically, performance of those participants with low verbal span was affected by the direction of the moving dot, underestimating at a larger extent when the dot moved leftward than rightward. Finally, it was also observed that participants’ verbal fluency ability contributed in the generation of biases in the numerical task. The finding of the involvement of abilities belonging to the verbal domain contributes to unveil the multi-componential nature of number interval bisection. Considering the debate on the nature of number interval bisection and its use in the clinical assessment of deficits following brain damage, this finding may be interesting also from a clinical perspective.

Ecological assessment of numerical skills in adults suffering from stroke

The present study first assesses calculation skills and number processing in patients suffering from cerebrovascular disease patients with Ecological Assessment Battery of Number (EABN), the only French test standardised and validated. Second, relationship between disorders-related lesions and brain lesion lateralization, and formal analytical testing and cognitive disorders were evaluated. Patients suffering from a stroke were included in three departments of physical and rehabilitation medicine. Inclusion criteria entailed having a stroke, over 18 years, and exempt from prior neurologic or psychiatric disease. The systematic assessment included: EABN, a formal analytical test: Évaluation clinique des aptitudes numériques (ECAN), an evaluation of speech processing (Boston Diagnostic Aphasia Examination = BDAE), a cognitive assessment (Montreal Cognitive Assessment = MOCA), and assessment of independence (Functional Independence Measure = FIM). We studied the link between variables through multivariate analyses. Non-parametric group comparisons were also conducted. Out of 48 strokes included, 36 showed left brain damage (LBD) (75%) and 10 right brain damage (RBD) (20.8%). Mean age was 59.2 years, mean duration after stroke was 8.5 months. 62.5% of subjects showed a pathological score on EABN. LBD patients were significantly more impaired ( P = 0.0089) and slower ( P = 0.0003) than RBD patients for all tests, especially for transcoding tests ( P = 0.0025). The total EABN score was correlated to the ECAN ( P < 0.0001), what accounts for its sensitivity to capture numerical skills disorders. The correlation found with the language functions ( P < 0.0001) was partly explained by the difficulties of LBD patients. Finally MOCA and MIF were correlated with the total score of the EABN ( P = 0.0009 and 0.004, respectively). The EABN is a robust promising tool that enable promote more systematic screening for calculation impairment in patients with a brain damage, (in particularly those with LBL left brain lesion) and assess its major impact on everyday life activity. This tool allows us to distinguish differences in performances according to differences in locations of the brain lesion. Therefore, it seems important to assess the number processing and calculation skills in clinical practice of all LBD patients, in addition to the formal cognitive assessment.

Imitation and matching of meaningless gestures: distinct involvement from motor and visual imagery.

The aim of the present study was to understand the underlying cognitive processes of imitation and matching of meaningless gestures. Neuropsychological evidence obtained in brain damaged patients, has shown that distinct cognitive processes supported imitation and matching of meaningless gestures. Left-brain damaged (LBD) patients failed to imitate while right-brain damaged (RBD) patients failed to match meaningless gestures. Moreover, other studies with brain damaged patients showed that LBD patients were impaired in motor imagery while RBD patients were impaired in visual imagery. Thus, we hypothesize that imitation of meaningless gestures might rely on motor imagery, whereas matching of meaningless gestures might be based on visual imagery. In a first experiment, using a correlational design, we demonstrated that posture imitation relies on motor imagery but not on visual imagery (Experiment 1a) and that posture matching relies on visual imagery but not on motor imagery (Experiment 1b). In a second experiment, by manipulating directly the body posture of the participants, we demonstrated that such manipulation evokes a difference only in imitation task but not in matching task. In conclusion, the present study provides direct evidence that the way we imitate or we have to compare postures depends on motor imagery or visual imagery, respectively. Our results are discussed in the light of recent findings about underlying mechanisms of meaningful and meaningless gestures.

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.

Long lasting reduction of postural asymmetry by prism adaptation after right brain lesion without neglect

Right brain damage (RBD) involves postural asymmetry and spatial frames disorders. In acute RBD patients, postural asymmetry is immediately reduced after one single session of prism adaptation (PA), without assessment of effects on spatial frames (Tilikete et al., 2001). To assess long-term effects of PA on posture and spatial frames in chronic RBD patients, without neglect. Six chronic RBD patients without neglect (mean delay: 45 months) were included. Each patient sustained 10 PA sessions of 20 minutes during 2 weeks. Outcome measures were: (i) posturographic analysis (mediolateral position of center of pressure (X cop ), (ii) subjective straight ahead (SSA) and perception of longitudinal body axis (LBA), (iii) the Scale for Controversive Pushing (SCP). Each parameter was assessed by 3 pre-tests and 3 post-tests (+2 h, Day + 3 and Day + 7). Moreover, the score of BBS, PASS, TUG and Barthel were measured. In pre-tests, all patients showed a shift of the X cop toward the right and a shift of SSA (4 toward the left and 2 toward the right). Four patients showed a shift of LBA (2 toward the right and 2 toward the left). The functional balance and the independence were decreased in all patients. In post-tests, results displayed (i) a significant reduction of mediolateral postural asymmetry at D + 7; (ii) a significant left deviation of SSA at D + 3 and enduring at D + 7; (iii) no significant modification of LBA and (iv) a significant increase of SCP at D + 3 and D + 7. Moreover, results showed a significant increase of PASS and BBS at D + 7. The mean curves of X cop and SSA between pre- and post-tests were similar. PA involves persistent reduction of postural asymmetry in RBD patients without neglect. These findings were obtained at a chronic stage. This new effect cannot be explained by reduction of spatial attentional shift. Improvement may be explained by a better calibration of extra-personal space frames used for posture, without effect on personal space frame. Findings argue in favour of a bottom-up effect of PA on mechanisms underlying spatial cognition.

Recuperation of daily activities and quality of life after stroke: The EAVQ-QdV scale

Stroke is a leading cause of long-term disability in adults. Few studies have investigated the impact of cognitive deficits on health-related quality of life (HRQOL) in patients or caregivers, notably in function of stroke laterality and of lesion volume. This research aims to a better evaluation of HRQOL with a new multi-dimensional scale based on description of the person's present state compared to the pre-stroke state. EAVQ-QdV is an auto-administered questionnaire composed of physical, cognitive, psychic and social domains. For each domain, difficulties and emotional report are evaluated. Patients’ and caregivers’ points of view are collected. Sixty-nine patients filled out the EAVQ-QdV in the chronic phase (46 right stroke, 23 left stroke). Patients also filled out SF36. MRI brain imaging was performed in all patients. Preliminary results show a significant negative correlation between EAVQ-QdV and SF36 (r = −0.54). Age, educational level, delay post-stroke or lesion volume did not correlated with the EAVQ-QdV scores. There was no difference between EAVQ-QdV scores in left-sided vs. right-sided strokes ( P > 0.45). However, right-brain damaged patients, but not left-brain damaged patients, underestimated their difficulties when their scores were compared to the caregivers’ ( P < 0.03). Analysis of the distinct domains of the scale revealed differences in language, attention, executive functions, memory and social relation, with greater severity in patients with left hemisphere strokes, and in the domain of visual neglect for patients with right-sided stroke ( P < 0.02). A single questionnaire exploring different cognitive domains, and comparing patients’ and caregivers’ assessments, with the evaluation of the emotional impact of patients’ and caregivers’ difficulties may permit to obtain a better estimation of residual handicap in stroke patients.