Right Hemisphere Damaged Patients Research Articles

Investigating the Effect of Different Types of Exercise on Upper Limb Functional Recovery in Patients with Right Hemisphere Damage Based on fNIRS.

To investigate the effects of functional occupational therapy (FOT) combined with different types of exercise on upper limb motor function recovery and brain function remodeling in patients with right hemisphere damage (RHD) by analyzing functional near-infrared spectroscopy (fNIRS). Patients (n = 32) with RHD at Beijing Bo'ai Hospital were recruited and randomly allocated to receive either FOT combined with passive motion (N=16) or FOT combined with assisted active movement (N=16). The passive motion group (FOT-PM) received functional occupational therapy for 20 min and passive exercise for 10 min in each session, while the assisted active movement group (FOT-AAM) received functional occupational therapy for 20 min and assisted active exercise for 10 min. Both groups received conventional drug therapy and other rehabilitation therapy. Treatment was performed once a day, 5 times a week for 4 weeks. The recovery of motor function and activities of daily living (ADL) was assessed using Fugl-Meyer Assessment upper extremity (FMA-UE) and modified Barthel index (MBI) before and after treatment, and brain activation of the bilateral motor area was analyzed with fNIRS. The findings suggested that FOT combined with AAM was more effective than FOT combined with PM in improving the motor function of RHD patients' upper limbs and fingers, improving their ability to perform activities of daily living, and facilitating brain function remodeling of the motor area.

Pragmatic deficits in patients with schizophrenia and right hemisphere damage: A pilot study.

While pragmatic deficits are well documented in patients with schizophrenia (SCZ) and right hemisphere damage (RHD), there is a paucity of research comparing the pragmatic deficits of these two groups. Do they experience similar cognitive dysfunction or is there a dissociation between the two patient groups? To investigate the nature of pragmatic deficits in these two groups and to gain an understanding of the underlying cognitive mechanisms that might be associated with these deficits to further future investigations. A total of 60 participants (15 patients with SCZ; 15 with RHD; 30 (15 + 15) healthy controls (HC) were administered the Bengali Audio-Visual Test-Battery for Assessment of Pragmatic Skills. Both SCZ and RHD patients were found to have significant pragmatic deficits compared with their matched controls. SCZ patients were found to score significantly better than the RHD group in six out of the 10 pragmatic skills when controlled for age and education. Discriminant function analysis was performed and 86.7% of the cases (HC = 100%, SCZ = 73.3% and RHD = 86.7%) were correctly reclassified into their original categories using the test scores. The study suggests that there is heterogeneity in the nature of the pragmatic breakdown within and across patient groups. Therefore, individualized restorative measures targeting the disrupted cognitive mechanism(s) might help elevate pragmatic competence and enhance the social functioning of patients with pragmatic deficits. What is already known on the subject Pragmatic deficits are common in adults with cognitive impairments of different etiologies. However, few studies have explored pragmatic deficits across clinical populations. Consequently, very little is known about the nature of pragmatic deficits in patients with schizophrenia and right hemisphere damage. What this paper adds to existing knowledge This work offers preliminary data on pragmatic difficulties in patients with schizophrenia and right hemisphere damage. This study overrides the boundaries of traditional classifications and evaluates pragmatic difficulties in these two clinical populations with reference to the underlying cognitive mechanisms, which might be disrupted. What are the potential or actual clinical implications of this work? The study adds a transdiagnostic perspective suggesting that there might be heterogeneity in pragmatic deficits, both within and across patient groups, and stresses the need for individualized therapy.

Unilateral Spatial Neglect without Hemiplegia: The Output-Mode Effect Revisited

BackgroundThe occurrence of unilateral spatial neglect (USN) in non-hemiplegic right-hemisphere damaged patients is rare. Earlier studies of such patients revealed a significant advantage when typical neglect tests were performed by the patient's left hand as compared to the dominant right hand. The mechanism underlying this "output-mode effect" remains elusive. MethodsWe analyzed the temporal dynamics of this effect using line-bisection task in 9 non-hemiplegic stroke patients with left-USN. ResultsIn 4 patients tested shortly after stroke onset (≤ 6 weeks), the impact of hand laterality was variable (left-hand advantage in one patient; right-hand advantage in 2 patients; similar performance in both hands in one patient). Only later (> 6 weeks) a clear advantage of the left hand emerged in the majority of patients, similar to the earlier reports which were all based on late testing. ConclusionsWe found variable dynamics in the expression of the output-mode effect in the first weeks following stroke onset, which may reflect changes of inter-hemispheric balance, related to recovery processes. We propose that therapeutic interventions aiming to manipulate the inter-hemispheric balance (e.g., by non-invasive brain stimulation) take into account the existence of such dynamics and their highly variate nature.

Discourse MarkerNa(那) as an Interpersonal-Level Compensatory Strategy in Clinical Interviews

AbstractDiscourse markers (DMs) are characterized by multifunctionality in different contexts. This study addressed the use of the Chinese DM,na(那), as a solution to topical divergence, during clinical interactions with right-hemisphere-damaged (RHD) patients. Drawing on data collected from clinical interviews between psychotherapists and RHD patients, this study examined the functions ofnain response to RHD topical divergence, focusing on the topic and attitudinal aspects. It was found thatnawas mainly employed by psychotherapists to mark a reproffer of interview topics (i. e., an attempt to return to earlier topics), and a display of disalignment and disaffiliation with RHD topical divergence. These functions ofnareflect the psychotherapists’ attempts to overcome communicative problems arising from RHD topical divergence, so as to ensure the achievement of the communicative goal. Thus,nacan be interpreted as a compensatory strategy for dealing with RHD topical divergence on an interpersonal level. These findings not only expand our knowledge about the function spectrum ofna, but also offer insights for RHD patients’ interlocutors to enhance conversational communication with RHD patients via the compensatory strategy.

Interactional consequences of topical divergences in clinical interviews: Indications of pragmatic impairment

Patients with right hemisphere damage (RHD) are often noticed to produce utterances that diverge from ongoing topics. These topical divergences are widely presumed to be pragmatic impairment that disrupt conversations, but there is little empirical research on how they actually impact the interactional progress in conversational communication. Similarly, topical divergences initiated by Chinese-speaking RHD patients have received hardly any attention in pragmatic research. Drawing on data from 30 clinical interviews between Chinese-speaking RHD patients and their psychotherapists, the present study investigates the interactional consequences of three types of RHD topical divergences mentioned in the literature and the resulting indications for pragmatic impairment. It is found that the three types of RHD topical divergences, i.e., the details type, the anecdotal type, and the disparate type, impacted the interview interactions differently. Among them, the details type, requiring interviewers to infer topical relevance, temporarily slows down the conversational progress and achievement of communicative goals. The anecdotal and the disparate types, both of which trigger rectification by interviewers, led to conversational breakdowns and even further to the failure of communicative goals. Such consequences reveal how topical divergences are inappropriate and/or communicatively inefficient in the institutional interactions of clinical interviews. These findings provide empirical grounds for characterizing them as pragmatic impairment and have important implications for evaluating the impact of those topical divergences on RHD patients’ participation in social interactions.

Is Theory of Mind the basis for exhaustivity in wh-questions? Evidence from TOM impairment after right hemisphere damage

Abstract How do we know when to provide an exhaustive answer to a wh-question, which mentions all the items that satisfy the property being asked about? We explored the nature of this exhaustivity requirement by investigating whether it is grammatical or based on assessing the information needs of the person asking the question. In Experiment 1 we tested 14 individuals after right hemisphere damage who had Theory of Mind (TOM) impairment (aTOMia), which compromised their ability to assess the information needs of their interlocutor, but whose grammatical abilities were normal. The rationale was that if they provided an exhaustive answer to certain question types, the exhaustivity requirement could not depend on considering the asker's intentions. We assessed their responses to single wh-questions (e.g., Who is painting?) and multiple wh-questions (e.g., Who is painting what?) in a question-about-a-picture task compared to 5 right-hemisphere damaged patients with good TOM, and to healthy controls. The individuals with aTOMia often failed to provide exhaustive responses to the single wh-questions, but consistently produced exhaustive responses to the multiple wh-questions. This finding suggests that the source of exhaustivity in single wh-questions is based on TOM, whereas exhaustivity in multiple wh-questions is grammatically-based. Following up on a further result from Experiment 1, Experiment 2 investigated the effect of the exhaustivity requirement on attention: 6 additional participants with left visuo-spatial neglect after right hemisphere damage were tested with a similar task to assess whether their answers omitted figures on the left. Both experiments -- Experiment 1 with eight neglect patients and Experiment 2 with six, revealed that the exhaustivity requirement also triggered attention shift to the left in individuals with left neglect: in their responses to single wh-questions they omitted the left figures, but in paired wh-questions they scanned the entire visual field and responded with exhaustive answers. The results provide clear evidence from neurolinguistics that exhaustivity in single wh-questions requires considerations of the asker's intentions, whereas multiple wh-questions mark the exhaustivity requirement grammatically.

Remembering a name: Neuropsychological validity studies and a computer proposal for detection of anomia.

ABSTRACTThere are contradictory results or lack of validity studies concerning the naming function and brain laterality. Although anomia is a frequent symptom of memory impairment, and the most relevant symptom of aphasia, few studies have been conducted to evaluate its validity for detecting patients with left-hemisphere damage (LD), as per the MeSH definition.Objective:To validate a paper-and-pencil confrontation naming test (CNT) according to side of brain injury; to select a valid and reliable abbreviated CNT wherein the effect of demographic variables is minimized; and to use the selected CNT to develop a computer-aided confrontation-naming evaluation (CACNE).Methods:Control data were obtained from 213 healthy participants (HP) aged 15 to 89 years. A subsample of 106 HP was demographically matched to 39 patients with LD and 40 patients with right-hemisphere damage (RD). Anomia definition and CNT cues were considered for the CACNE.Results:Test-retest and inter-rater reliability, internal consistency, and validity for detecting LD were demonstrated. A significant age effect was observed in HP. The CACNE was developed to detect anomia in interaction with environmental interventions.Conclusion:The inconsistencies observed in the CNT studies were probably due to the presence of anomia in almost 50% of the RD patients.

Re-assessing acalculia: Distinguishing spatial and purely arithmetical deficits in right-hemisphere damaged patients

Arithmetical deficits in right-hemisphere damaged patients have been traditionally considered secondary to visuo-spatial impairments, although the exact relationship between the two deficits has rarely been assessed. The present study implemented a voxelwise lesion analysis among 30 right-hemisphere damaged patients and a controlled, matched-sample, cross-sectional analysis with 35 cognitively normal controls regressing three composite cognitive measures on standardized numerical measures. The results showed that patients and controls significantly differ in Number comprehension, Transcoding, and Written operations, particularly subtractions and multiplications. The percentage of patients performing below the cutoffs ranged between 27% and 47% across these tasks. Spatial errors were associated with extensive lesions in fronto-temporo-parietal regions -which frequently lead to neglect- whereas pure arithmetical errors appeared related to more confined lesions in the right angular gyrus and its proximity. Stepwise regression models consistently revealed that spatial errors were primarily predicted by composite measures of visuo-spatial attention/neglect and representational abilities. Conversely, specific errors of arithmetic nature linked to representational abilities only. Crucially, the proportion of arithmetical errors (ranging from 65% to 100% across tasks) was higher than that of spatial ones. These findings thus suggest that unilateral right hemisphere lesions can directly affect core numerical/arithmetical processes, and that right-hemisphere acalculia is not only ascribable to visuo-spatial deficits as traditionally thought.

Theta-band functional connectivity in the dorsal fronto-parietal network predicts goal-directed attention

Functional imaging studies have identified a dorsal fronto-parietal network whose activity reflects shifts of attention in space and is sensitive to the behavioural relevance of stimuli. In patients with severe deficits of spatial attention this network is often structurally preserved. Here, we show that resting-state EEG functional connectivity in the dorsal fronto-parietal network predicts impaired goal-directed processing in stroke patients with spatial attention deficits. Eleven right-hemisphere damaged patients with different degrees of contralesional spatial deficits and sixteen age-matched healthy controls performed a visuo-spatial task which required them to react to a central target while ignoring task-relevant distracters presented left or right of fixation. Unlike controls, performance of patients was not modulated by the goal-relevance of peripheral distracters. Compared to controls patients showed a significant decrease in theta-band connectivity between the right dorsolateral prefrontal cortex and the right superior parietal region. Moreover, in both groups we observed a significant correlation between fronto-parietal connectivity and the behavioural effect of distracter relevance. These findings indicate that fronto-parietal functional connectivity is impaired in patients with spatial attention deficits and predicts effects of goal-relevant information on target processing.

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.

Beyond Neglect: Preliminary Evidence of Retrospective Time Estimation Abnormalities in Non-Neglect Stroke and Transient Ischemic Attack Patients.

Perception of the passage of time is essential for safe planning and navigation of everyday activities. Findings from the literature have demonstrated a gross underestimation of time interval in right-hemisphere damaged neglect patients, but not in non-neglect unilaterally-damaged patients, compared to controls. This study aimed to investigate retrospective estimation of the duration of a target detection task over two occasions, in 30 stroke patients (12 left-side stroke 15 right-side stroke, and 3 right-side stroke with neglect) and 10 transient ischemic attack patients, relative to 31 age-matched controls. Performances on visual short-term and working memory tasks were also examined to investigate the associations between timing abilities with residual cognitive functioning. Initial results revealed evidence of perceptual time underestimation, not just in neglect patients, but also in non-neglect unilaterally-damaged stroke patients and transient ischemic attack patients. Three months later, underestimation of time persisted only in left-side stroke and right-side stroke with neglect patients, who also demonstrated reduced short-term and working memory abilities. Findings from this study suggest a predictive role of residual cognitive impairments in determining the prognosis of perceptual timing abnormalities.

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

Hemispatial Neglect Shows That "Before" Is "Left".

Recent research has led to the hypothesis that events which unfold in time might be spatially represented in a left-to-right fashion, resembling writing direction. Here we studied fourteen right-hemisphere damaged patients, with or without neglect, a disorder of spatial awareness affecting contralesional (here left) space processing and representation. We reasoned that if the processing of time-ordered events is spatial in nature, it should be impaired in the presence of neglect and spared in its absence. Patients categorized events of a story as occurring before or after a central event, which acted as a temporal reference. An asymmetric distance effect emerged in neglect patients, with slower responses to events that took place before the temporal reference. The event occurring immediately before the reference elicited particularly slow responses, closely mirroring the pattern found in neglect patients performing numerical comparison tasks. Moreover, the first item elicited significantly slower responses than the last one, suggesting a preference for a left-to-right scanning/representation of events in time. Patients without neglect showed a regular and symmetric distance effect. These findings further suggest that the representation of events order is spatial in nature and provide compelling evidence that ordinality is similarly represented within temporal and numerical domains.

Right-hemisphere (spatial?) acalculia and the influence of neglect.

The present study aimed at exploring basic number and calculation abilities in right-hemisphere damaged patients (RHD), focusing primarily on one-digit orally presented tasks, which do not require explicit visuo-spatial abilities. Twenty-four non mentally-deteriorated RHD patients [12 with clinical neglect (RHDN+), 12 without clinical neglect (RHDN−)], and 12 healthy controls were included in the study. Participants were administered an ad hoc numerical battery assessing abilities such as counting, number magnitude comparison, writing and reading Arabic numerals and mental calculation, among others. Significant differences emerged among healthy controls and both the RHDN+ group and the RHDN− group, suggesting that the mathematical impairment of RHD patients does not necessarily correspond to the presence of left-neglect. A detailed analysis of the sub-tests of the battery evidenced expected differences among RHDN+ patients, RHDN− patients, and controls in writing and reading Arabic numerals. Crucially, differences between RHDN+ patients and controls were also found in tasks such as mental subtraction and mental multiplication, which do not require written visuo-spatial abilities. The present findings thus suggest that unilateral right hemisphere lesions may produce specific representational deficits that affect simple mental calculation, and not only the spatial arrangement of multi-digit written numbers as previously thought.

EPA-1071 – Emotion recognition deficit in patients with single right hemisphere damage

Introduction Research about psychological manifestations in right hemisphere damage (RHD) has increased in recent decades. The most characteristic alterations affect social cognition, which involves skills related to social interaction, as Theory of Mind, use of humor or metaphors comprehension inter alia. One of them is Facial Emotion Recognition (FER), which has been investigated in brain damaged patients, although studies present small samples and other metodological limitations. Objectives Comparing FER skills in a single RHD patients and non-brain damaged control group. Aims Identifying the FER patterns, analyzing differences according to the type of emotion. Method 46 patients with RHD due to stroke (mean age 68.93;SD12.62. 52% males) and 46 control subjects (67.28;SD18.29. 50% males), were assessed in sociodemographic and clinical variables. Mini-mental State Examination and Hamilton Depression Rating Scale were administered. To assess FER, 60 photographs from Pictures of Facial Affect (POFA) collection (Ekman, 1993) were shown to the sample, which identified them according to the type of emotion (i.e. happiness, fear, surprise, sadness, disgust, anger). Results Both samples, despite having similar characteristics, showed significant differences in FER (T=−2.751;p=0.007). In total sample, lowest performance was recorded in identifying fear (mean correct answers 0.45;SD0.252) and anger (0.48;SD0.301). RHD patients presented a deficit in FER skill compared to controls. Significant differences were found in recognizing anger (T=−2.043;p=0.044), disgust (T=−2.059;p=.042), happiness (T=−2.371;p=0.020), and sadness (T=−2.633;p=0.010). Conclusions Results confirm a probable relationship between single RH and FER, suggesting RH involvement in anger, disgust, happiness and sadness processing.

Crossed Dysgraphia: A case Report

Crossed Dysgraphia: A case Report

Immediate effects of exposure to positive and negative emotional stimuli on visual search characteristics in patients with unilateral neglect

The performance of patients with unilateral neglect (UN) in tasks demanding visual attention is characterized by contralesional disadvantage which is markedly unstable in magnitude. Such instability of the attentional system is seen very clearly in clinical practice and thus far has no satisfying explanation. Here we examined the immediate effect of exposure to non-lateralized emotional stimuli on UN patients' attentional bias and performance variability. We tested eight right-hemisphere damaged stroke patients with left-sided neglect and eight age-matched healthy subjects in a visual conjunction-search task, each trial performed immediately after viewing a centrally-presented picture, which was emotionally negative, positive or neutral. Both performance bias and variability in performing the search task was analyzed as a function of the valence of the picture, and a method for analyzing reaction time (RT) variance in a small sample is introduced. Overall, UN subjects, but not controls, were slower and more variable in their RT for left- compared to right-sided targets. In the UN group, detecting left-sided targets was significantly slower in trials that followed presentation of negative pictures as compared to positive pictures, regardless of the fact that both picture types were judged as equally arousing by the patients. Moreover, UN patients exhibited larger performance variance on the left then on the right, and negative emotional stimuli were associated with larger variance asymmetry than positive emotional stimuli. Examining the coefficient of variation pointed to a possible dissociation between the effects of emotional stimuli on the lateralized RT mean (reflecting attentional bias) and on the lateralized RT variance (reflecting system instability). We conclude that emotional stimuli affect the spatial imbalance of both performance speed and stability in UN patients.

Recovery of bimanual coordination is delayed after left hemispheric and/or purely cortical stroke lesions

Recovery of bimanual coordination is delayed after left hemispheric and/or purely cortical stroke lesions

Computer-Based Attention-Demanding Testing Unveils Severe Neglect in Apparently Intact Patients

We tested a group of ten post-acute right-hemisphere damaged patients. Patients had no neglect according to paper-and-pencil cancellation tasks. They were administered computer-based single- and dual-tasks, requiring to orally name the position of appearance (e.g. left vs. right) of briefly-presented lateralized targets. Patients omitted a consistent number of contralesional targets (≈ 40%) under the single-task condition. When required to perform a concurrent task which recruited additional attentional resources (dual-tasks), patients’ awareness for contralesional hemispace was severely affected, with less than one third of contralesional targets detected (≈ 70% of omissions). In contrast, performance for ipsilesional (right-sided) targets was close to ceiling, showing that the deficit unveiled by computer-based testing selectively affected the contralesional hemispace. We conclude that computer-based, attention-demanding tasks are strikingly more sensitive than cancellation tasks in detecting neglect, because they are relatively immune to compensatory strategies that are often deployed by post-acute patients.

Computer-based attention-demanding testing unveils severe neglect in apparently intact patients.

We tested a group of ten post-acute right-hemisphere damaged patients. Patients had no neglect according to paper-and-pencil cancellation tasks. They were administered computer-based single- and dual-tasks, requiring to orally name the position of appearance (e.g. left vs. right) of briefly-presented lateralized targets. Patients omitted a consistent number of contralesional targets (≈ 40%) under the single-task condition. When required to perform a concurrent task which recruited additional attentional resources (dual-tasks), patients’ awareness for contralesional hemispace was severely affected, with less than one third of contralesional targets detected (≈ 70% of omissions). In contrast, performance for ipsilesional (right-sided) targets was close to ceiling, showing that the deficit unveiled by computer-based testing selectively affected the contralesional hemispace. We conclude that computer-based, attention-demanding tasks are strikingly more sensitive than cancellation tasks in detecting neglect, because they are relatively immune to compensatory strategies that are often deployed by post-acute patients.