Hemisphere Damage Research Articles

Post-stroke deficits in the anticipatory control and bimanual coordination during naturalistic cooperative bimanual action

BackgroundUnilateral stroke leads to asymmetric deficits in movement performance; yet its effects on naturalistic bimanual actions, a key aspect of everyday functions, are understudied. Particularly, how naturalistic bimanual actions that require the two hands to cooperatively interact with each other while manipulating a single common object are planned, executed, and coordinated after stroke is not known. In the present study, we compared the anticipatory planning, execution, and coordination of force between individuals with left and right hemisphere stroke and neurotypical controls in a naturalistic bimanual common-goal task, lifting a box.MethodThirty-three individuals with chronic stroke (15 LCVA, 18 RCVA) and 8 neurotypical age-matched controls used both hands to lift a box fitted with force transducers under unweighted and weighted conditions. Primary dependent variables included measures of anticipation (peak grip and load force rate), execution (peak grip force, load force), and measures of within-hand (grip-load force coordination) and between-hand coordination (force rate cross-correlations). Primary analyses were performed using linear mixed effects modeling. Exploratory backward stepwise regression examined predictors of individual variability within participants with stroke.ResultsParticipants with stroke, particularly the RCVA group, showed impaired scaling of grip and load force rates with the addition of weight, indicating deficits in anticipatory control. While there were no group differences in peak grip force, participants with stroke showed significant impairments in peak load force and in grip-load force coordination with specific deficits in the evolution of load force prior to object lift-off. Finally, there were differences in spatial coordination of load force rates for participants with stroke, and especially the RCVA group, as compared to controls. Unimanual motor performance of the paretic arm and hemisphere of lesion (right hemisphere) were the key predictors of impairments in anticipatory planning of grip force and bimanual coordination among participants with stroke.ConclusionsThese results suggest that individuals with stroke, particularly those with right hemisphere damage, have impairments in anticipatory planning and interlimb coordination of symmetric cooperative bimanual tasks.

Diagnosis and treatment of subtentorial brain tumors in children 
 at the beginning of the XXI century

Cerebral tumors are among the most menacing pathologies occurring in children. Of all the cerebral tumors, posterior cranial fossa tumors have been most widespread in children. The review of literature provides a detailed description of clinical pattern. The sources related about earlier occurrence of non-focal symptoms, rather than focal signs: lack of energy, nausea, vomiting and headache. The authors provided detailed description of cerebellum damage in case of tumors, and split the symptoms of the hemisphere and vermis injuries as ataxy and typical cerebellar gait are common to spot the malignant process in the vermis, whereas dyssynergia and hypomyotonia occur in case of hemisphere damage. The clinical picture of hydrocephalus in tumor pathology of posterior cranial fossa is discussed: rapidly growing child head circumference, separation of cranial sutures, bulging of fontanelle, child restless behavior, and other signs. The need for CT and MRI was substantiated as the most important diagnostic techniques; the benefits of each were also stated. Discussion was given to the clinical pattern of hydrocephalus in tumor pathology of the posterior cranial fossa, and the authors put special emphasis on the significance of presurgical correction of hydrocephalus. The authors mentioned the use of a neuronavigation system during surgical intervention and characterized the major accesses (access via the median aperture, transvermial, telovelar access) and methods of craniotomy, indications for resection and osteoplastic trepanation. This article discussed the basic principles of radio and chemotherapy used to achieve a sustained remission, approximate treatment patterns for various posterior cranial fossa tumors are described. In addition, the authors mentioned the need for MRI with contrast agent each 3 months, and subsequent visits to the specialist in oncology.

Exploring Pragmatic Deficits in Relation to Theory of Mind and Executive Functions: Evidence from Individuals with Right Hemisphere Stroke.

Research investigating pragmatic deficits in individuals with right hemisphere damage focuses on identifying the potential mechanisms responsible for the nature of these impairments. Nonetheless, the presumed shared cognitive mechanisms that could account for these deficits have not yet been established through data-based evidence from lesion studies. This study aimed to examine the co-occurrence of pragmatic language deficits, Theory of Mind impairments, and executive functions while also exploring their associations with brain lesion sites. Twenty-five patients suffering from unilateral right hemisphere stroke and thirty-seven healthy participants were recruited for this study. The two groups were tested in pragmatics, Theory of Mind, and executive function tasks. Structural imaging data were also obtained for the identification of the lesion sites. The findings of this study suggest a potential convergence among the three aforementioned cognitive mechanisms. Moreover, we postulate a hypothesis for a neural circuitry for communication impairments observed in individuals with right hemisphere damage.

Immediate Effects of Anti-Spastic Epidural Cervical Spinal Cord Stimulation on Functional Connectivity of the Central Motor System in Patients with Stroke- and Traumatic Brain Injury-Induced Spasticity: A Pilot Resting-State Functional Magnetic Resonance Imaging Study.

Spinal cord stimulation (SCS) is one approach to the potential improvement of patients with post-stroke or post-traumatic spasticity. However, little is known about whether and how such interventions alter supraspinal neural systems involved in the pathogenesis of spasticity. This pilot study investigated whether epidural spinal cord stimulation at the level of the C3-C5 cervical segments, aimed at reducing spasticity, alters the patterns of functional connectivity of the brain. Eight patients with spasticity in the right limbs as a result of left cerebral hemisphere damage (due to hemorrhagic and ischemic stroke or traumatic and anoxic brain injury) were assessed with fMRI immediately before and immediately after short-term (1 to 6 days) test cervical epidural SCS therapy. Eight demographically and clinically comparable patients with spasticity in the right extremities due to a left hemisphere ischemic stroke and brain injury who received conventional therapy were examined as a control group. All patients also had paresis of one or two limbs and hyperreflexia. After the SCS therapy, there were three main findings: (1) higher functional connectivity of the brainstem to the right premotor cortex and changes in functional connectivity between cortical motor areas, (2) increased functional connectivity between the right and left lateral nodes of the sensorimotor network, and (3) a positive correlation between decreased spasticity in the right leg and increased functional connectivity within the right hemisphere sensorimotor cortex. All these changes in functional connectivity occurred with a statistically significant decrease in spasticity, as assessed using the modified Ashworth scale. The control group showed no decrease in spasticity or increase in functional connectivity in any of the seeds of interest. On the contrary, a decrease in functional connectivity of the brainstem and right postcentral gyrus was observed in this group during the observation period. We were thus able to detect intrinsic brain connectivity rearrangements that occurred during spasticity mitigation following short epidural SCS therapy. The clinical results obtained confirmed the efficacy of short-term anti-spastic SCS therapy. The obtained data on functional rearrangements of the central motor system may shed light on the mechanism of antispastic action of this procedure.

The right hemisphere's capacity for language: evidence from primary progressive aphasia.

The role of the right hemisphere (RH) in core language processes is still a matter of intense debate. Most of the relevant evidence has come from studies of gray matter, with relatively little research on RH white matter (WM) connectivity. Using Diffusion Tensor Imaging-based tractography, the current work examined the role of the two hemispheres in language processing in 33 individuals with Primary Progressive Aphasia (PPA), aiming to better characterize the contribution of the RH to language processing in the context of left hemisphere (LH) damage. The findings confirm the impact of PPA on the integrity of the WM language tracts in the LH. Additionally, an examination of the relationship between tract integrity and language behaviors provides robust evidence of the involvement of the WM language tracts of both hemispheres in language processing in PPA. Importantly, this study provides novel evidence of a unique contribution of the RH to language processing (i.e. a contribution independent from that of the language-dominant LH). Finally, we provide evidence that the RH contribution is specific to language processing rather than being domain general. These findings allow us to better characterize the role of RH in language processing, particularly in the context of LH damage.

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.

Discriminative value of different combinations of tests to detect unilateral neglect in patients with right hemisphere damage.

This study was undertaken to assess the most sensitive combination of tests to detect peripersonal unilateral neglect (UN) after stroke. The present study is a secondary analysis of a previously reported multicentric study of 203 individuals with right hemisphere damage (RHD), mainly subacute stroke, 11 weeks postonset on average, and 307 healthy controls. A battery of seven tests, providing 19 age- and education-adjusted z-scores, were given: the bells test, line bisection, figure copying, clock drawing, overlapping figures test, and reading and writing. Statistical analyses used a logistic regression and a receiver operating characteristic (ROC) curve after adjustment on demographic variables. A combination of four z-scores based on the following three tests provided good discrimination of patients with RHD from matched healthy controls: the starting point and the difference between the number of omissions on left and right sides from the bells test, rightward deviation in bisection of long lines (20 cm), and left-sided omissions in a reading task. The area under the ROC curve was 0.865 (95% confidence interval = 0.83-0.901), with sensitivity = 0.68, specificity = 0.95, accuracy = 0.85, positive predictive value = 0.90, and negative predictive value = 0.82. The most sensitive and parsimonious combination of tests to detect UN after stroke relies on four scores from three simple tests (bells test, line bisection, and reading). Future study is warranted to assess its ability to account for the functional difficulties of UN in daily life in the patient's actual environment.

Evaluation of driving fitness using driving simulators in patients with right-hemisphere damage: an unmatched case-control study

ABSTRACT Background Patients with right hemisphere damage (RHD) may exhibit mild unilateral spatial neglect (USN), which is difficult to detect in general assessments performed during driving rehabilitation. Objectives We compared driving simulator performance, practical driving performance, and neuropsychological test results between patients with RHD who were able and unable to return to driving to predict driving fitness based on driving simulator performance. Methods This unmatched case-control study included 29 patients with RHD who were able (return-to-driving group, n = 16) and unable (non-return-to-driving group, n = 13) to return to driving. Patient demographics, motor function, attention, driving simulator performance (participants’ reaction time and rate to green lamps appearing in any of the three displays and average lane position), and practical driving performance were compared between the groups. Receiver operating characteristic (ROC) analysis was performed to examine the predictive performance of driving fitness in reaction rate and paper-and-pencil tests. Results The non-return-to-driving group had a significantly lower reaction rate than the return-to-driving group (p = 0.027; 95% confidence interval [CI], 0–7; r = 0.407). No significant difference in reaction time or lane position in either the left or right lane during driving simulation was observed. ROC analysis of the reaction rate in the driving simulator task showed sensitivity of 0.692, specificity of 0.812, and area under the curve of 0.738 [95% CI, 0.541–0.935]. Conclusions Decreases in reaction rates during simulated driving assessments are associated with an inability to resume driving in patients with RHD. Such assessments may aid in predicting fitness for driving in these patients.

The continuous performance test aids the diagnosis of post-stroke cognitive impairment in patients with right hemisphere damage.

The purpose of the study was to investigate the time course difference of relative changes in oxygenated hemoglobin (Oxy-Hb) concentration in the prefrontal cortex (PFC) between controls and patients with post-stroke cognitive impairment (PSCI) who had right hemisphere damage (RHD) using the continuous performance test (CPT) and functional near-infrared spectroscopy (fNIRS) technology. The study aimed to evaluate the feasibility of CPT in the diagnosis and evaluation of PSCI with RHD. A total of 16 patients with RHD (RHD group) and 32 normal subjects (control group) were recruited. The Montreal Cognitive Assessment Scale was used to assess post-stroke cognitive impairment. The CPT and fNIRS were employed to investigate task-related changes in Oxy-Hb levels. The RHD group showed significantly lower accuracy and hit rates than the control group; however, the average reaction time was significantly longer in the former. Although the two groups showed no statistically significant difference in terms of left and right PFC integral values, the mean values were greater in the RHD group. The centroid value of the right PFC was significantly higher in the RHD group than in the control group. The time course of Oxy-Hb concentrations in the PFC differed between the two groups. In the RHD group, neural compensation was observed in both prefrontal lobes; however, the rate of compensation was slower on the affected side. The CPT may be helpful in the clinical diagnosis of PSCI with RHD. It may therefore be used to evaluate the effectiveness of cognitive interventions.

Perception of grammatical tone in Akan patients with left and right hemisphere brain damage

ABSTRACT It remains a matter of debate what roles the left and right hemispheres play in processing speech prosody. Brain lesion studies have demonstrated that lexical tone perception among native speakers of tonal languages is more disrupted in left hemisphere damaged (LHD) individuals than right hemisphere damaged (RHD) individuals. This has been taken to suggest that linguistically-relevant prosodic cues are predominantly left-lateralised, whereas non-linguistic stimuli are predominantly right-lateralised. However, this phenomenon has only been examined in lexical tone, leaving grammatical tone perception unexplored. The aim of this study was twofold: Firstly, to examine how individuals with LHD and RHD perceive grammatical tone, and secondly to compare grammatical tone to non-linguistic tone perception. Therefore, native Akan speakers with LHD, RHD and no-brain damage (NBD) controls were tested in two discrimination tasks that examined linguistic and non-linguistic tone perception. The results showed that while both the individuals with LHD and RHD show impairment in grammatical tone perception, there was a trend of a better performance for the RHD group. Nonetheless, for non-linguistic tone perception, individuals with LHD outperformed the RHD individuals, although both had reduced performance compared to the NBD individuals. A further analysis revealed that the reduced perceptual abilities of both the LHD and RHD groups in grammatical tone perception can be attributed to grammatical problems rather than tone per se. We conclude that there is potentially a bilateral involvement of the two hemispheres in grammatical tone processing, with the left being the dominant hemisphere.

The impact of visual and motor skills on ideational apraxia and transcortical sensory aphasia

Background Patients with extensive left hemisphere damage frequently have ideational apraxia (IA) and transcortical sensory aphasia (TSA). Difficulty with action coordination, phonological processing, and complex motor planning may not be indicative of higher-order motor programming or higher-order complex formation. We report on the effects of IA and TSA on the visual and motor skill of stroke patients. Purpose The study aims to address the question of whether IA and TSA in bilingual individuals are the results of an error of motor function alone or due to a combined motor plus and cognitive dysfunction effect. Method Twelve bilingual patients (seven males, and five females) were diagnosed with IA and TSA, and are divided into two groups of six patients. Then, 12 healthy bilingual controls were evaluated for comparing with both groups. Bilingual aphasia testing (BAT) and appropriate behavioral evaluation were used to assess motor skills, including coordination, visual-motor testing, and phonological processing. Results Findings (pointing skills) show that the performance of the L1 and L2 languages are consistently significant (p < 0.001) in healthy individuals compared to the IA and TSA groups. Command skills for L1 and L2 languages were significantly higher in healthy individuals compared to IA and TSA controls (p < 0.001). Further, the orthographic skills of IA and TSA vs controls in both groups were significantly reduced (p < 0.01). Visual skills in the L1 language were significantly improved (p < 0.05) in IA and TSA patients compared to healthy controls after 2 months. Unlike orthographic skills which were improved in IA and TSA patients, languages in bilingual patients did not simultaneously improve. Conclusion Dyspraxia is a condition that affects both motor and visual cognitive functions, and patients who have it often have less referred motor skills. The current dataset shows that accurate visual cognition requires both cognitive-linguistic and sensory-motor processes. Motor issues should be highlighted, and skills and functionality should be reinforced along with the significance of treatment between IA and TSA corresponding to age and education. This can be a good indicator for treating semantic disorders.

Undetected language deficits in left or right hemisphere post-stroke patients

Previous studies have reported that widely used tests for aphasia identification are unable to detect the subtle language deficits of left hemisphere brain damaged (LHBD) individuals. Similarly, the language disorders of individuals with right hemisphere brain damage (RHBD) usually remain undetected, due to the lack of any specialized test for the evaluation of their language processing skills. The aim of the present study was to evaluate the language deficits of 80 individuals suffering from the effects of either a LHBD or RHBD stroke, who were diagnosed as having no aphasia or language deficits based on the application of Boston Diagnostic Aphasia Examination. Their language abilities were examined with the use of the Adults’ Language Abilities Test, which explores morpho-syntactic and semantic phenomena of the Greek language in both the comprehension and production modalities. Results revealed that both groups of stroke survivors performed significantly worse compared to the group of healthy participants. Thus, it appears that the latent aphasia of LHBD and the language deficits of RHBD patients are likely to remain undetected and that patients are at risk of not receiving appropriate treatment if their language abilities are not evaluated by an effective and efficient battery of language tests.

Directional and general impairments in initiating motor responses after stroke.

Visuospatial neglect is a disorder characterized by an impairment of attention, most commonly to the left side of space in individuals with stroke or injury to the right hemisphere. Clinical diagnosis is largely based on performance on pen and paper examinations that are unable to accurately measure the speed of processing environmental stimuli-important for interacting in our dynamic world. Numerous studies of impairment after visuospatial neglect demonstrate delayed reaction times when reaching to the left. However, little is known of the visuospatial impairment in other spatial directions and, further, the influence of the arm being assessed. In this study, we quantify the ability of a large cohort of 204 healthy control participants (females = 102) and 265 individuals with stroke (right hemisphere damage = 162, left hemisphere damage = 103; mean age 62) to generate goal-directed reaches. Participants used both their contralesional and ipsilesional arms to perform a centre-out visually guided reaching task in the horizontal plane. We found that the range of visuospatial impairment can vary dramatically across individuals with some individuals displaying reaction time impairments restricted to a relatively small portion of the workspace, whereas others displayed reaction time impairments in all spatial directions. Reaction time impairments were observed in individuals with right or left hemisphere lesions (48% and 30%, respectively). Directional impairments commonly rotated clockwise when reaching with the left versus the right arms. Impairment in all spatial directions was more prevalent in right than left hemisphere lesions (32% and 12%, respectively). Behavioral Inattention Test scores significantly correlated (r = -0.49, P < 0.005) with reaction time impairments but a large portion of individuals not identified as having visuospatial neglect on the Behavioral Inattention Test still displayed reaction time impairments (35%). MRI and CT scans identified distinct white matter and cortical regions of damage for individuals with directional (insula, inferior frontal-occipital fasciculus and inferior longitudinal fasciculus) and general (superior and middle temporal gyri) visuospatial impairment. This study highlights the prevalence and diversity of visuospatial impairments that can occur following stroke.

Sensorimotor control of object manipulation following middle cerebral artery (MCA) stroke

Methods for assessing the loss of hand function post-stroke examine limited aspects of motor performance and are not sensitive to subtle changes that can cause deficits in everyday object manipulation tasks. Efficiently lifting an object entails a prediction of required forces based on intrinsic features of the object (sensorimotor integration), short-term updates in the forces required to lift objects that are poorly predicted (sensorimotor memory), as well as the ability to modulate distal fingertip forces, which are not measured by existing assessment tools used in clinics for both diagnostic and rehabilitative purposes. The presented research examined these three components of skilled object manipulation in 60 chronic, unilateral middle cerebral artery stroke participants. Performance was compared to age-matched control participants, and linear regressions were used to predict performance based on clinical scores. Most post-stroke participants performed below control levels in at least one of the tasks. Post-stroke participants presented with combinations of deficits in each of the tasks performed, regardless of the hemisphere damaged by the stroke. Surprisingly, the ability to modulate distal forces was impaired in those patients with damage ipsilateral (right hemisphere) to the hand being used. Sensorimotor integration was also impaired in patients with right hemisphere damage, though they performed at control levels in later lifts, whereas left-hemisphere-damaged patients did not. Lastly, during a task requiring sensorimotor memory, neither patient group performed outside of control ranges on initial lifts, with patients with right hemisphere damage showing impaired performance in later lifts suggesting they were unable to learn the mapping novel mapping of color and mass of the objects. The presented research demonstrates unilateral MCA stroke patients can have deficits in one or more components required for the successful manipulation of hand-held objects and that skillful object lifting requires intact bilateral systems. Further, this information may be used in future studies to aid efforts that target rehabilitation regimens to a stroke survivor's specific pattern of deficits.

Reading and listening comprehension in Cantonese-speaking people with right hemisphere versus left hemisphere brain damage

ABSTRACT The problem in language comprehension in people with right hemisphere damage (RHD) is more equivocal than people with left hemisphere damage. This study explores the reading and listening comprehension of Cantonese-speaking individuals with RHD, left hemisphere damage, and neurotypical healthy controls using the Cantonese Computerized Revised Token Test (CRTT-Cantonese) adapted from the English CRTT. Eighteen native Cantonese-speaking individuals with RHD, 32 individuals with left hemisphere damage and aphasia (PWA), and 42 healthy controls participated in this study. All the participants completed the Cantonese Aphasia Battery, Hong Kong Oxford Cognitive Screen, the listening comprehension version of CRTT-Cantonese (CRTT-L-Cantonese), and the reading comprehension version of CRTT-Cantonese (CRTT-R-WF-Cantonese) across different sessions. Linear mixed-effect analysis revealed significant differences among the groups in CRTT-Cantonese tests. However, there were no significant difference between CRTT-L-Cantonese and CRTT-R-WF-Cantonese within the PWA, RHD and healthy control groups. Tukey post-hoc pairwise comparisons showed that PWA scored significantly lower than RHD and healthy control groups (p < 0.0001) in both CRTT-L-Cantonese and CRTT-R-WF-Cantonese, and the RHD group scored significantly lower than healthy control group only on the CRTT-R-WF-Cantonese. The results demonstrate that the CRTT-L-Cantonese and CRTT-R-WF-Cantonese differentiate language comprehension abilities among PWA, RHD and healthy control groups. Although the current findings did not show any diversion between reading and listening comprehension in RHD group, this group showed poorer performance in reading comprehension when compared to healthy controls. The latter findings may support the view that the right hemisphere contributes to reading comprehension in Chinese.

Intersectionality of Race and Question-Asking in Women After Right Hemisphere Brain Damage.

Atypical pragmatic language can impede quality health care access. Right hemisphere brain damage (RHD) results in changes in pragmatic language use; however, little is known about whether there are racial/ethnic influences. Recent research indicated differences in question-asking when RHD survivors were compared with healthy controls, prompting the current examination of question production in women by race/ethnicity and the presence of RHD. Participants were eight Black and eight White women who sustained a single right hemisphere stroke at least 6 months prior to data collection (2016-2020), and eight Black and eight White control participants from the Right Hemisphere Damage Bank (https://rhd.talkbank.org). Videos of informal, first-encounter conversational discourse tasks were transcribed and coded. Analyses were conducted for frequency of questions and question type. Race/ethnicity had a statistically significant effect on the total number of questions and number of content and polar questions. The mean total of questions, number of content questions, and mean number of polar questions for Black participants was significantly less than White participants. There was less variability in question type for Black participants than White participants, and a tendency for Black participants to ask fewer questions regardless of RHD or control status. Acquisition of health information and ensuing health care might be less fruitful for Black women communicating with someone who may not know to conduct comprehension checks and be proactive in provision of information. To be culturally responsive to Black patients with communication disorders, providers might apply this awareness of reduced question-asking to their strategies to improve patient-provider communication. https://doi.org/10.23641/asha.21809475.

Immediate Effect of an Intervention Using a Head-mounted Display with a Modified Pitch Angle on Spatial Awareness and Standing Balance in Stroke Hemiparesis.

This study aimed to clarify the effect of an intervention using a head-mounted display with a web camera set at a modified pitch angle on spatial awareness, sit-to-stand movement, and standing balance in patients with left and right hemisphere damage. The participants were 12 patients with right hemisphere damage and 12 patients with left hemisphere damage. The line bisection test, a sit-to-stand movement, and balance assessment were performed before and after the intervention. The intervention task involved pointing at targets 48 times in an upward bias condition. Significant upward deviation on the line bisection test was noted in patients with right hemisphere damage. The load on the forefoot during the sit-to-stand movement was significantly increased. The range of anterior-posterior sway during forward movement in the balance assessment was reduced. An adaptation task performed in an upward bias condition may produce an immediate effect on upward localization, sit-to-stand movement, and balance performance in patients with right hemisphere stroke.

White Matter Correlates of Domain-Specific Working Memory.

Prior evidence suggests domain-specific working memory (WM) buffers for maintaining phonological (i.e., speech sound) and semantic (i.e., meaning) information. The phonological WM buffer's proposed location is in the left supramarginal gyrus (SMG), whereas semantic WM has been related to the left inferior frontal gyrus (IFG), the middle frontal gyrus (MFG), and the angular gyrus (AG). However, less is known about the white matter correlates of phonological and semantic WM. We tested 45 individuals with left hemisphere brain damage on single word processing, phonological WM, and semantic WM tasks and obtained T1 and diffusion weighted neuroimaging. Virtual dissections were performed for each participants' arcuate fasciculus (AF), inferior fronto-occipital fasciculus (IFOF), inferior longitudinal fasciculus (ILF), middle longitudinal fasciculus (MLF), and uncinate fasciculus (UF), which connect the proposed domain-specific WM buffers with perceptual or processing regions. The results showed that the left ILF, MLF, IFOF, and the direct segment of the AF were related to semantic WM performance. Phonological WM was related to both the left ILF and the MLF. This work informs our understanding of the white matter correlates of WM, especially semantic WM, which has not previously been investigated. In addition, this work helps to adjudicate between theories of verbal WM, providing some evidence for separate pathways supporting phonological and semantic WM.

Production and Comprehension of Prosodic Boundary Marking in Persons With Unilateral Brain Lesions.

Persons with unilateral brain damage in the right hemisphere (RH) or left hemisphere (LH) show limitations in processing linguistic prosody, with yet inconclusive results on their ability to process prosodically marked structural boundaries for syntactic ambiguity resolution. We aimed at systematically investigating production and comprehension of three prosodic cues (f 0 range, final lengthening, and pause) at structural boundaries in coordinate sequences in participants with right hemisphere brain damage (RHDP) and participants with left hemisphere brain damage (LHDP). Twenty RHDP and 15 LHDP participated in our study. Comprehension experiment: Participants and a control group listened to coordinate name sequences with internal grouping by a prosodically marked structural boundary (grouped condition, e.g., "(Gabi und Leni) # und Nina") or without internal grouping (ungrouped condition, e.g., "Gabi und Leni und Nina") and had to identify the target condition. The strength and combinations of prosodic cues in the stimuli were manipulated. Production experiment: Participants were asked to produce coordinate sequences in the two conditions (grouped, ungrouped) in two different tasks: a Reading Aloud and a Repetition experiment. Accuracy of participants' productions was subsequently assessed in a rating study and productions were analyzed with respect to use of prosodic cues. In the Comprehension experiment, RHDP and LHDP had overall lower identification accuracies than unimpaired control participants and LHDP were found to have particular problems with boundary identification when the pause cue was reduced. In production, LHDP and RHDP employed all three prosodic cues for boundary marking, but struggled to clearly mark prosodic boundaries in 28% of all productions. Both groups showed better performance in reading aloud than in repetition. LHDP relied more on using f 0 range and pause duration to prosodically mark structural boundaries, whereas RHDP employed final lengthening more vigorously than LHDP in reading aloud. We conclude that processing of linguistic prosody is affected in RHDP and LHDP, but not completely impaired. Therefore, prosody can serve as a relevant communicative resource. However, it should also be considered as a target area for assessment and treatment in both groups. https://doi.org/10.23641/asha.21637505.

Characteristics of language and communication after subcortical lesions in the left and right hemisphere

<h3>Research Objectives</h3> The present case comparison investigates to our knowledge for the first time, whether the dichotomy of specific linguistic and communicative characteristics following left and right hemisphere cortical lesions can also be demonstrated after subcortical damage. Classically, left hemisphere cortical lesions of language-relevant areas cause aphasia (Raymer & Rothi, 2018), with cardinal symptoms on a microlinguistic level (e.g. phonologic and semantic errors). Damage to right-hemisphere cortical areas typically results in Cognitive Communication Disorders (CCDs) (Blake, 2018). Symptoms of CCDs are mainly evident on a macrolinguistic level (e.g. tangentiality, verbosity). <h3>Design</h3> Systematic single-case comparison. <h3>Setting</h3> Neurological rehabilitation clinic. <h3>Participants</h3> Two persons with comparable subcortical lesions after postacute left (Patient A) and right (Patient B) basal ganglia hemorrhage stroke. Patient A: Anomic aphasia (Huber et al., 1983), fluent spontaneous speech, short, syntactically simple sentences, word-retrieval problems. Patient B: CCD (Quinting et al., 2020), fluent spontaneous speech, complex, partially paragrammatic syntax. <h3>Interventions</h3> Participants were assessed for communicative-pragmatic ability using the ANELT (Blomert et al., 1994; Rubi-Fessen et al., 2021). Responses were analyzed with regard to linguistic and communicative-pragmatic aspects. A linguistic evaluation was performed by computer-assisted software 'Aachen spontaneous speech analysis' (ASPA, Huber et al., 2005). <h3>Main Outcome Measures</h3> A-scale of the ANELT and linguistic parameters of ASPA. <h3>Results</h3> The results of the ANELT-A-scale were comparable for both patients (Patient A: 84/100, Patient B: 81/100 points). On a microlinguistic level, Patient A showed phonematic paraphasias; ASPA analyses revealed deviations from normative data from non-brain-damaged speakers (Hussmann et al., 2012) concerning all parameters except for type-token-ratio. Patient B´s reactions were syntactically complex and less coherent, indicating problems on a macrolinguistic level. However, ASPA analyses showed results slightly below average concerning percentage words and type-token-ratio. <h3>Conclusions</h3> Typical linguistic-communicative characteristics of cortical left- and right-hemispheric lesions may appear equivalently in left- and right hemispheric subcortical damage. With comparably good communicative effectiveness in the ANELT, these characteristics can also be shown quantitatively by specific patterns in spontaneous speech parameters in ASPA analyses. <h3>Author(s) Disclosures</h3> All authors report no conflicts of interest.