Anosognosia, neglect, extinction and lesion site predict impairment of daily living after right-hemispheric stroke

The effect of offline anosognosia for hemispatial neglect on neglect rehabilitation in patients with subacute and chronic right hemispheric brain injury. A retrospective cohort study

CLINICAL TRIALS REGISTRATION NUMBER

NCT05145855.

Impact of Spatial Neglect on Activity and Participation: A Mixed-Methods Study

Post-stroke neglect is disabling, yet it is unclear whether existing assessments capture the extent neglect affects activity and participation. The objective of the study is to explore stroke survivor and caregiver perspectives on how neglect affects activity and participation and to compare their experiences to neglect assessments items. We conducted an explanatory sequential mixed-methods study by conducting semi-structured interviews with stroke survivors (n = 7) and caregivers (n = 7) analyzed using thematic analysis. Stroke survivors completed the Catherine Bergego Scale (CBS) and Behavioral Inattention Test (BIT). Descriptive analyses characterized participant's neglect. The standardized CBS and BIT tests indicated that stroke survivors demonstrated mild-to-moderate (CBS) or no-to-mild (BIT) neglect. In contrast, the qualitative data revealed serious safety concerns and significant ongoing difficulties participating in school, work, and family activities because of neglect. Current assessments may not measure the impact of neglect on activity or participation in life for stroke survivors.

Clinical and demographic predictors of unilateral spatial neglect recovery after prism therapy among stroke survivors in the sub-acute phase of recovery

BACKGROUND AND AIMS: Unilateral Spatial Neglect (USN) affects the rehabilitation process and leads to poor outcomes after stroke. Factors that influence USN recovery following prism adaptation therapy have not been investigated. This study investigated predictors of USN recovery after prism therapy at the sub-acute phase of recovery. METHODS: This study was a randomized controlled trial. USN was assessed with the Behavioural Inattention Test and Catherine Bergego scale. Seventy-four patients with USN were divided into control and intervention group (prism). The prism group used 20 dioptre prism lenses for repeated aiming for 12 sessions while the control group used neutral lenses for aiming training. Regression analysis was conducted to establish clinical and sociodemographic factors that influence USN recovery. RESULTS: Gender, age, years of education, race, employment status, handedness, type of stroke, time since stroke and site of stroke (p > 0.005) showed no significant influence on USN recovery following PA treatment. Higher Cognitive function (OR  = 1.52, CI = 1.08-2.14, p =  0.016) and group allocationng (being in the prism group) (OR = 63.10, CI =  9.70-410.59, P < 0.001) were found to significantly influence USN recovery following PA treatment session. CONCLUSIONS: A significant modulating effect on general cognitive ability was found in this study. This suggests that prism adaptation therapy's effect on neural activity and spatial neglect depends on the cognitive function of stroke survivors.Trial registration: Pan African Clinical Trial Registry identifier: PACTR201903732473573.

An immersive virtual reality system for ecological assessment of peripersonal and extrapersonal unilateral spatial neglect

BACKGROUND

Unilateral spatial neglect (USN) is a debilitating neuropsychological syndrome that often follows brain injury, in particular a stroke affecting the right hemisphere. In current clinical practice, the assessment of neglect is based on old-fashioned paper-and-pencil and behavioral tasks, and sometimes relies on the examiner's subjective judgment. Therefore, there is a need for more exhaustive, objective and ecological assessments of USN.

METHODS

In this paper, we present two tasks in immersive virtual reality to assess peripersonal and extrapersonal USN. The tasks are designed with several levels of difficulty to increase sensitivity of the assessment. We then validate the feasibility of both assessments in a group of healthy adult participants.

RESULTS

We report data from a study with a group of neurologically unimpaired participants (N = 39). The results yield positive feedback on comfort, usability and design of the tasks. We propose new objective scores based on participant's performance captured by head gaze and hand position information, including, for instance, time of exploration, moving time towards left/right and time-to-reach, which could be used for the evaluation of the attentional spatial bias with neurological patients. Together with the number of omissions, the new proposed parameters can result in lateralized index ratios as a measure of asymmetry in space exploration.

CONCLUSIONS

We presented two innovative assessments for USN based on immersive virtual reality, evaluating the far and the near space, using ecological tasks in multimodal, realistic environments. The proposed protocols and objective scores can help distinguish neurological patients with and without USN.

The impact of apraxia and neglect on early rehabilitation outcome after stroke

Background

This study aims to characterize the impact of apraxia and visuospatial neglect on stroke patients’ cognitive and functional outcomes during early rehabilitation. Prior work implies an unfavorable effect of visuospatial neglect on rehabilitation; however, previous findings remain ambiguous and primarily considered long-term effects. Even less is known about the impact of apraxia on rehabilitation outcomes. Although clinicians agree on the significance of the first few weeks after stroke for the course of rehabilitation, studies exploring the impact of neglect and apraxia in this early rehabilitation period remain scarce.

Methods

Based on a screening of 515 hospitalized stroke patients from an early rehabilitation ward, 150 stroke patients (75 left-hemispheric strokes, 75 right hemispheric strokes) fulfilled the inclusion criteria and were enrolled in this observational, longitudinal study. The patients’ cognitive and functional statuses were documented at admission to the early rehabilitation ward and discharge. Also, detailed apraxia and neglect assessments were performed at midterm. The predictive values of age and apraxia and neglect severity (as reflected in two components from a principal component analysis of the neglect and apraxia assessments) for cognitive and functional outcomes at discharge were evaluated by multiple regression analyses.

Results

Besides the expected influence of the respective variables at admission, we observed a significant effect of apraxia severity on the cognitive outcome at discharge. Moreover, neglect severity predicted the Early Rehabilitation Barthel Index (Frühreha-Barthel-Index) at discharge. Supplementary moderator analysis revealed a differential effect of neglect severity on the cognitive outcome depending on the affected hemisphere.

Conclusion

Data indicate a strong association between apraxia and visuospatial neglect and early rehabilitation outcomes after stroke.

Current knowledge and practice of post-stroke unilateral spatial neglect rehabilitation: A cross-sectional survey of South African neurorehabilitation physiotherapists

Background

Unilateral spatial neglect (USN) affects the rehabilitation process leading to poor functional outcomes after stroke. South African physiotherapists’ level of uptake of available evidence in USN rehabilitation and the barriers they encounter are not known.

Objectives

To evaluate knowledge, current practice enablers and barriers to USN management in stroke survivors amongst physiotherapists in South Africa.

Methods

Our cross-sectional survey used a total sampling technique. Questionnaires were sent to neurorehabilitation physiotherapists in South Africa. Descriptive and inferential statistics analysed the data.

Results

The overall knowledge score of USN was 14.11 ± 5.23 of a total of 25. The knowledge was good for definitions of USN; moderate for incidences, causes, screening, diagnosis and prognosis of USN and poor for pharmacological approaches to the management of USN. A significant low positive correlation between respondents’ age (r = 0.46; p = 0.016) and years of practice as a physiotherapist (r = 0.43; p = 0.026) and knowledge of USN was found. The most frequently utilised intervention was constraint-induced movement therapy; the commonly utilised assessment tool was the comb and razor test. ‘Inadequate therapy time’ (55.56%) and ‘lack of relevant equipment for rehabilitation of USN’ (38.89%) were identified as major barriers to USN rehabilitation. Major enablers to USN rehabilitation were the ‘presence of multidisciplinary stroke team in clinical practice’ (83.35%) and ‘availability of adequate staff’ (76.47%).

Conclusion

Physiotherapists demonstrated a fair knowledge of USN although knowledge about pharmacological management of USN was modest. Current practice in post-stroke USN by South African neuro-physiotherapists follows current evidence and practice guidelines.

Clinical implication

Our study shows the level of knowledge and current practice of post-stroke USN rehabilitation. The demonstrated fair knowledge of USN may be improved through training, curriculum modifications or continuing professional development. Identified barriers to the rehabilitation of post-stroke USN can assist health policy, managers and clinicians to improve stroke-specific care.

Online awareness of performance on a functional cognitive assessment in individuals with stroke: A case-control study

Unawareness is a significant barrier to cognitive rehabilitation following acquired brain injury. Little is known about online awareness of cognitively-based instrumental activities of daily living (C-IADL) after stroke, particularly C-IADLs that emphasize executive functions. Our goal was to evaluate in stroke patients (1) online awareness during and immediately after a C-IADL task that emphasizes executive functions and (2) the association between awareness and performance on the C-IADL task. Seventy-seven stroke patients on an acute inpatient rehabilitation unit and 77 control participants completed the 10-item Weekly Calendar Planning Activity (WCPA-10), a standardized C-IADL task that requires working memory, planning, shifting, and inhibition. Trained examiners observed the use of a self-checking strategy and self-recognition of errors during the task. Immediately after the task, participants estimated their accuracy, and rated their own performance, which was compared with objective accuracy. Relative to the control group, stroke patients overestimated their accuracy, less often recognized errors, and less frequently used a self-checking strategy. Overestimation was associated with worse overall performance on the WCPA-10. Findings suggest that poor online awareness of C-IADL performance is common in stroke patients undergoing acute inpatient rehabilitation. Increasing awareness through metacognitive interventions should be a core focus of early post-stroke cognitive rehabilitation.

The Effect of Task-Oriented Training on Upper-Limb Function, Visual Perception, and Activities of Daily Living in Acute Stroke Patients: A Pilot Study

This pilot study aimed to investigate the effects of task-oriented training on upper-limb functioning, visual perception, and activities of daily living (ADL) in acute stroke patients. Of 20 participants, 10 were randomly assigned in a 1:1 ratio to experimental and control groups. Task-oriented training and table-top activity training were implemented for 6 weeks. Change in upper-limb functioning was assessed with the Manual Function Test (MFT); visual perceptual skill and ADL performance were evaluated using the Motor-Free Visual Perception Test—Vertical (MVPT-V) and Korean Modified Barthel Index (K-MBI), respectively. There was a significant interaction in the MFT and MBI score between the group and time (p < 0.05), but the group effect was not significant (p > 0.05). The MFT and MBI score significantly increased in both groups after the intervention (p < 0.001), but the effect size was greater in the task-oriented training group than the table-top activity training group. No significant interaction with MVPT-V score was found between the group and time (p > 0.05), and no statistical group difference was found either (p > 0.05). Both groups showed significant improvement in their MVPT-V score after the intervention (p < 0.001). The pilot study findings demonstrate that both task-oriented training and table-top activity training are effective in recovering upper-limb function, visual perception, and ADL in acute stroke patients.

Effects of visual-motor illusion in stroke hemiplegic patients with left-side personal neglect: A report of two cases

Personal neglect is the neglect of self-body space, which often occurs in patients with unilateral spatial neglect (USN), but lacks a dedicated rehabilitation. The purpose of this study was to investigate the effects of visual-motor illusion (VMI) on two-stroke hemiplegic patients with left-side personal neglect. Case 1 was a 53-year-old man diagnosed with a right lenticulostriate artery infarction. Case 2 was a 76-year-old woman diagnosed with a right middle cerebral artery infarction. USN symptoms were not observed in either patient in the desk USN assessment, but personal neglect and USN symptoms in daily life were observed in both patients. Intervention effects were verified using an ABA design, comprising a 5-day three-phase (A1, B, A2). In phase B, VMI was performed on the paralyzed upper limb for 10 min in addition to conventional physical therapy. Outcomes measures were the Fluff test, Catherine Bergego Scale (CBS), Fugl-Meyer Assessment (FMA), and Functional Independence Measure (FIM). In both patients, no improvements were noted in FMA, but improvements were observed in the Fluff test, CBS, and FIM in phase B; these effects were retained in phase A2. Therefore, VMI may have contributed to improvements in Personal neglect and USN symptoms in daily life.

Critical issue on the extinction and inattention subtest of NIHSS scale: an analysis on post-acute stroke patients attending inpatient rehabilitation

Objectives

This study aims to evaluate the diagnostic performance of NIHSS extinction and inattention item, compared to the results of the Oxford Cognitive Screen (OCS) heart subtest. Additionally, the possible role of the NIHSS visual field subtest on the NIHSS extinction and inattention subtest performance is explored and discussed.

Methods

We analysed scores on NIHSS extinction and inattention subtest, NIHSS visual field subtest, and OCS heart subtest on a sample of 118 post-stroke patients.

Results

Compared to OCS heart subtest, the results on NIHSS extinction and inattention subtest showed an accuracy of 72.9% and a moderate agreement level (Cohen’s kappa = 0.404). Furthermore, a decrease in NIHSS accuracy detecting neglect (61.1%) was observed in patients with pathological scores in NIHSS visual field item.

Conclusions

Extreme caution is recommended for the diagnostic performance of extinction and inattention item of NIHSS. Signs of neglect may not be detected by NIHSS, and may be confused with visual field impairment.

Trial registration

This study refers to an observational study protocol submitted to ClinicalTrials.gov with identifier: NCT03968627. The name of the registry is “Development of a National Protocol for Stroke Rehabilitation in a Multicenter Italian Institution” and the date of the registration is the 30th May 2019.

Recovery of Visuospatial Neglect Subtypes and Relationship to Functional Outcome Six Months After Stroke

Background/Objective. This study aims to investigate how complex visuospatial neglect behavioural phenotypes predict long-term outcomes, both in terms of neglect recovery and broader functional outcomes after 6 months post-stroke. Methods. This study presents a secondary cohort study of acute and 6-month follow-up data from 400 stroke survivors who completed the Oxford Cognitive Screen's Cancellation Task. At follow-up, patients also completed the Stroke Impact Scale questionnaire. These data were analysed to identify whether any specific combination of neglect symptoms is more likely to result in long-lasting neglect or higher levels of functional impairment, therefore warranting more targeted rehabilitation. Results. Overall, 98/142 (69%) neglect cases recovered by follow-up, and there was no significant difference in the persistence of egocentric/allocentric (X2 [1] = .66 and P = .418) or left/right neglect (X2 [2] = .781 and P = .677). Egocentric neglect was found to follow a proportional recovery pattern with all patients demonstrating a similar level of improvement over time. Conversely, allocentric neglect followed a non-proportional recovery pattern with chronic neglect patients exhibiting a slower rate of improvement than those who recovered. A multiple regression analysis revealed that the initial severity of acute allocentric, but not egocentric, neglect impairment acted as a significant predictor of poor long-term functional outcomes (F [9,300] = 4.742, P < .001 and adjusted R2 = .098). Conclusions. Our findings call for systematic neuropsychological assessment of both egocentric and allocentric neglect following stroke, as the occurrence and severity of these conditions may help predict recovery outcomes over and above stroke severity alone.

Effect of Prism Adaptation Therapy on the Activities of Daily Living and Awareness for Spatial Neglect: A Secondary Analysis of the Randomized, Controlled Trial

BACKGROUND

Rehabilitation for unilateral spatial neglect (USN) using prism adaptation (PA) is one of the most widely used methods, and the effectiveness of PA is well-evidenced. Although the effect of PA generalized various neglect symptoms, the effectiveness for some aspects of neglect is not fully proven. The Catherine Bergego Scale (CBS) was developed to identify problems with the activities of daily living (ADL) caused by USN. The CBS is composed of 10 observation assessments and a self-assessment questionnaire. To assess the self-awareness of USN, the anosognosia score is calculated as the difference between the observational scores and the self-assessment scores. To investigate how PA affects ADL and self-awareness in subacute USN patients during rehabilitation, we analyzed each item of the CBS and self-awareness from a randomized, controlled trial (RCT) that we previously conducted (Mizuno et al., 2011).

METHODS

A double-masked randomized, controlled trial was conducted to evaluate the effects of a 2-week PA therapy on USN in 8 hospitals in Japan. We compared each item of the CBS, anosognosia score, and absolute value of the anosognosia score between the prism group and the control group.

RESULTS

Two of ten items (gaze orientation and exploration of personal belongings) were significantly improved in the prism group compared with those in the control group. The absolute value of the anosognosia score was significantly improved by PA.

CONCLUSIONS

Improvement of oculomotor exploration by PA may generalize the behavioral level in a daily living environment. This study suggested that PA could accelerate the self-awareness of neglect during subacute rehabilitation.

Poststroke Cognitive Impairment Negatively Impacts Activity and Participation Outcomes: A Systematic Review and Meta-Analysis

This systematic review and meta-analysis aimed to investigate whether cognition is associated with activity and participation outcomes in adult stroke survivors. Five databases were systematically searched for studies investigating the relationship between general- and domain-specific cognition and longer-term (>3 months) basic activities of daily living (ADL), instrumental ADLs, and participation outcomes. Eligibility for inclusion, data extraction, and study quality was evaluated by 2 reviewers using a standardized protocol. Effect sizes (r) were estimated using a random-effects model. Sixty-two publications were retained for review, comprising 7817 stroke survivors (median age 63.57 years, range:18-96 years). Median length of follow-up was 12 months (range: 3 months-11 years). Cognition (all domains combined) demonstrated a significant medium association with all 3 functional outcomes combined, r=0.37 (95% CI, 0.33-0.41), P<0.001. Moderator analyses revealed these effects persisted regardless of study quality, order in which outcomes were collected (sequential versus concurrent), age, sample size, or follow-up period. Small to medium associations were also identified between each individual cognitive domain and the separate ADL, instrumental ADL, and participation outcomes. In conclusion, poststroke cognitive impairment is associated with early and enduring activity limitations and participation restrictions, and the association is robust to study design factors, such as sample size, participant age, follow-up period, or study quality. Cognitive assessment early poststroke is recommended to facilitate early detection of disability, prediction of functional outcomes, and to inform tailored rehabilitation therapies.

A novel computerized assessment of manual spatial exploration in unilateral spatial neglect

Unilateral spatial neglect is a neuropsychological syndrome commonly observed after stroke and defined by the inability to attend or respond to contralesional stimuli. Typically, symptoms are assessed using clinical tests that rely upon visual/perceptual abilities. However, neglect may affect high-level representations controlling attention in other modalities as well. Here we developed a novel manual exploration test using a touch screen computer to quantify spatial search behaviour without visual input. Twelve chronic stroke patients with left neglect and 27 patients without neglect (based on clinical tests) completed our task. Four of the 12 "neglect" patients exhibited clear signs of neglect on our task as compared to "non-neglect" patients and healthy controls, and six other patients (from both groups) also demonstrated signs of neglect compared to healthy controls only. While some patients made asymmetrical responses on only one task, generally, patients with the strongest neglect performed poorly on multiple tasks. This suggests that representations associated with different modalities may be affected separately, but that severe forms of neglect are more likely related to damage in a common underlying representation. Our manual exploration task is easy to administer and can be added to standard neglect screenings to better measure symptom severity.

Impact of visual impairment following stroke (IVIS study): a prospective clinical profile of central and peripheral visual deficits, eye movement abnormalities and visual perceptual deficits

AIM

This study evaluates the spectrum of visual impairment in stroke survivors.

METHODS

The Impact of Visual Impairment after Stroke (IVIS) study is a multi-centre, acute stroke unit, prospective epidemiology study. Comprehensive visual examination was offered to all stroke survivors.

RESULTS

1500 stroke admissions were recruited. 1204 stroke survivors had visual assessment. Reduced central vision was documented in 529, visual field loss in 308, ocular motility abnormalities in 533 stroke survivors, visual perception deficits in 59 stroke survivors and visual inattention in 315 stroke survivors. About half, regardless of visual impairment type, were visually asymptomatic. Recovery, whether full or partial, was best for central vision, ocular motility abnormalities and visual perception deficits (about 70% improvement) occurring over a mean follow-up period of 2-3 months.

CONCLUSIONS

Incidence of impaired central vision, visual field loss, ocular motility disorders and visual inattention was 29.4%, 24.8%, 39.3% and 26.2% respectively. Visual impairment was more likely to occur in more severe stroke and older stroke survivors. Asymptomatic cases raise concerns for acute stroke units where robust specialist vision screening is not routine. Those with partial/no recovery require specialist follow-up and management whilst the wide range of abnormalities highlight the need for specialist visual assessment acutely.Implications for rehabilitationVisual impairment is a common consequence of stroke.Incidence of visual impairment is about 60%.Significant numbers of stroke survivors are visually asymptomatic, highlighting the need for standardised vision assessments.Many stroke survivors have persistent long-term visual impairment, necessitating referral and access to specialist eye care services.

The importance of the insular cortex for vestibular and spatial syndromes

BACKGROUND AND PURPOSE

The aim of the study was to identify the neuroanatomical correlates and associations of neuropsychological syndromes after acute unilateral right-hemisphere brain lesions. The neuropsychological syndromes considered were orientation in three-dimensional space such as tilts of the subjective visual vertical or of the subjective haptic vertical, pusher syndrome, visual neglect and unawareness of paresis (anosognosia for hemiparesis). These neuropsychological phenomena have been found to occur separately or in different combinations after lesions to the right insular cortex.

METHOD

Magnetic resonance imaging scans were obtained from 82 patients with acute right-hemispheric stroke. A lesion-behavior mapping analysis was conducted to specify the neuroanatomical correlates of the above-mentioned neuropsychological syndromes.

RESULTS

In all analyses of the individual neuropsychological syndromes the insular cortex was affected.

CONCLUSIONS

Thus, the insular cortex is involved in (self-)perception and orientation within a three-dimensional space. Since isolated lesions of the insular cortex did not induce the above neuropsychological phenomena, there have to be other regions involved.

Feasibility and acceptability of the multicontext approach for individuals with acquired brain injury in acute inpatient rehabilitation: A single case series

The Multicontext (MC) approach, a metacognitive intervention designed to improve awareness, strategy use, and executive functioning, may be beneficial for individuals with acquired brain injury (ABI) undergoing acute inpatient rehabilitation. The goal of this study was to provide evidence of feasibility and acceptability of the MC approach and to explore clinical outcomes. A case series of eight individuals with acquired brain injury and at least mild executive functioning impairment were recruited from an acute inpatient rehabilitation unit. The MC approach - involving guided questioning and patient self-generation of strategies practiced across everyday functional cognitive tasks - was implemented within routine occupational therapy. Occupational therapists implemented the MC approach with high adherence to the treatment protocol. Therapists' perceived challenges were the time constraints of inpatient rehabilitation as well as client factors. Participants rated the MC approach as highly satisfying and engaging. They described subjective improvements in their ability to use executive functioning strategies. The MC approach was associated with improvement in awareness, strategy use, and executive functioning at the conclusion of treatment. The MC approach may be a beneficial intervention for individuals with acquired brain injury and executive dysfunction undergoing acute inpatient rehabilitation. Further evaluation with larger samples in controlled trials is warranted.Trial registration: ClinicalTrials.gov identifier: NCT04363645..

Speech-Language Pathology Practices for Adults With Right Hemisphere Stroke: What Are We Missing?

Purpose Limited evidence exists to guide the assessment and treatment of cognitive-communication disorders associated with right hemisphere stroke. The purpose of this study was to obtain information about speech-language pathologists' (SLPs') clinical practices and decision making for this population to understand what practices are being used and identify gaps in clinical practice. Method A survey was distributed via online ASHA Communities for the Special Interest Groups and other social media platforms. Respondents included 143 SLPs from across the United States representing 3-50 years of experience and a wide range of practice settings. Survey questions probed assessment practices including how tests are selected, what tests are used to diagnose specific deficits, and how confident SLPs were in their diagnoses. Treatment decisions were queried for a small set of disorders. Results SLPs routinely assess cognitive disorders using standardized tests. Communication disorders are less likely to be formally assessed. Three core right cerebral hemisphere deficits-anosognosia, aprosodia, and pragmatic deficits-are either not assessed or assessed only through observation by 80% of SLPs. Evidence-based treatments are commonly used for disorders of attention, awareness, and aprosodia. Conclusion Communication disorders are less likely to be formally assessed than cognitive disorders, creating a critical gap in care that cannot be filled by other allied health professionals. Suggestions for free or low-cost resources for evaluating pragmatics, prosody, and awareness are provided to aid SLPs in filling this gap. Supplemental Material https://doi.org/10.23641/asha.12159597.

Transcranial electric stimulation optimizes the balance of visual attention across space

OBJECTIVE

Transcranial direct current stimulation (tDCS) provides a way to modulate spatial attention by enhancing the ratio of neural activity between the left and right hemispheres, with a potential benefit for the rehabilitation of visual neglect.

METHODS

We tested the effect of bilateral tDCS in healthy individuals performing a visual detection task. This protocol consists in the positioning of the anode and cathode on mirror positions over the left and right parietal areas. The stimulation was repeated over three days to maximize the chance to observe a bias to the hemispace controlateral to the anode.

RESULTS

Compared to a sham treatment, left anodal - right cathodal stimulation enhanced attention across the full range of space, since the first day with no build-up effect on the next days, and modified the balance of left-right omissions when stimuli appeared at the same time.

CONCLUSION

Bilateral tDCS improved detection in both visual fields, with no privileged processing of one side, except when concurrent stimuli were presented. The results provide partial support to the hemispheric rivalry hypothesis.

SIGNIFICANCE

The technique has the potential to boost attention in neglect patients but should be used as an adjuvant rather than as an alternative to functional rehabilitation.

Frontal lesions predict response to prism adaptation treatment in spatial neglect: A randomised controlled study

Spatial neglect commonly follows right hemisphere stroke. It is defined as impaired contralesional stimulus detection, response, or action, causing functional disability. While prism adaptation treatment is highly promising to promote functional recovery of spatial neglect, not all individuals respond. Consistent with a primary effect of prism adaptation on spatial movements, we previously demonstrated that functional improvement after prism adaptation treatment is linked to frontal lobe lesions. However, that study was a treatment-only study with no randomised control group. The current study randomised individuals with spatial neglect to receive 10 days of prism adaptation treatment or to receive only standard care (control group). Replicating our earlier results, we found that the presence of frontal lesions moderated response to prism adaptation treatment: among prism-treated patients, only those with frontal lesions demonstrated functional improvements in their neglect symptoms. Conversely, among individuals in the standard care control group, the presence of frontal lesions did not modify recovery. These results suggest that further research is needed on how frontal lesions may predict response to prism adaptation treatment. Additionally, the results help elucidate the neural network involved in spatial movement and could be used to aid decisions about treatment.

Spatial Neglect in Stroke: Identification, Disease Process and Association with Outcome During Inpatient Rehabilitation

We established spatial neglect prevalence, disease profile and amount of therapy that inpatient stroke survivors received, and outcomes at discharge using Sentinel Stroke National Audit Programme (SSNAP) data. We used data from 88,664 National Health Service (NHS) admissions in England, Wales and Northern Ireland (July 2013–July 2015), for stroke survivors still in hospital after 3 days with a completed baseline neglect National Institute for Health Stroke Scale (NIHSS) score. Thirty percent had neglect (NIHSS item 11 ≥ 1) and they were slightly older (78 years) than those without neglect (75 years). Neglect was observed more commonly in women (33 vs. 27%) and in individuals with a premorbid dependency (37 vs. 28%). Survivors of mild stroke were far less likely to present with neglect than those with severe stroke (4% vs. 84%). Those with neglect had a greatly increased length of stay (27 vs. 10 days). They received a comparable amount of average daily occupational and physiotherapy during their longer inpatient stay but on discharge a greater percentage of individuals with neglect were dependent on the modified Rankin scale (76 vs. 57%). Spatial neglect is common and associated with worse clinical outcomes. These results add to our understanding of neglect to inform clinical guidelines, service provision and priorities for future research.

Visuospatial Neglect - a Theory-Informed Overview of Current and Emerging Strategies and a Systematic Review on the Therapeutic Use of Non-invasive Brain Stimulation

Visuospatial neglect constitutes a supramodal cognitive deficit characterized by reduction or loss of spatial awareness for the contralesional space. It occurs in over 40% of right- and 20% of left-brain-lesioned stroke patients with lesions located mostly in parietal, frontal and subcortical brain areas. Visuospatial neglect is a multifaceted syndrome - symptoms can be divided into sensory, motor and representational neglect - and therefore requires an individually adapted diagnostic and therapeutic approach. Several models try to explain the origins of visuospatial neglect, of which the "interhemispheric rivalry model" is strongly supported by animal and human research. This model proposes that allocation of spatial attention is balanced by transcallosal inhibition and both hemispheres compete to direct attention to the contralateral hemi-space. Accordingly, a brain lesion causes an interhemispheric imbalance, which may be re-installed by activation of lesioned, or deactivation of unlesioned (over-activated) brain areas through noninvasive brain stimulation. Research in larger patient samples is needed to confirm whether noninvasive brain stimulation can improve long-term outcomes and whether these also affect activities of daily living and discharge destination.

Impact of visuospatial neglect post-stroke on daily activities, participation and informal caregiver burden: A systematic review

OBJECTIVES

Visuospatial neglect (VSN) is a common cognitive disorder after stroke. The primary aim of this systematic review was to provide an overview of the impact of VSN in 3 aspects: (1) activities of daily living (ADL), (2) participation, and (3) caregiver burden. The second aim was to investigate the differences in studies focusing on populations with mean age<65 versus≥65 years.

METHODS

PubMed, EMBASE, Web of Science, Cochrane Library, Emcare, PsychINFO, Academic Search Premier and CENTRAL were searched systematically. Quality was assessed with the Mixed Methods Appraisal Tool.

RESULTS

Of the 115 included studies, 104 provided outcomes on ADL, 15 on participation (4 studies with mean age≥65), and 2 on caregiver burden (1 study with mean age≥65). Quality assessment yielded scores ranging from 0 to 100%. VSN had a negative impact on ADL (i.e., independence during ADL and performance in self-care, household tasks, reading, writing, walking, wheelchair navigation) and participation (i.e., driving, community mobility, orientation, work). The impact of VSN on fulfilling social roles was unclear. VSN had a negative effect on caregiver burden. We found no clear age-related differences.

CONCLUSIONS AND IMPLICATIONS

VSN has a negative impact not only on patients' independence but particularly on the performance of ADL. Despite the far fewer studies of VSN as compared with ADL, VSN also seems to hamper participation and increase caregiver burden, but further research is needed. Because of the large impact, VSN should be systematically and carefully assessed during rehabilitation. A considerable number of different instruments were used to diagnose VSN. Diagnosing VSN at more than one level [function (i.e., pen-and-paper test), activities, and participation] is strongly recommended. Consensus is needed on how to assess VSN and its negative impact for research and rehabilitation practice.

SYSTEMATIC REVIEW REGISTRATION NO

PROSPERPO Registration No. CRD42018087483.

Do stroke survivors agree with their clinicians on the extent of their post-stroke activity limitation and participation restriction?

This study aimed to examine discrepancies in the reporting of post-stroke functioning between stroke survivors and their clinicians across various disability domains and across current and predicted functioning. Fifty sub-acute stroke survivors (Age M = 70.30 SD = 15.80, 56% female) and their occupational therapist independently completed three measures assessing activity limitations (cognitive, physical, instrumental) and participation restrictions. Assessments were made of current functioning and predicted functioning at three months' post-discharge. Compared to physical functioning, appraisal discrepancies were more pronounced for cognitive functioning, instrumental activity limitation, and participation restriction. Discrepancies were more pronounced for current, as opposed to predicted, cognitive functioning (Z = -4.21, p < .001) and instrumental activity limitation (Z = -4.00, p < .001). Conversely, discrepancies in participation restriction were greatest for predicted functioning (Z = -4.03, p < .001). Follow-up (n = 39) showed that, compared to survivors' predictions, clinicians' predictions were more closely aligned with actual stroke survivor functioning at three months' post-discharge (as rated by a close other). These findings suggest appraisal discrepancy varies across disability domains and time reference points, with cognitive and complex functional activities being particularly discrepant between stroke survivors and clinicians. Furthermore, clinicians may hold more realistic expectations of short-term functional recovery.

Increased Risk of Traffic Injury After a Cerebrovascular Event

Background and Purpose- We aimed to determine the long-term risks of a motor vehicle collision after a cerebrovascular event and whether the risks were similar after left- or right-hemispheric events. Methods- We used a population-based registry to identify patients diagnosed with a transient ischemic attack or stroke (hemorrhagic or ischemic) between 2003 and 2013 in Ontario, Canada. Hemispheric laterality was determined using radiological and clinical findings. We identified subsequent serious injuries involving the patient as a driver using linked administrative data. Secondary outcomes included serious injuries involving the patient as a pedestrian, as a passenger, or other traumatic events (fall, fracture, ankle sprain). We used proportional hazard models accounting for death as a competing risk to test the association of hemispheric laterality and outcomes with and without adjustment for age, sex, discharge modified Rankin Scale score, home location, and prior driving record. Patients were followed through to 2017. Results- Among 26 144 patients with hemispheric cerebrovascular events, 377 subsequent serious traffic injuries as a driver (2.2 per 1000 person-year) were identified over a median follow-up of 6.4 person-years. The rate did not differ by laterality (adjusted hazard ratio, 1.00; 95% CI, 0.82-1.23). The risk of a serious traffic injury as a pedestrian was significantly higher after a right-sided than left-sided event (adjusted hazard ratio, 1.27; 95% CI, 1.02-1.58). Subsequent risks for other traumatic injuries did not differ by laterality of cerebrovascular event. Conclusions- The risk of a serious traffic injury as a pedestrian is substantially higher after a right-hemispheric cerebrovascular event compared with a left-sided event. Walking should be promoted for exercise in survivors of a stroke or transient ischemic attack, but these vulnerable road users may benefit from additional poststroke rehabilitation to optimize safety.

Visual Simultaneity Judgments Activate a Bilateral Frontoparietal Timing System

In everyday life, we often make judgments regarding the sequence of events, for example, deciding whether a baseball runner's foot hit the plate before or after the ball hit the glove. Numerous studies have examined the functional correlates of temporal processing using variations of the temporal order judgment and simultaneity judgment (SJ) tasks. To perform temporal order judgment tasks, observers must bind temporal information with identity and/or spatial information relevant to the task itself. SJs, on the other hand, require observers to detect stimulus asynchrony but not the order of stimulus presentation and represent a purer measure of temporal processing. Some previous studies suggest that these temporal decisions rely primarily on right-hemisphere parietal structures, whereas others provide evidence that temporal perception depends on bilateral TPJ or inferior frontal regions (inferior frontal gyrus). Here, we report brain activity elicited by a visual SJ task. Our methods are unique given our use of two orthogonal control conditions, discrimination of spatial orientation and color, which were used to control for brain activation associated with the classic dorsal ("where/how") and ventral ("what") visual pathways. Our neuroimaging experiment shows that performing the SJ task selectively activated a bilateral network in the parietal (TPJ) and frontal (inferior frontal gyrus) cortices. We argue that SJ tasks are a purer measure of temporal perception because they do not require observers to process either identity or spatial information, both of which may activate separate cognitive networks.

Underdiagnosis of Unilateral Spatial Neglect in stroke unit

OBJECTIVES

Unilateral spatial neglect (USN) is the incapacity to respond to stimuli presented opposite to a dysfunctional cerebral hemisphere. It is usually caused by non-dominant hemisphere lesions, leads to poorer prognosis and might be underdiagnosed. The objectives of the study were to ascertain the presence of USN in acute stroke patients and analyze the possible degree of underdiagnosis in a Stroke Unit.

MATERIALS AND METHODS

Prospective study of consecutive non-dominant hemisphere stroke patients within a period of 21 months. "Line Bisection" and "Triangles Cancellation" tests were used for USN screening and "Circle Gap Detection Task" to confirm the USN. The results were compared with routine Stroke Unit assessment using the NIHSS to determine the possible degree of underdiagnosis.

RESULTS

A total of 62 subjects, 38 women (61.29%), mean age of 74.05 (SD 10.5) years, were included. USN was diagnosed in 25 cases (40.3%) but 56% of them were not detected in routine evaluation using the NIHSS.

CONCLUSIONS

Unilateral spatial neglect, a common cognitive deficit after acute stroke, is greatly underdiagnosed in routine Stroke Unit assessment. The use of simple USN-specific screening tools would improve diagnosis and therefore the possibility of implementing appropriate rehabilitation strategies.

Eye-Tracking Provides a Sensitive Measure of Exploration Deficits After Acute Right MCA Stroke

The eye-tracking study aimed at assessing spatial biases in visual exploration in patients after acute right MCA (middle cerebral artery) stroke. Patients affected by unilateral neglect show less functional recovery and experience severe difficulties in everyday life. Thus, accurate diagnosis is essential, and specific treatment is required. Early assessment is of high importance as rehabilitative interventions are more effective when applied soon after stroke. Previous research has shown that deficits may be overlooked when classical paper-and-pencil tasks are used for diagnosis. Conversely, eye-tracking allows direct monitoring of visual exploration patterns. We hypothesized that the analysis of eye-tracking provides more sensitive measures for spatial exploration deficits after right middle cerebral artery stroke. Twenty-two patients with right MCA stroke (median 5 days after stroke) and 28 healthy controls were included. Lesions were confirmed by MRI/CCT. Groups performed comparably in the Mini-Mental State Examination (patients and controls median 29) and in a screening of executive functions. Eleven patients scored at ceiling in neglect screening tasks, 11 showed minimal to severe signs of unilateral visual neglect. An overlap plot based on MRI and CCT imaging showed lesions in the temporo-parieto-frontal cortex, basal ganglia, and adjacent white matter tracts. Visual exploration was evaluated in two eye-tracking tasks, one assessing free visual exploration of photographs, the other visual search using symbols and letters. An index of fixation asymmetries proved to be a sensitive measure of spatial exploration deficits. Both patient groups showed a marked exploration bias to the right when looking at complex photographs. A single case analysis confirmed that also most of those patients who showed no neglect in screening tasks performed outside the range of controls in free exploration. The analysis of patients' scoring at ceiling in neglect screening tasks is of special interest, as possible deficits may be overlooked and thus remain untreated. Our findings are in line with other studies suggesting considerable limitations of laboratory screening procedures to fully appreciate the occurrence of neglect symptoms. Future investigations are needed to explore the predictive value of the eye-tracking index and its validity in everyday situations.

Examining Anosognosia of Neglect

Unilateral neglect (neglect) and anosognosia often co-occur post stroke. It is unknown whether anosognosia of neglect varies for different types of daily activities. The objective is to examine the frequency of anosognosia of neglect for items on the Catherine Bergego Scale (CBS) and to determine the level of agreement between participant/assessor item ratings and total scores. Secondary analysis of data was carried out. We conducted descriptive analyses and interrater reliability analyses (Cohen's kappa) to determine the level of agreement between assessor and participant item ratings. A paired t test was conducted to compare assessor and participant total scores. The frequency of anosognosia among items varied (29.2%-83.3%) and Kappa statistics ranged from -0.07 (no agreement) to 0.23 (fair agreement) for item ratings. There was a significant difference- t(36) = 3.02, p ≤ .01)-between assessor ( M = 8.0, SD = 5.2) and participant-rated ( M = 5.3, SD = 4.5) total CBS scores. Anosognosia is prevalent among those with neglect. Findings highlight the importance of assessing for anosognosia.

Effect of subtypes of neglect on functional outcome in stroke patients

OBJECTIVE

Because of the loss of autonomy in daily-life activities, spatial neglect after stroke is one of the main causes of disability. According to the spatial domains, neglect can be divided into personal (body), peripersonal (reaching) and extrapersonal (far) space. We evaluated the effect of these subtypes of neglect on functional outcome of rehabilitation in stroke patients.

METHODS

A total of 1350 stroke patients were consecutively admitted into our neurorehabilitation unit from 2002 to 2016. We analyzed data for patients with a first ischemic or hemorrhagic right-hemispheric stroke in this observational retrospective study. The presence of neglect was evaluated by using structured tests for specific spatial domains. Patients underwent individual physical and occupational therapy, and those with neglect received specific therapy for 8 consecutive weeks consisting of visual scanning, reading and copying, copying line drawings on a dot matrix and describing scenes. The Functional Independence Measure (FIM) instrument was administered at both admission and discharge to assess functional autonomy. Rehabilitation effectiveness for FIM (percentage of potential improvement achieved) was calculated. Multiple regression analyses were performed.

RESULTS

Among 359 patients with right-brain damage, 130 showed left neglect, or unilateral spatial neglect (USN), and 229 only left hemiparesis, without neglect. Overall, 90 patients (69%) with USN showed peripersonal neglect, 89 (68%) extrapersonal neglect and 60 (46%) personal neglect. Functional motor and cognitive impairment was greater with than without USN as measured by FIM at admission and discharge and the rehabilitation hospital stay was longer. USN affected functional status at admission and rehabilitation effectiveness for FIM. Extrapersonal and peripersonal neglect significantly affected both function at admission and effectiveness.

CONCLUSIONS

Our data confirm the negative prognostic effect of neglect on functional outcome in a large sample. We also show the importance of evaluating and training according to neglect subtype to improve functional independence.

Exergames Encouraging Exploration of Hemineglected Space in Stroke Patients With Visuospatial Neglect: A Feasibility Study

Background

Use of exergames can complement conventional therapy and increase the amount and intensity of visuospatial neglect (VSN) training. A series of 9 exergames—games based on therapeutic principles—aimed at improving exploration of the neglected space for patients with VSN symptoms poststroke was developed and tested for its feasibility.

Objectives

The goal was to determine the feasibility of the exergames with minimal supervision in terms of (1) implementation of the intervention, including adherence, attrition and safety, and (2) limited efficacy testing, aiming to document possible effects on VSN symptoms in a case series of patients early poststroke.

Methods

A total of 7 patients attended the 3-week exergames training program on a daily basis. Adherence of the patients was documented in a training diary. For attrition, the number of participants lost during the intervention was registered. Any adverse events related to the exergames intervention were noted to document safety. Changes in cognitive and spatial exploration skills were measured with the Zürich Maxi Mental Status Inventory and the Neglect Test. Additionally, we developed an Eye Tracker Neglect Test (ETNT) using an infrared camera to detect and measure neglect symptoms pre- and postintervention.

Results

The median was 14 out of 15 (93%) attended sessions, indicating that the adherence to the exergames training sessions was high. There were no adverse events and no drop-outs during the exergame intervention. The individual cognitive and spatial exploration skills slightly improved postintervention (P=.06 to P=.98) and continued improving at follow-up (P=.04 to P=.92) in 5 out of 7 (71%) patients. Calibration of the ETNT was rather error prone. The ETNT showed a trend for a slight median group improvement from 15 to 16 total located targets (+6%).

Conclusions

The high adherence rate and absence of adverse events showed that these exergames were feasible and safe for the participants. The results of the amount of exergames use is promising for future applications and warrants further investigations—for example, in the home setting of patients to augment training frequency and intensity. The preliminary results indicate the potential of these exergames to cause improvements in cognitive and spatial exploration skills over the course of training for stroke patients with VSN symptoms. Thus, these exergames are proposed as a motivating training tool to complement usual care. The ETNT showed to be a promising assessment for quantifying spatial exploration skills. However, further adaptations are needed, especially regarding calibration issues, before its use can be justified in a larger study sample.

Integrating the Constructs of Anosognosia and Metacognition: a Review of Recent Findings in Dementia

The current review integrates recent findings regarding the construct of self-awareness in dementia from both clinical and cognitive perspectives. We present the predominant theoretical models of awareness and summarize both traditional and emerging approaches to assessing awareness from clinical and meta-cognitive perspectives. In this review, we focus primarily on findings from recent studies in anosognosia and meta-cognition in the context of neurodegenerative disease with special emphasis on Alzheimer's disease and frontotemporal dementia. Emerging trends in the study of awareness, including examination of the longitudinal course of anosognosia, and investigation of the neural substrates underlying meta-cognitive abilities are addressed. Finally, the practical importance of studying and assessing awareness from both theoretical and clinical angles is emphasized.

Spatial Neglect Predicts Upper Limb Use in the Activities of Daily Living

Background and Purpose: Motor tests performed at stroke onset have been shown to predict the recovery of upper limb motor impairment. Less is known about upper limb recovery at the level of functional activity or of participation and how spatial neglect may influence the integration of the upper limb in the activities of daily living (ADL). Our objective was to investigate whether the initial severity of spatial neglect may predict upper limb use in ADL. Methods: Eighty-two patients with a right-hemispheric stroke (RHS) were prospectively included in the study. They were assessed twice in the acute/subacute and in the subacute/chronic phases (mean time interval of 45 days) after stroke. The Catherine Bergego Scale (CBS) was used to quantify the influence of spatial neglect on the ADL. Contralesional upper limb use in the ADL was evaluated with the Lucerne international classification of function, disability and health-based Multidisciplinary Observation Scale. Hand strength was measured using the Jamar, dexterity with the Nine Hole Peg test, and tactile perception using the stereognosis subtest of the Nottingham Sensory Assessment. Cognitive functions were assessed with the Montreal Cognitive Assessment. Results: Regression analyses revealed that spatial neglect is an independent and a significant predictor of upper limb outcome. A CBS score of ≤5 at the time of admission to neurorehabilitation care was highly predictive for good upper limb use in the ADL 45 days later. Conclusions: This study demonstrates that spatial neglect severity, as observed in the ADL, is a significant and an independent predictor of upper limb outcome. Neglect therapy is thus needed to further improve contralesional upper limb use in the ADL in RHS patients.

Awareness of cognitive impairment in individuals with essential tremor

OBJECTIVE

The extent to which individuals with ET who have clinically significant cognitive impairment are aware of their cognitive changes is unclear. Reduced awareness has important implications for everyday function and decision-making.

METHODS

150 individuals with ET (109 Normal Cognition (ET-NC group), and 30 with MCI and 11 dementia (ET-CI group)) completed self-ratings and objective assessments of memory, language, and executive functioning. Discrepancy scores were calculated to assess awareness of cognitive functioning. One sample t-tests evaluated whether mean discrepancy scores in each group were comparable to zero (i.e., accurate). Analyses of covariance (ANCOVA) compared discrepancy scores across two groups controlling for age and education.

RESULTS

In the ET-NC group, discrepancy scores for language (M=-0.08, SD=1.10) and executive functioning (M=-0.01, SD=0.99) were comparable to zero. Memory discrepancy scores (M=0.32, SD=1.22) were greater than zero. In the ET-CI group, memory, (M=0.78, SD=1.01), language, (M=0.46, SD=0.95), and executive (M=0.39, SD=1.14) discrepancy scores were all greater than zero. Discrepancy scores were larger in ET-CI group than in ET-NC group for memory: F(1,148)=4.02, p=0.047, language: F(1,148)=6.16, p=0.014, and executive: F(1,148)=4.51, p=0.035.

CONCLUSIONS

Individuals with ET and normal cognition accurately assessed their language and executive abilities, demonstrating mild overconfidence in memory function. Individuals with ET and cognitive impairment overestimated their performance in all domains of functioning. Since ET is linked to increased risk for cognitive impairment, and such impairment may not be accurately perceived, cognitive functioning should be proactively and regularly screened in ET.

Acute Frontal Lobe Dysfunction Following Prefrontal Low-Frequency Repetitive Transcranial Magnetic Stimulation in a Patient with Treatment-Resistant Depression

The potential of repetitive transcranial magnetic stimulation (rTMS) to treat numerous neurological and psychiatric disorders has been thoroughly studied for the last two decades. Here, we report for the first time, the case of a 65-year-old woman suffering from treatment-resistant depression who developed an acute frontal lobe syndrome following eight sessions of low-frequency rTMS (LF-rTMS) to the right dorsolateral prefrontal cortex while also treated with sertraline and mianserin. The pathophysiological mechanisms underlying such an unexpected acute frontal lobe dysfunction are discussed in relation to the therapeutic use of LF-rTMS in combination with pharmacotherapy in depressed patients.

Effect of Right Insular Involvement on Death and Functional Outcome After Acute Ischemic Stroke in the IST-3 Trial (Third International Stroke Trial)

Background and Purpose—

In patients with acute ischemic stroke, whether involvement of the insular cortex influences outcome is controversial. Much of the apparent adverse outcome may relate to such strokes usually being severe. We examined the influence of right and left insular involvement on stroke outcomes among patients from the IST-3 study (Third International Stroke Trial) who had visible ischemic stroke on neuroimaging.

Methods—

We used multiple logistic regression to compare outcomes of left versus right insular and noninsular strokes across strata of stroke severity, on death, proportion dead or dependent, and level of disability (ordinalized Oxford Handicap Score) at 6 months, with adjustment for the effects of age, lesion size, and presence of atrial fibrillation.

Results—

Of 3035 patients recruited, 2099 had visible ischemic strokes limited to a single hemisphere on computed tomography/magnetic resonance scans. Of these, 566 and 714 had infarction of right and left insula. Six months after randomization, right insular involvement was associated with increased odds of death when compared with noninsular strokes on the left side (adjusted odds ratio, 1.83; 95% confidence interval, 1.33−2.52), whereas the adjusted odds ratio comparing mortality after insular versus noninsular strokes on the left side was not significant. Among mild/moderate strokes, outcomes for right insular involvement were worse than for left insular, but among more severe strokes, the difference in outcomes was less substantial.

Conclusions—

We found an association between right insular involvement and higher odds of death and worse functional outcome. The difference between right- and left-sided insular lesions on outcomes seemed to be most evident for mild/moderate strokes.

Clinical Trial Registration—

URL: http://www.isrctn.com . Unique identifier: ISRCTN25765518.

Investigating structure and function in the healthy human brain: validity of acute versus chronic lesion-symptom mapping

Modern voxel-based lesion-symptom mapping (VLSM) analyses techniques provide powerful tools to examine the relationship between structure and function of the healthy human brain. However, there is still uncertainty on the type of and the appropriate time point of imaging and of behavioral testing for such analyses. Here we tested the validity of the three most common combinations of structural imaging data and behavioral scores used in VLSM analyses. Given the established knowledge about the neural substrate of the primary motor system in humans, we asked the mundane question of where the motor system is represented in the normal human brain, analyzing individual arm motor function of 60 unselected stroke patients. Only the combination of acute behavioral scores and acute structural imaging precisely identified the principal brain area for the emergence of hemiparesis after stroke, i.e., the corticospinal tract (CST). In contrast, VLSM analyses based on chronic behavior-in combination with either chronic or acute imaging-required the exclusion of patients who had recovered from an initial paresis to reveal valid anatomical results. Thus, if the primary research aim of a VLSM lesion analysis is to uncover the neural substrates of a certain function in the healthy human brain and if no longitudinal designs with repeated evaluations are planned, the combination of acute imaging and behavior represents the ideal dataset.

Space-related confabulations after right hemisphere damage

Confabulations usually refer to memory distortions, characterized by the production of verbal statements or actions that are inconsistent with the patient's history and present situation. However, behavioral patterns reminiscent of memory confabulations can also occur in patients with right hemisphere damage, in relation to their personal, peripersonal or extrapersonal space. Thus, such patients may be unaware of their left hemiplegia and confabulate about it (anosognosia), deny the ownership of their left limbs (somatoparaphrenia), insult and hit them (misoplegia), or experience a "third", supernumerary left limb. Right brain-damaged patients can also sometimes confabulate about the left, neglected part of images presented in their peripersonal space, or believe to be in another place (reduplicative paramnesia). We review here these instances of confabulation occurring after right hemisphere damage, and propose that they might reflect, at least partially, the attempts of the left hemisphere to make sense of inappropriate input received from the damaged right hemisphere.

Cerebrovascular disease

With 16.9 million people who suffered a first-ever stroke in 2010 worldwide, stroke is a very common vascular disease. Epidemiologic studies have played an essential role in assessing this burden and in detecting the risk factors for stroke. Primary prevention of these risk factors, primarily hypertension, smoking, diabetes, and atrial fibrillation, has reduced the incidence in high-income countries. However, stroke remains a major cause of death and disability, and therefore research should be continued. Subarachnoid hemorrhages are less prevalent than strokes but have an even higher risk of death. Similar to stroke, epidemiologic studies identified smoking and hypertension as its most important risk factors, together with excessive alcohol intake. Although rare, arterial dissections, CADASIL, arteriovenous malformations, venous sinus thrombosis, moyamoya disease, and vasculitis can lead to serious symptoms. The burden and risk factors of those rare diseases are more challenging to assess. Whenever possible, they should be recognized in a timely manner for their increased risk of stroke, but most often they are diagnosed only at the time of stroke. Some cerebrovascular abnormalities do not result in immediate symptoms. This subclinical cerebrovascular disease includes silent infarcts, white-matter lesions, and microbleeds, and is incidentally found by neuroimaging. These lesions are not innocent, as several epidemiologic studies have associated subclinical cerebrovascular disease with an increased risk of stroke, cognitive decline, dementia, and death.

Ready, set, point: the effects of alertness on prism adaptation in healthy adults

Prism adaptation (PA) is a promising rehabilitation technique for visuo-spatial neglect, an attention disorder that is characterized by spatial attention deficits (i.e., deficits in orienting). PA involves visuo-motor adaptation to rightward shifting prism goggles. Following goggle removal, this adaptation results in leftward shifts in visuo-motor aiming and amelioration of spatial neglect. Even though some studies clearly support the beneficial effects of PA for spatial neglect, not all studies find benefits, thus it remains unclear how PA effects could be improved. Taking advantage of the known interactions between orienting and alerting reported in the attention literature (i.e., alerting enhances orienting function; e.g., Ishigami and Klein in J Individ Differ 30:220-237. doi: 10.1027/1614-0001.30.4.220 , 2009, in J Neurosci Methods 190:117-28. doi: 10.1016/j.jneumeth.2010.04.019 , 2010; Robertson et al. in Nature 395:169-72. doi: 10.1038/25993 , 1998), we examined the effects of alerting tones on PA with healthy young and older adults. We found that the effects of alerting on PA with young adults were negative, while there was a positive effect with older adults, specifically on a visuo-motor outcome task. Thus, enhancement of PA effects by alerting may be age specific and task specific. Therefore, we can conclude that while the impact of alerting tones is not always positive, further research in patients with neglect may be warranted.