Improving orientation with respect to gravity enhances balance and gait recovery after stroke: DOBRAS cohort.

BACKGROUND: Lateropulsion is a deficit in body orientation with respect to gravity, frequent after stroke. Although it is a primary factor affecting mobility, the impact of its attenuation on balance and gait recovery has never been investigated. Moreover, most studies on the lateropulsion time-course focus on severe forms suspected to have a poor recovery, which is not proven. OBJECTIVES: To investigate lateropulsion attenuation and test 2 hypotheses: 1) lateropulsion attenuation greatly contributes to balance and gait recovery and 2) severe forms of lateropulsion recover slower than moderate forms. METHODS: This longitudinal study involved individuals included in the Determinants of Balance Recovery After Stroke (DOBRAS) cohort, after a first-ever hemispheric stroke, with data collected on day 30 (D30), D60 and D90 post-stroke. Body orientation with respect to gravity was assessed using the Scale for Contraversive Pushing (both scores and severity grouping), in parallel with balance (Postural Assessment Scale for Stroke) and gait (modified Fugl-Meyer Gait Assessment). RESULTS: Among the 106 eligible individuals (mean age 66.5 [SD 9.7] years), on D30, 43 (41%) were considered upright and 63 (59%) showed lateropulsion: 30 (28%) moderate and 33 (31%) severe. Most individuals with lateropulsion (73%) improved their body orientation, progressing from severe to moderate lateropulsion, or becoming upright. However, half were still not upright on D90. The improvement in body orientation had a large impact on mobility, especially in individuals with severe lateropulsion, in whom it explained about 50% of balance and gait recovery between D30 and D60, then 20% (D60-D90). For moderate lateropulsion, its attenuation explained about 20% of balance and gait recovery until D90. Lateropulsion attenuation was not slower in individuals with severe forms. CONCLUSIONS: Lateropulsion attenuation enhances balance and gait recovery in individuals after stroke suggesting that specific rehabilitation of body orientation with respect to gravity might help to recover mobility. REGISTRATION: NCT03203109.

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

BACKGROUND AND PURPOSE: This study was undertaken to assess the most sensitive combination of tests to detect peripersonal unilateral neglect (UN) after stroke. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Clinical practice recommendations for management of lateropulsion after stroke determined by a Delphi expert panel.

OBJECTIVE: People exhibiting post-stroke lateropulsion actively push their body across the midline to the more affected side and/or resist weight shift toward the less affected side. Despite its prevalence and associated negative rehabilitation outcomes, no clinical practice guidelines exist for the rehabilitation of post-stroke lateropulsion. We aimed to develop consensus-based clinical practice recommendations for managing post-stroke lateropulsion using an international expert panel. DESIGN: This Delphi panel process conformed with Guidance on Conducting and Reporting Delphi Studies recommendations. PARTICIPANTS: Panel members had demonstrated clinical and/or scientific background in the rehabilitation of people with post-stroke lateropulsion. MAIN MEASURES: The process consisted of four electronic survey rounds. Round One consisted of 13 open questions. Subsequent rounds ascertained levels of agreement with statements derived from Round One. Consensus was defined a priori as ≥75% agreement (agree or strongly agree), or ≥70% agreement after excluding 'unsure' responses. RESULTS: Twenty participants completed all four rounds. Consensus was achieved regarding a total of 119 recommendations for rehabilitation approaches and considerations for rehabilitation delivery, positioning, managing fear of falling and fatigue, optimal therapy dose, and discharge planning. Statements for which 'some agreement' (50%-74% agreement) was achieved and those for which recommendations remain to be clarified were recorded. CONCLUSIONS: These recommendations build on existing evidence to guide the selection of interventions for post-stroke lateropulsion. Future research is required to elaborate specific rehabilitation strategies, consider the impact of additional cognitive and perceptual impairments, describe positioning options, and detail optimal therapy dose for people with lateropulsion.

Latent disconnectome prediction of long-term cognitive-behavioural symptoms in stroke.

Stroke significantly impacts the quality of life. However, the long-term cognitive evolution in stroke is poorly predictable at the individual level. There is an urgent need to better predict long-term symptoms based on acute clinical neuroimaging data. Previous works have demonstrated a strong relationship between the location of white matter disconnections and clinical symptoms. However, rendering the entire space of possible disconnection-deficit associations optimally surveyable will allow for a systematic association between brain disconnections and cognitive-behavioural measures at the individual level. Here we present the most comprehensive framework, a composite morphospace of white matter disconnections (disconnectome) to predict neuropsychological scores 1 year after stroke. Linking the latent disconnectome morphospace to neuropsychological outcomes yields biological insights that are available as the first comprehensive atlas of disconnectome-deficit relations across 86 scores-a Neuropsychological White Matter Atlas. Our novel predictive framework, the Disconnectome Symptoms Discoverer, achieved better predictivity performances than six other models, including functional disconnection, lesion topology and volume modelling. Out-of-sample prediction derived from this atlas presented a mean absolute error below 20% and allowed personalize neuropsychological predictions. Prediction on an external cohort achieved an R2 = 0.201 for semantic fluency. In addition, training and testing were replicated on two external cohorts achieving an R2 = 0.18 for visuospatial performance. This framework is available as an interactive web application (http://disconnectomestudio.bcblab.com) to provide the foundations for a new and practical approach to modelling cognition in stroke. We hope our atlas and web application will help to reduce the burden of cognitive deficits on patients, their families and wider society while also helping to tailor future personalized treatment programmes and discover new targets for treatments. We expect our framework's range of assessments and predictive power to increase even further through future crowdsourcing.

Determining an optimal posturography dataset to identify standing behaviors in the post-stroke subacute phase. Cross-sectional study.

BACKGROUND: A key issue for posturography is the expression of robust results, in a simplified way. Most studies of individuals post-stroke concern the chronic phase, with small sample sizes. OBJECTIVES: By reducing the number of posturographic indices, we aimed to determine an optimal dataset and understand typical postural behaviors in the subacute post-stroke phase. METHODS: In this cross-sectional study ancillary to the DOBRAS cohort, individuals were assessed as soon they could complete a full posturography session (with and without vision) after a first hemispheric stroke. Body-weight distribution on the mediolateral (ML) axis, position of the center of pressure on the antero-posterior (AP) axis, and postural sway on both axes were computed. Balance ability in daily life was quantified with the Postural Assessment Scale for Stroke. Data were analyzed by principal component and hierarchical clustering analyses as well as multiple linear regression. RESULTS: We enrolled 95 individuals (median age: 67.0 years [Q1; Q3 56.0; 72.0]; 68% males). Vision suppression had a marginal effect, only increasing postural sway. Regardless of the visual condition, posturographic behavior was captured by a set of 3 indices that explained almost all the information. One postural sway index (ML or AP) gave more information (48%) than both position indices (ML 26% and AP 15%). These 3 indices identified 3 standing behaviors: 1) stable and symmetric, 2) asymmetric, unstable, and positioned backward, and 3) very unstable and positioned forward. Balance ability in daily life was explained (49% of the information, 95%CI [35; 63]) by weight-bearing asymmetry and postural sway on the ML axis, which played an independent role (both p<10-5), with similar impact. CONCLUSIONS: Three typical behaviors allow standing after stroke: described by only 3 posturographic indices. Weight-bearing asymmetry is not the primary parameter and should not be considered in isolation as an outcome. To increase the feasibility of posturography in the early subacute phase and to simplify evaluation sessions, trials could be limited to eyes open. REGISTRATION: NCT03203109.

Spatial neglect encompasses impaired verticality representation after right hemisphere stroke.

Spatial neglect after right hemisphere stroke (RHS) was recently found to encompass lateropulsion, a deficit in body orientation with respect to gravity caused by altered brain processing of graviception. By analogy, we hypothesized that spatial neglect after RHS might encompass an altered representation of verticality. We also assumed a strong relation between body neglect and impaired postural vertical, both referring to the body. To tackle these issues, we performed contingency and correlation analyses between two domains of spatial neglect (body, extra-body) and two modalities of verticality perception (postural, visual) in 77 individuals (median age = 67) with a first-ever subacute RHS (1-3 months). All individuals with a transmodal (postural and visual) tilt in verticality perception (n = 26) had spatial neglect, but the reverse was not found. Correlation and multivariate analyses revealed that spatial neglect (and notably body neglect) was associated more with postural than visual vertical tilts. These findings indicate that after RHS, an impaired verticality representation results from a kind of graviceptive neglect, bearing first on somaesthetic graviception and second on vestibular graviception. They also suggest that the human brain uses not only a mosaic of 2D representations but also 3D maps involving a transmodal representation of verticality.

Post-stroke lateropulsion terminology: pushing for agreement amongst experts.

Post-stroke lateropulsion is prevalent. The global inconsistency in terminology used to describe the condition presents obstacles in accurately comparing research results, reaching consensus on use of measurement tools, agreeing upon a consistent approach to rehabilitation, and translating research to clinical practice. Commencing in 2021, 20 international experts undertook a Delphi Process that aimed to compile clinical practice recommendations for the rehabilitation of lateropulsion. As a part of the process, the panel agreed to aim to reach consensus regarding terminology used to describe the condition. Improved understanding of the condition could lead to improved management, which will enhance patient outcomes after stroke and increase efficiency of healthcare resource utilisation. While consensus was not reached, the panel achieved some agreement that 'lateropulsion' is the preferred term to describe the phenomenon of 'active pushing of the body across the midline toward the more affected side, and / or actively resisting weight shift toward the less affected side'. This group recommends that 'lateropulsion' is used in future research and in clinical practice.

Lateropulsion Prevalence After Stroke: A Systematic Review and Meta-analysis.

BACKGROUND AND OBJECTIVES: Lateropulsion is a deficit of active body orientation with respect to gravity in the frontal plane, mostly observed after a stroke. It magnifies mobility limitations and represents an emerging target in rehabilitation. Efforts to design specific interventional studies require some basic knowledge of epidemiology, which is insufficient today because many studies have focused on a few severe forms in individuals called pushers. The objectives of this study were to bridge this gap. METHODS: We systematically searched MEDLINE, EMBASE, CINAHL, and Cochrane Clinical Trials up to 31 May 2021 for original research reporting a prevalence or incidence of poststroke lateropulsion. We followed MOOSE and PRISMA guidelines. Eligibility for inclusion, data extraction, and study quality (Joanna Briggs Institute guidelines) were evaluated by 2 reviewers who used a standardized protocol (PROSPERO; CRD42020175037). A random-effects meta-analysis was used to obtain the pooled prevalence, whose heterogeneity was investigated by subgroup analysis (stroke locations and poststroke phases) and metaregression. RESULTS: We identified 22 studies (5,125 individuals; mean age 68.5 years; 42.6% female; assessed 24 days, on average, after stroke), most published after 2000. The studies' quality was adequate, with only 8 (36.4%) showing risk of bias. The pooled lateropulsion prevalence was 55.1% (95% CI 35.9-74.2) and was consistent across assessment tools. After supratentorial stroke, lateropulsion prevalence was 41% (95% CI 33.5-48.5), and only 12.5% (95% CI 9.2-15.9) in individuals with severe lateropulsion, called pushers. Metaregression did not reveal any effect of age, sex, geographic region, publication year, or study quality. Lateropulsion prevalence progressively decreased from 52.8% (95% CI 40.7-65) in the acute phase to 37% (95% CI 26.3-47.7) in the early subacute phase and 22.8% (95% CI 0-46.3) in the late subacute phase. The ratio of right to left hemispheric stroke with lateropulsion increased as a function of time: 1.7 in the acute phase to 7.7 in the late subacute phase. After infratentorial stroke, lateropulsion prevalence was very high, reaching 83.2% (95% CI 63.9-100.3). DISCUSSION: Poststroke lateropulsion prevalence is high, which appeals for its systematic detection to guide early interventions. Uprightness is predominantly controlled from the right hemisphere.

Cognitive assessment scale for stroke patients (CASP): A multicentric validation study.

BACKGROUND: The Mini Mental State Examination and Montreal Cognitive Assessment are commonly used as short screening batteries for assessing cognitive impairment after stroke. However, aphasia or hemispatial neglect may interfere with the results. For this reason, we developed the Cognitive Assessment scale for Stroke Patients (CASP), which takes these conditions into consideration and previously demonstrated its superiority over these scales in terms of feasibility. OBJECTIVES: Our goal was to verify the psychometric properties of the (original) French version of the CASP. METHODS: We included 201 patients with a recent first hemispheric stroke and 50 controls. Stroke patients were examined 4 times (visit 1 [V1] to visit 4 [V4]) in the subacute post-stroke phase. The structural validity of the CASP was studied by principal factorial analysis, convergent validity by comparison with several variables including a comprehensive neuropsychological assessment, divergent validity by comparison with the total score between stroke patients and controls, and sub-scores between right and left stroke. Internal consistency, reproducibility and sensitivity to change were assessed. We propose the Minimal Clinically Important Difference (MCID) value and a pathological threshold as well as a threshold to predict cognitive change between V1 and V4. RESULTS: Of the 201 participants included (63% male; mean [SD] age 63 [13] years), CASP data were available for 199/150/133/93 at V1/V2/V3/V4, respectively. CASP has a one-dimensional structure. The hypotheses of convergent/divergent validities were confirmed. Internal consistency was good and reliability excellent. Responsiveness was small to moderate, but the MCID could still be estimated. We discuss the choice of a pathological threshold and a predictive threshold of V1 over V4. CONCLUSIONS: CASP has good psychometric properties for screening cognitive impairment in the subacute post-stroke phase, which is consistent with its Italian and Korean versions. It can be used for patients with severe motor aphasia or left hemispatial neglect but not in case of severe oral comprehension or visual impairment.