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

Lateropulsion Prevalence After Stroke

International audienceBackground 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

Inter- and Intra-Rater Reliability of the Visual Vertical in Subacute Stroke

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Balance, Lateropulsion, and Gait Disorders in Subacute Stroke

International audienceObjective To test the hypothesis that impaired body orientation with respect to gravity (lateropulsion) would play a key role in poststroke balance and gait disorders. Methods Cohort study of 220 individuals consecutively admitted to a neurorehabilitation ward after a first hemisphere stroke (DOBRAS cohort [Determinants of Balance Recovery After Stroke] 2012–2018, ClinicalTrials.gov: NCT03203109 ), with clinical data systematically collected at 1 month, then at discharge. Primary outcomes were balance and gait disorders, quantified by the Postural Assessment Scale for Stroke and the modified Fugl-Meyer Gait Assessment, to be explained by all deficits on day 30, including lateropulsion assessed with the Scale for Contraversive Pushing. Statistics comprised linear regression analysis, univariate and multivariate analyses, and receiver operating characteristic curves. Results Lateropulsion was frequent, especially after right hemisphere stroke (RHS, D30, 48%; discharge 24%), almost always in right-handers. Among all deficits, impaired body orientation (lateropulsion) had the most detrimental effect on balance and gait. After RHS, balance disorders were proportional to lateropulsion severity, which alone explained almost all balance disorders at initial assessment (90%; 95% confidence interval [CI] [86–94], p < 0.001) and at discharge (92%; 95% CI 89–95, p < 0.001) and also the greatest part of gait disorders at initial assessment (66%; 95% CI 56–77, p < 0.001) and at discharge (68%; 95% CI 57–78, p < 0.001). Conclusion Lateropulsion is the primary factor altering poststroke balance and gait at the subacute stage and therefore should be systematically assessed. Poststroke balance and gait rehabilitation should incorporate techniques devoted to misorientation with respect to gravity

Lateropulsion After Hemispheric Stroke

International audienceObjective To test the hypothesis that lateropulsion is an entity expressing an impaired body orientation with respect to gravity in relation to a biased graviception and spatial neglect. Methods Data from the DOBRAS cohort (ClinicalTrials.gov: NCT03203109 ) were collected 30 days after a first hemisphere stroke. Lateral body tilt, pushing, and resistance were assessed with the Scale for Contraversive Pushing. Results Among 220 individuals, 72% were upright and 28% showed lateropulsion (tilters [14%] less severe than pushers [14%]). The 3 signs had very high factor loadings (>0.90) on a same dimension, demonstrating that lateropulsion was effectively an entity comprising body tilt (cardinal sign), pushing, and resistance. The factorial analyses also showed that lateropulsion was inseparable from the visual vertical (VV), a criterion referring to vertical orientation (graviception). Contralesional VV biases were frequent (44%), with a magnitude related to lateropulsion severity: upright −0.6° (−2.9; 2.4), tilters −2.9° (−7; 0.8), and pushers −12.3° (−15.4; −8.5). Ipsilesional VV biases were less frequent and milder ( p < 0.001). They did not deal with graviception, 84% being found in upright individuals. Multivariate, factorial, contingency, and prediction analyses congruently showed strong similarities between lateropulsion and spatial neglect, the latter encompassing the former. Conclusions Lateropulsion (pusher syndrome) is a trinity constituted by body tilt, pushing, and resistance. It is a way to adjust the body orientation in the roll plane to a wrong reference of verticality. Referring to straight above, lateropulsion might correspond to a form of spatial neglect (referring to straight ahead), which would advocate for 3D maps in the human brain involving the internal model of verticality

What is the relation between unilateral spatial neglect and verticality perception biases after stroke?

International audienceObjectiveUnilateral spatial neglect (USN) and verticality perception biases are frequently associated after right hemispheric cerebral stroke (Pérennou et al., 2006). These troubles in spatial cognition have also in common to present different clinical types, according to the space considered: personal (PN) and extra-personal neglect (EPN), and biases in the visual (VV) or the postural (PV) vertical. Here, we hypothesized that PN is specially related to a biased PV, and that EPN could be more related to a biased VV.Material/Patients and methodsForty-six patients (25 females, 41 right-handed, mean age = 62) were submitted to neuropsychological and verticality perception assessment at 30, 60, and/or 90 days after a first right hemispheric stroke. Z-scores on neuropsychological tests were used to compute a composite score for PN (based on Bisiach test, thumb find test, Comb test, Fluff test and 4 items of the Catherine Bergego Scale, CBS) and EPN (based on bells cancellation test, clock drawing test, overlapping figures task, copy of a landscape, text reading, and 4 items of the CBS). A diagnosis of PN or EPN required at least two abnormal tests. Verticality assessment comprised both VV and PV, considered abnormal for a contralesional bias over 2.5°. We tested the link between neglect and verticality perception by conducting linear regression analyses, on NC and NEC, with VV and PV as predictors.ResultsPN and EPN were found in 28 and 32 patients, respectively. A biased verticality perception was found in 24 patients for VV; among them, 5 without NSU, 12 had PN + EPN, 1 PN, 6 EPN and in 17 patients for PV; among them, 1 without NSU, 13 PN + EPN, 3 EPN. Regression analyses showed that PV was significantly associated to PN (F = 15.4; P < 0.001) but also to EPN (F = 9.4; P < 0.01). No significant effect was found for VV.Discussion - ConclusionFindings confirm the link between neglect and verticality perception. However, instead of showing specific links VV-EPN and VP-PN, results showed that both EPN and PN severity predict a biased PV (but not a biased VV). The stronger links was found between PV and PN, in relation with the body space

Interpreting spatial dysgraphia after stroke: Straight ahead or straight above?

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Maintaining Trunk and Head Upright Optimizes Visual Vertical Measurement After Stroke

International audienceBackground. Visual vertical (VV) measurement provides information about spatial cognition and is now part of posturaldisorders assessment. Guidelines for clinical VV measurement after stroke remain to be established, especially regardingthe orientation settings for patients who do not sit upright. Objectives. We analyzed the need to control body orientationwhile patients estimate the VV. Methods. VV orientation and variability were assessed in 20 controls and 36 subacutepatients undergoing rehabilitation after a first hemisphere stroke, in 3 settings: body not maintained (trunk and head free),partially maintained (trunk maintained, head free), or maintained (trunk and head). VV was analyzed as a function of trunkand head tilt, also quantified. Results. Trunk and head orientations were independent. The ability to sit independently wasaffected by a tilted trunk. The setting had a strong effect on VV orientation and variability in patients with contralesionaltrunk tilt (n = 11; trunk orientation −18.4 ± 11.7°). The contralesional VV bias was severe and consistent under partiallymaintained (−8.4 ± 5.2°) and maintained (−7.8 ± 3.5°) settings, whereas various individual behaviors reduced the mean biasunder the nonmaintained setting (−3.6 ± 9.3°, P < .05). VV variability was lower under the maintained (1.5 ± 0.2°) thannonmaintained (3.7 ± 0.4°, P < .001) and partially maintained (3.6 ± 0.2°, P < .001) settings. In contrast, setting had no effectin patients with satisfactory postural control in sitting. Conclusion. Subject setting improves VV measurement in strokepatients with postural disorders. Maintaining the trunk upright enhances the validity of VV orientation, and maintainingthe head upright enhances the validity of within-subject variability. Measuring VV without any body maintaining is valid inpatients with satisfactory balance abilities

Interplay of Pisa syndrome and scoliosis in individuals with Parkinson's disease treated with bilateral stimulation of subthalamic nuclei: IPOLAP study.

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