Objective 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.

Objective 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.

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. Our goal was to verify the psychometric properties of the (original) French version of the CASP. 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. 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. 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.

The visual vertical (VV) consists of repeated adjustments of a luminous rod to the earth vertical. How many trials are required to reach consistency in this measure? This question has never been addressed despite the widespread clinical use of the measurement in stroke rehabilitation. VV perception was assessed (10 trials) in 117 patients undergoing rehabilitation after a first hemisphere stroke. The intraclass correlation coefficient (ICC) and standard error of measurement (SEM) were calculated for each patient category: with contralesional VV bias (n = 48), ipsilesional VV bias (n = 17) and normal VV (n = 52). For patients with VV biases, 6 trials were required to reach high inter-trial reliability (contralesional: ICC = 0.9, SEM = 1.36°; ipsilesional: ICC = 0.896, SEM = 0.96°). For patients with normal VV, a minimum of 10 trials was required (ICC = 0.728, SEM = 1.13°). A set of 6 trials correctly classified 96 % of patients. In the literature, 10 is the most frequently used number of trials used to assess VV orientation. Our study shows that 10 trials are required to adequately measure VV orientation in non-selected subacute stroke patients. For complex protocols imposing a decrease in the number of trials in each condition, 6 trials are needed to identify VV biases in most patients.