Renaissance of "lateropulsion"

The association between neuroimaging data and presence of lateropulsion after stroke

BACKGROUND

Post-stroke lateropulsion is prevalent and has been associated with varied lesion locations, but existing imaging studies are limited by small participant cohorts. Evidence to guide lateropulsion rehabilitation is also limited. Improved understanding of lesion localization associated with lateropulsion post-stroke may inform more targeted intervention approaches.

OBJECTIVES

This study investigated the associations between stroke neuroimaging data and presence of lateropulsion at inpatient rehabilitation admission.

METHODS

This prospective, observational study included participants aged ≥65 years, admitted for inpatient stroke rehabilitation. Using routinely collected clinical neuroimaging data, stroke type, location, and volume were reported, and their association with lateropulsion presence (Four-Point Pusher Score - 4PPS) at admission was explored.

RESULTS

Of 144 included participants, 82 (56.9%) had lateropulsion (4PPS ≥1). Lateropulsion presence was univariately associated with hemorrhagic stroke (p = 0.002), frontal cortical involvement (OR = 2.17, 95%CI 1.02-6.46), and white matter involvement (OR = 2.45, 95%CI 1.24-4.85), particularly frontal white matter (p = 0.021). Lesions involving the posterior limb of the internal capsule (OR = 2.88, 95% CI 1.14-7.27) and those involving the entire thalamus (OR = 1.0, p = 0.03) were associated with lateropulsion presence. When stratified by stroke type, no specific location was significantly associated with lateropulsion presence in hemorrhagic strokes. Among participants with ischemic stroke, involvement of the pre-central gyrus (OR = 2.45, 95%CI 1.05-5.76), post-central gyrus (OR = 2.76, 95%CI 1.15-6.60), inferior parietal cortex (OR = 3.95, 95%CI 1.43-10.90), and supramarginal gyrus (OR = 3.73, 95%CI 1.25-11.13) were associated with lateropulsion presence. The stroke laterality and size were not significantly associated with lateropulsion presence.

CONCLUSIONS

The findings indicate a role of network disconnection in the post-stroke lateropulsion presence. Future, larger-cohort lesion-network mapping studies are recommended.

Lateropulsion resolution and outcomes up to one year post-stroke: a prospective, longitudinal cohort study

BACKGROUND

Post-stroke lateropulsion is prevalent and associated with poor rehabilitation outcomes; however, data regarding long-term function associated with lateropulsion are lacking.

OBJECTIVES

This study aimed to explore lateropulsion resolution and associations between lateropulsion, functional outcomes, and fall occurrence up to 12 months post-stroke.

METHODS

Participants for this prospective, longitudinal cohort study were recruited from a Stroke Rehabilitation Unit (SRU). Assessments were conducted at SRU admission, at discharge, and at three, six, nine, and twelve months post-stroke. Outcomes included the Four-Point Pusher Score (4PPS), Functional Independence Measure (FIM), and fall occurrence. Longitudinal outcomes were modeled using generalized linear mixed-effects models.

RESULTS

The final analyses included data from 144 participants. Eighty-two participants (56.9) had lateropulsion (4PPS ≥ 1) on admission. Odds of resolved lateropulsion (4PPS = 0) increased longitudinally from discharge for people who participated in rehabilitation physiotherapy (OR: 9.7, 28.1, 43.1, 81.3: <0.001 at three, six, nine, and twelve months respectively). The greatest FIM improvement among participants in all 4PPS categories occurred during the SRU inpatient phase. The probability of falls post-discharge was greatest among participants with 4PPS = 1 at three months, when compared with 4PPS = 0 (p= 0.022).

CONCLUSIONS

This study showed that lateropulsion can continue to resolve up to one year post-stroke. Earlier lateropulsion resolution was associated with ongoing rehabilitation physiotherapy participation. Long-term functional gains were maintained among people discharged home, whereas functional status deteriorated after six months among those in residential care. Study findings will allow rehabilitation and service providers to better plan for and accommodate the long-term rehabilitation and care needs of people with post-stroke lateropulsion.

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.

Dynamic changes of the direction and angle of radiographic ocular lateral deviation in patients with lateropulsion after stroke onset

OBJECTIVE

To examine if radiographic ocular lateral deviation (rOLD) could be provoked in stroke patients with mild-to-moderate lateropulsion according to vertical perception.

METHODS

In this single-center, retrospective study, acute stroke patients with mild-to-moderate lateropulsion assessed by the Scale for Contraversive Pushing were enrolled. Computed tomography or magnetic resonance imaging was performed on all patients on admission and then according to their conditions. The direction and angle of rOLD were compared among three groups according to the responsible lesion: lateral medullary (LM), pontine (P), and hemispheric (H).

RESULTS

Sixty-six patients (male, 47; average age, 67 years) were enrolled and divided into the LM (n = 37), P (n = 8), and H (n = 21) groups. All patients had body tilt. Patients in the LM group showed body tilt to the ipsilesional side during hospitalization, while those in the P and H groups tilted to the contralesional side. All patients had rOLD at the final assessment at an average of 13 days after onset; patients in the P and H groups showed contralateral rOLD, while those in the LM group showed ipsilateral rOLD if they did not have cerebellar or pontine lesions. Significant decreases in the angle and changes in direction of rOLD according to lesion site were observed during hospitalization.

CONCLUSION

Serial changes in rOLD findings after stroke onset are different according to the responsible lesion. The direction of rOLD in most patients is in accordance with vertical perception after the acute stage of stroke.

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.

Association between spatial neglect and impaired verticality perception after stroke: A systematic review

BACKGROUND

Although most research on spatial neglect (SN) has focused on spatial perception deficits with regard to the lateral (left-right) axis, deficits of spatial perception with regard to the vertical (up-down) axis, such as disturbances in the perception of verticality (e.g., judgement of vertical orientations), have also been suggested.

OBJECTIVE

We aimed to systematically analyse reported associations between SN and characteristics of verticality perception while considering the time post-stroke.

METHODS

PubMed, Web of Science, Scopus, PubPsych and PsycArticles databases were searched on May 24, 2022 for articles written in English that evaluated the association between SN and verticality perception (i.e., the subjective visual vertical [SVV], subjective postural vertical [SPV] and subjective haptic vertical [SHV]) in adults after stroke. Left and right SN were considered and had to be assessed using standardized methods. Data were manually extracted, and risk of bias was assessed with the Newcastle-Ottawa Scale. The tilt of the line/chair relative to the gravitational vector and its direction, together with uncertainty (i.e., variability across measurements), were evaluated.

RESULTS

Thirteen studies were included (431 participants after stroke); at least 191 participants exhibited SN. Mainly the first 3 to 6 months post-stroke were evaluated. SN was associated with SVV misperception, which resulted in larger SVV tilts (mostly in the contralesional direction) and uncertainty in participants with than without SN. SVV tilt magnitudes ranged from a mean/median of -8.9° to -2.3° in SN participants and from -1.6° to 0.6° in non-SN participants, the latter falling within normative ranges. For SPV and SHV measurements, the magnitude of tilt and the uncertainty were insufficiently assessed or results were inconclusive.

CONCLUSIONS

SN was associated with larger SVV tilts and uncertainty, which suggests that SVV misperception is a key feature of SN. This observation highlights the importance of regular SVV assessment in people with SN in clinical practice.

PROSPERO

CRD42019127616.

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 so 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 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 post-stroke lateropulsion. We followed MOOSE and PRISMA guidelines. Eligibility for inclusion, data extraction, and study quality (Joanna Briggs Institute guidelines) were evaluated by two 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 post-stroke phases) and meta-regression.

RESULTS

We identified 22 studies (5125 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% confidence interval [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. Meta-regression 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]).

CONCLUSIONS

Post-stroke lateropulsion prevalence is high, which appeals for its systematic detection to guide early interventions. Uprightness is predominantly controlled from the right hemisphere.