Prognosis of contraversive pushing

Six-month outcomes and patterns of recovery for people with lateropulsion following stroke

PURPOSE

This study investigated the (1) six-month outcomes of individuals with lateropulsion; (2) the relationship between baseline measures (from in-patient hospitalisation) and six-month functional abilities; and (3) recovery patterns for lateropulsion in stroke survivors.

MATERIALS AND METHODS

Forty-one individuals with lateropulsion participated in this study. Measures of lateropulsion, postural function, and weight-bearing asymmetry in standing were taken initially and fortnightly over eight weeks. Functional independence and walking abilities were assessed at six months post-stroke.

RESULTS

Compared to individuals with moderate to severe lateropulsion, those with mild lateropulsion achieved higher levels of functional outcome at six months. However, there were a wide range of scores. Baseline lateropulsion severity explained 26% of the variation in functional outcome. A stronger correlation with functional outcome was observed for lateropulsion (-0.526) than function independence at baseline (0.384). For the task of standing with arm support, patterns of asymmetry were divergent at baseline, favouring either the paretic or non-paretic leg. Over the eight-week period, asymmetry moved towards the non-paretic leg and lateropulsion reduced consistently.

CONCLUSIONS

Individuals with lateropulsion can recover from lateropulsion and make meaningful functional gains, including some individuals with more severe lateropulsion. Lateropulsion severity is a key indicator of functional outcome post-stroke.IMPLICATIONS FOR REHABILITATIONIndividuals with lateropulsion can make significant gains in terms of mobility and functional abilities by six months post-stroke, learning to compensate for their verticality impairment in standing by loading their non-paretic leg.It is important that stroke survivors with lateropulsion, including those with moderate and severe lateropulsion, are provided with adequate rehabilitation to optimise their longer-term mobility and functional abilities.Routine screening of acute stroke survivors for lateropulsion is recommended, given lateropulsion may negatively impact longer-term functional outcomes in stroke survivors.Therapists should carefully analyse the weight-bearing pattern which an individual with lateropulsion adopts in standing and subsequently tailor treatment to target this.

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.

Accuracy of the Australian National Sub-Acute and Non-Acute Patient Classification in predicting rehabilitation length of stay for stroke survivors who are ≥65 years of age and have lateropulsion

BACKGROUND

Lateropulsion is a common impairment after stroke. Regardless of stroke severity, functional recovery is slower in people with lateropulsion, resulting in requirement for longer rehabilitation duration. In Australia, inpatient rehabilitation funding is determined via the Australian National Sub-Acute and Non-Acute Patient Classification (AN-SNAP). AN-SNAP class is determined using age, diagnosis, weighted Functional Independence Measure (FIM) motor score, and FIM cognitive score.

OBJECTIVES

To explore accuracy of the AN-SNAP to predict length of stay (LOS) for people with poststroke lateropulsion.

METHODS

A retrospective database audit was undertaken. AN-SNAP predicted LOS for each participant was calculated based on 2019 calendar year national benchmarks. A multivariable linear regression model estimated mean differences in reported LOS and AN-SNAP predicted LOS after adjusting for lateropulsion severity (Four Point Pusher Score). A separate logistic regression model assessed whether FIM change during admission was associated with reported LOS exceeding AN-SNAP predicted LOS.

RESULTS

Data were available from 1126 admissions. Reported LOS exceeding AN-SNAP predicted LOS was associated with greater lateropulsion severity on admission. Where AN-SNAP predicted LOS was longer, those with no lateropulsion on admission showed shorter reported than predicted LOS. Greater improvement in FIM during rehabilitation was associated with increased odds of reported LOS exceeding AN-SNAP predicted LOS (OR 1.02, 95%CI 1.01-1.03, p < .001).

CONCLUSIONS

Inclusion of a measure of poststroke lateropulsion in the AN-SNAP classification model would result in more accurate LOS predictions to inform funding. Costs of longer rehabilitation LOS may be countered by optimized long-term physical function, reducing requirement for ongoing care.

Treatment approaches for pusher behaviour: a scoping review

BACKGROUND

Some individuals with hemiplegia show a postural disorder called pusher behavior. Various underlying theoretical mechanisms have been proposed, thus leading to various treatment approaches.

OBJECTIVES

The aim of this scoping review is to identify and analyze the available evidence on the treatment approaches for pusher behavior.

METHODS

Two independent reviewers conducted a literature search for original studies reporting on treatments for pusher behavior. Studies were searched in PubMed, Scopus, Web of Science, CINAHL and PEDro from their inception to December 2020. Treatment approaches were grouped in homogeneous areas based on the supposed underlying mechanism. To assess the reporting of the interventions, the Template for Intervention Description and Replication (TIDieR) was used.

RESULTS

Thirty-one papers describing 45 interventions were included in the review. Most of the studies were case reports (i.e. including 1 person) (n = 16), followed by randomized controlled trials (n = 5), single subject design trials (n = 5), non-randomized controlled trials (n = 3), and case series (i.e. including more than 1 person) (n = 2). Treatment approaches were grouped into five categories: visual feedback, somatosensory cues, visual-somatosensory integration, brain stimulation, and other nonspecific treatments. The median number of TIDIeR items reported was 7 (range 4 to 10).

CONCLUSION

Pusher behavior is still little-known. Five main categories of treatment approaches based on the alleged etiological underlying mechanisms have been identified. Most of studies are case reports; controlled trials should be further conducted. Intervention reporting should be improved to allow treatment replication in larger trials.

Unilateral cathodal transcranial direct current stimulation over the parietal area modulates postural control depending with eyes open and closed

Objective

Cathodal transcranial direct current stimulation (C-tDCS) is generally assumed to inhibit cortical excitability. The parietal cortex contributes to multisensory information processing in the postural control system, and this processing is proposed to be different between the right and left hemispheres and sensory modality. However, previous studies did not clarify whether the effects of unilateral C-tDCS of the parietal cortex on the postural control system differ depending on the hemisphere. We investigated the changes in static postural stability after unilateral C-tDCS of the parietal cortex.

Methods

Ten healthy right-handed participants were recruited for right- and left-hemisphere tDCS and sham stimulation, respectively. The cathodal electrode was placed on either the right or left parietal area, whereas the anodal electrode was placed over the contralateral orbit. tDCS was applied at 1.5 mA for 15 min. We evaluated static standing balance by measuring the sway path length (SPL), mediolateral sway path length (ML-SPL), anteroposterior sway path length (AP-SPL), sway area, and the SPL per unit area (L/A) after 15-minute C-tDCS under eyes open (EO) and closed (EC) conditions. To evaluate the effects of C-tDCS on pre- and post-offline trials, each parameter was compared using two-way repeated-measures analysis of variance (ANOVA) with factors of intervention and time. A post-hoc evaluation was performed using a paired t-test. The effect sizes were evaluated according to standardized size-effect indices of partial eta-squared (ηp²) and Cohen’s d. The power analysis was calculated (1-β).

Results

A significant interaction was observed between intervention and time for SPL (F (2, 27) = 4.740, p = 0.017, ηp² = 0.260), ML-SPL (F (2, 27) = 4.926, p = 0.015, ηp² = 0.267), and sway area (F (2, 27) = 9.624, p = 0.001, ηp² = 0.416) in the EO condition. C-tDCS over the right hemisphere significantly increased the SPL (p < 0.01, d = 0.51), ML-SPL (p < 0.01, d = 0.52), and sway area (p < 0.05, d = 0.83) in the EO condition. In contrast, C-tDCS over the left hemisphere significantly increased the L/A in both the EC and EO condition (EO; p < 0.05, d = 0.67, EC; p < 0.05, d = 0.57).

Conclusion

These results suggest that the right parietal region contributes to static standing balance through chiefly visual information processing during the EO condition. On the other hand, L/A increase during EC and EO by tDCS over the left parietal region depends more on somatosensory information to maintain static standing balance during the EC condition.

Relationship Between Body-Specific Attention to a Paretic Limb and Real-World Arm Use in Stroke Patients: A Longitudinal Study

Learned nonuse is a major problem in upper limb (UL) rehabilitation after stroke. Among the various factors that contribute to learned nonuse, recent studies have focused on body representation of the paretic limb in the brain. We previously developed a method to measure body-specific attention, as a marker of body representation of the paretic limb and revealed a decline in body-specific attention to the paretic limb in chronic stroke patients by a cross-sectional study. However, longitudinal changes in body-specific attention and paretic arm use in daily life (real-world arm use) from the onset to the chronic phase, and their relationship, remain unknown. Here, in a longitudinal, prospective, observational study, we sought to elucidate the longitudinal changes in body-specific attention to the paretic limb and real-world arm use, and their relationship, by using accelerometers and psychophysical methods, respectively, in 25 patients with subacute stroke. Measurements were taken at baseline (TBL), 2 weeks (T2w), 1 month (T1M), 2 months (T2M), and 6 months (T6M) after enrollment. UL function was measured using the Fugl-Meyer Assessment (FMA) and Action Research Arm Test (ARAT). Real-world arm use was measured using accelerometers on both wrists. Body-specific attention was measured using a visual detection task. The UL function and real-world arm use improved up to T6M. Longitudinal changes in body-specific attention were most remarkable at T1M. Changes in body-specific attention up to T1M correlated positively with changes in real-world arm use up to T6M, and from T1M to T6M, and the latter more strongly correlated with changes in real-world arm use. Changes in real-world arm use up to T2M correlated positively with changes in FMA up to T2M and T6M. No correlation was found between body-specific attention and FMA scores. Thus, these results suggest that improved body-specific attention to the paretic limb during the early phase contributes to increasing long-term real-world arm use and that increased real-world use is associated with the recovery of UL function. Our results may contribute to the development of rehabilitation strategies to enhance adaptive changes in body representation in the brain and increase real-world arm use after stroke.

Preexisting brain lesions in patients with post stroke pusher behavior and their association with the recovery period: A one year retrospective cohort study in a rehabilitation setting

The presence of preexisting brain lesions due to previous stroke and cerebral small vessel disease has been reported to influence stroke related disability or rehabilitation outcomes. However, there is no data about the impact of such lesions on the recovery period after pusher behavior (PB). This retrospective cohort study aimed to determine the influence of preexisting brain lesions on PB recovery time. Nineteen patients who were suffering from PB were included in the study. The presence of preexisting brain lesions, including previous stroke, silent brain infarcts, microbleed, white matter hyperintensity, and enlarged perivascular spaces were assessed using medical history reports, radiological reports, and magnetic resonance imaging data. The lesion score, ranging from 0 to 6, was calculated based on each preexisting brain lesion. The time to recovery from PB was assessed using the Scale for Contraversive Pushing. Based on the median value of the lesion score, we divided patients into those with a lesion score <2 and those with a lesion score ≥2. A Kaplan Meier survival analysis was performed between these two groups. A multivariable Cox proportional hazards analysis was also performed using the side with hemiparesis and the score of preexisting brain lesions as covariates to determine the hazard ratio. The results showed that the group with a lesion score ≥2 had significantly delayed recovery from PB and the hazard ratio of preexisting brain lesions score was 0.458 (95 % confidence interval: 0.221, 0.949), while the side of hemiparesis was not identified a significant covariate. Our results indicated that patients with PB having higher score of preexisting brain abnormalities might require a longer time to recover, and this might be useful in planning inpatient rehabilitation and treatment goals for patients with PB.

Spanish translation and validation of the Scale for Contraversive Pushing to measure pusher behaviour

INTRODUCTION

The aim of this study was to develop and validate a Spanish-language version of the Scale for Contraversive Pushing, used to diagnose and measure pusher behaviour in stroke patients.

METHODS

Translation-back translation was used to create the Spanish-language Scale for Contraversive Pushing; we subsequently evaluated its validity and reliability by administering it to a sample of patients. We also analysed its sensitivity to change in patients identified as pushers who received neurological physiotherapy.

RESULTS

Experts indicated that the content of the scale was valid. Internal consistency was very good (Cronbach's alpha of 0.94). The intraclass correlation coefficient showed high intra- and interobserver reliability (0.999 and 0.994, respectively). The Kappa and weighted Kappa coefficients were used to measure the reliability of each item; the majority obtained values above 0.9. Lastly, the differences between baseline and final evaluations of pushers were significant (paired sample t test), showing that the scale is sensitive to changes obtained through physical therapy.

CONCLUSIONS

The Spanish-language version of the Scale for Contraversive Pushing is valid and reliable for measuring pusher behaviour in stroke patients. In addition, it is able to evaluate the ongoing changes in patients who have received physical therapy.

Effects of dynamic supported standing training in a patient with pusher behavior: a case report

BACKGROUND

The effects of task-specific and voluntary exercise in upright positions for pusher behavior remain unclear. In this report, we aimed to describe the effects of dynamic supported standing training using a modified standing frame to correct the alignment in a patient with severe pusher behavior.

CASE DESCRIPTION

A 76-year-old man with cardioembolic ischemic stroke demonstrated pusher behavior. The patient underwent 3 days of dynamic supported standing training using a modified standing frame. The Scale for Contraversive Pushing, the Burke Lateropulsion Scale, and the Trunk Control Test were used to assess changes.

OUTCOMES

Immediate improvements in sitting balance were observed after the intervention, and the effects persisted to 8 days later.

CONCLUSION

Dynamic supported standing training using a modified standing frame may improve pusher behavior with short-term training. The collapsed posture of the patient in the present case was corrected using the modified standing frame. This neutral standing position could have a positive effect on motor learning with respect to holding one's posture.

Scale for contraversive pushing in stroke patients: pusher behavior vs Thalamic astasia differential diagnosis and psychometric properties

BACKGROUND

: Few studies have investigated the psychometric properties of the Scale for Contraversive Pushing (SCP) in depth, and none have evaluated its ability to establish differential diagnosis between pusher behavior (PB) and thalamic astasia (TA).

OBJECTIVES

: To study the ability of the SCP to establish differential diagnosis, its reliability, content, construct, and internal validity in the assessment of subacute stroke patients.

METHODS

: 120 individuals were evaluated using the SCP over a four-week period of treatment. Intra- and inter-observer reliability, floor and ceiling effects, minimum detectable change (MDC), internal validity and sensitivity to change were explored. In addition, the Barthel Index and the Trunk Control Test were used to study their correlations with the SCP.

RESULTS

: Discriminant validity provides evidence that the correlation between SCP items was large or moderate. Convergent validity demonstrated that the correlation of each item with the total score of the scale was high (at around 0.8). Sensitivity to change was large (W = 0.274). Intra- and inter-observer reliability were excellent (Intraclass Correlation Coefficient > 0.9; k > 0.8), except for items B standing and C sitting (k > 0.7). The MDC was 1.39, and ceiling (8.333%) and floor (15.833%) effects were adequate. Cronbach's alpha (α) was equal to 0.901 (0.874-0.924) and McDonald's Omega (ω) was equal to 0.883 (0.856-0.973), showing excellent internal consistency.

CONCLUSIONS

: The SCP is a reliable and valid tool which can successfully establish differential diagnosis between PB and TA and evaluate the changes generated by physiotherapy treatment.

Post-stroke lateropulsion and rehabilitation outcomes: a retrospective analysis

PURPOSE

A person with post-stroke lateropulsion actively pushes themselves toward their hemiplegic side, or resists moving onto their non-hemiplegic side. This study aimed to determine the association of lateropulsion severity with: • Change in function (Functional Independence Measure - FIM) and lateropulsion severity (Four-Point Pusher Score - 4PPS) during inpatient rehabilitation; • Inpatient rehabilitation length of stay (LOS); • Discharge destination from inpatient rehabilitation.

METHODS

Retrospective data for 1,087 participants (aged ≥65 years) admitted to a stroke rehabilitation unit (2005-2018) were analysed using multivariable regression models.

RESULTS

Complete resolution of lateropulsion was seen in 69.4% of those with mild lateropulsion on admission (n = 160), 49.3% of those with moderate lateropulsion (n = 142), and 18.8% of those with severe lateropulsion (n = 181). Average FIM change was lower in those with severe lateropulsion on admission than those with no lateropulsion (p < 0.001). Higher admission 4PPS was associated with reduced FIM efficiency (p < 0.001), longer LOS (p < 0.001), (adjusted mean LOS: 35.6 days for those with severe lateropulsion versus 27.0 days for those without), and reduced likelihood of discharge home (p < 0.001).

CONCLUSION

Post-stroke lateropulsion is associated with reduced functional improvement and likelihood of discharge home. However, given a longer rehabilitation duration, most stroke survivors with moderate to severe lateropulsion can achieve important functional improvement.Implications for RehabilitationWhile people with post-stroke lateropulsion can be difficult to treat and require more resources than those without lateropulsion, the majority of those affected, even in severe cases, can make meaningful recovery with appropriate rehabilitation.Although those with moderate to severe post-stroke lateropulsion may have poorer outcomes (longer LOS and reduced likelihood of discharge home) it is still important to advocate for access to rehabilitation for this patient group to give them the opportunity for optimal functional recovery.

The association between contraversive lateropulsion and outcomes post stroke: A systematic review

Background: Contraversive lateropulsion is a common post-stroke impairment. Rehabilitation outcomes in stroke survivors exhibiting lateropulsion may differ from those without lateropulsion.Objectives: To systematically review evidence regarding associations between:1. Presence/severity of lateropulsion after stroke and functional outcome, rehabilitation length of stay, and discharge destination;2. Stroke-related factors and resolution of lateropulsion, functional outcome, rehabilitation length of stay, and discharge destination in affected stroke survivors.Methods: Medline, CINAHL, and Embase databases were searched. Journal articles published in English reporting on resolution of lateropulsion, length of stay, functional outcome, and/or discharge destination associated with post-stroke lateropulsion were included for review. Studies that did not include a comparison group (stroke survivors without lateropulsion, or sub-groups of participants with lateropulsion based on stroke-related factors), animal studies, and studies reporting only on ipsiversive lateropulsion and/or lateral medullary syndrome were excluded. Two authors independently assessed studies for inclusion. Included studies were evaluated using the Risk of Bias Assessment Tool for Nonrandomized Studies.Results: Screening identified 133 articles. Seven articles met inclusion criteria. People with contraversive lateropulsion after stroke can achieve similar improvements in function as those without lateropulsion, increasing likelihood of discharge home, but require longer rehabilitation durations to do so.Conclusions: The finding that longer rehabilitation durations are required for people with post-stroke lateropulsion to achieve their functional potential and increase likelihood of discharge home has implications for resourcing rehabilitation services. Given an additional three to four weeks in rehabilitation, people with post-stroke lateropulsion can achieve functional improvements function similar to those without lateropulsion.

Lesion Localization of Poststroke Lateropulsion

Background and Purpose- Hemispheric stroke studies associating lateropulsion (pusher syndrome) with the location of brain lesions have had mixed results from small, unmatched samples. This study was designed to determine whether lateropulsion localizes to specific brain regions across patients with stroke using a case-control design. Methods- Fifty patients with lateropulsion after stroke were matched with 50 stroke patients without lateropulsion using age, time since onset of stroke, admission motor Functional Independence Measure score, lesion side, and gender. The primary analysis included multivariate lesion symptom mapping using sparse canonical correlations to identify regions most associated with lateropulsion as assessed with the Burke Lateropulsion Scale. Secondary analyses included evaluating paired comparisons for lesion volume, degree of motor impairment, motor and cognitive Functional Independence Measure scores. Results- The lesion symptom mapping analysis of all lesions mapped onto a common hemisphere produced an overall significant model ( P<5×10^-5) with a regional peak at the inferior parietal lobe at the junction of the post-central gyrus (Brodmann Area 2) and Brodmann Area 40 as the lesion location most associated with lateropulsion. Lesion volume was larger for patients with lateropulsion. Despite adequate matching, motor performance and total Functional Independence Measure scores differed at a group level between patients with and without lateropulsion. Conclusions- This analysis implicated lesion involvement of the inferior parietal lobe as a key neuroanatomical determinant of developing lateropulsion. A better understanding of the anatomic underpinnings of lateropulsion may improve rehabilitation efforts, including the potential for informing noninvasive neuromodulation approaches.

Electromyography-guided electrical stimulation therapy for patients with pusher behavior: A case series

BACKGROUND

Pusher behavior (PB) is a posture disorder due to a subjective bias in verticality perception. However, muscle activity characteristics in this disorder and the effective treatments are not known.

OBJECTIVE

To investigate electromyographic (EMG) activity and the effect of electrical stimulation (ES) in PB.

METHODS

Two PB patients were enrolled. The EMG activity was measured over the upper and lower limb muscles on the non-paretic side, and over the trunk muscles on both sides during sitting. We used a modified ABA single-case design consisting of consecutive baseline, intervention, and follow-up, each phase lasting 2 d. During the intervention, together with conventional treatment, the patient received ES for 5 min/d on the muscle antagonist to the muscle where excessive activity was observed. PB was assessed before and after each phase using the scale for contraversive pushing and the Burke lateropulsion scale. Truncal balance was evaluated using the trunk control test.

RESULTS

In both patients, electromyography of the non-paretic triceps brachii muscle revealed excessive activity. To inhibit the excessive activity, ES was applied to the non-paretic biceps muscle. All scores improved after the intervention and follow-up phases.

CONCLUSION

ES based on EMG activity is therapeutic for PB.

Robot-assisted gait training effectively improved lateropulsion in subacute stroke patients: a single-blinded randomized controlled trial

BACKGROUND

Some stroke patients are known to use nonparetic extremities to push toward the paretic side, a movement known as lateropulsion. Lateropulsion impairs postural balance and interferes with rehabilitation.

AIM

The aim of the present study was to investigate the effect of robot-assisted gait training (RAGT) on recovery from lateropulsion compared with conventional physical therapy (CPT).

DESIGN

This was a single-blinded, randomized controlled trial.

SETTING

Participants were recruited from a rehabilitation department of a tertiary hospital.

POPULATION

Patients diagnosed with lateropulsion after a stroke.

METHODS

Thirty-six subacute stroke patients with lateropulsion were recruited. RAGT was performed in the experimental group (N.=18), and CPT was performed in the control group (N.=18). The participants received treatment for 3 weeks, 30 minutes per day, 5 days per week. Outcomes were assessed before the intervention (T0), immediately after the intervention (T1), and 4 weeks after the intervention (T2). The Burke Lateropulsion Scale (BLS) was evaluated as a primary outcome to assess the severity of lateropulsion. The secondary outcome measures were the Berg Balance Scale (BBS), the Postural Assessment Scale for Stroke (PASS), and Somatosensory Evoked Potentials (SSEP).

RESULTS

After intervention, the experimental group showed greater improvement in the BLS score at T1 (experimental group: Δ=-1.9, control group: Δ=-1.1, P=0.032) and T2 (experimental group: Δ=-2.8, control group: Δ=-6.5, P<0.001) than the control group. In addition, the BBS was significantly improved in the experimental group at T1 (experimental group: Δ=+7.1, control group: Δ=+1.9, P<0.001) and T2 (experimental group: Δ=+13.0, control group: Δ=+6.1, P<0.001). There were significant between-group differences in the PASS at T1 (experimental group: Δ=+3.2, control group: Δ=+1.6, P=0.014) and T2 (experimental group: Δ=+8.8, control group: Δ=+4.3, P<0.001).

CONCLUSIONS

RAGT ameliorated lateropulsion and balance function more effectively than CPT in subacute stroke patients.

CLINICAL REHABILITATION IMPACT

Early RAGT may be recommended for patients with lateropulsion after stroke.

Spanish translation and validation of the Scale for Contraversive Pushing to measure pusher behaviour

INTRODUCTION

The aim of this study was to develop and validate a Spanish-language version of the Scale for Contraversive Pushing, used to diagnose and measure pusher behaviour in stroke patients.

METHODS

Translation-back translation was used to create the Spanish-language Scale for Contraversive Pushing; we subsequently evaluated its validity and reliability by administering it to a sample of patients. We also analysed its sensitivity to change in patients identified as pushers who received neurological physiotherapy.

RESULTS

Experts indicated that the content of the scale was valid. Internal consistency was very good (Cronbach's alpha of 0.94). The intraclass correlation coefficient showed high intra- and interobserver reliability (0.999 and 0.994, respectively). The Kappa and weighted Kappa coefficients were used to measure the reliability of each item; the majority obtained values above 0.9. Lastly, the differences between baseline and final evaluations of pushers were significant (paired sample t test), showing that the scale is sensitive to changes obtained through physical therapy.

CONCLUSIONS

The Spanish-language version of the Scale for Contraversive Pushing is valid and reliable for measuring pusher behaviour in stroke patients. In addition, it is able to evaluate the ongoing changes in patients who have received physical therapy.

Relationship of white matter lesions and severity of pushing behavior after stroke

[Purpose] The relationship between white matter lesions (WMLs) and pushing behavior (PB) is still poorly understood. The purpose of this study was to investigate whether damage from WMLs affects the functional outcome of PB after acute stroke. [Subjects and Methods] In total, 37 patients were included. PB was assessed using the standardized Scale for Contraversive Pushing (SCP). Stroke types were classified as total anterior circulation infarct (TACI), partial anterior circulation infarct (PACI), or lacunar syndrome using the Bamford classification. WML severity was categorized into four groups using the Fazekas visual scale. Thereafter, patients were divided into 4 groups according to the stroke type and/or presence of WMLs. The SCP, Trunk Control Test (TCT), Stroke Impairment Assessment Set (SIAS), and Barthel Index were the outcome measures. [Results] The SCP and TCT in patients with PACI without WMLs were better than those in patients with TACI with or without WMLs. Regarding SCP, TCT, and SIAS, patients with TACI had poorer values compared with PACI, regardless of WML severity. Barthel Index efficiency was not significantly different between the groups. [Conclusion] Our results suggest that moderate to severe WMLs and PACI had a relationship with PB severity and truncal balance.

Novel Treatment Approach to Contraversive Pushing after Acute Stroke: A Case Report

Purpose: The purpose of this case report is to provide an alternative treatment approach to pushing behavior (PB), adapting widely used equipment for persons with stroke demonstrating such behaviour. The aim is to change their graviceptive experience during interventions while performing repeated stepping and righting practice to resolve PB more quickly. Client Description: The subject is a man aged 56 years who sustained a right middle-cerebral-artery ischemic stroke. He entered in-patient rehabilitation from an acute care hospital 7 days post-stroke. Intervention: Lateral stepping with body weight-supported treadmill training (LS-BWSTT) was used such that the subject stepped laterally toward the uninvolved side. Measures and Outcome: Scores on the Scale for Contraversive Pushing and the FIM were recorded at regular intervals. After intervention, the subject demonstrated decreased PB and improved function. Implications: The individual's PB improved after LS-BWSTT. LS-BWSTT is a novel treatment intervention that could be considered in future clinical decision making using evidence-based principles.

Prone positioning reduces severe pushing behavior: three case studies

[Purpose] Pushing behavior is classically described as a disorder of body orientation in the coronal plane. Most interventions for pushing behavior have focused on correcting the deviation in vertical perception. However, pushing behavior seems to involve erroneous movements associated with excessive motor output by the non-paretic limbs and trunk. The present study aimed to inhibit muscular hyper-activity by placing the non-paretic limbs and trunk in the prone position. [Subjects and Methods] The subjects of the present study were 3 acute stroke patients with severe pushing behavior. The study consisted of the following 3 phases: baseline, intervention, and follow-up. In addition to conventional therapy, patients received relaxation therapy in the prone position for 10 minutes a day over 2 days. The severity of pushing behavior was assessed using the scale for contraversive pushing, and truncal balance was evaluated using the trunk control test. These assessments were performed before and after the baseline phase, and after the intervention and follow-up phases. [Results] At the baseline phase, both scores were poor. Both scores improved after the intervention and follow-up phases, and all the patients could sit independently. [Conclusion] Relaxation therapy in the prone position might ameliorate pushing behavior and impaired truncal balance.

The Scale for Contraversive Pushing: A Reliability and Validity Study

Objective. Pushing toward the hemiplegic side can interfere with mobility training after stroke. This study estimated the internal consistency, interrater reliability, and validity of the Scale for Contraversive Pushing (SCP).

Methods. Twenty-six patients with recent stroke were diagnosed with pusher behavior (PB). Two testers, randomly selected from 3 other examiners, independently assessed each patient using the SCP on the same day within 3 days of admission for rehabilitation. Cohen kappa coefficient was used to determine the agreement between the clinical and SCP diagnosis. The interrater reliability of the scale was estimated by calculation of the intraclass correlation coefficient. Cronbach’s alpha coefficient and Pearson’s coefficients were used to estimate the internal consistency of the scale and correlations between the subscores and the total score.

Results. The agreement between SCP and clinical diagnosis was very low when the original cutoff criterion for SCP diagnosis was used but was almost perfect with a modified criterion. The interrater reliability was good to excellent with regard both to each sub-score and to the total score. The internal consistency was very high, along with correlations between subscores and total score of the scale.

Conclusions. The results provide support for use of the SCP based on its reliability and validity using a modified cutoff criterion to make a diagnosis of PB.

Time to Recovery From Lateropulsion Dependent on Key Stroke Deficits

Background. Lateropulsion, a postural control disorder, delays recovery following hemispheric stroke. The number of stroke impairments may lead to differential recovery rates, depending on the intact systems available for recovery from lateropulsion. Objective. To study the impact of key postural control deficits on lateropulsion rate of recovery following stroke. Methods. Through retrospective analysis: 169 patients with hemispheric stroke in an in-patient rehabilitation facility were divided into 3 groups: (1) motor deficits only; (2) motor and hemianopic or visual–spatial deficits or motor and proprioceptive deficits; and (3) motor, proprioceptive, and hemianopic or visual–spatial deficits. Kaplan–Meier survival analysis determined if time to recovery from lateropulsion (achieving a score of 0 or 1 on the Burke Lateropulsion Scale) differed by group. Results. Log rank tests showed that time to recovery from lateropulsion differed based on the number of deficits (group, P = .012). Post hoc analyses by lesion side showed that group differences only occurred in right brain lesion ( P < .05) as compared with left brain lesions ( P = .34). Patients recovered from lateropulsion during in-patient rehabilitation if they had only motor deficits; those with all 3 postural control deficits showed the most protracted recovery. Conclusions. Rate of recovery from lateropulsion after stroke is dependent on the side of lesion, and number of key motor, proprioceptive, and/or hemianopic or visual–spatial deficits. The more postural control systems affected, the slower the recovery. Our data identify patients likely to need protracted rehabilitation targeting key postural control deficits.

Higher-level gait disorders: an open frontier

The term higher-level gait disorders (HLGD) defines a category of balance and gait disorders that are not explained by deficits in strength, tone, sensation, or coordination. HLGD are characterized by various combinations of disequilibrium and impaired locomotion. A plethora of new imaging techniques are beginning to determine the neural circuits that are the basis of these disorders. Although a variety of neurodegenerative and other pathologies can produce HLGD, the most common cause appears to be microvascular disease that causes white-matter lesions and thereby disrupts balance/locomotor circuits.

Determinants and consequences for standing balance of spontaneous weight-bearing on the paretic side among individuals with chronic stroke

Hemiparetic stroke patients commonly bear more weight on the non-paretic side which seems intuitively linked to unilateral control deficits. However, there is evidence that some post-stroke favour weighting the paretic side, which may be problematic given altered capacity of the paretic limb to contribute to the control of upright posture. This study explores the prevalence and clinical determinants of stance asymmetry, and the relationship between stance asymmetry and postural control among chronic stroke patients. Subjects (n=147; >6 months post-stroke) stood on two force plates in eyes-open and eyes-closed conditions; 59 were symmetric, 18 had paretic asymmetry (PA), and 70 had non-paretic asymmetry (NPA). Root mean square (RMS) of antero-posterior and medio-lateral centre-of-pressure under each limb and both limbs combined were compared. RMS of total medio-lateral centre-of-pressure was greater for both asymmetric groups compared with the symmetric group. PA subjects relied less on the loaded limb for control than NPA subjects and relied more on visual information for postural control than those who were symmetric. There were no differences in the characteristics of individuals between the PA and NPA groups. The loading of the paretic limb was not related to impaired postural control during stationary standing which was attributable, in part, to individuals relying on control from the non-paretic limb, in spite of lower vertical load, and a greater dependence on visual contributions. There was no evidence that greater loading on the paretic limb was related to persisting dyscontrol but may rather reflect a learned strategy.

Somatosensory findings of pusher syndrome in stroke patients

Objective

To investigate the somatosensory findings of pusher syndrome in stroke patients.

Methods

Twelve pusher patients and twelve non-pusher patients were enrolled in this study. Inclusion criteria were unilateral stroke, sufficient cognitive abilities to understand and follow instructions, and no visual problem. Patients were evaluated for pusher syndrome using a standardized scale for contraversive pushing. Somatosensory finding was assessed by the Cumulative Somatosensory Impairment Index (CSII) and somatosensory evoked potentials (SEPs) at 1 and 14 weeks after the stroke onset. Data of SEPs with median and tibial nerve stimulation were classified into the normal, abnormal, and no response group.

Results

In the baseline characteristics (sex, lesion character, and side) of both groups, significant differences were not found. The score of CSII decreased in both groups at 14 weeks (p<0.05), but there were no significant differences in the CSII scores between the two groups at 1 and 14 weeks. There were no significant differences in SEPs between the two groups at 1 and 14 weeks after the stroke onset.

Conclusion

It appears that somatosensory input plays a relatively minor role in pusher syndrome. Further study will be required to reveal the mechanism of pusher syndrome.

Posterior pusher syndrome — case report

Pusher syndrome is classically described as disorder of body orientation in the coronal plane. It is characterized by a tilt towards the contralesional paretic side and a resistance to external attempts to rectify. It occurs mainly in stroke patients, however, non-stroke causes have been described too. In 2010 the concept of the posterior pusher syndrome had been proposed, defined as disturbance of body orientation in the sagittal plane with imbalance, posterior tilt and an active resistance to forward pulling or pushing. The author describes, on the basis of the literature and own research, symptoms and methods of the treatment of the little-known posterior pusher syndrome.

Training rapid stepping responses in an individual with stroke

BACKGROUND AND PURPOSE

Compensatory stepping reactions are important responses to prevent a fall following a postural perturbation. People with hemiparesis following a stroke show delayed initiation and execution of stepping reactions and often are found to be unable to initiate these steps with the more-affected limb. This case report describes a targeted training program involving repeated postural perturbations to improve control of compensatory stepping in an individual with stroke.

CASE DESCRIPTION

Compensatory stepping reactions of a 68-year-old man were examined 52 days after left hemorrhagic stroke. He required assistance to prevent a fall in all trials administered during his initial examination because he showed weight-bearing asymmetry (with more weight borne on the more-affected right side), was unable to initiate stepping with the right leg (despite blocking of the left leg in some trials), and demonstrated delayed response times. The patient completed 6 perturbation training sessions (30-60 minutes per session) that aimed to improve preperturbation weight-bearing symmetry, to encourage stepping with the right limb, and to reduce step initiation and completion times.

OUTCOMES

Improved efficacy of compensatory stepping reactions with training and reduced reliance on assistance to prevent falling were observed. Improvements were noted in perturbation asymmetry and step timing. Blocking the left foot was effective in encouraging stepping with the more-affected right foot.

DISCUSSION

This case report demonstrates potential short-term adaptations in compensatory stepping reactions following perturbation training in an individual with stroke. Future work should investigate the links between improved compensatory step characteristics and fall risk in this vulnerable population.

Clinical examination tools for lateropulsion or pusher syndrome following stroke: a systematic review of the literature

Objective: To examine the clinimetric properties and clinical applicability of published tools for `quantifying' the degree of lateropulsion or pusher syndrome following stroke.

Data sources: Search through electronic databases (MEDLINE, EMBASE, CINAHL, Science Citation Index) with the terms lateropulsion, pushing, pusher syndrome, validity, reliability, internal consistency, responsiveness, sensitivity, specificity, posture and stroke. Databases were searched from their inception to October 2008.

Review methods: Abstracts were selected by one author. A panel of experts then determined which should be included in this review. Five abstracts were reviewed and the panel agreed to omit one abstract because those authors did not write a full manuscript. The panel critiqued manuscripts according to predetermined criteria about clinical and clinimetric properties.

Results: Four manuscripts referencing three tools for examining lateropulsion were found. Validity and reliability data support the clinical use of the Scale for Contraversive Pushing, the Modified Scale for Contraversive Pushing and the Burke Lateropulsion Scale. The Scale for Contraversive Pushing has the most extensive testing of clinimetric properties. The other tools show promising preliminary evidence of clinical and research utility. More testing is needed with larger, more diverse samples.

Reviewers' conclusions: The Scale for Contraversive Pushing, the Modified Scale for Contraversive Pushing and the Burke Lateropulsion Scale are reliable and valid measures with good clinical applicability. Larger, more varied samples should be used to better delineate responsiveness and other clinimetric properties of these examination tools.

La rétropulsion du sujet âgé: mise au point sur un symptôme grave et proposition d'une échelle pour une évaluation quantifiée

PURPOSE

Although there is currently no epidemiological data on backward disequilibrium, this disturbance of posture does not seem to be rare in frail elderly.

ACTUALITIES AND STRONG POINTS

Backward disequilibrium is characterized by the following criteria: the location of buttocks on the anterior side of the seat while the trunk rested at the back of the armchair in the sitting position; an inadequate forward of the trunk and a backward projection of the trunk outside the base of support during sit-to-stand; and a posterior projection of the center of mass outside the base of support in the standing position. Several pathological situations either somatic (degenerative, ischemic and traumatic brain lesions), psycho-somatic (psychomotor disadaptation syndrome, extended bed confining, non-use) or psychological (depression) affections can entail backward disequilibrium. Falls, loss of autonomy and the risk of the vicious circle with its causes are the main consequences of backward disequilibrium.

PROSPECTS AND PROJECTS

Although the geriatrician is familiarized with backward disequilibrium, there is no scale to quantify it. In this paper we review causes, consequences and management of backward disequilibrium, and in order to assess it, we propose a semi-quantitative scale, based on some activities of everyday living which are sitting position, sit-to-stand, back-to-sit and standing position. So, a backward disequilibrium score could be determined.

Pusher syndrome--a frequent but little-known disturbance of body orientation perception

Disturbances of body orientation perception after brain lesions may specifically relate to only one dimension of space. Stroke patients with "pusher syndrome" suffer from a severe misperception of their body's orientation in the coronal (roll) plane. They experience their body as oriented 'upright' when it is in fact markedly tilted to one side. The patients use the unaffected arm or leg to actively push away from the un-paralyzed side and resist any attempt to passively correct their tilted body posture. Although pusher patients are unable to correctly determine when their own body is oriented in an upright, vertical position, they seem to have no significant difficulty in determining the orientation of the surrounding visual world in relation to their own body. Pusher syndrome is a distinctive clinical disorder occurring characteristically after unilateral left or right brain lesions in the posterior thalamus and -less frequently- in the insula and postcentral gyrus. These structures thus seem to constitute crucial neural substrates controlling human (upright) body orientation in the coronal (roll) plane. A further disturbance of body orientation that predominantly affects a single dimension of space, namely the transverse (yaw) plane, is observed in stroke patients with spatial neglect. Apparently, our brain has evolved separate neural subsystems for perceiving and controlling body orientation in different dimensions of space.

Effect of Posture on the Perception of Verticality in Neglect Patients

BACKGROUND AND PURPOSE

The anticlockwise (ACW) deviation of the visual and visuohaptic subjective verticals (SVs), known to occur in patients with right hemisphere lesion, is amplified by spatial neglect (N). These patients have only been assessed when sitting. We investigated the hypothesis that postural changes modulate visuohaptic SV deviation.

METHODS

Eight patients presenting with a right hemisphere lesion and spatial N were compared with 6 matched control subjects (C). In the dark, they had to rotate a luminous rod to put it at the vertical in 4 conditions: (1) sitting with plantar sole support; (2) sitting without plantar sole support; (3) sitting with legs extended on a support; and (4) supine position.

RESULTS

N patients showed a significant ACW deviation (-4.5 degrees) of the SV compared with C subjects (+0.01 degrees). The effect of body position depended on the group (P=0.022) because changes had definite effects in the N but not in the C group. In fact, the former showed a reduction of the ACW deviation, from the first to the fourth condition.

CONCLUSIONS

Although the possible role of plantar and leg somaesthetic inputs remains to be thoroughly investigated, the modulation of gravitational inputs at trunk or vestibular level influences the SV deviation in N patients. This has to be put in relation with the modulation of N signs reported by other authors when passing from the sitting to the supine position.

Vers une meilleure compréhension et une évaluation quantifiée du « pushing », un comportement postural dû à certains AVC

INTRODUCTION

Postural control aims to build up and align the body orientation (posture) and stabilize body segments. The existence of two separate mechanisms, one for the control of body orientation with respect to gravity and one for its stabilisation, is an emerging concept that allows a better understanding of postural disorders, including pushing, after stroke. Objectives. - Literature review concerning pushing, one of the most puzzling postural behaviours after stroke.

METHODS

Critical review of papers indexed in Medline and book chapters dealing with pushing.

RESULTS

There is no agreement about the definition of pushing: some authors consider that pushers push himself toward the paretic side using the healthy arm or leg; others consider that pushers lean (list) toward the side opposite the lesion and resist any attempt to become more upright. Surprisingly, the push itself has never been measured. Some ordinal scales have been recently proposed, but their psychometric properties have not been analysed. These methodological insufficiencies explain in part the disagreements about frequency (from 5% to 50% of patients with stroke) and cause(s) of pushing.

CONCLUSION

Pushing may be the most dramatic clinical manifestations of an extreme bias in the construction of the biological vertical. We argue for a better assessment of vertical perception/representation after stroke involving the three modalities of the biological (subjective) vertical: the visual vertical, the haptic or tactile vertical, and especially the postural vertical.

Subjective visual vertical in pitch and roll in right hemispheric stroke

BACKGROUND AND PURPOSE

Patients with right hemispheric stroke usually present an anticlockwise deviation of the subjective visual vertical (SVV) in the frontal (roll) plane. However, the occurrence of a similar disorder in the sagittal (pitch) plane has never been assessed. We investigated the subjective visual vertical in both planes in those patients.

METHODS

Eight patients, 4 with spatial neglect (N+) and 4 without neglect (N-), were compared with 4 healthy participants (C). They sat facing a luminous bar adjustable in rotation, either in the roll or in the pitch plane, and had to orient it in a vertical position, in the dark.

RESULTS

Compared with N- (-0.1 degrees) and C (+1.1 degrees) groups, N+ patients presented with a significant backward deviation (-4.5 degrees) of the SVV in pitch. In accordance with other studies, they also showed a significant anticlockwise deviation (-8.8 degrees) of the SVV in roll, as compared with N- (-1.9 degrees) and C (+0.4 degrees) subjects. This was associated with an opposite trunk deviation in both planes.

CONCLUSIONS

While confirming the anticlockwise deviation already reported in the frontal plane, we showed for the first time to our knowledge a backward deviation of the SVV in neglect patients, which has to be put in relation with their balance disorders.

Poststroke "pushing": natural history and relationship to motor and functional recovery

BACKGROUND AND PURPOSE

Patients with hemiparetic stroke have impaired balance control. Some patients ("pushers") are resistant to accepting weight on and actively "push" away from the nonparetic side. This research identified pushers from stroke patients with moderate to severe hemiparesis and examined longitudinal changes in symptoms, level of impairment, and functional independence.

METHODS

Prospective sample of hemiparetic stroke patients (n=65) located in Toronto, Canada. Detailed clinical assessments were performed within 10 days postonset, at 6 weeks, and at 3 months.

RESULTS

At 1 week after stroke, 63% of patients demonstrated features of pushing. In 62% of pushers, symptoms resolved by 6 weeks, whereas in 21%, pushing symptoms persisted at 3 months. Motor recovery and functional abilities at 3 months were significantly lower among the pushers compared with the nonpushers. Pushers also had a significantly longer hospital length of stay (89 days versus 57 days). It is noteworthy that motor and functional recovery improved significantly over the 3-month study period for both pushers and nonpushers.

CONCLUSIONS

Identification of stroke patients with pushing symptoms has prognostic implications for recovery. In light of this potential recovery, rehabilitation specialists need to refine treatment approaches for the pushers to further improve functional outcome.

Contraversive pushing in non-stroke patients

BACKGROUND

Pusher syndrome is a disorder of postural control observed in patients with right or left brain damage associated with hemiparesis. Those patients show a peculiar behavior of actively pushing away from the nonhemiparetic side and resisting against passive correction, with a tendency to fall toward the paralyzed side. Thus far this phenomenon has been exclusively associated with stroke patients.

OBJECTIVE

We investigate the occurrence, imaging features and clinical evolution of pusher behavior in patients with acute encephalic lesions at a tertiary emergency hospital.

METHODS

Pusher patients were identified from 530 inpatients during a 1 year period. Patients were evaluated using a standardized Scale for Contraversive Pushing (SCP), neurological examination, assessment of neuropsychological symptoms, activities of daily living function and neuroimaging studies.

RESULTS

We found eight patients (1.5%) with severe contraversive pushing, three female and five male. Age at symptoms onset ranged from 48 to 80 years (mean 65.4). All patients had scores equal or above 1.5 in each tested parameter of the SCP. Six patients (75 %) had right-hemisphere brain damage. A stroke etiology was found in four patients. The other four patients had non-stroke etiology (three traumatic, one metastatic tumor). Stroke patients showed complete recovery of pusher behavior at a mean duration of 15.3 weeks. In patients with brain trauma, pushing behavior was completely resolved in a mean time of 5 weeks.

CONCLUSIONS

The results demonstrate that contraversive pushing may also occur in patients with non-stroke neurological lesions and suggest that resolution of symptoms may vary according to the underlying etiology.