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Background: Pilot studies suggest potential effects of neck muscle vibration (NMV) and prism adaptation (PA) on postural balance disturbances related to spatial cognition., Objectives: To evaluate the effect of 10 sessions of NMV and/or PA on ML deviation. We used the mediolateral centre of pressure position (ML deviation) as a biomarker for spatial cognition perturbation, hypothesising that PA and NMV would improve ML deviation, with a potential synergistic impact when used together., Methods: We conducted a multicentre, single-blind, randomised controlled study. Participants within 9 months of a right-hemisphere supratentorial stroke and with less than 40% body weight supported on the paretic side in standing were randomised into 4 groups (PA, NMV, PA+NMV, or control)., Primary Outcome: ML deviation at Day 14., Secondary Outcomes: force platform data, balance abilities, autonomy, and ML deviation, measured just after the first session (Day 1), at Day 90, and Day 180. A generalised linear mixed model (GLMM) assessed intervention effects on these outcomes, adjusting for initial ML deviation and incorporating other relevant factors., Results: 89 participants were randomised and data from 80 participants, mean (SD) age 59.2 (10.2) years, mean time since stroke 94 (61) days were analysed. At Day 14, a weak time x group interaction (P = .001, omega-squared = 0.08) was found, with no significant between-group differences in ML deviation (P = .12) or in secondary outcomes (P = .08). Between-group differences were found on Day 1 (P = .03), Day 90 (P = .001) and Day 180 (P < .0001) regardless of age and stroke-related data. On Day 1, ML deviation improved in both the PA and NMV groups (P = .03 and P = .01). In contrast, ML deviation deteriorated in the NMV+PA group on Day 90 and Day 180 (P = .01 and P = .01)., Conclusions: The study found no evidence of any beneficial effects of repeated unimodal or combined sessions of NMV and/or PA on ML deviation after stroke., Trial Registration: ClinicalTrials.gov identifier NCT01677091., Competing Interests: Declaration of competing interest The authors declare that they have no competing interests., (Copyright © 2024. Published by Elsevier Masson SAS.)

Background: Findings regarding the impact of language bias on treatment effect estimates (TEE) are conflicting, and very few studies have assessed these impacts in rehabilitation. The purpose was to compare TEE between studies published in non-English language (SPNEL) and those published in English language (SPEL) included in a previously published meta-analysis assessing the effects of physical therapy on balance and postural control after stroke., Methods: Six databases were searched until January 2019. Two independent reviewers selected randomised trials, extracted data, and assessed risk of bias. We conducted subgroup meta-analyses according to the language of study publication, then compared TEE between SPEL and SPNEL subgroups by using a random-effects meta-regression model., Results: From 13,123 records, 132 SPEL (n = 5219) and 13 SPNEL (n = 693) were included. SPNEL had a weight in the pooled estimate (8.2%) significantly lower than SPEL (91.8%; p<0.001). Compared to SPEL, SPNEL had both significantly worse methodological quality (p = 0.002) and quality of reporting for blinding of outcome assessment (p<0.001); and a significantly worse quality of reporting for incomplete outcome data (p<0.001). SPNEL had a significantly worse precision (i.e. inverse of variance) of TEE than SPEL (p = 0.005). Overall, the TEE was not significantly different between SPNEL and SPEL (standardised mean difference -0.16, 95% confidence interval [-0.53; 0.22], heterogeneity I2 = 78%). However, when PT was compared to sham treatment or usual care, SPNEL significantly over-estimated treatment effects (SMD -0.68, 95%CI [-1.03; -0.33], I2 = 39%) compared to SPEL. Restriction of the search to SPEL only did not change the direction of TEE for 8 out of 9 comparisons., Conclusions: SPNEL had a worse methodological quality than SPEL and were likely to over-estimate treatment effect. If inclusion of SPNEL in a systematic review is considered to be relevant, the impact of such studies on TEE should be explored by sensitivity analyses to ensure the findings validity., Competing Interests: The authors have declared that no competing interests exist.

Background: Stroke results in balance disorders and these directly affect autonomy and quality of life. The purpose of this systematic review and meta-analysis was to determine the efficacy of physical therapy (PT) on balance and postural control after stroke., Methods: We included all randomized controlled trials assessing the efficacy of PT on balance and postural control in adult patients after stroke without language restriction. Medline, Embase/Scopus, Cochrane Central Register of Controlled Trials, PEDro, Pascal, and Francis databases were searched until January 2019. Primary outcomes were balance (Berg Balance scale and Postural Assessment Scale for Stroke) and postural control with postural deviation or stability measurement in sitting or standing static evaluation. A pair of independent reviewers selected studies, extracted data, and assessed risk of bias. Meta-analyses with subgroups (categories of PT, time post-stroke, and lesion location) and meta-regression (duration of PT) were conducted., Results: A total of 145 studies (n = 5912) were selected from the 13,123 records identified. For balance, evidence was found in favor of the efficacy of functional task-training alone (standardized mean difference 0.39, 95% confidence interval [0.09; 0.68], heterogeneity I2 = 63%) or associated with musculoskeletal intervention and/or cardiopulmonary intervention (0.37, [0.19; 0.55], I2 = 48%), electrostimulation (0.91, [0.49; 1.34], I2 = 52%) immediately after intervention, compared to sham treatment or usual care (ST/UC). For postural deviation eyes open, assistive devices were more effective than no treatment (-0.21, [-0.37; -0.05], I2 = 0%) immediately after intervention; for postural stability eyes open, functional task-training and sensory interventions were more effective than ST/UC (0.97, [0.35; 1.59], I2 = 65% and 0.80, [0.46; 1.13], I2 = 37% respectively) immediately after intervention., Conclusions: Functional task-training associated with musculoskeletal intervention and/or cardiopulmonary intervention and sensory interventions seem to be immediately effective in improving balance and postural stability, respectively. The heterogeneity of PT and the weak methodological quality of studies limited the interpretation and the confidence in findings., Competing Interests: The authors have declared that no competing interests exist.

Asymmetrical postural behaviors are frequently observed after a stroke. They are due in part to the sensorimotor deficit, but they could also be related to a disorder of the representation of the body in space. The objective was to determine whether the asymmetrical postural behaviors of chronic stroke patients are related with a disruption of the perception of spatial frame. 30 chronic stroke patients (mean age 60.3 year ± 10, mean delay post-stroke 4.78 year ± 3), 15 patients with right brain damage (RBD) and 15 patients with left brain damage (LBD), and 20 healthy subjects participated in the study. Postural asymmetry was detected by the evaluation of body weight repartition on a force platform (weight body asymmetry) and was related to the longitudinal body axis (LBA) and the subjective straight ahead (SSA) (egocentric space representation) and to the subjective visual vertical (SVV) (allocentric space representation) by a multivariate analysis of variance adjusted with motor function and sensitivity as covariables. Both patients with RBD (35% ± 8) and LBD (39% ± 4) had body weight asymmetry and there was still space misperception at this stage of recovery, especially in the RBD group. WBA was related to LBA when considering both patients with RBD and LBD (p = 0.03). However, this relation was dependent on the side of the lesion (p = 0.0006) with a stronger relation in the RBD group (0.01). No relation with WBA was found neither with SSA (p = 0.58) nor with SVV (p = 0.47). This study pointed out a strong relationship between disturbance in the perception of the longitudinal body axis and postural asymmetry in chronic strokes, and especially within the RBD group. Conversely, no other spatial perturbations seemed to be involved in this particular postural behavior.

Introduction: Stroke frequently results in balance disorders, leading to lower levels of activity and a diminution in autonomy. Current physical therapies (PT) aiming to reduce postural imbalance have shown a large variety of effects with low levels of evidence. The objectives are to determine the efficiency of PT in recovering from postural imbalance in patients after a stroke and to assess which PT is more effective., Methods and Analysis: We will search several databases from inception to October 2015. Only randomised controlled trials assessing PT to recover from poststroke postural imbalance in adults will be considered.Outcome measures will be the Berg Balance Scale (BBS), the Postural Assessment Scale for Stroke (PASS), the 'weight-bearing asymmetry' (WBA), the 'centre of pressure' (COP) and the 'limit of stability' (LOS). WBA, COP and LOS are measured by a (sitting or standing) static evaluation on force plate or another device.Two independent reviewers will screen titles, abstracts and full-text articles, evaluate the risk of bias and will perform data extraction. In addition to the outcomes, measures of independence will be analysed. This study will aim at determining the effects of PT on the function (WBA, COP, LOS), the activity (BBS, PASS) and the independence of patients. Subgroup analyses will be planned according to the location of brain lesion (hemispheric, brainstem or cerebellum), the time since stroke (early, late, chronic), the PT (type, main aim (direct effect or generalisation), overall duration), the type of approaches (top-down or bottom-up) and the methodological quality of studies., Ethics and Dissemination: No ethical statement will be required. The results will be published in a peer-reviewed journal. This meta-analysis aims at managing the rehabilitation after postural imbalance by PT after a stroke., Trial Registration Number: Prospero CRD42016037966;Pre-results., Competing Interests: PJ presents a conflict of interest with GlaxoSmithKline. Her PhD thesis was supported by GSK. PJ will contribute in this study by helping to search electronic databases. She will not participate in the selection process and in the analyses., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.)

Balance disorders after stroke have a particularly detrimental influence on recovery of autonomy and walking. The present study is aimed at assessing the effect of proprioceptive stimulation by neck muscle vibration (NMV) on the balance of patients with right hemispheric lesion (RHL) and left hemispheric lesion (LHL). Thirty-one (31) patients (15 RHL and 16 LHL), mean age 61.5 years (±10.6), mean delay 3.1 (±1.6) months after one hemispheric stroke were included in this prospective study. The mean position in mediolateral and anteroposterior plane of the CoP (center of pressure) and the surface were evaluated using a force platform at rest and immediately after 10 min of vibration on the contralesional dorsal neck muscle. NMV decreases the lateral deviation balance induced by the stroke. Twenty patients (64.5 %) experienced a visual illusion of light spot moving toward the side opposite stimulus. These patients showed more improvement by vibration than those without visual illusion. There was an interaction between sensitivity and side of stroke on the effect of NMV. Proprioceptive stimulation by NMV reduces postural asymmetry after stroke. This short-term effect of the vibration is more effective in patients susceptible to visual illusion. This result was consistent with a central effect of NMV on the structures involved in the elaboration of perception of body in space.

Objective: To investigate the postural effect of 2 types of sensory stimulation in patients with a left hemispheric lesion (LHL) or right hemispheric lesion (RHL) compared with controls., Methods: 35 patients (18 LHL, 17 RHL) and 27 controls (mean age 54.1 years), with a mean delay post-stroke of 3.0 months were enrolled. Subjects stood on a force platform and were stimulated on the left and right side by optokinetic (Okn) and galvanic vestibular (Gv) stimulation. Lateral displacement following stimulation toward the right and left directions was calculated as the mean position of the centre of pressure (CP) during the stimulation period minus the mean position at rest., Results: Postural asymmetry was reduced in LHL and RHL patients. CP displacement was higher in cases of left-sided stimulation in the RHL group compared with control subjects and LHL patients (respectively 2.8 and 2.4 times higher, group effect, p<0.001, group × direction of stimulation interaction, p=0.007). The magnitude of displacement under Okn significantly correlated with Gv in all cases (ρ=0.635, p<0.001)., Conclusions: Both GV and Okn stimulations can modulate hemiparetic's CP and their postural effects are correlated., Significance: Results support a high level cortical postural effect of sensory stimulation on supramodal spatial network., (Published by Elsevier Ireland Ltd.)

Balance disorders related to disturbances in perception of spatial reference systems are common especially after right hemispheric stroke. Mental misrepresentation of bodily orientation in space is then often superimposed upon other factors affecting imbalance such as motor and sensory impairments. Traditional rehabilitation for balance recovery has not been specifically designed to improve balance disorders related to spatial cognition. The traditional approach, consisting of stimulating the conscious perception of body orientation in space, is demanding and laborious. The approach based on sensorial stimulation is completely different. The relevance of this method lies in the fact that, firstly it is specifically active in the cognitive component of balance disorders; and secondly, it can passively be applied with minimal patient participation, which is of particular importance for this patient group characterized by disorders of attention and concentration. These techniques, such as proprioceptive, visual or vestibular stimulation, have been found to correct spatial neglect but also postural bias. Clinical and data from functional neuro-imaging suggest a direct central action on cortical structures involved in the elaboration of spatial representation. These are promising techniques for the rehabilitation of postural disturbances related to spatial cognition disorders but are as yet at the stage of preliminary results., (Copyright © 2015 Elsevier Masson SAS. All rights reserved.)

After stroke, the causes of balance disorders include motor disorders, sensory loss, perceptual deficits and altered spatial cognition. This review focuses on motor strategies for postural control after stroke. Weight-bearing asymmetry, smaller surface of stability, increased sway, body tilting and sometimes pushing syndrome are observed. Weakness and sensory impairments account only for some of these disturbances; altered postural reactions and anticipated postural adjustments as well as abnormal synergistic muscular activation play an important part. These disorders are often linked to cognitive impairments (visuospatial analysis, perception of verticality, use of sensory information, attention, etc.), which explain the preeminent disorders of postural control seen with right rather than left-hemisphere lesions. Most of the motor changes are due to an impaired central nervous system but some could be considered adaptive behaviors. These changes have consequences for rehabilitation and need further studies for building customized programs based on the motor comportment of a given patient., (Copyright © 2015 Elsevier Masson SAS. All rights reserved.)

Background: Right brain damage (RBD) involves postural asymmetry and spatial frame disorders. In acute RBD patients, postural asymmetry is immediately reduced after one single session of prism adaptation (PA), without assessment of effects on spatial frames., Aim: To assess long-term effects of PA on posture and spatial frames in chronic RBD patients, without neglect., Method: Six chronic RBD patients without neglect (mean delay 45 months) were included. Each patient sustained 10 PA sessions of 20 min during 2 weeks. Outcome measures were: (1) posturographic analysis (mediolateral position of centre of pressure (X cop), (2) subjective straight ahead (SSA) and perception of longitudinal body axis (LBA). Each parameter was assessed by three pretests and three post-tests (+2 h, day + 3 and day + 7)., Results: In pretests, patients showed a shift of the X cop and SSA. In post-tests, results displayed (1) a significant reduction in mediolateral postural asymmetry at D + 7; (2) a significant left deviation of SSA at D + 3 and enduring at D + 7; and (3) no significant modification of LBA. The mean curves of X cop and SSA between pre- and post-tests were similar., Conclusions: PA involves persistent reduction in postural asymmetry in RBD patients without neglect. These findings were obtained at a chronic stage. This new effect cannot be explained by reduction in spatial attentional shift. Improvement may be explained by a better calibration of extra personal space frames used for posture, without effect on personal space frame. Findings argue in favour of a bottom-up effect of PA on mechanisms underlying spatial cognition.

Objective: To test sensitivity to proprioceptive, vestibular and visual stimulations of stroke patients with regard to balance., Method: The postural control of 20 hemiparetic patients after a single hemispheric stroke that had occurred at least 6 months before the study along with 20 controls was probed with vibration, optokinetic, and vestibular galvanic stimulations. Balance was assessed using a force platform (PF) with two miniature inertial sensors placed on the head (C1) and the trunk (C2) under each sensory condition and measured by three composite scores as the mean displacement of the body (PF, C1, C2) during the stimulation. A subject with a composite score greater than the 75th percentile of the composite scores found in the control subjects was arbitrarily considered to be sensitive to that stimulation., Results: Both control and stroke patients showed large inter-individual variations in response to the three types of sensory stimulation. Among the hemiparetic patients, nearly 65% were sensitive to the optokinetic stimulation, 60% to the galvanic stimulation and 65% to the vibration stimulation. In contrast to the control group, all the hemiparetic subjects were sensitive to at least one type of stimulation., Conclusion: Stroke patients are highly dependent on visual, proprioceptive and vestibular information in order to control their standing posture and individually differ in their relative sensitivity to each type of sensory stimulation., Significance: Contrarily to what one might suppose, the increased visual dependence manifested by stroke patients does not necessarily entail any neglect of proprioceptive and vestibular information., (Published by Elsevier Ireland Ltd.)

Three main issues have to be addressed by the examination of a patient complaining from balance disorders: physiopathology and aetiology, severity and consequences, and evolution. A precise clinical analysis must be then conducted, including close anamnesis and clinical examination, with scale measurements depending on the objectives. Daily consequences can be assessed by the Dizziness Handicap Inventory, which considers a large field of daily activities. The International Classification of Functioning evaluates activities and participation, influence of environmental factors, and quality of life. Then, patient's examination aims at objectifying and measuring the balance disorder. Quantified measurement is possible even in a simple doctor's office. Clinical scales for balance assessment should be used for a standardized assessment and to allow comparison of different subjects. Although the Tinetti test is the most-widely used in older people, it is quite approximate. The Berg Balance Scale has also been first validated in older people, it is rather easy to use, but uncertainty between two close scores is frequent. The Timed Up-and-Go Test is the simplest one and probably the most reliable. The Unipodal Stance Testing is also a simple test and a good predictor of fall. The Functional Ambulation Classification focuses attention on the physical support needed by the patient during walking. The Postural Assessment Scale for Stroke Patients (PASS) is easy to use after a recent stroke. Instrumental analysis by means of static and dynamic platforms, often coupled together with accelerometers or video, can be used to complete the clinical examination. Its main interest is to contribute to give insight into physiologic and pathologic mechanisms underlying the postural trouble.

Background: Subjective visual vertical (SVV) perception can be perturbed after stroke, but its effect on balance recovery is not yet known., Aim: To evaluate the influence of SVV perturbations on balance recovery after stroke., Methods: 28 patients (14 with a right hemisphere lesion (RHL) and 14 with a left hemisphere lesion (LHL)) were included, 5 were lost to follow-up. SVV perception was initially tested within 3 months after stroke, then at 6 months, using a luminous line, which the patients adjusted to the vertical position in a dark room. Mean deviation (V) and uncertainty (U), defined as the standard deviation of the SVV, were calculated for eight trials. Balance was initially assessed by the Postural Assessment Scale for Stroke (PASS), and at 6 months by the PASS (PASS6), a force platform (lateral and sagittal stability limits (LSL6 and SSL6)), the Rivermead Mobility Index (RMI6) and gait velocity (v6). Functional outcome was also assessed by the Functional Independence Measure at 6 months (FIM6)., Results: The scores for balance and for FIM6 were related to the initial V value: PASS6 (p = 0.01, tau = -0.38); RMI6 (p = 0.002, tau = -0.48), LSL6 (p = 0.06, tau = -0.29), SSL6 (p = 0.004, tau = -0.43), v6 (p = 0.01, tau = -0.36) and FIM6 (p = 0.001, tau = -0.49), as well as to the initial U value: PASS6 (p = 0.03, tau = -0.32), RMI6 (p = 0.02, tau = -0.35), SSL6 (p = 0.005, tau = -0.43) and FIM6 (p = 0.01, tau = -0.38)., Conclusions: Initial misperception of verticality was related to a poor score for balance after stroke. This relationship seems to be independent of motricity and neglect. Rehabilitation programmes should take into account verticality misperceptions, which could be an important factors influencing balance recovery after stroke.

Introduction: This study was conducted to assess visual dependence of postural control early after stroke., Design: Case control study., Setting: A Physical Medicine and Rehabilitation Department., Method: Twenty-five patients impaired by severe hemiplegia due to a recent first stroke, were examined. Fourteen had a right and 11 a left hemispheric lesion. There were aged 52+/-13 years, time since stroke was 30+/-12 days. Patients' data were compared to data for 25 healthy subjects. Sitting posture was assessed on a dynamic balance, using two parameters: frontal plane displacement of the centre of pressure under optokinetic stimulation (OKS), and the total length of centre of pressure displacement for the stability reaction. On the basis of 90th percentile control data, patients' behaviour was classified as totally visuo independent (VI), totally visuo dependent (VD) or mixed., Results: Body tilt under OKS was greater in patients than controls. No control subject was totally VD, 19 subjects were totally VI. Four patients were totally VD and only six were VI. The only clinical parameter linked to the effect of OKS was the sensitivity impairment. Overall patients with visuospatial neglect were the most perturbed, but two were totally visuo independent., Discussion and Conclusion: Assessment of postural variations in sitting under OKS is proposed for estimating visual dependence early after stroke. Individual reactions are more important than mean group reactions. Visual dependence is not solely due to neurological impairment, implying that previous physiological behaviour may be involved. Knowledge of these characteristics may affect rehabilitation programmes., (Copyright 2005 Elsevier B.V.)

Summary Objective To test the effect of gluteus medius (GM) vibration on the reduction of asymmetric body weight distribution in individuals with hemiparesis (HP) at two stages of postural recovery. Methods The effects of GM vibration according to the shift of the body weight (%Shift) onto the paretic leg during GM vibration were registered while standing on a force-platform in 40 HP (19 left and 21 right; mean age 54.7 ± 10.6 years, mean time after stroke 2.0 ± 1.3 months), as soon as they could stand without assistance and 4 to 6 weeks later, and in 40 control subjects (mean age 54.7 ± 10.5 years). Results Without vibration, baseline body weight (BW) distribution was characterized by underloading of the paretic limb (mean BW on the paretic limb 37.2% ± 13.1%). At the early stage of balance recovery, % shift toward the paretic limb induced by GM vibration differed significantly between left and right HP ( P = 0.049) and between left HP and controls (C) ( P = 0.022) and was related to BW asymmetry (r = 0.437, P = 0.004). Later, GM vibration reduced asymmetric BW distribution in most HP and no difference was found between left and right HP and between left and C. Conclusion At an advanced stage of postural recovery, GM vibration could help encourage HP to put weight on the affected limb. Interestingly, a behavioral difference was initially observed between right and left HP that could probably be explained by a different strategy due to the baseline severity of the BW asymmetry. [ABSTRACT FROM AUTHOR]

Introduction/Background Muscle vibration, in particular applied to the neck muscle is increasingly being used as a mean of rehabilitation treatment. Neck muscle vibration (NMV) is thought to have an effect on the representation of the body in space through sensory recalibration. The objective of this systematic scoping review was to map out the characteristics of the existing studies and gather the effect of neck muscle vibration on both spatial frame of reference and on postural balance. Material and method following the PRISMA guidelines, a systematic search was carried out using the databases MEDLINE, EMBASE, Cochrane library and PEDrO applying the following key words [(Postural balance) OR (Spatial reference)] AND (Neck muscle vibration) for those articles published through to July 2016. Results Altogether 67 studies were assessed and they unveiled both a large heterogeneity and a standard quality of methodology with a total of 1522 participants included. Under unilateral neck muscle vibration, the visual environment (illusion of a visual target) seemed to move towards the opposite side of the vibration, and both the visual vertical and the straight ahead were shifted towards the vibrated side. In addition, NMV produce a body tilt. This effect is however not constant at all times. Conclusion NMV is considered as a useful remedy tool in rehabilitation therapy which has shown to induce a body sway on the force platform and a deviation of the spatial representation in both healthy subjects and patients. That said, however, owing to the heterogeneity of the experiences and the various significant shortfalls highlighted, this research does not allow us to firmly conclude our results. [ABSTRACT FROM AUTHOR]