Postural visual dependence after recent stroke: Assessment by optokinetic stimulation

doi:10.1016/j.gaitpost.2005.09.007

Gait & Posture

Volume 24, Issue 3, November 2006, Pages 262-269

https://doi.org/10.1016/j.gaitpost.2005.09.007 Get rights and content

Abstract

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.

Section snippets

Subjects

Twenty-five patients and 25 healthy subjects were enrolled. When questioned, all of them said they were right handed.

The patients included had recently experienced their first and only cerebral hemispheric stroke, resulting in at least initial motor and balance impairment. They were examined 1–3 days after admission to our Physical Medicine and Rehabilitation Department, immediately after the acute stage in the neurological vascular unit. The patients included had to be able to remain sitting

Spontaneous position

Spontaneous projection of the CoP was slightly left deviated (−6.8 ± 7.35 mm). In the patients, the same left tilt projection of the CoP was observed. The degree of stability, as measured by the length of CoP’ projection was 111 ± 29, with a large range, from 82 to 166.

Reactions under OKS

Displacement of the CoP under OKS ranged from 0 to 12.5 mm on the frontal axis. The mean absolute value was 3.0 ± 3.1 mm under rightward rotation and 2.7 ± 2.8 mm under leftward rotation. Different types of behaviour were observed, over 0.5

Discussion

This study was conducted with the aim of describing the postural reactions to optokinetic stimulation of hemiplegic patients after a recent stroke. In this way, we set out to describe different kinds of reactions to the stimulation and to define visual dependence as the body tilt induced by optokinetic stimulation.

In a previous study, chronic post-stroke hemiplegic patients were shown to exhibit a visual dependence behaviour in relation to standing postural control [1]. A specific

Conclusion

The procedure proposed in this study allows assessment of the visual dependence of posture early after stroke. The fact that under optokinetic stimulation visual dependence is not, or not only, the consequence of neurological impairments, argues in favour of the existence of a constitutional behaviour present before the stroke. Early examination after stroke with our procedure allows the detection of such visual dependence or independence, before rehabilitation can induce a new visual

References (29)

I. Bonan et al.
Reliance on visual information after stroke. Part I: Balance on dynamic posturography
Arch Phys Med Rehabil
(2004)
B. Isableu et al.
How dynamic visual field dependence-independence interacts with the visual contribution to postural control
Hum Mov Sci
(1998)
E. Golomer et al.
Visual contribution to self-induced body sway frequencies and visual perception of male professional dancers
Neurosci Lett
(1999)
I. Bonan et al.
Reliance on visual information after stroke. Part II: Effectiveness of a balance rehabilitation programme with visual cue deprivation after stroke: a randomised controlled trial
Arch Phys Med Rehabil
(2004)
D.A. Perennou et al.
Biased postural vertical in humans with hemispheric cerebral lesions
Neurosci Lett
(1998)
D.A. Perennou et al.
Transcutaneous electric nerve stimulation reduces neglect-related postural instability after stroke
Arch Phys Med Rehabil
(2001)
J.P. Azulay et al.
Increased visual dependence in Parkinson's disease
Percept Mot Skills
(2002)
M. Guerraz et al.
Visual vertigo: symptom assessment, spatial orientation and postural control
Brain
(2001)
H. Suarez et al.
Assessment of the risk of fall, related to visual stimulation, in patients with central vestibular disorders
Acta Otolaryngol
(2001)
R.H. Blanks et al.
Postural adjustments produced by moving visual (horizontal optokinetic) patterns
J Am Acad Audio
(1996)

J.S. Tobis et al.

Visual perception dominance of fallers among community-dwelling older adults

J Am Geriatr Soc

(1985)

S.R. Lord et al.

Visual field dependence in elderly fallers and non-fallers

Int J Aging Hum Dev

(1990)

L. Sundermier et al.

Postural sensitivity to visual flow in aging adults with and without balance problems

J Gerontol A Biol Sci Med Sci

(1996)

H. Cohen et al.

Changes in sensory organization test scores with age

Age Ageing

(1996)

Cited by (38)

The association between visuospatial neglect and balance and mobility post-stroke onset: A systematic review
2021, Annals of Physical and Rehabilitation Medicine
Citation Excerpt :
With regard to the mediolateral direction, 2 studies of moderate methodological quality found no significant association between VSN and mediolateral CoP excursions [29,44] or velocities [44], whereas one study of good methodological quality found a significant association for mediolateral CoP excursions [57]. Yelnik et al. [25] investigated sitting balance under optokinetic stimulation (OKS) and showed that VSN was unrelated to body tilt under OKS, but it was positively related to the stabilization reaction (i.e., ratio for total length of CoP displacement under OKS). In summary, although consensus was reached on an absent association in the anteroposterior direction, the association between CoP excursions in the mediolateral direction and VSN is still uncertain.
Although previous narrative reviews have highlighted a potential association between visuospatial neglect (VSN) and balance disorders, to what extent different areas of balance and mobility could be affected is still unclear.
This systematic review updates previous literature findings and systematically reviews sitting balance, standing balance and mobility outcomes.
PubMed, Web of Science, ScienceDirect, Naric-Rehabdata, PEDro and the Cochrane Trials Library were systematically searched. Methodological quality was assessed by the National Heart, Lung, and Blood Institute Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies. The association between VSN and sitting balance, standing balance and mobility (walking, stair climbing/descending and transfers) was investigated.
In total, 48 studies were included (4595 stroke survivors): at least 1319 (29%) showed symptoms of VSN. VSN was associated with less independence during sitting, with an asymmetric posture toward the affected body side. For standing balance, we revealed a significant negative association between VSN and mediolateral stability and weight shifting, whereas only activities of daily living-related VSN was associated with weight-bearing asymmetry during static stance. While walking, patients with VSN laterally deviated from their path. Results were inconclusive regarding other aspects of mobility. The association between VSN and balance/mobility seemed to decrease over time.
Despite great heterogeneity in results, this study suggests that stroke survivors with VSN show specific deviations in posture and movement in the mediolateral direction. Although the association between VSN and balance/mobility has been extensively investigated, explanatory studies evaluating underlying mechanisms of the frequently present association are lacking. Future studies should address this by combining clinical and instrumented assessment of balance and gait performance, preferably longitudinally to investigate the associations over time.
Sensory reweighting in frail aged adults: Are the balance deficiencies mainly compensated by visual or podal dependences?
2021, Neuroscience Letters
Postural control is based on the integration of different sensory inputs. The process of scaling the relative importance of these sensory cues (visual, vestibular and proprioceptive) depends on individuals and creates sensory preferences, leading to sensory dependences when one particular source is preponderant. In this context, the literature showed a frequent visual dependence (visual inputs weighting) in aged adults. However, the somaesthetic inputs can also be prioritised in a podal-dependent profile. In the frail aged adults, none study has shown the distribution of these two dependences.
Which sensory orientation profile is preferentially adopted by frail aged males and females?
In this cross-sectional study, we compared 33 frail aged adults to 16 non frail aged adults during a static postural control task in three conditions on a force platform: i) a standard condition, ii) a no-vision condition and iii) a foam condition. An analysis with the factor sex was also performed in each group of participants.
The analysis of stabilometric parameters (mean velocity and mean velocity variance) highlighted a significant difference in no-vision or foam conditions when compared to the standard condition in frail aged males and only in the foam condition when compared to the standard condition for females in the frail group. No significant difference was observed between conditions in the control group.
Our study showed the predominance of both visual and podal information in frail aged adults when controlling their posture. Considering the sex factor, frail males were more dependents to their visual cues than frail females. This result should be used when designing the rehabilitation programs in this population.
Time-course investigation of postural sway variability: Does anxiety exacerbate the sensory reweighting impairment in chronic stroke survivors?
2019, Neuropsychologia
Although anxiety is one of the most prevalent psychological disorders in stroke survivors, its effect on sensory reweighting has not yet been fully studied. The aim of this work was to investigate how anticipation of collision avoidance events affects sensory reweighting in chronic stroke survivors with low and high levels of anxiety (LA-stroke and HA-stroke, respectively), as compared with healthy controls (HC), under the condition of perturbed proprioception. Eighteen LA-stroke and 18 HA-stroke survivors, as well as 18 gender- and age-matched HC, participated in this study. Postural sway variability (i.e. Root Mean Square (RMS) of the COP velocity) was measured for a duration of 180 s under two conditions: quiet standing and standing while predicting random virtual spheres to be avoided. Proprioceptive perturbation was simulated using bilateral Achilles tendon vibration at mid duration (60 s) for both conditions. The results showed that the HC were able to timely use visual anticipation to reduce the postural sway variability induced by tendon vibration. However, marked delay in using such anticipation was observed in stroke participants, especially in the HA-stroke group, as indicated by a significant decrease in the RMS of the COP velocity late in the vibration phase. This is the first study to consider the effect of anxiety while comparing sensory reweighting between stroke and healthy participants. The results indicated that chronic stroke survivors, particularly those with HA, could not efficiently use sensory reweighting to maintain balance in sensory conflicting conditions, which may subject them to loosing balance and/or falling. These findings are critical for future assessment and planning of rehabilitation interventions and balance in chronic stroke survivors.
The iFST: An instrumented version of the Fukuda Stepping Test for balance assessment
2018, Gait and Posture
The maintenance of the upright posture during dynamic balance requires the integration of sensory inputs regulated by the brain. After a neurological event, the assessment of balance control impairments is crucial for supporting health professionals in the design of personalized rehabilitation protocols. A commonly used test to assess balance ability is the Fukuda Stepping Test (FST). However, the clinical parameters traditionally considered are not fully representative of the patient’s motor ability. The purpose of this study was to devise an instrumented version of the FST (iFST) that embodies inertial sensors and allows to obtain individual motor strategy information. Twenty-seven sub-acute stroke patients and 18 healthy adults performed a repeated stepping task with closed eyes wearing five inertial sensors located on both distal tibiae and at pelvis, sternum, and head levels. From final foot position, body rotation and linear displacements were measured. A set of indices related to upper-body stability were estimated from pelvis, sternum, and head accelerations: Root Mean Square, Attenuation Coefficients, and improved Harmonic Ratio. Two additional parameters based on upper-body angular velocities were devised to assess step-by-step repeatability and inter-segment velocity variations. The results suggest that the clinical parameters do not provide enough information about the two groups’ motor strategies. Conversely, five iFST parameters were identified as predictors of patients’ motor ability, discriminating not only between healthy and pathological subjects, but also between different motor deficit levels within the same pathology. The iFST could be included in the clinical routine assessment of balance impairments, supporting the design of personalized treatments.
Rod and frame test and posture under optokinetic stimulation used to explore two complementary aspects of the visual influence in postural control after stroke
2017, Gait and Posture
Citation Excerpt :
VS OKS implies 4 different types of behaviour [13]: 1) visual independence, absence of tilt with no loss of stability; 2) VS, marked tilt with no stabilization reaction; 3) partial VS, body tilt despite an increased stabilization reaction; and 4) compensated VS, absence of body tilt but a marked increase in the stabilization reaction. After leftward and rightward OKS, patients were classified into 2 groups [13]: 1) visual insensitive with OKS (VS OKS-), total VI with OKS regardless of the direction or mixed reaction (visual independence in one direction and VS in the other direction) and others with various VS reactions; and 2) visual sensitive with OKS (VS OKS + ), total VS with OKS regardless of the direction. Data distribution was tested by Kolmogorov-Smirnov test.
Balance rehabilitation should consider individual comportments according to visual input (VI). Indeed, visual dependence (VD), defined as the predominance given to the VI whatever the circumstances, frequent after stroke it could disturb balance. Because the term VD is a bit restrictive and cannot be deduced from clinical tests, the term visual sensitivity (VS) is preferred here.
VI could have different influence depending on the task for a given individual.
We retrospectively compared 2 VS tests routinely used: the rod and frame test (RFT) and optokinetic stimulation (OKS). In RFT, VS was defined by a misperception of the visual verticality induced by a tilted frame (VS RFT) and in OKS by tilted sitting posture induced by rotational OKS (VS OKS). We studied the relations between VS RFT and VS OKS.
We analysed data for 84 patients, mean age 55 ± 10 years, 45 ± 30 days after stroke. Scores for both tests were correlated with autonomy measured by the functional independence measure (r = −0.3, p = 0.01 and r = −0.2, p = 0.02). VS OKS score was also correlated with balance measured by the postural assessment scale for stroke (r = −0.3, p = 0.03). VS RFT score was not correlated with VS OKS score (p = 0.4, r = 0.04).
A patient may display VS for one test without sensitivity for the other because these tests investigate different neural organisation — perception for RFT or action for OKS. Their relation to balance disorders should be further investigated to build individualized rehabilitation programs.
The effect of optokinetic and galvanic vestibular stimulations in reducing post-stroke postural asymmetry
2016, Clinical Neurophysiology
Citation Excerpt :
In this study, we observed that the corrective effect was 1.6 times higher with Okn than with Gv, however, the quantitative smaller beneficial effect of Gv compared to Okn is probably due to the intensity of the stimulation which was arbitrarily chosen and based on our previous studies. In these studies, we used Gv and Okn stimulation in a different context (Bonan et al., 2013; Yelnik et al., 2006) as we manipulated sensory information through multidirectional Okn and Gv stimulation in order to test the response of stroke patients to sensory information and to study sensory dependence (Bonan et al., 2013; Yelnik et al., 2006). Interestingly we observed that some patients were stabilised by Okn stimulation (Yelnik et al., 2006) and that Okn or Gv lateral stimulation usually induced a corrective lateral displacement of the CP (Bonan et al., 2013).
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.
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.
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).
Both GV and Okn stimulations can modulate hemiparetic’s CP and their postural effects are correlated.
Results support a high level cortical postural effect of sensory stimulation on supramodal spatial network.

View all citing articles on Scopus

View full text

Postural visual dependence after recent stroke: Assessment by optokinetic stimulation

Abstract

Introduction

Design

Setting

Method

Results

Discussion and conclusion

Section snippets

Subjects

Spontaneous position

Reactions under OKS

Discussion

Conclusion

Arch Phys Med Rehabil

Hum Mov Sci

Neurosci Lett

Arch Phys Med Rehabil

Neurosci Lett

Arch Phys Med Rehabil

Increased visual dependence in Parkinson's disease

Percept Mot Skills

Visual vertigo: symptom assessment, spatial orientation and postural control

Brain

Assessment of the risk of fall, related to visual stimulation, in patients with central vestibular disorders

Acta Otolaryngol

Postural adjustments produced by moving visual (horizontal optokinetic) patterns

J Am Acad Audio

Visual perception dominance of fallers among community-dwelling older adults

J Am Geriatr Soc

Visual field dependence in elderly fallers and non-fallers

Int J Aging Hum Dev

Postural sensitivity to visual flow in aging adults with and without balance problems

J Gerontol A Biol Sci Med Sci

Changes in sensory organization test scores with age

Age Ageing