Postural sway as a marker of progression in Parkinson's disease: A pilot longitudinal study (original) (raw)
Related papers
Assessment of postural control in patients with Parkinson’s disease: Sway ratio analysis
Human Movement Science, 2011
Analysis of the postural stability impairments in neurodegenerative diseases is a very demanding task. Age-related declines in posturographic indices are usually superimposed on effects associated with the pathology and its treatment. We present the results of a novel postural sway ratio (SR) analysis in patients with Parkinson's disease (PD) and age-matched healthy subjects. The sway ratios have been assessed based upon center of foot-pressure (CP) signals recorded in 55 parkinsonians (Hoehn and Yahr: 1-3) and 55 age-matched healthy volunteers while standing quiet with eyes open (EO) and then with eyes closed (EC). Complementing classical sway measure abnormalities, the SR exhibited a high discriminative power for all controlled factors: pathology, vision, and direction of sway. Both the anteroposterior (AP) and mediolateral (ML) sway ratios were significantly increased in PD patients when compared to the control group. An additional SR increase was observed in the response to eyes closure. The sway ratio changes documented here can be attributed to a progressive decline of a postural stability control due to pathology. In fact, a significant correlation between the mediolateral SR under EO conditions and Motor Exam (section III) score of the UPDRS was found. The mediolateral sway ratios computed for EO and EC conditions significantly correlated with the CP path length (r = .87) and the mean anteroposterior CP position within the base of support (r = .38). Both indices reflect postural stability decline and fall tendency # in parkinsonians. The tremor-type PD patients (N = 34) showed more pronounced relationships between the mediolateral SR and selected items from the UPDRS scale, including: falls (Kendall Tau = .47, p < .05), rigidity (.45, p < .05), postural stability (retropul-0167-9457/$ -see front matter Ó journal hom ep ag e: www.elsevier.com/loc ate/humov sion) (.52), and the Motor Exam score (.73). The anteroposterior SR correlated only with tremor (Kendal Tau = .77, p < .05). It seems that in force plate posturography the SR can be recommended as a single reliable measure that allows for a better quantitative assessment of postural stability impairments.
Journal of Central Nervous System Disease, 2020
Purpose: The establishment of early diagnostic methods for Parkinson disease (PD) is one of the key features to clinically control the rate of PD progression. This study aimed to give a first step toward recognizing the efficacy of multiple postural indices of balance control in differentiating medicated PD patients from health participants. Methods: Nine individuals with PD (Hoehn and Yahr Stage up to 2), 9 staged 2.5 and up, and 9 healthy age-matched Controls performed bipedal stances for 120 seconds with eyes either open or closed on a stable force platform. All participants with PD were under anti-Parkinsonian medication. Non-parametric tests investigated the effects of PD and visual input on postural indices extracted from the center of pressure coordinates. Results: Independent of the stage of the disease, individuals with PD presented faster and shakier body sway compared with Controls. Advanced stages of PD also revealed increased body sway length and variability. In additio...
Movement Disorders, 2008
We compared postural performances in early stage Parkinson's disease (PD) patients and healthy subjects, and to determine if PD patients have infraclinical postural instability. Nine PD patients and 18 age-and sex-matched control subjects were recorded with open eyes (OE) and closed eyes (CE) using a force platform in static and dynamic conditions with a mobile platform allowing antero posterior and medio lateral oscillations. Oscillations of the mobile platform and balance strategy were quantified using both a force platform and the Vicon system. Under static conditions with both OE and CE, PD patients had a larger center foot pressure sway area than the control subjects (P ϭ 0.007 and P ϭ 0.04, respectively). Under dynamic conditions, the PD patients' sway area was greater than that of the control subjects in the CE antero posterior position (P ϭ 0.04). Oscillations of the mobile platform were not different between the two groups. Lastly, all subjects used an ankle strategy, but PD patients had larger head oscillations than the control subjects. Early stage PD patients have an infraclinical postural instability which is compensated when it is more difficult to maintain good balance, suggesting that the neurological mechanisms of balance are partially still operating at this stage of the disease.
Postural Instability in Parkinson’s Disease: A Review
Brain Sciences
Parkinson’s disease (PD) is a heterogeneous progressive neurodegenerative disorder, which typically affects older adults; it is predicted that by 2030 about 3% of the world population above 65 years of age is likely to be affected. At present, the diagnosis of PD is clinical, subjective, nonspecific, and often inadequate. There is a need to quantify the PD factors for an objective disease assessment. Among the various factors, postural instability (PI) is unresponsive to the existing treatment strategies resulting in morbidity. In this work, we review the physiology and pathophysiology of postural balance that is essential to treat PI among PD patients. Specifically, we discuss some of the reported factors for an early PI diagnosis, including age, nervous system lesions, genetic mutations, abnormal proprioception, impaired reflexes, and altered biomechanics. Though the contributing factors to PI have been identified, how their quantification to grade PI severity in a patient can hel...
Assessment of postural instability in patients with Parkinson’s disease
Experimental Brain Research, 2007
Postural instability is one of the most disabling features of idiopathic Parkinson's disease (PD). In this study, we focused on postural instability as the main factor predisposing parkinsonians to falls. For this purpose, changes in sway characteristics during quiet stance due to visual feedback exclusion were studied. We searched for postural sway measures that could be potential discriminators for an increased fall risk. A group of 110 subjects: 55 parkinsonians (Hoehn and Yahr: 1-3), and 55 age-matched healthy volunteers participated in the experiment. Their spontaneous sway characteristics while standing quiet with eyes open and eyes closed were analyzed. We found that an increased mediolateral sway and sway area while standing with eyes closed are characteristic of parkinsonian postural instability and may serve to quantify well a tendency to fall. These sway indices signiWcantly correlated with disease severity rated both by the Hoehn and Yahr scale as well as by the Motor Section of the UPDRS. A forward shift of a mean COP position in parkinsonians which reXects their Xexed posture was also signiWcantly greater to compare with the elderly subjects and exhibited a high sensitivity to visual conditions. Both groups of postural sway abnormalities identiWed here may be used as accessible and reliable measures which allow for quantitative assessment of postural instability in Parkinson's disease.
Changes in postural control in patients with Parkinson's disease: a posturographic study
Physiotherapy, 2016
Objectives Postural instability is one of the most disabling features in Parkinson's disease (PD), and often leads to falls that reduce mobility and functional capacity. The objectives of this study were to analyse the limit of stability (LOS) and influence of the manipulation of visual, somatosensorial and visual-vestibular information on postural control in patients with PD and healthy subjects. Design Cross-sectional. Setting Movement Disorders Unit, university setting. Participants Eighty-two subjects aged between 37 and 83 years: 41 with Parkinson's disease in the 'on' state and 41 healthy subjects with no neurological disorders. Both groups were matched in terms of sex and age. Main outcome measures Unified Parkinson's Disease Rating Scale (UPDRS)-motor score, modified Hoehn and Yahr staging, Dynamic Gait Index (DGI) and posturography with integrated virtual reality. The parameters analysed by posturography were LOS area, area of body centre of pressure excursion and balance functional reserve in the standing position in 10 conditions (open and closed eyes, unstable surface with eyes closed, saccadic and optokinetic stimuli, and visual-vestibular interaction). Results The mean UPDRS motor score and DGI score were 27 [standard deviation (SD) 14] and 21 (SD 3), respectively. Thirteen participants scored between 0 and 19 points, indicating major risk of falls. Posturographic assessment showed that patients with PD had significantly lower LOS area and balance functional reserve values, and greater body sway area in all posturographic conditions compared with healthy subjects.
Postural behavior and Parkinson's disease severity
2016 1st International Conference on Technology and Innovation in Sports, Health and Wellbeing (TISHW), 2016
Progression of Parkinson disease (PD) increases severe motor symptoms such as bradykinesia, tremor, gait disturbance and postural instability, interfering with patients' daily life autonomy. Clinical evaluation is based on specific Scales like Hoehn & Yahr (H&Y) or UPDRS scales. The main goal of the study was to identify motor changes in the kinematic parameters related to different stages of Parkinson's disease progression according to H&Y scale. A secondary goal was to determine more objectively the stage of the disease reducing the discomfort of scales subjectivity. Our sample integrated 103 patients (45 female and 58 male, 70.5±8.4 years) diagnosed with PD by neurologists specialized in movement disorders. Postural Behavior was evaluated using Computerized Dynamic Posturography equipment (Balance Master System). Postural behavior was based on posturographic analysis of the center of pressure (CoP) time series (corresponding to the vertical projection of the center of gravity) to determine kinematic parameter(s) considered suitable to identify postural behavior modification. The posturographic tests applied were: 1) modified Clinical Test of Sensory Interaction on Balance (mCTSIB); 2) Limits of Stability (LOS); 3) Rhythmic Weight Shift (RWS). The results, concerning four stages of the H&Y scale (I-IV), showed significant differences between groups/stages. Static balance parameters like velocity, total distance, amplitude and frequency of CoP sway, increase with disease severity. In early to medium stages (I-II) of the disease, CoP presents a projection backwards, while in stage IV, this projection showed a trend to change forwards. Concerning dynamic balance, LOS presents a reduction mainly in the forward direction in all stages. The directional control in anterior-posterior RWS decreases with disease progression.
European Geriatric Medicine, 2018
The objective of this study is to identify clinical determinants for postural instability and gait difficulty in persons with Parkinson's disease (PD). Ninety-one persons (68 males; 74.7%) with PD were studied. Their mean age was 68.73 ± 8.74 years. The average time since diagnosis was 7.69 ± 5.23 years. The average Hoehn and Yahr stage was 2.43 ± 0.44. Age, gender, disease duration, disease severity and motor impairment were recorded. Participants were asked to perform timed clinical mobility tests that included a 5-step test, turns, forward walk, backward walk, and a sideways walk. The mobility tests were investigated for their contribution to predict the postural instability and gait difficulty (PIGD) score (falling, freezing, walking, gait and postural stability) of the Unified Parkinson Disease Rating Scale (UPDRS). PIGD score was significantly correlated with age, disease duration, Hoehn and Yahr score, comorbidity, UPDRS motor score, gait speed of forward, backward and sideways walks, and time to turn. PIGD score was marginally significantly correlated with timed 5-step test. After controlling for age, disease duration, disease severity, comorbidity, and motor impairment, sideway gait speed (b =-0.335; p = 0.024), timed 5-step test (b =-0.397; p = 0.003) and time to turn (b = 0.289; p = 0.028) significantly predicted postural instability and gait difficulty. Walking sideways, 5-step test, and turning are significant predictors of PIGD score. These simple mobility tests can be quickly applied in clinical practice to determine postural instability and gait problems in persons with PD.
Trunk accelerometry reveals postural instability in untreated Parkinson's disease
Parkinsonism & related disorders, 2011
While several studies have shown that subjects with advanced Parkinson’s disease (PD) exhibit abnormalities in sway parameters during quiet standing, abnormalities of postural sway associated with untreated PD have not been reported. Although not clinically apparent, we hypothesized that spontaneous sway in quiet stance is abnormal in people with untreated PD.We examined 13 subjects, recently diagnosed with PD, who were not yet taking any anti-parkinsonian medications and 12 healthy, age-matched control subjects. Postural sway was measured with a linear accelerometer on the posterior trunk (L5 level) and compared with traditional force plate measures of sway. Subjects stood for 2 min under two conditions: eyes open (EO) and eyes closed (EC).One of the most discriminative measures of postural changes in subjects with untreated PD was the increased ‘JERK’ of lower trunk in the EO condition, measured with the accelerometer. Root mean square and the frequency dispersion of postural sway in the EO condition also discriminated sway in untreated PD subjects compared to control subjects.We conclude that accelerometer-based sway metrics could be used as objective measures of postural instability in untreated PD. Accelerometer-based analysis of spontaneous sway may provide a powerful tool for early clinical trials and for monitoring the effects of treatment of balance disorders in subjects with PD.