Expanded Disability Status Scale (EDSS) estimation in multiple sclerosis from posturographic data

Impact of textured surfaces on the orthostatic balance of patients with multiple sclerosis

OBJECTIVE

To perform posturographic measurements with eyes open or closed using floor coverings with different textured surfaces to study postural control in patients with multiple sclerosis (MS).

METHODS

Static posturographic recordings were performed with eyes open and eyes closed on a forceplate with no covering (control condition) or covered by a textured mat with small pimples (height 2 mm) or large pimples (height 7 mm). Several posturographic variables were measured, focusing on displacements of the center of pressure (CoP) including the average velocity (Vav), the total length (L) of all displacements, and the surface (S) of the confidence ellipse. The recordings made with the textured mats were compared to the control condition with eyes open or closed. Then, the differences between the recordings made with large vs. small pimples on the one hand, and with eyes closed vs. open were calculated to assess the impact of pimple height or eye closure on posturographic measurements. Clinical assessment was based on the Expanded Disability Status Scale (EDSS) and its functional system (FS) subscores, the Modified Fatigue Impact Scale (MFIS), the Unipodal Stance test (UST), and the Timed Up-and-Go test (TUG).

RESULTS

Forty-six MS patients (mean EDSS score: 3.6) completed the study. Several posturographic variables, including Vav and L, deteriorated when measured on a textured mat, especially with large pimples and in eyes open condition. In contrast, no difference was found with small pimples and eyes closed, as compared to the control condition (no covering). The deleterious impact of pimple height on posturography correlated positively with the alteration of balance and gait clinically assessed by the UST and the TUG, and also with the MFIS physical and cerebral EDSS-FS subscores, and negatively with the cerebellar and brainstem subscores. On the other hand, the impact of eye closure on posturography was negatively correlated with the visual EDSS-FS subscore.

DISCUSSION

Static posturographic measurements made with different textured surfaces and visual conditions can be considered as a sensitive tool to measure "proprioceptive reserves". Actually, when cerebellar, brainstem, or visual functions are impaired, the resources of the sensory (proprioceptive) system, if preserved, can be recruited at a higher level and compensate for dysfunctions of other postural controls to maintain a satisfactory balance. In addition, this procedure of static posturographic examination can provide objective measurements correlated with clinical testing of balance and gait and could usefully complement EDSS scoring to assess disability affecting postural control and the risk of falling in MS patients.

The Relationship between Cognitive Dysfunction and Postural Stability in Multiple Sclerosis

Background and Objectives: Multiple Sclerosis (MS) is a demyelinating disease of the central nervous system (CNS), most commonly characterized by balance dysfunction, fatigue syndrome and cognitive impairment. The goal of our study was to determine the association between cognitive functions and static posture control. Materials and Methods: The research group consisted of 76 randomized MS patients (ICDG 35.0) hospitalized at the Neurological Rehabilitation Clinic of the Medical University of Lodz. This group was divided into three subgroups according to the cognitive assessment based on the Mini Mental State Examination (MMSE) for patients over 65 years of age and the Montreal Cognitive Assessment (MoCA) under the age of 65. Fatigue syndrome was assessed using the Fatigue Severity Scale (FSS), and postural stability using a stabilometric platform. Results: The men demonstrated poorer stabilometric platform measurements than the women. Statistically significant differences were observed between patients without dysfunction and severe cognitive impairment. The results of the stabilometric platform were found to correlate with body mass index in all three groups of patients (Spearman’s test). Conclusions: Body mass index and cognition have impact on postural stability in MS patients with moderate disability and fatigue syndrome.

Prospective study of thyroid functions in multiple sclerosis patients treated with interferon beta in Alexandria University MS clinic

Background

The incidence of thyroid dysfunction in multiple sclerosis (MS) patients on interferon (as a disease-modifying line) has been reported in many studies performed on patients already on interferon therapy. Our study adopted a prospective follow-up of the thyroid profile in those patients newly starting interferon beta therapy over 1 year trying to find a correlation between the start of therapy and the occurrence of this dysfunction.

Objectives

To evaluate the incidence of thyroid dysfunction in MS patients before and 1 year after of interferon beta.

Methods

A prospective cohort study on 48 MS patients newly receiving interferon beta therapy through MS clinic were subjected to assessment of thyroid profile including serum TSH, free T3, and T4 at the start of treatment; they were followed-up at 6- and 12-month intervals after the start of therapy.

Results and conclusion

There was a statistically significant increase in serum-free T3 levels in those treated with interferon beta therapy in a follow-up of 1 year. Our work also showed a decrease in serum-free T4 levels without statistical significance. TSH levels showed a tendency towards increase without statistical significance.

Validity and Reliability of the Satel 40 Hz Stabilometric Force Platform for Measuring Quiet Stance and Dynamic Standing Balance in Healthy Subjects

BACKGROUND

A force platform must have validity and reliability for optimal use. The objective of this study was to analyze the validity and the reliability of the Satel 40 Hz stabilometric force platform.

METHODS

A study of instrumental validity and reliability, involving a cross-sectional correlational and comparative analysis was performed. To determine the validity, four certified weights located on three axes were used and the ability of the stabilometric force platform to detect changes in the position of the different axes was observed. A test-retest was performed to analyze the reliability. Forty-two symptom-free volunteers participated in the study. Assessments were taken in a standing static position and in a dynamic position, with the eyes open and closed. Three measurements were taken and the intra-class correlation coefficient (ICC) was calculated.

RESULTS

The validity increased as the weight increased for all the variables measured in the stabilometric parameters (p < 0.05). The reliability was shown to be good to excellent for the two visual conditions. The positional variables obtained a higher ICC. The variable with the best ICC was the Y mean in OE (ICC 0.874 and a p < 0.001). All the values showed an increase in a dynamic situation.

CONCLUSION

The findings support the reliability and validity of the Satel 40 Hz stabilometric force platform. The platform could be recommended to evaluate static and dynamic standing balance in healthy adult individuals. Guidelines for treatment and the level of quality of stabilometry could be obtained from its use.

Balance Testing in Multiple Sclerosis-Improving Neurological Assessment With Static Posturography?

Background: Balance problems can severely limit the quality of life for people with Multiple Sclerosis (pwMS) already in the early stages of the disease. PwMS are usually assessed with the Expanded Disability Status Scale (EDSS), which includes a Romberg test for assessing balance. As the EDSS assessments are subjective to the examining neurologist, the postural stability of pwMS could be objectively quantified by implementing static posturography to detect balance problems and address preventive medical care. Methods: In this cross-sectional study, we added static posturography to the neurological EDSS examination in pwMS and healthy subjects to determine how this technique could supply additional information during the evaluation of the cerebellar functional system of the neurostatus EDSS as clinical outcome already in early disease stages. Static posturography was performed with subjects standing on a force platform while outcome variables such as delineated area, average speed and average sway were obtained. Unpaired t-test as well as (Welch's) analysis of variance (ANOVA) with pairwise post-hoc comparisons according to Games-Howell were used. Spearman rank correlations were implemented to study associations of balance outcomes with EDSS-associated outcomes. Results: A total of 99 pwMS (mean age: 35.01 years; EDSS median: 2.0, 68.69% females) and 30 healthy subjects (mean age: 34.03 years; 70% females) were enrolled. PwMS had worse performances in the three evaluated balance parameters than the healthy group (all p < 0.001). Even patients without postural instability as documented in the Romberg test score of the EDSS assessment showed significantly worse outcome regarding the delineated area [+1.97 cm², 95%-CI (0.61-3.34); p = 0.002] vs. healthy controls. Similar results were observed for the comparison between pwMS with normal cerebellar function EDSS-systems and healthy subjects. There were significant correlations with the EDSS, cerebellar function score and Romberg test for the delineated area and average speed (r's ranging from 0.330 to 0.537, p < 0.001). Conclusions: Static posturography can complement neurological assessment of EDSS as an objective and quantitative test, especially for MS patients in early stages of the disease.

Static postural control disturbances among the different multiple sclerosis phenotypes: A Neurocom Balance Manager® evaluation study

BACKGROUND

The computerized stabilometric platform can be used and privileged over clinical scales, as self-administered questionnaires to asses postural control and balance evaluation in Multiple sclerosis (MS). Aim of our study was to evaluate static postural control assessed by Neurocom Balance Manager® through the modified Clinical Test of Sensory Interaction on Balance (mCTSIB) in relapsing-remitting MS (RRMS), progressive MS (PMS) and CIS, compared to healthy controls (HC).

METHODS

We screened MS patients consecutively referring to our MS Center at University of Catania, during July 2013-June 2014 diagnosed as CIS, RRMS and PMS. All MS patients underwent clinical and neurological evaluations and a complete postural exam by Neurocom Balance Manager® in order to evaluate Center of Pressure (COP), through mCTSIB. We evaluated the following parameters: Total Path Length-open eyes (TPL-OE), Total Path Length-closed eyes (TPL-CE), Sway Area-open eyes (SA-OE), Sway Area-closed eyes (SA-CE), Mean sway velocity-open eyes (MSV-OE), Mean sway velocity-closed eyes (MSV-CE). Additionally, patients were tested by Berg balance scale (BBS) for balance and Barthel Index (BI) for disability outcomes.

RESULTS

Out of 170 MS patients assessed for eligibility, 163 met the inclusion/exclusion criteria and were finally enrolled. All balance parameters were found more impaired in MS group compared to controls and CIS. Moreover, no differences in terms of balance assessment were found between HC and CIS. The correlation analysis showed that BBS was strongly associated to SA-OE, SA-CE, TPL-OE and MSV-OE. We also found a correlation between BI and SA-CE.

CONCLUSION

Our study revealed significant differences among HCs, CIS and MS. MS, especially PMS, exhibit the worst balance performances especially in EC trials. The higher correlation between balance parameters, especially sway area, and BBS score confirmed the reliability and sensibility of mCTSIB assessment in evaluating static postural control in MS patients.

Measuring standing balance in multiple sclerosis: Further progress towards an automatic and reliable method in clinical practice

BACKGROUND

Balance deficits in multiple sclerosis (MS) are often monitored by means of observer-rated tests. These may provide reliable data, but may also be time-consuming, subject to inter-rater variability, and potentially insensitive to mild fluctuations throughout the clinical course. On the other hand, laboratory assessments are often not available. The Nintendo Wii Balance Board (WBB) may represent a low-cost solution. The purpose of the current study was to examine the methodological quality of WBB data in MS (internal consistency, test-retest reliability), convergent validity with observer-rated tests (Berg Balance Scale, BBS; Timed-Up and Go Test, TUG), and discriminative validity concerning clinical status (Expanded Disability Status Scale, EDSS).

METHODS

Standing balance was assessed with the WBB for 4min in 63 MS patients at two assessment points, four months apart. Additionally, patients were examined with the BBS, TUG and the EDSS.

RESULTS

A period of 4min on the WBB provided data characterized by excellent internal consistency and test-retest reliability. Significant correlations between WBB data and results of the BBS and TUG were obtained after merely 2min on the board. An EDSS median-split revealed that higher EDSS values (>3) were associated with significantly increased postural sway on the WBB.

CONCLUSIONS

WBB measures reflecting postural sway are methodologically robust in MS, involving excellent internal consistency and test-retest reliability. They are also characterized by convergent validity with other considerably lengthier observer-rated balance measures (BBS) and sensitive to broader clinical characteristics (EDSS). The WBB may hence represent an effective, easy-to-use monitoring tool for MS patients in clinical practice.

Reliability and Validity of the Computerized Dynamic Posturography Sensory Organization Test in People with Multiple Sclerosis

BACKGROUND

People with multiple sclerosis (MS) frequently have impaired postural control (balance). Psychometric properties of clinical tests of balance for individuals with MS, including the computerized dynamic posturography sensory organization test (CDP-SOT), are poorly understood. This study aimed to determine the reliability and discriminant validity of the CDP-SOT in people with MS.

METHODS

The CDP-SOT was performed on 30 participants with MS. A 2-week-interval, repeated-measures (sessions 1 and 2) design was implemented to investigate test-retest reliability of the CDP-SOT and the ability of the CDP-SOT to discriminate between participants with lower versus higher disability. Self-reported disability level was based on Patient-Determined Disease Steps (PDDS) scale scores: lower (PDDS scale score, 0-3; n = 17) and higher (PDDS scale score, 4-6; n = 13).

RESULTS

All six conditions of the CDP-SOT had good-to-excellent reliability (interclass correlation coefficients, 0.70-0.90) and excellent reliability for composite scores (0.90). Composite scores were significantly greater in the lower-disability group versus the higher-disability group at session 1 (70.89 vs. 48.60, P = .001) and session 2 (74.82 vs. 48.85, P = .002).

CONCLUSIONS

The CDP-SOT is a reliable measure of balance and accurately differentiates disability status in people with MS. Collectively, the results support clinical application of the CDP-SOT as a reliable and valid measure of disease-related progression of impaired balance related to sensory integration and its utility in determining changes in balance in response to treatment.

Static posturography across the EDSS scale in people with multiple sclerosis: a cross sectional study

BACKGROUND

Posturography is considered the gold standard objective measure of standing postural control in people with multiple sclerosis (PwMS). This reliable tool provides quantitative data related to risk of falling and white and gray matter brain damage due to MS. Nevertheless, it remains unclear whether and to what extent, postural control declines throughout the disease process. We therefore examined the impact of disability on posturography measures in PwMS.

METHODS

In this cross-sectional study, the data pool was divided into seven levels of disability based on the Expanded Disability Status Scale (EDSS) score. The study group comprised 464 PwMS, mean disease duration was 6.2 (SD = 7.5) years and mean age 42.6 (SD = 14.1). Static postural control parameters were obtained from the Zebris FDM-T instrumented Treadmill (Medical GmbH, Germany).

RESULTS

A significant positive correlation between the EDSS and posturography parameters was found. Scores for the ellipse area, center of pressure (CoP) path length and sway rate with eyes open were Spearman's rho =0.512, 0.527, 0.528; (P-value < 0.001), respectively. Non-significant differences were observed between the EDSS subgroups at the lower end of the spectrum (EDSS 0-2.5) in all posturography parameters. In contrast, MS patients with an EDSS score of 3.0-3.5 demonstrated a significant increase in the ellipse area with eyes open (~108 %) and closed (~169 %), CoP path length with eyes open (~83 %) and closed (~88 %) and sway rate with eyes open (~39 %) and closed (~148 %), compared with those who scored within the range of 0-2.5 in the EDSS. Non-significant differences were observed between MS patients with an EDSS score of 3.0-5.5. MS patients with an EDSS score of 6.0-6.5 were significantly poorer in 4 (out of 6) balance measures compared to other disability subgroups.

CONCLUSIONS

Posturography CoP trajectories are appropriate outcome measures indicating disability deterioration in PwMS.

A comparison of linear and nonlinear stability parameters in different clinical forms of multiple sclerosis

Background

Multiple sclerosis (MS) is one of the neurological diseases that affect the ability of subjects to stand and walk. The stability of MS subjects has been evaluated in various studies, mostly based on linear approach. Based on this approach it is controversial weather stability of MS subjects differ from normal or not. Therefore, the aim of this study was to evaluate stability in three groups of MS subjects (spastic, ataxic and ataxic-spastic) using both linear and non-linear approaches.

Method

Seventeen healthy and 36 subjects with MS participated in this study. The MS group presenting with spastic, ataxic and ataxic-spastic (each group consisted of 12 subjects) participated in the study. The stability of the subjects was evaluated using Kistler force plate. The difference between stability of the subjects was evaluated using the Multi Analysis of Variance and significant value was set at P < 0.05.

Result

There was a significant difference in the mean value of Approximate Entropy (ApEn) in anterior-posterior direction between normal (0.66 ± 0.13) and ataxic (0.85 ± 0.12) and ataxic-spastic (0.90 ± 0.12) subjects (P < 0.05) and no difference between normal and spastic groups (0.76 ± 0.13). The results of both linear and nonlinear approaches confirmed that both ataxic and ataxic-spastic subjects had more instability than normal subjects. Although, the mean values of stability parameters increased in spastic compared to normal, the difference was not statistically significant.

Conclusion

Subjects with ataxic and ataxic-spastic MS disorder had difficulty in controlling their stability during quiet standing. The results of this study also confirmed that spasticity of muscles surrounding the hip and knee joints did not influence standing stability in patients with spastic MS.

Evaluation of an Expanded Disability Status Scale (EDSS) modeling strategy in multiple sclerosis

The Expanded Disability Status Scale (EDSS) is the most widely used scale to evaluate the degree of neurological impairment in multiple sclerosis (MS). In this paper, we report on the evaluation of an EDSS modeling strategy based on recurrence quantification analysis (RQA) of posturographic data (i.e., center of pressure, COP). A total of 133 volunteers with EDSS ranging from 0 to 4.5 participated in this study, with eyes closed. After selection of time delay (τ), embedding dimension (m) as well as threshold (radius, r) to identify recurrent points, several RQA measures were calculated for each COP's position and velocity data in the mono- and multi-dimensional RQAs. Estimation results lead to the selection of the recurrence rate (RR) of the COP's position as the most pertinent RQA measure. The performance of the models versus raw and noisy data was higher in the mono-dimensional analysis than in the multi-dimensional. This study suggests that the posturographic signal's mono-dimensional RQA is a more pertinent method to quantify disability in MS than the multi-dimensional RQA.

Association of Postural Sway with Disability Status and Cerebellar Dysfunction in People with Multiple Sclerosis: A Preliminary Study

BACKGROUND

The aims of this study were 1) to examine postural sway in the eyes open (EO) and eyes closed (EC) conditions in people with multiple sclerosis (MS) with moderate levels of disability compared with controls and 2) to examine relationships between postural sway and total Expanded Disability Status Scale (EDSS) scores, functional system subscores, and clinical measures of strength and spasticity in the MS group.

METHODS

Thirty-four people with moderate MS and ten matched controls completed measures of postural sway with EO and EC, knee extension and ankle dorsiflexion isometric strength, EDSS total score and subscores, and spasticity levels.

RESULTS

Participants with MS swayed significantly more with EO and EC and had reduced knee extension and ankle dorsiflexion strength compared with controls (P < .001). In the MS group, increased sway was associated with higher total EDSS scores and cerebellar function subscores, whereas increased sway ratio (EC/EO) was associated with reduced sensory function subscores. Postural sway was not significantly associated with strength or spasticity.

CONCLUSIONS

Participants with MS swayed more and were significantly weaker than controls. Cerebellar dysfunction was identified as the EDSS domain most strongly associated with increased sway, and sensory loss was associated with a relatively greater dependence on vision for balance control. These findings suggest that exercise interventions targeting sensory integration and cerebellar ataxia may be beneficial for enhancing balance control in people with MS.

The potential of human umbilical cord-derived mesenchymal stem cells as a novel cellular therapy for multiple sclerosis

Multiple sclerosis (MS) is a complex disease of neurological disability, affecting more than 300 out of every 1 million people in the world. The purpose of the study was to evaluate the therapeutic effects of human umbilical cord-derived mesenchymal stem cell (hUC-MSC) transplantation in MS patients. Twenty-three patients were enrolled in this study, and 13 of them were given hUC-MSC therapy at the same time as anti-inflammatory treatment, whereas the control patients received the anti-inflammatory treatment only. Treatment schedule included 1,000 mg/kg of methylprednisolone intravenously (IV) daily for 3 days and then 500 mg/kg for 2 days, followed by oral prednisone 1 mg/kg/day for 10 days. The dosage of prednisone was then reduced by 5 mg every 2 weeks until reaching a 5-mg/day maintenance dosage. Intravenous infusion of hUC-MSCs was applied three times in a 6-week period for each patient. The overall symptoms of the hUC-MSC-treated patients improved compared to patients in the control group. Both the EDSS scores and relapse occurrence were significantly lower than those of the control patients. Inflammatory cytokines were assessed, and the data demonstrated a shift from Th1 to Th2 immunity in hUC-MSC-treated patients. Our data demonstrated a high potential for hUC-MSC treatment of MS. This manuscript is published as part of the International Association of Neurorestoratology (IANR) special issue of Cell Transplantation.

The clinical relevance of force platform measures in multiple sclerosis: a review

Balance impairment and falls are frequent in patients with multiple sclerosis (PwMS), and they may occur even at the earliest stage of the disease and in minimally impaired patients. The introduction of computer-based force platform measures (i.e., static and dynamic posturography) has provided an objective and sensitive tool to document both deficits and improvements in balance. By using more challenging test conditions, force platform measures can also reveal subtle balance disorders undetectable by common clinical scales. Furthermore, posturographic techniques may also allow to reliably identify PwMS who are at risk of accidental falls. Although force platform measures offer several theoretical advantages, only few studies extensively investigated their role in better managing PwMS. Standardised procedures, as well as clinical relevance of changes detected by static or dynamic posturography, are still lacking. In this review, we summarized studies which investigated balance deficit by means of force platform measures, focusing on their ability in detecting patients at high risk of falls and in estimating rehabilitation-induced changes, highlighting the pros and the cons with respect to clinical scales.

Multiple sclerosis and mitochondrial gene variations: a review

Multiple sclerosis (MS) is a debilitating disease of the central nervous system. Its etiology is still an unanswered enigma; its symptoms are varied and unpredictable; and there is no cure for it. Genetics has been introduced as a contributing factor to MS. Not only may MS stem from nuclear gene variations/mutations, but also it may arise from mitochondrial gene variations/mutations. The association of mitochondrial DNA variations/mutations with the pathogenesis of MS has, so far, been analyzed by several studies. This paper reviews the literature with regard to MS and corresponding mitochondrial DNA variations.