Visual Feedback and Postural Control in Multiple Sclerosis

Abstract

As people with multiple sclerosis (pwMS) manifest heterogeneous demyelinating lesions that could affect somatosensory or vestibular ways, visual stimulus as feedback could be especially relevant to achieve postural control. This has clinical importance for the development of preventive measures and rehabilitation therapies in order to avoid falls and accidents in this group. In our study, we objectively evaluated the influence of visual feedback on the stabilization of balance in pwMS versus healthy controls (HC) and its potential utility in clinical evaluation. Static posturography tests were performed in 99 pwMS and 30 HC. Subjects stood on a force platform with open and closed eyes. During this procedure, three balance parameters were obtained for both vision conditions: average sway, average speed, and average speed of sway. Neurostatus-Expanded Disease Disability Score (EDSS) and Multiple Sclerosis Functional Composite (MSFC) were performed in parallel as well. A two-way mixed repeated measures ANCOVA, controlling for sex and age, was performed to evaluate the effect of vision, MS diagnosis, and the interaction of both in static posturography parameters. The difference between both closed and open eyes conditions was calculated for each parameter and further analyzed according to MS-relevant clinical variables. The magnitude of the vision effect differed between pwMS and HC as a significant interaction between the vision and the MS diagnosis in the delineated area (p < 0.001) and average speed of sway (p = 0.001) was seen. These parameters had a greater increase in pwMS than in HC after closing eyes. For the average sway, a significant main effect of vision was present (p = 0.047). Additionally, the differences obtained between open and closed eyes conditions assessed with the delineated area and average speed of sway were moderately correlated to the assessed clinical tests EDSS (r = 0.405 and r = 0.329, respectively) and the MSFC (r = −0.385 and r = −0.259, respectively). In our study, pwMS were more dependent of visual feedback than HC to maintain postural control. This easy and short evaluation by static posturography could support the development of targeted preventive measures and interventions in pwMS.

The Dresden Protocol for Multidimensional Walking Assessment (DMWA) in Clinical Practice

“…Using a treadmill integrated system, Kalron et al found that minimally impaired pwMS chose a slower jogging tempo, with wider steps and higher double support time, which might be attributed to a safety strategy (Kalron et al, 2013). In balance assessment, a recent study suggested a high sensitivity of the range of the sway area from the patient's center of gravity as well as of the average speed, to uncover early balance deficits in pwMS not detectable for the physician (Inojosa et al, 2020b). Regarding a risk-of-fall screening, balance outcomes measured by force platforms showed better discriminative properties compared to the Berg Balance Score (Prosperini et al, 2013).…”

“…For balance testing, the Romberg test is used to evaluate variations of the body while standing on a flat surface with the feet hip-wide and parallel to each other (Inojosa et al, 2020b). For comparing the stability, the test is performed with open and closed eyes (Inojosa et al, 2020c).…”

“…Consequently, it is important to identify subtle signs of WI as early as possible to adjust the disease-modifying treatment and prevent further progression (Ziemssen and Thomas, 2017). Furthermore, more attention needs to be paid to balance disorders as they may be indicators for falls (Brandstadter et al, 2020;Inojosa et al, 2020b). A regular monitoring of individual WI is necessary to assess this relevant FS (Hobart et al, 2019).…”

New methods of posturographic data analysis may improve the diagnostic value of static posturography in multiple sclerosis

“…visual or sensory) and results of the cerebrospinal fluid analysis ( Doshi and Chataway, 2016 ; Deangelis and Miller 2014 ). Also, the static posturography revealed to be valuable in the MS clinic, particularly in the diagnosis of motor dysfunctions related to falls ( Boes et al, 2012 ; Cameron and Lord, 2010 ; Inojosa et al, 2020a , b ; Kalron et al, 2016a , b ; Nilsagård et al, 2009 ; Pau et al, 2017 ; Prosperini et al, 2013 ; Prosperini and Castelli, 2018 ) Simplicity and safety of static posturographic tests make it attractive for use in the neurological clinic. Additionally, static posturography seems very sensitive to every change within the sensory-motor system which may be of key importance in the diagnosis and monitoring of MS (for review see Prosperini and Castelli, 2018 ).…”

“…So far, the diagnostic value of static posturography has been proved in the aging of the nervous system, and motor disorders and injuries. Recently, substantial research efforts focus on MS ( Wajda et al, 2016 ; Prosperini et al, 2013 ; Inojosa et al, 2020a , b ; Kalron et al, 2016a , b ) Continuing this line of research we focused here on sway characteristics in MS. Multiple sclerosis signs and symptoms may differ greatly from patient to patient and throughout the disease depending on the location of affected nerve fibers.…”