Author Of 1 Presentation
P0134 - Preliminary validation of static posturography as a disability outcome measure in progressive multiple sclerosis. (ID 685)
Abstract
Background
People with multiple sclerosis (pwMS) frequently experience impairment in postural control, a multifaceted measure related but distinct to walking ability.
Objectives
To assess clinical validity of static posturography as a disability outcome measure in people with progressive MS; to assess feasibility of use of the force platform in pwMS with moderate-to-severe disability; to explore the relationship between multiple cognitive domains and postural control in pwMS with a high burden of cognitive and physical impairments.
Methods
Twenty-three pwMS with Expanded Disability Status Scale (EDSS) 3.5–6.0 stood on a force platform under various test conditions (single task: Eyes Open (EO), Eyes Closed (EC); dual-task: posturography with concurrent cognitive tasks, N-Back, and Sustained Attention Response Task) and completed a battery of ambulation, balance and cognitive tests.
Results
EO Centre of Pressure (COP) Path Length correlated with proprioceptive (r=0.65, p=0.001), cerebellar (r=0.62, p=0.002), vestibular (r=0.46, p=0.027) and visual (r=0.53, p=0.009) dysfunction, but not with age, gender, body mass index, anxiety, or standard walking measures (EDSS, Timed 25 Foot Walk). EO Path Length significantly predicted the Dynamic Gait Index (adjusted R2=25.8%, p=0.008), Dizziness Handicap Inventory score (adjusted R2=24.9%, p=0.008) and 9 Hole Peg Test score (adjusted R2=14.2%, p=0.043). Of pwMS with EDSS 6.0, EO mediolateral displacement predicted distance walked during the Two Minute Walk Test (adjusted R2=53.2%, p=0.016). Diminished postural control was associated with mediolateral direction of sway (p<0.001), EC (p=0.004), fampridine use (p=0.004) and poorer physical (p=0.039) and psychological (p=0.026) quality of life. A consistent pattern of poorer cognitive function associated with better postural control was observed across multiple cognitive domains (information processing speed, verbal memory, visuospatial memory, attentional capacity). No significant differences in postural control were detected between EO and dual-tasks. During the N-Back task, poorer postural control correlated with lower % N-Back scores (p=0.049).
Conclusions
Static posturography is a non-invasive, brief and easy-to-administer test with high construct and concurrent validity as a disability outcome measure in people with progressive MS. The finding of diminished postural control with fampridine use suggests that static posturography can identify effects of treatment in pwMS. Demonstration of cognitive-postural interference in pwMS provided insight into distinct postural control strategies adopted by pwMS with different levels of cognitive and physical disability, and may complement balance rehabilitation methods in falls prevention programmes.