Instrumented Postural Sway Test Differentiates Fallers From Non-Fallers in MS

Ishu Arpan, PT, PhD

A recent study found that a quick and simple postural sway test may be an important tool in identifying patients with mild to moderate multiple sclerosis (MS) at risk of falling.

The study’s findings were presented virtually by Ishu Arpan, PT, PhD, senior research associate, neurology department, Oregon Health & Science University, and colleagues, at the Americas Committee for Treatment and Research in Multiple Sclerosis (ACTRIMS) Forum 2021, February 25-27, 2021. They found that instrumented postural sway measures that differentiate people with MS from healthy controls (HC) also differentiate fallers from non-fallers with MS.

“People with MS are at a higher risk of falls since balance impairment is an early and common symptom in MS. Assessment of fall risk may be facilitated by measurements of postural sway, which reflects complex sensorimotor, neural control of postural equilibrium that is affected by MS,” Arpan and colleagues wrote.

The researchers enrolled 22 people with MS with an average age of 45 years (standard deviation [SD], 10) and Expanded Disability Status Scale (EDSS) scores of under 4.5, as well as 20 age-matched HC (mean age, 41 years [SD, 13]). The participants stood on a firm surface for 30 seconds with open eyes while wearing a wireless inertial sensor (Opan by APDM) on the lumbar spine as part of the instrumented postural sway test.

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The MS group consisted of 11 patients (50%) categorized as fallers and 11 categorizes as non-fallers, based on their 6-month history of falls. The researchers conducted independent t-tests to determine which measures of the sway test differentiated HC from people with MS. These MS-sensitive measures were used to assess the mean differences between fallers and non-fallers in the mS group.

Arpan and colleagues confirmed established findings that people with MS performed significantly worse on the instrumented postural sway test compared to HC. Specific measures that were found to be significantly associated with MS were increased jerk, as well as range and the root mean square of sway.

The researchers found these MS-sensitive measures to successfully differentiate fallers from non-fallers in the MS group. The sway measures were significantly higher in people with MS that reported falls in the last 6 months compared to those who did not.

“The reported postural sway abnormalities indicate that people with MS, especially fallers, experience a significant decrease in postural stability reflected by increased size and jerkiness of sway. To better understand the pathophysiology of balance disorders in MS, future studies should relate abnormalities of postural sway to specific sensory, motor, and cognitive impairments in MS,” Arpan and colleagues concluded.

For more coverage of ACTRIMS Forum 2021, click here.

REFERENCE

Rude A, Prewitt AL, Horak F, Arpan I. Feasibility of postural sway measures to predict falls in multiple sclerosis. Presented at ACTRIMS Annual Forum; February 25-27, 2021. Abstract P027