Real-life walking impairment in multiple sclerosis: preliminary comparison of four methods for processing...

Area of Science:

• Neurology
• Biomedical Engineering
• Rehabilitation Science

Background:

• Multiple sclerosis (MS) significantly impacts mobility and quality of life.
• Objective quantification of walking impairment in MS is crucial for monitoring disease progression and treatment efficacy.
• Accelerometers offer a promising tool for assessing real-world physical activity and mobility limitations.

Purpose of the Study:

• To validate accelerometers as a measure of walking impairment in individuals with MS.
• To compare different accelerometer data processing methods for quantifying walking impairment.
• To assess the correlation between accelerometer-derived metrics and patient-reported walking difficulties.

Main Methods:

• Seventy individuals with MS completed validated patient-rated walking impairment assessments.
• Participants wore an ActiGraph accelerometer for 7 days to collect movement data.
• Data were analyzed using multivariate analysis of variance and bivariate correlation analysis.

Main Results:

• Total daily movement counts and standard deviation of daily movement counts differed significantly across disability levels and ambulatory statuses.
• These two accelerometer metrics showed strong correlations with patient-rated measures of walking impairment.
• Novel metrics (approximate entropy, detrended fluctuation analysis) showed weaker associations with disability and patient reports.

Conclusions:

• Total daily movement counts and their variability, measured by accelerometers, are valid indicators of walking impairment in MS.
• Accelerometer data, particularly movement counts and standard deviation, correlate well with clinical disability and patient-reported outcomes.
• Accelerometer variability is not merely noise but provides meaningful insights into MS-related mobility deficits.