To correlate measures of gait and balance and the revised ALS Functional Rating Scale (ALSFRS-R).

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease characterized by motor neuron degeneration. The ALSFRS-R is a patient-reported rating scale evaluating the functional status in patients with ALS. It is also a validated measure of disease progression. Objective measures of disease progression are lacking, and it is unclear whether components of gait correlate with the ALSFRS-R and can be used to track disease progression.

Patients who met the revised El Escorial diagnostic criteria for clinically possible, probable, or definite ALS were enrolled in an NIH IRB approved protocol “Investigating Complex Neurodegenerative Disorders Related to Amyotrophic Lateral Sclerosis and Frontotemporal Dementia.” An instrumented 25-foot walking and a 30-second sway test were performed using APDM wearable sensors. Only patients who could complete the tests without bracing or assistive devices were analyzed in this study. Descriptive statistics and correlation analysis were used to analyze the data.

Fifteen (11 male, 4 female) participants were included in this analysis. The total ALSFRS-R score strongly correlated with walking speed (R² = 0.8715), walk time (R² = 0.8095), step duration of the right foot (R² = 0.7757), and gait cycle duration (R² = 0.7448). Similar findings were seen when the ALSFRS-R lower limb component scores were used. The gait measures weakly correlated with disease duration and age. Additionally, ALSFRS-R weakly correlated with components of balance.

Measures of gait components strongly correlated with the ALSFRS-R and may be useful as an objective measure of disease progression. While gait speed has the strongest correlation, other gait components that show high correlations may be promising measures to track disease progression. A larger prospective study will be needed to validate these findings.