Functional Motor Change Across Time and Phenotypes in Patients With Amyotrophic Lateral Sclerosis: A Descriptive Study

Abstract

Purpose:

Progressive disability occurs in persons with amyotrophic lateral sclerosis (pALS), but change over time across phenotypes remains understudied, limiting clinical decision-making. This descriptive study describes functional motor change with detailed measures across ALS phenotypes to enhance clinical decision making.

Materials and Methods:

Electronic health record data from an interdisciplinary ALS clinic (n = 109 pALS, 2018-2022) including demographics, disability (ALS Functional Rating Scale-[ALSFRS-R]), and functional motor scores (10 m Walk, Handheld dynamometry [grip and ankle]) was utilized. Phenotype groups were defined by site of onset (bulbar, limb onset; upper limb or lower limb). Analysis was conducted using R and included changes scores and measures of central tendency in 3-month intervals.

Results:

PALS included n = 43 bulbar, n = 32 upper limb, n = 34 lower limb onset, age 65, 60 to 71 (median, interquartile range). ALFSRS-R decline was greatest in bulbar, and similar in upper and lower limb. Patterns of change within motor scores suggest greatest loss of grip strength in bulbar and upper limb, ankle strength in upper limb, walking speed in lower limb, and preservation of community ambulation in upper limb.

Conclusion:

While ALSFRS-R scores were similar in upper and lower limb, detailed functional motor measures indicated differences in groups. These patterns provide insight to guide clinical decision making and future research to enhance care in pALS.