# Twitch force in human Amyotrophic Lateral Sclerosis

## TL;DR

This study found that slower progression of ALS is linked to better muscle strength and higher creatine kinase levels, which could help predict disease progression.

## Contribution

The study identifies muscle twitch force and CK levels as potential biomarkers for ALS progression heterogeneity.

## Key findings

- Slow progressors showed significantly higher muscle peak force and AUC compared to fast progressors.
- Elevated creatine kinase levels were observed in slow progressors, indicating better muscle integrity.
- Muscle function profiles and CK levels may serve as indicators of ALS progression.

## Abstract

This study investigated differences in muscle twitch force between slow and fast progressors of amyotrophic lateral sclerosis (ALS) to better understand disease heterogeneity and identify potential biomarkers of disease progression.

Forty-four ALS patients were classified as slow or fast progressors based on disease progression rates. Electrophysiological assessments, including compound muscle action potential (CMAP) and muscle force measurements, were conducted. Creatine kinase (CK) levels were also evaluated.

Slow progressors demonstrated significantly higher muscle peak force and area under the curve (AUC) compared to fast progressors, reflecting greater muscle strength and endurance. CK levels were also elevated in slow progressors.

Despite similar CMAp values, slow progressors retained greater muscle strength, possibly due to a reduced degeneration of fast-twitch fibers and compensatory axonal sprouting. These adaptations may preserve muscle function and elevate CK levels, suggesting better muscle integrity in slow progressors.

Muscle function profiles and CK levels are promising indicators of ALS progression. These findings could enhance early detection of disease progression and lead to targeted interventions to preserve muscle function. Further research is needed to validate these results and explore the underlying functional mechanisms of disease heterogeneity.