Increased Exertion Variability is Linked to Disruptions in Effort Assessment in Multiple Sclerosis

Area of Science:

• Neuroscience
• Motor Control
• Rehabilitation Science

Background:

• Accurate exertion assessment is vital for managing physical activity.
• Multiple sclerosis (MS) is associated with fatigue and motor impairments, impacting effort perception.
• Motor variability's role in effort assessment is known in healthy individuals but unexplored in MS.

Purpose of the Study:

• To investigate the relationship between physical exertion variability and effort assessment in individuals with MS.
• To compare these relationships between individuals with MS and healthy controls.
• To explore how MS severity influences exertion variability and effort perception.

Main Methods:

• Participants performed physical exertion tasks at varying intensity levels.
• Participants retrospectively assessed their perceived level of exertion.
• Exertion variability and assessment accuracy were quantified and compared between groups.

Main Results:

• Individuals with MS demonstrated higher variability in physical exertion compared to healthy controls.
• Participants with MS tended to overestimate their exerted effort.
• Greater exertion variability was linked to poorer effort assessment accuracy, especially in advanced MS.

Conclusions:

• Motor variability may be a key mechanism behind inflated effort perception in MS.
• This finding offers insight into why physical exertion feels disproportionately taxing for individuals with MS.
• Targeting motor variability presents a potential avenue for MS treatment and rehabilitation.