Early Upper Limb Motor Impairment in Multiple Sclerosis Across EDSS Levels: A Case-Control Study

Area of Science:

• Neurology
• Rehabilitation Science
• Disability Studies

Background:

• Upper limb (UL) dysfunction is prevalent in multiple sclerosis (MS) from early disease stages.
• UL impairment significantly impacts daily activities, quality of life, and autonomy in people with MS (PwMS).
• The Expanded Disability Status Scale (EDSS) may underestimate the extent of UL involvement in PwMS.

Purpose of the Study:

• To compare UL function between PwMS (stratified by EDSS ≤3.5 and >3.5) and healthy controls (HCs).
• To investigate differences in UL function among PwMS subgroups based on EDSS scores.
• To evaluate the sensitivity of the EDSS in capturing UL deficits compared to objective functional measures.

Main Methods:

• A case-control study adhering to STROBE guidelines.
• PwMS were categorized into EDSS ≤3.5 and >3.5 groups; HCs served as controls.
• UL function assessed via Hand Grip Strength (HGS), Box and Block Test (BBT), Nine-Hole Peg Test (NHPT), and ABILHAND questionnaire. Fatigue (FSS) and disease impact (MSIS-29) were also measured.

Main Results:

• PwMS exhibited significant UL functional impairments across all objective measures compared to HCs, irrespective of early disability levels.
• Significant differences in BBT and NHPT were found between EDSS subgroups for the more affected UL; HGS did not differ.
• Only NHPT showed significant differences between EDSS subgroups for the less affected UL; ABILHAND, FSS, and MSIS-29 did not differ significantly.

Conclusions:

• The EDSS may not sufficiently reflect UL dysfunction in PwMS.
• Objective, sensitive, and validated UL assessments are crucial for detecting subtle deficits, even in early MS.
• A multidimensional approach is necessary for accurate UL disability assessment in MS management.