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 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 severity 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 identify differences in UL function among PwMS subgroups based on EDSS scores.
• To evaluate the sensitivity of the EDSS in capturing UL deficits.

Main Methods:

• A case-control study adhering to STROBE guidelines.
• PwMS were categorized into two groups: EDSS ≤3.5 and EDSS >3.5.
• 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 impairments across all objective measures compared to HCs, even with low neurological disability.
• Differences between EDSS subgroups were noted in BBT and NHPT for the more affected UL, but not HGS.
• For the less affected UL, only NHPT showed significant differences between EDSS subgroups. ABILHAND, FSS, and MSIS-29 did not differ significantly between subgroups.

Conclusions:

• The EDSS alone may be insufficient for fully assessing UL dysfunction in PwMS.
• Objective, sensitive, and validated UL assessments are vital for detecting even subtle deficits early in MS.
• A multidimensional approach is necessary for comprehensive UL disability assessment in multiple sclerosis.