Can fatigue predict the worsening of multiple sclerosis one year later? An explorative study with participants referred to assess their ability to work.

Background: Multiple sclerosis (MS) is an inflammatory and degenerative disease of the central nervous system and is triggered by several environmental factors in genetically predisposed people.

Objectives: To explore which evaluation battery items used for evaluation of work capacity at baseline can best predict MS progression at 1 year follow-up.

Methods: In this prospective single-centre study, participants with MS were recruited consecutively when visiting a neurologist for referral for the determination work capacity status at the Disability and Working Capacity Assessment Office. At baseline, a neurologist assessed patients using the following evaluation scales: Fatigue self-assessment, Fatigue Descriptive Scale (FDS), Memory self-assessment, Brief International Cognitive Assessment for Multiple Sclerosis (BICAMS), Short Form 36 (SF-36), and the Brief International Classification of Functioning and Disability (ICF) core set for MS. The Expanded Disability Status Scale (EDSS) was evaluated by neurologists at baseline and one year later. An increase in EDSS by 0.5 points after one year was defined as MS progression.

Results: During the one year period among 72 participants, 21 fulfilled the criteria for MS progression. In more than 75% of these participants, impairments were found in the following ICF subitems at baseline: "energy and drive functions", "muscle and power functions", and "moving around". Greater impairments were identified in progressing participants. Progressing participants scored higher on the FDS and scored lower on the BICAMS and SF-36. Regression analysis indicated that the FDS sum score predicted MS progression one year later.

Conclusions: Increased fatigue might indicate worsening in MS one year later.