Utilization of the multiple sclerosis functional composite in follow-up: relationship to disease phenotype, disability and treatment strategies

Abstract

As multiple sclerosis (MS) has a dynamic process, monitoring of the disability is important in the remission period. The main aim of the present study was to investigate the usefulness of MSFC instead of EDSS in the follow-up period of MS. In addition, evaluation of the effect of immunomodulatory therapy, and the difference among the type of MS in follow-up was purposed. One hundred and eighty-three patients with definite MS were enrolled in the present study. Patients were diagnosed as having relapsing–remitting (RR) MS ( n=149) or secondary progressive (SP) MS ( n=34). Fifty-eight out of 149 RRMS patients who had at least two relapses in the last 2 years have received any of the immunomodulator agents. The Multiple Sclerosis Functional Composite (MSFC) and Expanded Disability Status Scale (EDSS) were performed at baseline and after 2 years to assess disability. Patients who were under disease modifying therapy were assessed before the treatment and 2 years after starting the treatment. Cross-sectional correlations between MSFC and EDSS score at baseline and follow-up were studied. Patients were divided into three subgroups: (1) RRMS patients who did not receive disease modifying therapy (DMT)—non-DMT group, (2) RRMS patients who received DMT—DMT group, (3) SPMS patients who did not receive DMT—SPMS group. EDSS and MSFC scores got worsened significantly at the end of the second year. Decreases in either EDSS or MSFC scores were more prominent in SPMS group. The most significant worsening was found in T25WT. The most prominent and significant decrease was in PASAT of SPMS group. Moderately strong cross-sectional correlations were found between MSFC and EDSS scores at baseline and follow-up. The most prominent correlation was between EDSS and T25WT scores with an excellent correlation. We concluded that the MSFC assesses aspects of neurological function not measured by the EDSS, suggesting that it is more sensitive to detect change over time and better able to demonstrate a therapeutic effect. The pattern of correlations among the MSFC, its components, and the EDSS supported the validity of MSFC.