RESUMEN
BACKGROUND: The causes of the individual differences in the rate of disability progression in multiple sclerosis (MS) are still not completely clear. According to the long-term prognosis of MS patients, the search for new valuable prognostic markers of "benign" or "malign" MS is necessary. OBJECTIVES: Our aim was to assess the possible association of MS onset age with the disease disability progression rate in Slovak patients with MS. METHODS: By the unique pattern of evaluation of disability progression rate using Multiple Sclerosis Severity Score (MSSS), each of 270 MS patients was defined as slow-progressing, mid-rate progressing or rapidly progressing. RESULTS: We found a significant differences in the age at onset between MS patients with different rate of disability progression (p(K-W)<0,00005). The faster was a disability progression assessed by MSSS score, the higher was the MS onset age. CONCLUSION: We showed for the first time in Central European Slovak population that MS onset age is an early marker that is in the positive correlation with disease disability progression rate, evaluated by MSSS score. We conclude that relapsing-remitting MS patients older at clinical onset have a higher risk of unfavorable prognosis (Tab. 2, Fig. 1, Ref. 21).