While most people with MS develop neurological impairments over time it is clear that some do not. This has been termed benign MS. Its existence and definition are often debated, so researchers have conducted a study to determine if people with MS can have a ‘benign’ outcome 30 years after first symptom onset.
Members of the first London-based clinically isolated syndrome (CIS) cohort of 132 people were traced and either assessed clinically in person, or by telephone interview. At the 30-year follow-up, 29 had deceased (of whom 19 had MS). Of the remaining 103 individuals, clinical outcome data was obtained from 91 people. 30 still had CIS, 35 had relapsing remitting MS (RRMS), and 26 had secondary progressive MS (SPMS). Eleven had received an MS disease modifying treatment (DMT) at some point over the 30 years. The 35 people in the RRMS group, 31 (88%) had an expanded disability scale score (EDSS) of less than or equal to 3.0. All of them remained in employment, or had retired at national state pension age. Test results from Brief International Cognitive Assessment for MS (BICAMS) were available in 20 of the 31 individuals, with only one subject scoring < -1.5.
Researchers concluded that in this 30-year follow-up of a CIS onset cohort, 31 out of 80 participants were known to have MS had no or mild physical disability, and of these subjects, only one of 20 who were tested were classified as having cognitive impairment. This suggests that it is not uncommon for people with CIS to have only mild or no physical or cognitive dysfunction approximately three decades after clinical onset.