What defines a "benign course" of MS?

A "benign course" of multiple sclerosis (MS) is characterized by the presence of minimal disabilities after a significant period, typically around 20 years. This definition emphasizes a form of MS where patients experience milder symptoms and fewer complications over time, allowing them to maintain a good quality of life despite the disease's presence.

In the context of MS, a benign course can be seen in individuals who may have had relapses but ultimately do not accumulate substantial disability as the disease progresses. This is in contrast to other forms of MS that may lead to significant long-term disabilities or decline in function.

The other options describe characteristics that indicate a more severe impact of the disease. Frequent relapses with significant disability, constant severe symptoms from the onset, and inability to recover from clinical episodes do not align with the benign course concept, as they suggest a progressive or more debilitating form of MS. Thus, the option indicating minimal disabilities after a long duration accurately encapsulates the essence of a benign course in MS.