Which type of MS is characterized by both relapses and gradual progression?

The type of MS characterized by both relapses and gradual progression is Secondary Progressive MS (SPMS). This form typically follows an initial period of Relapsing-Remitting MS (RRMS), which is marked by distinct episodes of neurological symptoms (relapses) followed by periods of recovery (remissions). In SPMS, patients may continue to experience relapses, but there is also a gradual worsening of symptoms and disability over time, which is indicative of progressive disease activity.

The progression in SPMS can vary significantly among individuals, with some experiencing a more gradual decline and others experiencing more pronounced relapses. This dual nature of SPMS—where both relapse and progressive elements coexist—distinguishes it from other forms of MS. For instance, Primary Progressive MS is characterized primarily by a steady decline without relapses, while Relapsing-Remitting MS does not include the progressive component seen in SPMS. Progressive-Relapsing MS presents with a steady decline from the onset but with occasional superimposed relapses, which is different from the pattern observed in SPMS.

Understanding these distinctions is crucial for the management and treatment of MS, as each type may respond differently to therapies and interventions.