The 2013 clinical course descriptors for multiple sclerosis: A clarification.

Area of Science:

• Neurology
• Clinical Research
• Disease Classification

Background:

• Established definitions for multiple sclerosis (MS) clinical courses were set in 1996 and updated in 2013.
• These classifications are vital for clinicians, clinical trialists, and regulatory bodies in assessing individual patient status over time.

Purpose of the Study:

• To clarify the underlying concepts of MS clinical course descriptions.
• To address recent variations and discrepancies in the application of these definitions by regulatory authorities.
• To re-emphasize the principles guiding the development of these clinical course classifications.

Main Methods:

• Conceptual clarification of existing MS clinical course definitions.
• Review of principles used in the development of these definitions.
• Analysis of time-framing for disease course modifiers like activity and progression.

Main Results:

• Recent regulatory decisions have led to inconsistent use of established MS clinical course descriptions.
• Highlighting the critical importance of time-based assessments for disease activity and progression.
• Clarification of the distinction between 'worsening' and 'progressing' in the context of MS.

Conclusions:

• Accurate, time-based assessment of multiple sclerosis clinical courses is crucial for consistent clinical practice and research.
• Reiteration of the foundational principles ensures the appropriate application of MS disease course modifiers.
• Distinguishing between worsening and progression is essential for precise patient management and therapeutic evaluation.