Multiple sclerosis: emerging epidemiological trends and redefining the clinical course

Area of Science:

• Neuroscience
• Immunology
• Epidemiology

Background:

• Multiple sclerosis (MS) is a chronic, inflammatory, neurodegenerative disease impacting the central nervous system.
• MS is a leading cause of neurological disability in young adults, with increasing global prevalence and incidence.
• Recent trends show a shift in MS prevalence towards older age groups.

Purpose of the Study:

• To provide an overview of the evolving clinical course and epidemiological trends of MS in Europe.
• To focus on Progression Independent of Relapse Activity (PIRA) as a potential primary mechanism of disability acquisition.
• To discuss challenges in defining and identifying PIRA and its implications for MS classification.

Main Methods:

• Review of traditional clinical course descriptions and European epidemiological trends in MS.
• Analysis of the concept of Progression Independent of Relapse Activity (PIRA).
• Discussion of ongoing research, varying definitions of PIRA, and assessment of hidden clinical manifestations.

Main Results:

• Evidence suggests MS should be viewed as a continuum where relapsing and progressive features coexist early.
• Progression Independent of Relapse Activity (PIRA) is increasingly recognized as a significant factor in disability accumulation.
• The definition and identification of PIRA present ongoing challenges.

Conclusions:

• Reconsidering MS as a continuum challenges traditional views of its clinical course.
• Assessing hidden clinical manifestations is vital for quantifying PIRA and improving patient management.
• A new understanding of PIRA is essential for future clinical classification and treatment strategies in MS.