Assessing treatment response in multiple sclerosis.

PURPOSE OF THE REVIEW: The evaluation of treatment response in multiple sclerosis (MS) has become increasingly nuanced as the field shifts from a primarily relapse-oriented perspective toward a more comprehensive understanding of the continuous interaction between inflammatory and neurodegenerative mechanisms.

RECENT FINDINGS: Traditional clinical measures, while indispensable, capture only a fraction of the disease process and are insufficient to detect the insidious progression that accounts for a substantial proportion of long-term disability. Enhanced functional assessments provide greater sensitivity to subtle clinical deterioration, and MRI remains the principal modality for identifying subclinical focal inflammatory activity. In parallel, biomarkers of neurodegeneration, including inner retinal layer thinning measured by optical coherence tomography (OCT) and fluid biomarkers such as serum neurofilament light chain (sNfL) and glial fibrillary acidic protein (GFAP), offer complementary insights into diffuse pathological processes that elude conventional monitoring.

SUMMARY: A personalized monitoring strategy that integrates clinical assessment, imaging and fluid biomarkers holds the greatest promise for improving the detection of subclinical disease activity, refining risk stratification, and enabling more informed and individualized treatment decisions in contemporary MS care.