Advances in neuroimaging of multiple sclerosis

Abstract

Purpose of review: To summarize recent advancements in understanding multiple sclerosis (MS) pathophysiology, predicting disease course, and monitoring treatment responses using MRI.

Recent findings: Paramagnetic rim lesions (PRLs) are highly specific to MS and clinically relevant. Detected from the earliest disease phases, PRLs aid in distinguishing MS from other conditions, improving diagnostic accuracy. Moreover, PRLs are associated with more severe disability and measures of brain damage and may predict disease progression. Similarly, slowly expanding lesions (SELs) are associated with more severe disability and predict a more severe disease course. Disease-modifying therapies have limited effectiveness in reducing PRLs or SELs. Choroid plexus (CP) enlargement is associated with structural brain damage and clinical disability and predicts disease evolution. Enlarged perivascular spaces (ePVS) suggest microangiopathic changes rather than direct MS-related inflammation. Glymphatic dysfunction, evaluated using diffusion tensor image analysis along the perivascular space, emerges early in MS and correlates with disability, cognitive impairment, and structural brain damage. Aging and comorbidities exacerbate MS-related damage, complicating diagnosis and treatment. Emerging technologies, such as brain-age paradigms, aim to disentangle aging from MS-specific neurodegeneration.

Summary: Advances in MRI have highlighted the clinical significance of chronic inflammation and glymphatic dysfunction as early contributors to MS progression as well as the interplay between aging, comorbidities and MS.

Keywords: aging; choroid plexus; comorbidities; enlarged perivascular space; glymphatic system; multiple sclerosis; paramagnetic rim lesions.