What role should spinal cord MRI take in the future of multiple sclerosis surveillance?

ABSTRACT

Introduction

In multiple sclerosis (MS), inflammatory, demyelinating, and neurodegenerative phenomena affect the spinal cord, with detrimental effects on patients’ clinical disability. Although spinal cord imaging may be challenging, improvements in MRI technologies have contributed to better evaluate spinal cord involvement in MS.

Areas covered

This review summarizes the current state-of-art of the application of conventional and advanced MRI techniques to evaluate spinal cord damage in MS. Typical features of spinal cord lesions, their role in the diagnostic work-up of suspected MS, their predictive role for subsequent disease course and clinical worsening, and their utility to define treatment response are discussed. The role of spinal cord atrophy and of other advanced MRI techniques to better evaluate the associations between spinal cord abnormalities and the accumulation of clinical disability are also evaluated. Finally, how spinal cord assessment could evolve in the future to improve monitoring of disease progression and treatment effects is examined.

Expert opinion

Spinal cord MRI provides relevant additional information to brain MRI in understanding MS pathophysiology, in allowing an earlier and more accurate diagnosis of MS, and in identifying MS patients at higher risk to develop more severe disability. A future role in monitoring the effects of treatments is also foreseen.

KEYWORDS:

• Magnetic resonance imaging
• multiple sclerosis
• spinal cord
• treatment monitoring

Box 1. Search strategy and selection criteria

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Article highlights

• Spinal cord involvement, in terms of focal lesions, microstructural abnormalities and irreversible tissue loss, is frequent in MS and has a relevant impact on patients’ clinical disability.

• The assessment of spinal cord lesions on conventional MRI provides relevant additional information to brain MRI in the earliest phases of the disease, to allow an earlier and more accurate diagnosis of MS, and to identify those patients at higher risk to accumulate more severe disability over time.

• In patients with definite MS, spinal cord MRI is typically not included to monitor disease course, but, according to recent findings, it could identify a significant amount of disease activity which goes undetected by brain MRI.

• The application of advanced MRI techniques (mainly atrophy assessment) allows to better investigate the different pathological substrates of the disease (e.g. demyelination, neuro-axonal loss) and their associations with clinical features, although they cannot be included in the clinical setting yet.

• Assessment of spinal cord lesions and atrophy can represent, in the near future, reliable outcomes to monitor the effects of novel treatments to prevent inflammation and demyelination, to limit neurodegeneration and to promote tissue repair and recovery in MS.

Declaration of interest

MA Rocca received speakers’ honoraria from Bayer, Biogen Idec, Celgene, Genzyme, Merck-Serono, Novartis, Roche and Teva and receives research support from the Italian Ministry of Health, Multiple Sclerosis society of Canada and Fondazione Italiana Sclerosi Multipla. P Preziosa received speaker’s honoraria from Biogen Idec, Novartis and ExceMED. M Filippi is Editor-in-Chief of the Journal of Neurology; received compensation for consulting services and/or speaking activities from Bayer, Biogen Idec, Merck-Serono, Novartis, Roche, Sanofi Genzyme, Takeda and Teva Pharmaceutical Industries and research support from Biogen Idec, Merck-Serono, Novartis, Roche, Teva Pharmaceutical Industries, the Italian Ministry of Health, Fondazione Italiana Sclerosi Multipla and ARiSLA (Fondazione Italiana di Ricerca per la SLA. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or conflict with the subject matter or materials discussed in this manuscript apart from those disclosed.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Additional information

Funding

This paper was not funded.