Maria A. Rocca on Spinal Cord Atrophy Among Patients With MS
Spinal cord atrophy increases over 1 year among patients with multiple sclerosis (MS), but not among those with clinically isolated syndrome, according to results of a new study.
The study was led by Maria A. Rocca, who is the of the Neuroimaging Research Unit and Neurology Unit at the Institute of Experimental Neurology, Division of Neuroscience, at the IRCCS San Raffaele Scientific Institute in Milan, Italy.
Neurology Consultant caught up with Dr Rocca about her team’s study and its results.
NEURO CON: For this study, you and your colleagues characterized the distribution and regional evolution of cervical cord atrophy in patients with MS. Can you tell us more about how this study came about?
Maria Rocca: The spinal cord is a clinically eloquent area of the central nervous system. Due to its size, location, and extensive pattern of connections, damage of the spinal cord causes many clinical manifestations, in particular locomotor impairment. Spinal cord lesions occur in more than 90% of MS patients. However, we know that in this disease, damage is not limited to focal lesions visible on conventional magnetic resonance imaging sequences, but an extensive and irreversible tissue loss, which can reflect different pathological substrates (eg, axonal loss, demyelination), is present.
The development in the past few years of novel methods of MRI acquisitions and analysis has made feasible the evaluation, in vivo, of tissue loss in terms of atrophy. In this study, we thought that the collection of a large number of MRI scans of the spinal cord in patients with the main clinical phenotypes of MS would have allowed us to better characterize the phenotypic heterogeneity of these patients. In particular, we hypothesized that such an effort would have contributed to deepen the mechanisms responsible for the presence of more severe disability and/or of a progressive course of the disease. In addition, we wished to explore the clinical relevance of spinal cord atrophy progression over 1 year.
NEURO CON: One finding from your study was that cord atrophy increased in patients with MS, except for those with clinically isolated syndromes, over 1 year. What factors might account for this increase? And how might clinicians improve quality of life for their patients with MS?
MR: As previously mentioned, the factors that could contribute to explain an increase of cord atrophy (that is, progression of tissue loss) over 1 year are axonal damage and loss, neuronal loss, and demyelination. In patients with relapsing-remitting MS, in whom inflammatory processes may be more pronounced, a resolution of inflammation can also be considered. This is important information for clinicians because, on the one hand, it prompts them to look at atrophy, not only at lesions, when investigating the spinal cord. On the other hand, it urges the development and use of neuroprotective drugs, capable to act on irreversible tissue loss.
NEURO CON: Did any of your findings surprise you?
MR: At least 2 findings were unexpected. The first was the presence of a regional pattern of distribution of damage in the cervical cord, with atrophy involving the more cranial parts of the cord (from C1 to C5) in patients with relapsing-remitting MS and also the more caudal parts of the cord (C6 and C7) in patients with progressive MS, particularly in those with secondary progressive MS. This can be due to local damage at this level, as well as to secondary degeneration phenomena due to damage at the level of the dorsal cord.
The second unexpected finding was from the longitudinal analysis that disclosed that atrophy progression in the cervical cord is more pronounced in patients in the first years of the disease course (early relapsing-remitting MS) and then tends to decrease, probably due to a plateauing effect.
NEURO CON: Taken together, what do these findings mean for clinicians who manage patients with MS?
MR: These findings have several meanings for the clinicians. First, they suggest looking at the spinal cord. Second, they indicate a need to obtain a global assessment of spinal cord involvement (not only lesions, but also atrophy; not only a cranial part, but also a caudal part). Third, they indicate that spinal cord atrophy is not only relevant for patients with progressive MS but is also relevant for patients with early relapsing-remitting MS. And finally, as previously mentioned, they indicate the need to search for neuroprotective drugs.
Reference:
- Rocca MA, Valsasina P, Meani A, et al; MAGNIMS Study Group. Clinically relevant cranio-caudal patterns of cervical cord atrophy evolution in MS. Neurology. 2019;93(20):e1852-e1866. https://doi.org/10.1212/WNL.0000000000008466.