MS Session at CONy 2019

For the 13th consecutive time, this year’s World Congress on Controversies in Neurology (CONy 2019, held in Madrid, Spain on April 4–7, 2019) covered a range of current, intriguing topics in the field of Multiple Sclerosis (MS).

Friday’s MS sessions opened with a thorough examination of neurofilaments as viable biomarkers of MS progression, as well as their potential to replace magnetic resonance imagining (MRI) as a monitoring tool. Due to her opponent not being present for the debate, Dr. Georgina Arrambide from the Center of Multiple Sclerosis of Catalonia (Cemcat) had the daunting task of representing both sides of the argument as a pro-NfL advocate herself.

Neurofilament light chain (NfL) is released in the cerebrospinal fluid (CSF) after axonal injury leading to higher blood and CSF levels in patients with MS—and other neurological diseases—than in healthy subjects. Increased levels have been shown to correlate with MRI lesions and other measures of disease activity. Measurement of NfL serum levels, however, is fraught with reproducibility and validation challenges that render its widespread adoption difficult at this point in time. The audience in attendance was in strong agreement with this observation and overwhelmingly voted that they did not see NfL serum levels as replacing MRI anytime soon as the gold standard for monitoring MS progression.

In stark contrast, the next panel debated the continued value of evoked potentials (EPs) in the diagnosis and monitoring of MS. These painless, non-invasive, cost effective, and quick clinical tests—first proposed by Dr. Charles M. Poser in 1986 in the context of MS diagnosis—have been progressively losing steam as more emphasis was being put on MRI. The broad acceptance of the McDonald’s criteria in 2001—which elevated MRI to the gold standard in MS diagnosis—have rendered EPs obsolete in the eyes of a broad section of the MS community. Dr. Letizia Leocani from the University Hospital San Raffaele in Milan, however, reminded the audience that “old” doesn’t necessarily mean obsolete. As an illustrative example, Dr. Leocani noted that reflex hammers have been used since the 19th century and are still relevant today in neurological examination. She also pointed to recent research that indicates that EPs are more sensitive than MRI to early brainstem damage and for the prediction of long-term disability levels.

On the other side of the debate, Dr. Bianca Weinstock-Guttman from the University of Buffalo, New York, expressed concerns about the validation and reproducibility of EP testing. She noted that EP metrics are indeed sensitive to external factors such as temperature and medications. Additionally, EPs have shown to be poor indicators of cognitive and cerebellar dysfunctions, thus decreasing their value as a diagnostic and monitoring tool. The audience in attendance eventually sided with Dr. Weinstock-Guttman’s anti-EP argument in a 2:1 ratio. It appears that we may have entered a post-EP world, but ongoing research by Dr. Leocani could indicate that the fight is far from over. We will be monitoring the progress of the EP debate with great attention in anticipation of next year’s CONy conference!