The present study provides evidence for a prodromal phase of multiple sclerosis, with implications for studying disease aetiology and underscoring the limitations of therapies that solely target inflammation. The findings also suggest an opportunity to apply secondary prevention strategies at the very earliest stages of the disease. Specifically, the authors studied whether serum neurofilament light chain (sNfL) levels are elevated before clinical multiple sclerosis onset. Results indicated that levels of sNfL were increased 6 years before clinical multiple sclerosis onset, indicating that multiple sclerosis may have a prodromal phase lasting several years and that neuroaxonal damage occurs already during this phase.
Bjornevik K, Munger KL, Cortese M, Barro C, Healy BC, Niebuhr DW, Scher Al, Kuhle J and Ascherio A: Serum Neurofilament Light Chain Levels in Patients with presymptomatic Multiple Sclerosis. JAMA Neurol. [Epub ahead of print, Sept. 13, 2019; doi: 10.1001/jamaneurol.2019.3238.].