In an interesting article from the series “Controversies in Neurology,” different points of view address the topic of whether multiple sclerosis (MS) and neuromyelitis optica (NMO) are distinct diseases or parts of a unique nosological spectrum.1,2 These views should be considered in the light of the following, additional points. First, oligoclonal bands, a hallmark of MS, tend to disappear over time when present in the cerebrospinal fluid of patients with NMO.3 Second, an intrathecal, polyspecific immune response to measles, rubella, and zoster virus (MRZ reaction) is detectable in about 80% of patients with MS but rarely in NMO (1 of 20 patients in our series)4 and helps in differential diagnosis. Third, titers of anti–Epstein-Barr virus nuclear antigen antibodies in patients with MS are higher than in controls5 and in NMO patients with NMO (mean [SEM] values: 13.5 [1.4] DU/mL, n = 16 for NMO; 18.9 [1.0], n = 23 for MS; 11.6 [1.5], n = 37 for blood donors; P < .002, MS vs NMO/blood donors; D. Franciotta, MD; S. Jarius, MD; 2007, unpublished data). Fourth, new recombinant assays for anti-aquaporin-4 antibodies can increase diagnostic sensitivity (91%6) and specificity (98.6%7-100%6) for NMO, reinforcing their role as robust disease markers.
Franciotta D, Jarius S, Aloisi F. More on Multiple Sclerosis and Neuromyelitis Optica. Arch Neurol. 2007;64(12):1802. doi:10.1001/archneur.64.12.1802-a