An Attempt to Subclassify and Understand Further the MS/NMOSD “Overlap” Syndromes and Beyond
Results: Based on the imaging (MRI), clinical, serologic and immunologic (CSF) phenotypes there were 31 overlap cases who were subclassified in four patterns:
Pattern 1: Clinical and imaging phenotypes consistent with MS who were seropositive for AQP4-IgG & MOG-IgG on repeated testing (N:2).
Pattern 2: Clinical and/or imaging phenotypes suggestive of NMOSD, who were seronegative for AQP4-IgG & MOG-IgG on repeated testing and/or with CSF consistent with MS (N:8).
Pattern 3: Clinical and/or imaging phenotypes who shared features suggestive of both MS and NMOSD with either serology (N:17).
Pattern 4: Atypical/unclassifiable seronegative brainstem inflammatory disorders(N:4).
Conclusions: The results of our observational study are suggestive that a significant number of cases share clinical, imaging and serologic features of both MS and NMOSD/MOG-Ab-AD that may be subclassified as overlap cases. Another subgroup with atypical features that may be associated with yet unidentified auto-antibodies also emerged with each having its diagnostic and therapeutic consequences.