Coexistent MOG, NMDAR, CASPR2 antibody positivity: Triumph over the triumvirate

Abstract

Myelin oligodendrocyte glycoprotein (MOG) antibody (MOG -Ab) positive cases can have a focal encephalitis like presentation. Many reports of anti N-methyl-D-aspartate receptor (NMDAR) encephalitis have documented simultaneous coexistence of MOG-Ab which is explained by the coexpression of NMDA receptors and MOG on oligodendrocytic processes. Contactin-associated protein-like 2 (CASPR2) is expressed in central and peripheral nervous system (PNS) axons and there are no case reports of coexistent NMDAR, CASPR2 and MOG antibodies. We describe a young adult male who had neuropsychiatric, cognitive symptoms and long tract signs with a strong positivity for all three antibodies. Bilateral cingulate gyri involvement, especially with contrast enhancement may be an imaging clue suggesting coexistent MOG and NMDAR antibodies. Bilateral T2 hyperintensities affecting hippocampi, have been described in both CASPR2 and anti NMDAR encephalitis. Our patient had both, bilateral cingulate and hippocampal lesions, which may be an imaging clue favouring the presence of all three antibodies.

Keywords: Autoimmune encephalitis; Cingulate hyperintensity; Demyelination; Hippocampal hyperintensity; Immunofluorescence.