Given the high specificity of AQP4-IgG, the neurologic manifestations are expected to be secondary to AQP4-IgG as opposed to the rheumatologic condition. (o–t) GFAP IgG positive 63 year old woman with subacute progressive encephalomyelitis with no underlying malignancy and MRI findings of (o) sagittal patchy, extensive ventral T2 hyperintense lesions from the craniocervical junction to C7, (p) Axial ventral T2 hyperintensity, (q) sagittal dorsal and central enhancement at the margin of the craniocervical junction as well as ventral enhancement at the margin of the cord at C3 and C6, (r) axial dorsal and ventral subpial enhancement, (s) sagittal diffuse enhancement of the ventral and dorsal margins of the distal thoracic cord from T8 to T11, and (t) axial ventral subpial enhancement.Ĭoexisting systemic autoimmunity is common, including systemic lupus erythematosus, Sjögren syndrome, and antiphospholipid syndrome. (i–n) CRMP5 IgG positive 54-year-old woman with paraplegia, found to have a neuroendocrine carcinoma suggestive of thymus or small cell lung origin and MRI with (i) sagittal T2 hyperintensity with cord swelling from C2 to T1, (j) axial posterior and lateral T2 hyperintensity, (k) sagittal dorsal subpial contrast enhancement from C2 through T1, (l) axial anterior, lateral, and dorsal subpial contrast enhancement, (m) sagittal T2 hyperintensity from T1 to T11, and (n) axial central predominant T2 hyperintensity. (e–h) MOG IgG positive 12-year-old-girl with gait abnormality and mild lower extremity weakness with MRI showing (e) sagittal T2 hyperintensity with mild cord edema from C4 to C7, (f) axial gray matter T2 hyperintensity with appearance of an “H” sign, (g) sagittal T2 hyperintensity of the conus medullaris, and (h) Axial subtle symmetric central T2 hyperintensity. (a–d) AQP4-IgG positive 52-year-old woman with progressive limb weakness and sensory loss with MRI showing (a) sagittal confluent T2 hyperintensity with cord edema from C2 to T1, (b) axial central predominant T2 hyperintense lesion, (c) sagittal ring-enhancement pattern from C3 to C5, and (d) Axial ring enhancement pattern with central and lateral involvement. Lesions are often located centrally sometimes with associated ring enhancement ( 3) ( Figures 1a–d).Īll images collected from cases seen at the Autoimmune and Neuroimmunology clinics at the University of Colorado. Short segment lesions can occur in 15% of NMOSD attacks, which can be mistaken as multiple sclerosis (MS) ( 6). Longitudinally extensive myelitis (LETM), defined as a myelitis extending ≥3 or more continuous vertebral segments, is commonly seen and frequently recurrent in NMOSD ( 1). Optimal testing uses a blood cell-based assay (CBA) with fluorescence-activated cells sorting (FACS) ( 5). AQP4-IgG is highly specific and highly sensitive for NMOSD. Binding of AQP4-IgG leads to an inflammatory cascade, ultimately resulting in secondary demyelination. NMOSD is 5–10 times more common in women, with a median age of 40 ( 1, 3).ĪQP-4 is located on the end feet of astrocytes. Most experience a relapsing course, and relapses are often severe and associated with disability. There are three cardinal features: transverse myelitis, optic neuritis, and area-postrema syndrome ( 4). NMOSD is an antibody-mediated disease of the central nervous system associated with AQP4-IgG ( 1, 3). In this review, we describe autoimmune myelopathies such as AQP4-IgG positive NMOSD and anti-myelin oligodendrocyte glycoprotein (MOG) antibody associated disease (MOGAD), in addition to less commonly described antibodies including anti-CRMP5, anti-glial fibrillary acidic protein (GFAP), amphiphysin, Hu/ANNA1, among others. Clinical history, unique radiographic findings, and identification of autoantibodies can help guide appropriate treatment. These indirect pathogenic mechanisms occur in syndromes with an intracellular antigen target as opposed to antibodies against cell surface antigen targets. Some autoantibodies in this group of disorders are considered pathogenic such as aquaporin-4 (AQP4) in neuromyelitis optica spectrum disorder (NMOSD), whereas other antibodies are not directly pathogenic but are rather markers of cytotoxic T cell mediated autoimmunity. Early and accurate diagnoses of these conditions improves clinical outcomes ( 1). Autoimmune and paraneoplastic myelopathies are a heterogenous group of disorders.
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