Figure 1 -. Representative examples of negative spinal cord MRI in patients with MOG-IgG-associated myelitis.

The left part of the figure shows cervical (top rows) and thoracic (bottom rows) T2-weighted spinal cord MRI images in four patients with MRI-negative MOG-IgG associated myelitis. In the first patient (A), despite a normal aspect of spinal cord parenchyma on sagittal images (A1, A3), a subtle focal area of T2-hyperintensity can be noted on axial images in the cervical spinal cord (A2, arrowhead), that was likely considered insufficient to justify symptoms severity (EDSS: 4.5) during the initial MRI review. In the second (B) and third (C) examples, spinal cord MRIs appear normal despite an EDSS of 7 and 4.5, respectively. In the fourth patient (D) with encephalomyelitis, the first (D1-D4) and second (not shown) spinal cord MRI were negative despite an EDSS of 7.5. The patient was empirically started on intravenous methylprednisolone and plasma exchange with improvement and a third MRI obtained 22 days later showed diffuse T2-hyperintense lesions in the spinal cord on both sagittal (D5, D7; arrows) and axial (D6, D8) images. In the right part of the figure (E), axial brain MRI images of the patient in B with fluid attenuated inversion recovery abnormalities in the corona radiata (E1), and mesial left thalamus (E2) that are unlikely to contribute to the myelopathic symptoms/signs.