Pediatric Neuromyelitis Optica Spectrum Disorder: Case Series and Literature Review

Abstract

Neuromyelitis Optica Spectrum Disorder (NMOSD) is a central nervous system (CNS) inflammatory demyelinating disease characterized by recurrent inflammatory events that primarily involve optic nerves and the spinal cord, but also affect other regions of the CNS, including hypothalamus, area postrema and periaqueductal gray matter. The aquaporin-4 antibody (AQP4-IgG) is specific for NMOSD. Recently, myelin oligodendrocyte glycoprotein antibodies (MOG-IgG) have been found in a group of AQP4-IgG negative patients. NMOSD is rare among children and adolescents, but early diagnosis is important to start adequate therapy. In this report, we present cases of seven pediatric patients with NMOSD and we review the clinical and neuroimaging characteristics, diagnosis, and treatment of NMOSD in children.

Keywords: aquaporin-4 antibody; children; longitudinally extensive transverse myelitis; myelin oligodendrocyte glycoprotein antibodies; neuromyelitis optica spectrum disorder; optic neuritis.

Figure 1

NMOSDs with AQP4-IgG. (A). Coronal T2-weighted image (WI) shows hyperintense lesion in brainstem (case 1), (B). sagittal T2-WI shows multiple and confluent hyperintense lesions in cervical and dorsal spine consistent with LETM (case 2), (C). axial T2-WI shows hyperintense lesion in cervical spine (case 2).

Figure 2

NMOSDs without AQP4-IgG. (A). Sagittal T2-WI shows multiple and confluent hyperintense lesions in the cervical and dorsal spine consistent with LETM (case 4), (B). sagittal T2-WI shows multiple and confluent hyperintense lesions in the dorsal spine extending from level T5 to the conus medullaris (case 5), (C). sagittal T1-WI acquired after the intravenous (iv) administration of gadolinium (gd) shows intramedullary enhancement between T6 and T8 levels (case 6), (D). sagittal T2-WI shows hyperintense lesions in the cervical spine (C2–C7) consistent with LTM (case 7), (E). axial T1-WI acquired after iv administration of gd shows left optic nerve enhancement consistent with left ON (case 7), (F) axial T2-FLAIR shows multiple brain hyperintense lesions (case 5).

Figure 3

Proposed diagnostic and treatment algorithm for pediatric NMOSD. NMOSD: neuromyelitis optica spectrum disorders; CSF: cerebrospinal fluid; MRI: magnetic resonance imaging; MS: multiple sclerosis; ADEM: acute disseminated encephalomyelitis; AQP4: aquaporin-4; MOG: myelin oligodendrocyte glycoprotein; IV: intravenous; PLEX: plasma exchange; IVIG: intravenous immunoglobulin; AZA: azathioprine; MMF: mycophenolate mofetil; RTX: rituximab; HCST: hematopoietic stem cell transplantation.