Whole spinal transverse myelitis in neuromyelitis optica spectrum disorder

Spinal cord is one of the prominent targets of autoimmune mechanisms in Neuromyelitis Optica Spectrum Disorder (NMOSD). Rarely, NMOSD causes damage to the entire length of the spinal cord, from cervical segments to conus medullaris, which has not been characterized in the existing literature.

We reviewed medical records, demographic information, and magnetic resonance imaging (MRI) sequences of 174 NMOSD patients from January 2011 to January 2023 who were admitted to Isfahan Multiple Sclerosis center to find patients with whole spinal transverse myelitis (TM).

Whole spinal TM was present in five patients (2.9 %). Three patients were seropositive for Aquaporin-4 (AQP4) antibody; Myelin Oligodendrocyte Glycoprotein antibody (MOG IgG) tested negative for all of them. Lower limb weakness was the most frequent clinical complaint. Two patients presented with optic neuritis; One patient reported having episodes of nausea and vomiting. These patients, overall, yielded a higher expanded disability status scale (EDSS) score than the other NMOSD patients.

Whole spinal TM is a rare finding in NMOSD, which is strongly associated with a higher severity and a worse outcome of the disease. The role of anti-AQP4 antibodies in the extent of myelitis in NMOSD has yet to be investigated.