Spinal cord tumor versus transverse myelitis

Abstract

Longitudinally extensive transverse myelitis (LETM) is one of the defining features of neuromyelitis optica (NMO). Despite the well-established criteria, clinical and paraclinical features, the disease is often misdiagnosed and erroneously treated. We report on a case of LETM in a patient with spatially limited NMO spectrum disorder that was misdiagnosed as spinal cord tumor and underwent spinal cord biopsy. A 43-year-old female patient is described. The patient developed spastic tetraparesis over 1 week. Spinal cord magnetic resonance imaging (MRI) revealed LETM, and she was treated with steroids and recovered. Nine months later, her condition worsened and repeat spinal cord MRI was interpreted as a large intramedullary tumor in the cervical region with irregular postcontrast enhancement. Biopsy revealed demyelination. Cerebrospinal fluid (CSF) analysis revealed positive oligoclonal IgG bands, and serum was positive for NMO-IgG antibody. The patient was diagnosed with spatially limited NMO spectrum disorder, treated with plasma exchange, high-dose corticosteroids, and cyclophosphamide, and with good recovery. The factors favoring inflammatory LETM are acute or subacute onset of clinical symptoms, positive oligoclonal bands in the CSF, positive NMO-IgG or other antibodies, and brain MRI showing demyelinating lesions. Postcontrast axial MRI sequences of the spinal cord can also be helpful. In doubtful situations, a trial of therapy and follow-up MRI a month later might be a more prudent approach if the patient is not rapidly deteriorating.