Evolution of longitudinally extensive transverse myelitis in an aquaporin-4 IgG-positive patient.

A 36-year-old woman presented with hemiplegia and loss of pain and temperature sensation 1 day after the subacute onset of intractable vomiting. Paresthesia followed. She was tetraplegic at day 12. Initial MRI revealed a lesion in the medulla oblongata, involving primarily the area postrema (figure). The lesion progressively extended into the upper cervical cord. Forebrain MRI was normal. CSF contained 11 leukocytes/mm3. Brainstem tumor and multiple sclerosis were early diagnostic considerations. Aquaporin-4 immunoglobulin (Ig)G was detected in serum. This case supports the concept that fenestrated capillaries in the area postrema are an important initial CNS entry site for pathogenic neuromyelitis optica–IgG in neuromyelitis optica spectrum disorders.1,2