Multicystic demyelinating myelopathy

A 10-year-old girl presented with subacute lower limb weakness and gait ataxia. MRI revealed a large multicystic spinal cord lesion with patchy enhancement (figure 1, A and B) and 3 small (<6 mm) periventricular and deep white matter brain lesions. The presence of serum anti-aquaporin-4 (AQP4) immunoglobulin G (ELISA assay) and compatible neuropathologic features from neurosurgical specimens1 (figure 2) suggested the diagnosis of a neuromyelitis optica spectrum disorder.2 Targeted immunotherapy was started, with partial lesion resolution (figure 1C).