A case of anti-AQP4 antibody–positive neuromyelitis optica spectrum disorder with MRI-proven lesions in lumbar nerve roots

Summary Neuromyelitis optica spectrum disorder (NMOSD) affects the central nervous system but is rarely reported to cause peripheral nervous system damage. We report a case of a 57-year-old woman with numbness and muscle weakness of the left lower limb during the course of 12 years of anti-AQP4 antibody–positive NMOSD. Lumbar magnetic resonance imaging (MRI) showed a contrast effect on the left L4, L5, and S1 nerve roots, which is a highly unusual presentation. Although radiculopathy without myelopathy is unusual in AQP4-positive NMOSD, the MRI-confirmed nerve root lesions in our case indicate that it can occur.