Recurrent aquaporin 4-immunoglobulin G-positive neuromyelitis optica spectrum disorder in a patient with long-standing rheumatoid arthritis: A case report.

Neuromyelitis optica spectrum disorder is an autoimmune astrocytopathy that primarily affects the optic nerves and spinal cord. Its association with rheumatoid arthritis is remarkably rare, with only 15 documented cases reported globally to date. This report describes the unique case of a 34-years-old woman with rheumatoid arthritis who developed concurrent aquaporin 4-immunoglobulin G-positive relapsing neuromyelitis optica spectrum disorder. The case underscores the substantial risk of initial misdiagnosis as stroke in patients with autoimmune diseases presenting with acute or atypical neurological deficits. We explored the potential shared immunopathological mechanisms between the two disorders and propose integrated therapeutic strategies for concurrent management. Importantly, this report strongly advocates prompt magnetic resonance imaging of the brain and spinal cord, along with aquaporin 4-immunoglobulin G serological testing, in rheumatoid arthritis patients presenting with optic neuritis, a critical omission in current rheumatological guidelines.