Development of Neuromyelitis Optica Spectrum Disorder and Spinal Arachnoid Cysts in a Patient With Intractable Epilepsy.

Neuromyelitis optica is an inflammatory, demyelinating disease of the central nervous system that is characterized by severe relapsing attacks of optic neuritis and transverse myelitis. The current case describes a 29-year-old man with intractable epilepsy and diplegic spastic cerebral palsy who was given the diagnosis of neuromyelitis optica spectrum disorder after presenting with weakness, incontinence, and decreased visual acuity. His symptoms recurred 21 months after initial presentation. Magnetic resonance imaging of his spine revealed arachnoid cysts with regional mass effects. Differentiation of arachnoid cysts from a demyelinating process may be difficult in the early stages of the disease. Close monitoring of patients with neuromyelitis optica spectrum disorder is important, especially in patients with recurrent or refractory symptoms.