Chapter 16 - Neuromyelitis Optica Spectrum Disorders

Abstract

Neuromyelitis optica spectrum disorders (NMOSD), formerly known as Devic’s disease or neuromyelitis optica, are rare autoimmune diseases affecting the brain and the spinal cord. In the majority of patients, a pathogenic autoantibody targeting the water channel aquaporin-4 on astrocytes is found, classifying NMOSD as primary astrocytopathies. NMOSD take a relapsing course and disability accumulates from incomplete remission of attacks. Uni- or bilateral optic neuritis and myelitis, often presenting as longitudinal extensive transverse myelitis (LETM), are the main clinical manifestations. Less frequently, brainstem involvement, area postrema syndrome, diencephalic syndrome, and other supratentorial symptoms occur. Diagnosis of NMOSD is made by occurrence of at least one core clinical characteristic, detection of typical lesions on brain and spinal MRI and of serum aquaporin-4 antibodies. Acute attacks are treated by high-dose steroids or apheresis therapies. Long-term treatment is immunosuppressive, e.g., with azathioprine, or by biologicals, e.g., with rituximab. The long-term outcome is defined by the remission status of attacks.