Neuromyelitis Optica Spectrum Disorder (NMOSD)

Symptoms of neuromyelitis optica spectrum disorder include visual loss, muscle spasms, paraparesis or quadriparesis, and incontinence.

Specific characteristic presentations include

Diagnosis of neuromyelitis optica spectrum disorder usually includes brain and spinal cord MRI and visual evoked potentials (1 Diagnosis reference Neuromyelitis optica spectrum disorder is a demyelinating disorder that predominantly affects the eyes and spinal cord but can affect other structures in the central nervous system (CNS) that... read more ).

The following features help distinguish neuromyelitis optica from multiple sclerosis (MS):

Visual evoked potentials Measurement of Evoked Responses Visual, auditory, or tactile stimuli are used to activate corresponding areas of the cerebral cortex, resulting in focal cortical electrical activity. Ordinarily, these small potentials are... read more can help differentiate neuromyelitis optica from other optic neuropathies. Findings in neuromyelitis optica spectrum disorder include reduced amplitudes or prolonged latencies. This test is also useful for detecting clinically inapparent damage before symptoms develop.

Blood tests to measure an IgG antibody specific for neuromyelitis optica spectrum disorder (aquaporin-4 antibody [also known as NMO-IgG]) may be done to differentiate it from MS. Anti-MOG (myelin oligodendrocyte glycoprotein) antibodies identify a subset of patients who have neuromyelitis optica spectrum disorder and who appear to have different clinical features, fewer exacerbations, and better recovery than patients with aquaporin-4 antibodies or with neither antibody. Some patients with clinical evidence of neuromyelitis optical spectrum disorder do not have either antibody and are classified as having double antibody negative neuromyelitis optica spectrum disorder.

There is no cure for neuromyelitis optica. However, treatment can prevent, slow, or decrease the severity of exacerbations and may reduce the risk of disability in the short term (1 Treatment references Neuromyelitis optica spectrum disorder is a demyelinating disorder that predominantly affects the eyes and spinal cord but can affect other structures in the central nervous system (CNS) that... read more , 2 Treatment references Neuromyelitis optica spectrum disorder is a demyelinating disorder that predominantly affects the eyes and spinal cord but can affect other structures in the central nervous system (CNS) that... read more ).

Eculizumab, a C5 complement inhibitor, is available for the treatment of aquaporin-4 antibody-positive neuromyelitis optica spectrum disorder. Adverse effects include respiratory infections, headache, and pneumonia and may be significant; thus, patients should be closely monitored (3 Treatment references Neuromyelitis optica spectrum disorder is a demyelinating disorder that predominantly affects the eyes and spinal cord but can affect other structures in the central nervous system (CNS) that... read more ) Because one patient developed meningococcal sepsis, vaccination for meningococcus is required before initiating therapy.

Satralizumab (a monoclonal antibody that targets the interleukin-6 receptor) and inebilizumab (a monoclonal antibody that targets CD19 on B-cells) are also available for the treatment of aquaporin-4 antibody-positive neuromyelitis optica spectrum disorder. Patients should be closely monitored for infections such as urinary tract and respiratory infections.

Methylprednisolone and azathioprine are often used together. Plasma exchange Plasma exchange Apheresis refers to the process of separating the cellular and soluble components of blood using a machine. Apheresis is often done on donors where whole blood is centrifuged to obtain individual... read more may help people who do not respond to corticosteroids.

Rituximab, an anti–B-cell antibody, has been shown to reduce relapses in a double-blind, placebo-controlled trial (4 Treatment references Neuromyelitis optica spectrum disorder is a demyelinating disorder that predominantly affects the eyes and spinal cord but can affect other structures in the central nervous system (CNS) that... read more ). Other immunomodulatory and immunosuppressive therapies are sometimes used.

Natalizumab and fingolimod appear ineffective and may be harmful.

Treatment of symptoms Symptom control is similar to that for MS. Baclofen or tizanidine may relieve muscle spasms.