There is currently no cure for NMO.
What Are Symptoms of NMO?
NMO (neuromyelitis optica) symptoms may include:
- Optic neuritis, which affects the eyes
- Loss or blurring of vision in one or both eyes
- Loss of color vision
- Eye pain
- Transverse myelitis, which affects the spinal cord
- Loss of bowel or bladder control
- Urinary retention or difficulty emptying the bladder
- Muscle spasticity (increased tone or stiffness in the extremities)
- Shooting pain or tingling in the neck, back, or abdomen
- Uncontrollable nausea and vomiting
- Uncontrollable hiccups
- Confusion, seizures, or coma (in children)
What Causes NMO?
NMO (neuromyelitis optica) is an autoimmune condition that occurs when the body attacks the myelin that covers the nerves. Most cases of NMO are caused by a specific attack on a type of protein called aquaphorins. The aquaporin-4 (AQP4) water channel is located within the optic nerves and spinal cord which is why these parts of the body are affected.
How Is NMO Diagnosed?
NMO (neuromyelitis optica) is diagnosed with a patient history and physical examination. There must be evidence of optic neuritis and transverse myelitis in order to diagnose NMO.
Other findings that support the diagnosis of NMO include:
- Findings on the brain MRI that do not meet diagnostic criteria for multiple sclerosis (MS), and
- Distinctive, elongated lesions in the spinal cord called longitudinally extensive transverse myelitis (LETM)
- Lesions that involve a large part of the optic nerve or a specific part of the optic nerve, called the optic chiasm
- Positive anti-AQP4 antibodies
Tests used to diagnose NMO includes:
- Neurologic exam, to assess:
- Muscle strength
- Memory and thinking functions
- Magnetic resonance imaging (MRI) scan of the brain, optic nerves, and spinal cord
- Spinal tap (lumbar puncture) to examine cerebrospinal fluid (CSF)
- Eye and vision studies
- Optical coherence tomography (OCT)
- Blood tests
What Is the Treatment for NMO?
Treatment for an initial attack of NMO (neuromyelitis optica) includes:
- Intravenous (IV) high-dose corticosteroids (methylprednisolone)
- Plasma exchange (PLEX) if there is no improvement with corticosteroids
There is a high likelihood of recurrence (more than 90%) and attacks are usually severe.
Treatment is needed to suppress the immune system. Three drugs are approved by the US Food and Drug Administration (FDA) to treat anti-AQP4 positive NMO:
Other drugs used off-label to prevent NMO attacks include:
- Rituximab (Rituxan)
- Mycophenolate mofetil (CellCept)
- Azathioprine (Imuran, Azasan)
Other treatments may include:
- Medications for pain, stiffness, muscle spasms
- Medications for bladder and bowel problems
- Physical and occupational therapy
- Social services to address rehabilitation needs