Symptoms and Diagnosis of NMO
What are the symptoms of NMO?
Symptoms can include all of the following, although visual symptoms and spinal cord inflammation (transverse myelitis) are primary.
Abrupt changes in vision caused by optic neuritis
- Loss or blurring of vision in one or both eyes
- Loss of color vision
- Eye pain
Changes in sensation and function in the limbs caused by spinal cord inflammation (transverse myelitis), which usually affects multiple levels in the spinal cord.
- Numbness -- loss of sensation
- Loss of function (paralysis)
- Loss of blowel or bladder control
- retention of urine or difficulty emptying the bladder
- 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 can occur in children
- Abrupt changes in vision caused by optic neuritis
How is NMO diagnosed?
- The diagnosis of NMO requires evidence of optic neuritis and transverse myelitis.
- Additional findings that support the diagnosis of NMO include: findings on the brain MRI that do not meet criteria for MS, and distinctive, elongated lesions in the spinal cord ( referred to as Longitudinally Extensive Transverse Myelitis – LETM).
- Seventy percent of people with NMO test positive for antibodies against aquaporin 4 antigen (NMO-IgG). The percentage that test positive is lower in people with more limited forms of NMO such as isolated optic neuritis or transverse myelitis.
What tools are used to diagnose NMO?
- Medical history
- Neurologic exam-a neurologist examines the person’s mobility, muscle strength, coordination, sensation, memory and thinking functions, speech and vision
- MRI of the brain, optic nerves and spinal cord
- Lumbar puncture (spinal tap) to examine cerebrospinal fluid
- Ophthalmology (eye and vision) studies; optical coherence tomography (OCT)
- Blood tests to detect NMO-IgG
- Evoked potential testing helps find lesions or damaged areas in the nerves, spinal cord, optic nerve, or brainstem
Is early diagnosis important?
- Early diagnosis is critical. Unlike MS, NMO episodes are typically quite severe. If left untreated, these episodes can have devastating, irreversible effects.