What is NMO?
Neuromyelitis optica (NMO), also known as Devic’s disease, is an autoimmune disorder in which immune system cells and antibodies mistakenly attack and destroy myelin cells in the optic nerves and the spinal cord. The damage to the optic nerves produces swelling and inflammation that cause pain and loss of vision; the damage to the spinal cord causes weakness or paralysis in the legs or arms, loss of sensation, and problems with bladder and bowel function.
NMO occurs in two different forms: a single attack extending over a month or two, or a more common relapsing form in which the person experiences multiple attacks.
Who gets pediatric NMO?
Current studies suggest that approximately 3% of all NMO patients experience their first symptoms in childhood or adolescence. Patients as young as 16 months have been reported with NMO. The average age for children is 10 years old. Both boys and girls can be affected, but like in adults, there is a female bias at approximately 2:1.
Symptoms of pediatric NMO
Children with NMO usually present with “attacks” of new neurological symptoms appearing within a few hours or days. Children with NMO can have attacks with symptoms of blurred vision, or loss of vision in one eye or both eyes. Other symptoms are weakness or numbness of the arms or legs. Some children experience confusion or extreme lethargy at their attacks. Other possible symptoms including vomiting, fever or seizures.
Diagnosis of pediatric NMO
Diagnosis is usually made by a combination of clinical features, appearance of lesions or “spots” on MRI. Approximately 2/3 of children with NMO can also have an antibody to aquaporin-4 in their blood or spinal fluid, however this antibody may not be present at the onset of the disease, and may be appear up to 2-3 years later. Pediatric NMO differs from MS in the distribution of MRI lesions, as well as the presence of the aquaporin-4 antibody.
Treatment of pediatric NMO
Although there are no FDA approved treatments for adults or children with NMO, children are usually offered immunomodulatory treatments. Attacks are treated with a short course (usually up to a week) of intravenous steroids, or IVIG or plasmapheresis. It is important to prevent new attacks in children with established NMO, and treatment with mycophenolate mofetil, azathioprine or rituximab is usually offered.
Research in pediatric NMO
There is ongoing research to understand the causes of pediatric NMO including genetic associations. As well, studies of better diagnostic and imaging criteria are underway to improve recognition of this condition. Treatment studies and clinical trials of new treatments include children when appropriate.
Management and support for pediatric NMO
There are several centers across the world that have experience in treatment children and adolescents with NMO. Care includes neurological expertise, family support, therapists and affiliation with an educational specialist. Care is often co-managed by a specialist team as well as a patient’s local neurologist or pediatrician.