Neuromyelitis optica (NMO) or Devic’s syndrome – is an inflammatory demyelinating disease characterized by damage to a selective optic nerve (acute and subacute neuritis) and spinal cord (extensive transverse myelitis LETM).
NMO was considered as a serious variant of multiple sclerosis (MS) and is often misdiagnosed as multiple sclerosis, but the prognosis and treatment are different. At the moment, in connection with the isolation of a specific marker (NMO-IgG), which is not found in multiple sclerosis, opticology is separated into a separate nosological unit.
Until recently, Devic’s disease was thought to be a kind of MS. It was described by Devic in 1894 and called Devic’s syndrome.
Demyelinating lesions of the optic nerves and spinal cord can occur simultaneously or sequentially. One of the first symptoms is temporary blindness, sometimes permanent, in one or both eyes. The other symptoms include different degrees of paresis or paralysis in the legs, loss of sensitivity and/or dysfunction of the bladder and intestines due to damage to the spinal cord. A complete clinical picture of the disease may occur within 8 weeks.
Neuromyelitis optica occurs due to the wrong reaction of the immune system to own cells in the central nervous system mainly in the optic nerves and spinal cord, but sometimes in the brain.
The cause of NMO is usually unknown, but it may arise after infection or be associated with another autoimmune disorder.
- blindness in one or both eyes
- painful spasms
- weakness or paralysis in the legs and arms
- nerve pain
- loss of sensation
- sexual problems
- uncontrollable vomiting and hiccups
- bladder or bowel dysfunction
Children may suffer from confusion and coma.
The condition may also target other parts of the brain, especially the brainstem and hypothalamus, causing signs and symptoms such as severe and persistent vomiting and hiccups, or sleeping and eating disorders.
NMO is an autoimmune disorder what means that immune system starts to attack the body’s tissues and organs. There is an antibody called aquaporin-4 in a blood of 80% of people with NMO. In Neuromyelitis optica, the immune system damages aquaporin-4 which destroys the myelin sheath (the protective layer that surrounds nerve cells in the brain and spinal cord and helps transmit nerve signals).
[See also: Kleine-Levin syndrome]
It is important to diagnose NMO correctly as it may be confused with multiple sclerosis as it has similar symptoms.
In order to diagnose NMO, you should visit a neurology specialist with whom you will discuss your symptoms and medical history. Also, you can make the MRI exam (magnetic resonance imaging) scan of the brain and spinal cord.
A lumbar puncture is another test you may have. A sample of cerebrospinal fluid (CSF) is taken from the spine using a hollow needle that’s inserted into the lower part of the spine.
In 2006 the Mayo Clinic proposed a revised criteria that help to diagnose Devic’s syndrome. Those criteria include absolute (optic neuritis, acute myelitis) and supportive (brain MRI, spinal cord MRI, NMO-IgG seropositive status ) criteria.
Today there is no generally accepted treatment of Devic’s syndrome. Usually, the treatment is symptomatic and supportive to manage symptoms and prevent relapses. Your doctor may prescribe corticosteroid preparations, intravenous immunoglobulin, and methylprednisolone.
Rehabilitation techniques, such as physiotherapy, can also help with any reduced mobility that the relapses cause.