This resource has been developed by Alexion, AstraZeneca Rare Disease.
Neuromyelitis Optica Spectrum Disorder (NMOSD) is a rare, chronic autoimmune neurological disease that is characterised by inflammation and demyelination in the spinal cord, optic nerve and brain. The main clinical features of NMOSD include recurrent attacks or relapses of optic neuritis, transverse myelitis, persistent vomiting and intractable hiccups.1-3
Attacks can be very debilitating and may lead to permanent disability, such as blindness and paralysis,2,3 or even death.4 Within 5 years of the first attack, about half of patients will be blind and require a wheelchair while a third will have died if NMOSD is untreated.3
Seropositive NMOSD, a subset of NMOSD, involves circulating IgG1 autoantibodies targeting the bidirectional water channel protein aquaporin-4 (AQP4), which is expressed at the plasma membrane of astrocytes throughout the central nervous system (CNS).5,6
An acute attack of NMOSD is a new onset of patient-reported or objectively observed neurological signs and symptoms or worsening of existing neurological symptoms attributable to NMOSD in the absence of other recognised causes.7
Suspected Acute Attack
In the case of a suspected acute attack, an urgent neurological evaluation should be performed.8
Information for healthcare professionals only.
Prompt treatment of acute attacks is crucial to prevent the physical impairment in NMOSD that accumulates with each relapse9 and to improve clinical outcomes.10,11
Irreversible damage may be prevented by reducing the acute inflammation.12
Dependent on the clinical presentation, below steps may be considered by the treating physician:
- High-dose intravenous steroids may be used promptly to control attacks.1,13,22
- If improvement is not immediate or if neurological impairment is severe, plasma exchange may be implemented early in order to optimise recovery.1,10,13 Plasma exchange usually consists of five treatments performed every other day.13
- Plasma exchange may also be used in combination with steroids.12,14
- Intravenous immunoglobulin (IVIgG) treatment has been used but supporting data are scarce.15
A number of diseases can mimic some of the clinical characteristics of NMOSD because they involve the optic nerves and/or the spinal cord.18,19 These diseases include stroke, infections and other neurological and systemic autoimmune diseases (e.g. multiple sclerosis (MS) and systemic lupus erythematosus).18,19 Other potential differential diagnoses are compression and toxic or metabolic causes.20,21
A differential diagnosis is therefore important to confirm the presence of NMOSD, particularly as this has important treatment implications.
A differential diagnosis is therefore important to confirm the presence of NMOSD, particularly as this has important treatment implications.
A patient with NMOSD may be receiving certain medications which can increase their susceptibility to meningococcal infection.19 Physicians should be alert to the possibility that a patient’s symptoms may be due to a meningococcal infection.19