Synopsis
Recognise the distinctive optic-nerve, spinal-cord and area-postrema syndromes of NMOSD, secure the correct antibody diagnosis and escalate attacks before irreversible disability accumulates.
- Neuromyelitis optica spectrum disorder is an autoimmune astrocytopathy, most often associated with serum aquaporin-4 immunoglobulin G; it is not simply a severe form of multiple sclerosis.
- Core presentations are severe or bilateral optic neuritis, acute myelitis, area-postrema syndrome, an acute brainstem syndrome, symptomatic diencephalic disease and characteristic cerebral syndromes.
- Longitudinally extensive transverse myelitis spans three or more vertebral segments, although an early or treated lesion can be shorter and a normal first scan does not settle a convincing case.
Key red flags
Eye pain is followed by marked monocular or bilateral visual loss, impaired colour perception and a relative afferent pupillary defect. Chiasmal involvement, poor recovery or recurrent attacks should raise NMOSD above typical MS-associated optic neuritis.
Investigation priorities
Locate active optic-nerve, medullary, cerebral and cord inflammation while excluding compression and vascular or neoplastic alternatives.
Management branches
New objective optic, spinal, brainstem or cerebral deficit compatible with inflammatory relapse.
- Admit when vision, walking, respiration, swallowing or sphincter function is threatened; document a neurological baseline and arrange urgent MRI while excluding compression, vascular disease and infection.
- After senior neuroinflammatory agreement, give high-dose intravenous methylprednisolone, commonly 1 g daily for three to five days in adults, with glucose, blood-pressure, gastric and infection precautions under local policy.
Key medicines
Intravenous methylprednisoloneA common specialist attack regimen is 1 g intravenously once daily for three to five days.
Therapeutic plasma exchangeSpecialist services commonly deliver five to seven exchanges over about one to two weeks.