Multiple sclerosis vs Neuromyelitis optica
How to tell Multiple sclerosis and Neuromyelitis optica apart when a board question makes them look alike.
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Longitudinal spinal cord lesion spanning 3 or more vertebral segments with aquaporin-4 positivity identifies NMO over MS.
Side by side
Relapsing neurologic deficits disseminated in time and space with periventricular brain lesions support multiple sclerosis.
Severe optic neuritis plus longitudinally extensive transverse myelitis and aquaporin-4 antibody positivity support neuromyelitis optica spectrum disorder.
Autoimmune CNS demyelination targets oligodendrocytes with multifocal plaque formation in brain and spinal cord.
Aquaporin-4 IgG mediated astrocyte injury causes secondary demyelination, especially in optic nerves and long spinal cord segments.
Brain MRI shows periventricular or juxtacortical plaques, CSF often has oligoclonal bands, and spinal lesions are usually shorter than 3 vertebral segments.
NMO shows spinal cord T2 lesion extending 3 or more vertebral segments, aquaporin-4 IgG positivity, often severe bilateral optic neuritis, and CSF oligoclonal bands are less common.
The trap
Starting standard MS disease-modifying therapy before confirming NMO can worsen relapses in aquaporin-4 disease. The resolving clue is LETM pattern and antibody profile before long-term treatment selection.
The repair move
Next best step: treat acute attack with IV methylprednisolone 1 g daily for 3 to 5 days, then perform plasma exchange if response is incomplete. For long-term prevention in NMO, start relapse-prevention immunotherapy such as rituximab, satralizumab, or eculizumab rather than MS-specific interferon-based therapy.
Try a free question
CoreA 29-year-old woman presents with unilateral optic neuritis and numbness in both legs. BP 116/70 mm Hg, HR 82/min, temp 36.9 C. MRI brain shows periventricular ovoid lesions and spinal MRI shows a short C3 lesion under one vertebral segment. What is the most likely diagnosis?
Show answer and explanation
Answer: B. Multiple sclerosis. Disseminated CNS lesions with classic periventricular plaques and short cord lesion are most consistent with multiple sclerosis.
Why the other choices are tempting
- A. NMO is less likely without LETM or aquaporin-4 antibody evidence.
- C. Meningitis would present with meningeal signs and CSF inflammation, not focal demyelinating plaques.
- D. Myasthenia causes neuromuscular junction weakness without CNS MRI lesions.
- E. Guillain-Barre is peripheral neuropathy and does not cause CNS plaques.
Flashcards
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What spinal MRI threshold strongly favors neuromyelitis optica over multiple sclerosis?
A contiguous lesion spanning at least 3 vertebral segments favors neuromyelitis optica.
Which antibody test is most specific for neuromyelitis optica spectrum disorder?
Serum aquaporin-4 IgG is highly specific for NMO spectrum disorder.
Quick answers
What is the fastest way to tell Multiple sclerosis from Neuromyelitis optica?
Longitudinal spinal cord lesion spanning 3 or more vertebral segments with aquaporin-4 positivity identifies NMO over MS.
What is the key clue for Multiple sclerosis?
Relapsing neurologic deficits disseminated in time and space with periventricular brain lesions support multiple sclerosis.
What is the key clue for Neuromyelitis optica?
Severe optic neuritis plus longitudinally extensive transverse myelitis and aquaporin-4 antibody positivity support neuromyelitis optica spectrum disorder.
What is the common trap with Multiple sclerosis vs Neuromyelitis optica?
Starting standard MS disease-modifying therapy before confirming NMO can worsen relapses in aquaporin-4 disease. The resolving clue is LETM pattern and antibody profile before long-term treatment selection.