Progressive inflammatory disorder primarily manifesting with demyelination of the central white matter
Optic neuritis and transverse myelitis (spinal cord lesion) are common presentations
Generally develops over a few days; very uncommon to happen suddenly (e.g. pts will complain about a dark spot appearing in their vision that expands over several days)
Evaluation
MRI w/wo contrast can identify lesions and determine chronicity
“Active” MS plaque will contrast enhance and continues to enhance for weeks (even after treatment)
Modified MacDonald Criteria: ≥3 characteristic demyelinating lesions (>1 cm, periventricular, infratentorial (brainstem/cerebellum/cord) or juxtacortical in location) with evidence of separation in time (active and chronic). Positive oligoclonal bands on LP can substitute as dissemination in time.
LP with studies for oligoclonal bands, IgG index, cell count and protein, anti-MOG, anti-AQP4
Management
Treat flares and optic neuritis with high-dose steroids
Speeds up recovery, but does not improve the degree of recovery
Often dosing starts with Methylprednisolone IV 1gm x 3-5 days
If a pt with known MS has worsening of chronic symptoms, then recrudescence (pseudoflare) is the likely cause à infectious/toxic/metabolic workup is needed
Steroid-sparing agents are the long-term therapy goal but often have significant adverse effects requiring monitoring:
Interferon (SQ injections): flu-like symptoms, injection site reactions
Glatiramer acetate (SQ): injection site reactions
Fingolimod (PO): macular edema, liver injury, increased risk of skin cancer
