Multiple Sclerosis

BASICS

Autoimmune demyelinating disease affecting primarily CNS white matter, leading to axonal loss and CNS atrophy
Subtypes:
Clinically Isolated Syndrome (CIS): first symptoms, ~80% progress to MS
Radiologically Isolated Syndrome (RIS): MRI findings, asymptomatic; 30–40% progress to CIS/MS
Relapsing-Remitting MS (RRMS): most common; defined by attacks and partial/completion improvement
Secondary Progressive MS (SPMS): progressive worsening after initial RRMS
Primary Progressive MS (PPMS): progressive decline from onset (~10%)

Pregnancy: Exacerbations decrease in pregnancy, relapse post-partum; interferon-β, glatiramer acetate preferred if needed

T-cell/B-cell-mediated attack on myelin sheath proteins → demyelination, oligodendrocyte loss, slowed nerve conduction
Partial remyelination may occur, leaving scars/atrophy
Genetics: >100 loci (notably HLA-DRB1 on Chr 6); antigen-specific

Highly variable: cognitive dysfunction, fatigue, dizziness, vision changes, muscle weakness/spasms, pain, bowel/bladder/sexual dysfunction

Infectious: Lyme, syphilis, ADEM, PML, GBS, HIV, etc.
Autoimmune: SLE, antiphospholipid, neurosarcoid, Behçet, vasculitis, Bell’s palsy
CNS/Metabolic: NMO, tumors, stroke, migraine, B12 deficiency, toxins, paraneoplastic, hypothyroid, psychiatric, CMT

Rule out mimics: ANA, ANCA, dsDNA, APL, ESR, IgG/IgM, RF, HIV, RPR, TSH, B12, Lyme, CBC
MRI brain/spine: periventricular, callosal lesions; gadolinium to detect active lesions
CSF: Oligoclonal bands (90%), normal/elevated protein
McDonald Criteria: dissemination in time and space; clinical/MRI/CSF-based
PPMS: ≥1 year progression + MRI/CSF evidence

Multidisciplinary team (rehab, PT/OT, mental health, neurology, urology, dietitian)
Acute relapses, disease-modifying therapy, symptomatic therapy
Steroids for acute episodes
Early DMT slows progression (MS specialist recommended)
Smoking cessation

Injectable:
IFN-β1a (Avonex/Rebif), IFN-β1b (Betaseron/Extavia)
- Monitor: CBC, LFTs, TSH; SE: flu, depression, site rxn, thyroid/liver dysfunction
Glatiramer acetate (Copaxone); SE: site rxn, lipoatrophy, postinjection reaction
Monoclonal antibodies: rituximab, natalizumab, alemtuzumab (infection, PML, thyroid, blood clots)
Oral:
Dimethyl fumarate, teriflunomide, fingolimod
- Monitor: CBC, LFTs; SE: GI, arrhythmia, infection, liver, hair loss, etc.

Immune-mediated demyelination, neuronal loss, and CNS scarring
Most common cause of nontraumatic neuro disability in young adults
Diagnosis: McDonald criteria
Treatment is complex/rapidly changing—MS specialist and multidisciplinary therapy are essential