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Internal MedicineNeurologyRelapsing‑Remitting Multiple Sclerosis

Relapsing‑Remitting Multiple Sclerosis

Must-Not-Miss / Red Flags

  • Optic neuritis: rapid unilateral vision loss, pain with eye movement – high‑dose IV steroids indicated
  • Transverse myelitis: bilateral weakness, sensory level, bowel/bladder retention – spinal MRI urgently
  • Brainstem demyelination: diplopia, vertigo, dysarthria, dysphagia – risk of aspiration
Patient Explanation
“Your immune system is mistakenly attacking the protective covering of your nerves, causing different symptoms. We have strong treatments to reduce attacks and slow the disease.”
Board Fact
“Oligoclonal bands in the CSF (not present in serum) are found in >90% of MS patients and indicate intrathecal antibody synthesis.”
ICD-10
G35

Definition & Core Concept

Multiple sclerosis (MS) is a chronic, immune‑mediated demyelinating disease of the central nervous system characterized by relapses, remissions, and progressive neurodegeneration, most commonly presenting in young adults.

Epidemiology & Risk Factors

  • Affects 2.8 million people worldwide; female‑to‑male ratio 3:1
  • Peak onset 20‑40 years
  • More common in temperate regions (vitamin D hypothesis)

Pathophysiology (Rule of 3)

  1. Autoreactive T‑cells cross the blood‑brain barrier → attack myelin basic protein
  2. Inflammatory demyelination → axonal damage and gliosis
  3. Remyelination initially occurs, but repeated attacks lead to irreversible axonal loss and progressive disability

Clinical Presentation

  • Acute relapses: optic neuritis, transverse myelitis, brainstem syndrome, sensory or motor deficits lasting >24 hours
  • Fatigue (most common symptom), Uhthoff’s phenomenon (worsening with heat)
  • Lhermitte’s sign (electric shock sensation down spine with neck flexion)

Diagnostic Workup

Brain and spinal MRI with gadolinium: periventricular, juxtacortical, infratentorial, or spinal cord lesions; active lesions enhance with contrast. CSF analysis: oligoclonal bands (not in serum), elevated IgG index. Evoked potentials: visual evoked potentials may show delayed conduction.

Management Protocol

  1. Acute relapse: Methylprednisolone 1 g IV daily ×3‑5 days (shortens recovery but does not affect long‑term disability)
  2. Disease‑modifying therapy (DMT): Ocrelizumab (anti‑CD20), Natalizumab (if JCV negative), Fingolimod (S1P modulator), Dimethyl fumarate
  3. Symptom management: Baclofen for spasticity, Gabapentin for neuropathic pain, Modafinil for fatigue
  4. Vitamin D supplementation (if levels low)

Complications & Prognosis

  • Progressive disability: wheelchair dependence, cognitive impairment
  • Bladder dysfunction: recurrent UTIs, urosepsis
  • Aspiration pneumonia from dysphagia
  • Progressive multifocal leukoencephalopathy (PML) with Natalizumab (risk of 1:1,000 if JCV positive)

ICU Criteria

ICU admission if: severe brainstem relapse with respiratory compromise, status epilepticus, or severe infection related to immunosuppression.

Clinical Vignette

A 28‑year‑old woman presents with acute onset of blurred vision and pain in her right eye. Examination reveals decreased visual acuity, afferent pupillary defect, and optic disc swelling. Brain MRI shows multiple periventricular T2 hyperintensities with one enhancing lesion. CSF shows oligoclonal bands.

Pearls & Pitfalls

  • Early initiation of high‑efficacy DMT improves long‑term outcomes – do not wait for disability to accumulate.
  • A normal brain MRI does not rule out MS; spinal cord imaging and CSF analysis are essential if clinical suspicion is high.

Discharge & Follow-Up

Neurology follow‑up every 3‑6 months with MRI monitoring. JCV antibody testing every 6 months if on Natalizumab. Annual influenza vaccine; avoid live vaccines.

Literature & Guidelines

2024 McDonald Criteria for MS Diagnosis and ECTRIMS/EAN Guidelines. PMID: 38712000.

Personal Clinical Notes