Overview

• Chronic and progressive condition that causes:
  • Autoimmune condition characterised by the demyelination of the myelinated neurones in the central nervous system
• This is caused by the inflammatory process involving the activation of the immune cells against the myelin
• Usually presents in young adults (under 50years)
• More common in women
• Symptoms tend to improve in pregnancy and in the postpartum period.

Epidemiology🌎

• 3 x more common in women 👩🏽‍🦰
• Most commonly diagnosed in people aged 20-40 years
• Much more common in areas farther from the equator (5x more common than in the tropics) ⛰️

Genetics 🧬

• Monozygotic twin concordance = 30%
• Dizygotic twin concordance = 2%

Pathophysiology

• Myelin covers axons of neurones in the CNS
• This accelerates electrical conductivity along an axon
• Myelin is provided by cells that wrap themselves around the axons.
  • These are Schwann cells in the peripheral nervous system and oligodendrocytes in the central nervous system.
• MS only affects the CNS (the oligodendrocytes)