MS · Multiple Sclerosis

The immune system mistakes wiring insulation for invader

Imagine your brain's nerve fibers are like electrical cables in a house, each wrapped in thick rubber insulation (myelin) to speed electricity safely from room to room. In MS, the immune system mistakenly thinks the rubber coating is a dangerous intruder and sends in attack dogs (T cells) to chew it off. The dogs strip bare patches of wire, so electricity crawls instead of races—your light switch takes seconds to turn on a lamp, or doesn't work at all. After each attack, repair workers (oligodendrocytes) patch the wire with thinner insulation, but not as good as the original, and scars harden around the damage (plaques). Over time, the bare wires corrode from repeated attacks and lack of proper coating, the attack dogs keep coming back to new patches, and eventually whole sections stop working, leaving rooms dark forever—this is permanent disability.