What is Multiple Sclerosis?

 N.B. There is a more reader friendly version at the bottom (shorter and bullet pointed) as well as an infographic and translations

I must start by saying that I am not a doctor, this is just my understanding of the condition.

So, your brain and your spine make up your Central Nervous System (CNS).  And for some reason, in MS, the immune system, rather than targeting foreign bodies as it's supposed to do, turns in on itself and attacks the CNS.

Everybody's symptoms of MS are different and there is no real course that can be charted for its progression.  This is because it very much depends on where in the CNS the immune system attacks as to what symptoms a person gets (e.g. occipital lobe lesions may lead to vision issues or brain stem lesions may lead to temperature regulation issues).  And also depends on how active the immune system attacks are (and subsequent lesions) as to how badly a person if affected or how quickly they may deteriorate.  

What's happening when an area of the brain is damaged is that it's removing the myelin sheath from around the nerve.  This is basically like the plastic casing that surrounds wires.  The electrical signal that travels down nerves travels super quickly through this.  But without it, it travels at a fraction of the speed.  And this is what leads to the symptoms.

I have posted a link to a youtube video here that goes into deeper detail about how myelin helps generate action potentials (signals) along the nerves and what happens when you don't have it.

https://www.youtube.com/watch?v=K55J1JnAq18 

The brain does not 'self-repair' in the same way other organs do.  Most organs have a stock of stem cells.  These are cells which haven't turned into a designated cell type yet.  So when an area is injured, these cells can differentiate into new muscle, skin, ligament... and heal the wound.  But the brain doesn't have these in the same way (it only has stem cells in some very specific regions).  So it repairs itself very very slowly, if at all.  There is something called Neuroplasticity though which is basically where the brain rewires itself (so makes new pathways, bypassing the damaged areas).  But this still isn't quick, or a total fix.

So when a person has what is called a 'relapse' (the immune system attacks the CNS, causing a lesion, causing symptoms), they may be fortunate and recover completely, or they may recover partially, or they may not recover at all.  Relapses can also last from 24 hours to many many months.

There are different types of MS, but I will look at these at another time.

If you have questions, please ask.

Reference

(No date) Myelin and saltatory conduction | action potentials in neurons - youtube. Available at: https://www.youtube.com/watch?v=K55J1JnAq18 (Accessed: 25 June 2026).

Reader friendly

- MS comes about when the central nervous system (spine and brain) is attacked by its own immune system.

- It depends on where the immune system attacks in the CNS as to what symptoms a person gets - so everybody gets different symptoms.

- The more active the immune system, the more likely the person is to be badly affected / to deteriorate quickly

- There is a covering around the nerve (like a wire casing) called the myelin sheath and during attacks, it is this that is being removed.

- This myelin carries electric signals from the brain at super fast speed.  So without it, a person cannot carry out the action.

- There is a youtube video (above) about how the myelin sheath helps create an action potential (signal) through a nerve.

- The brain cannot 'self repair' like other organs as it does not have stem cells throughout it.

- However, it can use neuroplasticity to rewire itself to at least compensate a little

- People may recover completely from a relapse, partially, or not at all.  And they can last from a day to months on end.

Mandarin Chinese

• Duo fa xing ying zheng (MS) shi dang ren ti de mian yi xi tong cuo wu di gong ji zhong shu shen jing xi tong (ji zhui he nao) shi fa sheng de.

• zheng zhuang de zhong lei qu jue yu mian yi xi tong zai zhong shu shen jing xi tong de na ge bu wei fa qi gong ji — yin ci mei ge ren de zheng zhuang dou ke neng bu tong.

• Mian yi xi tong huo yue de cheng du yue gao, ren ti yue ke neng shou dao yan zhong ying xiang, bing qie bing qing ke neng geng kuai e hua.

• Shen jing yuan zhou you yi ceng bao mo (jiu xiang dian xian wai mian de bao pi), jiao zuo sui qiao. Zai mian yi gong ji qi jian, sui qiao hui bei po huai huo tui qu.

• Zhe ceng sui qiao fu zhu nao bu yi chao kuai su du chuan di dian xin hao. Yin ci, mei you ta, shen ti jiu wu fa zheng chang chuan di shen jing xin hao bing wan cheng mou xie dong zuo.

• Shang mian you yi ge YouTube shi pin, jie shi sui qiao ru he bang zhu shen jing yuan chan sheng dong zuo dian wei (xin hao), bing tong guo shen jing jin xing chuan di.

• Nao bu neng xiang qi ta qi guan na yang "zi wo xiu fu", yin wei nao nei bing mei you bu chu dou cun zai de gan xi bao.

• Ran er, nao ke yi li yong shen jing ke su xing (neuroplasticity) chong xin zu zhi shen jing lian jie, zhi shao zai yi ding cheng du shang bu chang shou sun de gong neng.

• You xie ren ke yi cong yi ci fu fa zhong wan quan hui fu, you xie ren zhi neng bu fen hui fu, er you xie ren ze wu fa hui fu. Fu fa ke neng chi xu yi tian, ye ke neng chi xu shu ge yue huo geng chang shi jian.

Hindi

• Multiple Sclerosis (MS) tab hota hai jab sharir ka apna immune system central nervous system (reedh ki haddi aur dimaag) par hamla karta hai.

• Vyakti ko kaun se symptoms honge, yah is baat par nirbhar karta hai ki immune system CNS ke kis hisse par hamla karta hai — isi liye har vyakti mein symptoms alag ho sakte hain.

• Immune system jitna zyada active hota hai, vyakti ke gambhir roop se prabhavit hone ya uski sthiti ke jaldi kharab hone ki sambhavna utni hi zyada hoti hai.

• Nerve ke chaaron taraf ek covering hoti hai, bilkul taar ke casing ki tarah, jise myelin sheath kehte hain. Attack ke dauraan isi myelin sheath ko nuksan pahunchta hai aur yah hat sakti hai.

• Yah myelin dimaag se electric signals ko bahut tez gati se le jaati hai. Isliye jab myelin nahi hoti ya bahut damage ho jaati hai, to nerve signal theek se nahi pahunch pata aur vyakti ke liye kuch actions karna mushkil ho sakta hai.

• Upar ek YouTube video hai jo batata hai ki myelin sheath nerve ke madhyam se action potential (signal) banne mein kaise madad karti hai.

• Dimaag doosre organs ki tarah "khud ko repair" nahi kar sakta, kyunki poore dimaag mein stem cells maujood nahi hote.

• Halaanki, dimaag neuroplasticity ka istemal karke apne neural connections ko dobara organise kar sakta hai aur kam se kam kuch had tak khoi hui functioning ki bharpai kar sakta hai.

• Kuch log relapse se poori tarah recover kar sakte hain, kuch log sirf aanshik roop se recover karte hain, aur kuch log bilkul recover nahi karte. Relapse ek din se lekar kai mahino tak chal sakta hai.

Spanish

• La esclerosis múltiple (EM) ocurre cuando el propio sistema inmunitario del cuerpo ataca al sistema nervioso central (el cerebro y la médula espinal).

• Los síntomas que presenta una persona dependen de la zona del sistema nervioso central que sea atacada por el sistema inmunitario; por eso, cada persona puede presentar síntomas diferentes.

• Cuanto más activo está el sistema inmunitario, mayor es la probabilidad de que la persona se vea gravemente afectada o de que su enfermedad progrese rápidamente.

• Alrededor de los nervios hay una capa protectora, parecida al recubrimiento de un cable, llamada vaina de mielina. Durante los ataques, esta capa es la que resulta dañada y puede desaparecer.

• La mielina permite que las señales eléctricas viajen desde el cerebro a una velocidad extremadamente rápida. Por eso, cuando falta o está gravemente dañada, las señales nerviosas pueden no transmitirse correctamente y la persona puede tener dificultades para realizar determinadas acciones.

• Hay un vídeo de YouTube (arriba) que explica cómo la vaina de mielina ayuda a crear un potencial de acción (señal) a través de un nervio.

• El cerebro no puede "repararse a sí mismo" de la misma manera que otros órganos porque no tiene células madre distribuidas por todo el cerebro.

• Sin embargo, puede utilizar la neuroplasticidad para reorganizar sus conexiones neuronales y compensar, al menos parcialmente, algunas de las funciones afectadas.

• Algunas personas pueden recuperarse completamente de una recaída, otras solo parcialmente y otras no se recuperan en absoluto. Las recaídas pueden durar desde un día hasta varios meses.