Nervous system of body is made from nerve cells called as Neurons. Chains of neurons make nerves that run in whole body to carry impulses from brain to body and body to brain. These nerve cells or neurons are covered with myelin sheath.This myelin sheath is not continuous over whole body of neurons but leave few patches called as ‘nodes of ranvier’ ,this helps in fast travelling of impulses. Multiple sclerosis is autoimmune disorder of unknown etiology that lead to inflammation and injury to myelin sheath. As whole nervous is made out of nerves including brain ,spinal cord multiple sclerosis can affect all of them. Symptoms can vary from from mild weakness to numbness and loss of cognition.