Spine in multiple sclerosis. Coloured magnetic resonance imaging (MRI) scan of a section through the cervical (neck, top) and thoracic (bottom) spine of a 32-year-old patient with multiple sclerosis (MS), showing demyelinating plaques affecting the spinal cord. MS is a disease in which the myelin sheaths that cover the axons of nerve cells in the brain and spinal cord are damaged by cells of the immune system attacking and destroying the myelin cells. Myelin sheaths help facilitate the propagation of nerve signals along the axons, Damage to this system disrupts the ability of parts of the nervous system to communicate, leading to various physical and mental problems. Common symptoms of MS can include double vision or blindness in one eye, muscle weakness and loss of coordination.