Lesions, sometimes called scars or plaques, are the hallmarks of multiple sclerosis. Lesions are areas of damage that occur to tissue as a result of some sort of trauma. In this case, the lesions occur as a result of trauma induced by multiple sclerosis, which causes the immune system to mistakenly attack an area of the body. Symptoms of MS and its accompanying relapses tend to manifest according to where in the body the disease creates these lesions. For example, when a lesion occurs in the optic nerve, vision problems tend to result. MS lesions most commonly occur in the optic nerve, spinal cord, and brain stem or cerebellum, though they can also appear in different areas of the brain. Lesions in the brain are unpredictable, and there is no one-to-one comparison for how lesions in different areas of the brain correspond to specific symptoms.
How do lesions manifest as symptoms?