A progressive disease of the BRAIN and SPINAL CORD, which, although slow in its onset, may in time produce marked symptoms such as PARALYSIS and tremors (see TREMOR), and may ultimately result in severe disability. The disorder consists of hardened patches, from the size of a pin-head to that of a pea or larger, scattered at random through the brain and spinal cord as well as widespread damage to axons, the long processes leading from neurons (nerve cells). Each patch is made up of a mass of the CONNECTIVE TISSUE (neuroglia), which should be present only in sufficient amount to bind the nerve-cells and fibres together. In the earliest stage, the insulating sheaths (MYELIN) of the nerve-fibres in the hardened patches break up, are absorbed, and leave the nerve-fibres bare, the connective tissue being later formed between these.
Although this is one of the most common diseases of the central nervous system in Europe, the cause is still not known. The disease comes on in young people (onset being rare after the age of 40), apparently without previous illness. There may be a hereditary factor for MS, which could be an autoimmune disorder, the body's defence system attacking myelin in the central nervous system as if it were a ‘foreign’ tissue.
These depend greatly upon the part of the brain and cord affected by the sclerotic patches. Temporary paralysis of a limb, or of an eye muscle, causing double vision, and tremors upon exertion, first in the affected parts, and later in all parts of the body, are early symptoms. Stiffness of the lower limbs causing the toes to catch on small irregularities in the ground and trip the person in walking, is often an annoying symptom and one of the first to be noticed. Trembling handwriting, interference with the functions of the bladder, giddiness, and a peculiar ‘staccato’ or ‘scanning’ speech are common symptoms at a later stage. Numbness and tingling in the extremities occur commonly, particularly in the early stages of the disease. As the disease progresses, the paralyses, which were transitory at first, now become confirmed, often with great rigidity in the limbs. In many patients the disease progresses very slowly. About 85% of patients have a relapsing-remitting form with episodes when their symptoms get much better or even seem to disappear for a time before returning. The remainder have a gradually progressive form.
There is much uncertainty about how best to treat this disease: symptoms can be helped: for example, bladder frequency may respond to oxybutynin, spasm to baclofen and depression to antidepressants. However most patients and their neurologists believe that disease modifying drugs, which might reduce the frequency or severity of relapses, should be used at an early stage, while bearing in mind the risks they carry of unwanted effects. Such medication includes INTERFERON beta, glatiramer acetate and the MONOCLONAL ANTIBODY DRUG, alemtuzumab.