Neurological disorder associated with the damage to nerve tissue in the brain and spinal column; the cause is unknown. Multiple sclerosis (MS) causes widespread foci of inflammation in the myelin sheath of a nerve; the insulating material around the nerve tracts is broken down, with the result that impulses can no longer be transmitted. Damaged material is replaced with scar tissue. The first symptoms often occur unannounced, and disappear completely within a few weeks or months. The situation is then repeated, the symptoms are renewed, but on each occasion they leave residual symptoms behind. Tension and fatigue can worsen the condition. Multiple sclerosis sometimes develops so slowly that the patient remains relatively active for several decades; on the other hand there are cases in which brain tissue breaks down so rapidly that death occurs within weeks. Because many areas of the brain and spinal column are affected, there may be failure symptoms of various kinds. Inflammation of one of the optic nerves, impairing vision, often occurs in the early stages of the disease (retrobulbar neuritis). Usually vision is restored to a reasonable extent. All sorts of sensory disorders can also occur, such as a feeling of numbness associated with loss of deep sensation. Spasticity may begin with walking difficulties and a tendency to stumble; serious weakening occurs later. Ataxia may also occur, involving problems of muscular coordination. Double vision (diplopia) and attacks of dizziness (vertigo) are also possible. Finally all the above-named disorders are permanently present, and it is no longer possibly to care for the patient even in a wheelchair. In its early stages MS often resembles other disorders of the nervous system. Diagnosis is finally confirmed by the characteristic course of the illness, with supplementary examination. Tests on cardiac fluid show excessive and also abnormal immune substances. The rapidity with which stimuli are carried by nerve tracts in brain and spinal column is often reduced. Sites of the disorder can be identified by CAT scan or NMR (nuclear magnetic resonance) scan. As yet there is no treatment. If the condition deteriorates rapidly, bed rest is important. Discomfort can be reduced by means of inflammation-inhibiting hormones, but this cannot alter the course of the disease. The long-term effect of many experimental treatments (such as oxygen therapy under pressure) is not yet known. There are drugs which can reduce spasticity. Physiotherapy is consistently important. Mumps (parotitis) Infectious disease of the salivary glands caused by a virus. The illness occurs worldwide, mainly in children in their fifth to ninth year, but also in young adults (in barracks, for example), and above all in the winter and spring. About a third of sufferers undergo no discomfort. By the age of 20 about 60 per cent of the population has had mumps. Infection occurs through the air or direct contact with saliva. A patient is infectious to those around him five days before symtoms appear until about nine days afterwards. The mumps virus causes infection of the air passages, where it multiplies, and is conveyed in the bloodstream to the salivary glands and organs such as the brain and reproductive organs. Two to three weeks after infection the illness begins with high fever and pain when chewing. The salivary glands on one side swell, and other glands swell a few days later. The swelling is painful, particularly when the mouth is opened. Sometimes the salivary glands on the other side of the face swell as well. Most patients suffer from headaches. Swelling of the salivary glands subsides after about a week and disappears completely after three weeks. Mumps is usually harmless in children, and generally clears up without persisting symptoms. In young adult males there is an increased possibility of inflammation of the testicles (orchitis). One testicle swells painfully, and sometimes the other testicle can be affected as well. This complication is practically always completely cured, seldom resulting in sterility. The mumps virus sometimes also causes meningitis or pancreatitis. Infection with mumps results in immunity to the virus; it is a disease which you have only once. It can be prevented by immunization, but this is rarely used. Treatment is by controlling the pain and a liquid diet. There is no medication effective against the mumps virus itself. In the case of orchitis, corticosteroids can be used to limit the possibility of irreperable damage.