According to the part of the brain damaged variations of paralytic symptoms may arise ; thus occasionally the paralysis may be limited more or less to the face, the arm or the leg. In such case it is termed a monoplegia, a condition sometimes aris ing from cerebral tumour. Occasionally the face is paralysed on one side and the arm and leg on the other (alternate hemiplegia); this is because the disease has damaged the motor path from the brain to the leg and arm before it has crossed over to the opposite side, whereas the path to the face muscles is damaged of ter it has crossed. In rare cases both leg, arm and face on one side may be paralysed—triplegia; or all four limbs—bilateral hemiplegia. Infantile spastic paralysis, infantile diplegia, is a birth palsy caused by injury from protracted labour, the use of forceps or other causes. The symptoms are generally not observed until long after birth. Convulsions are common, and the child is unable to sit up or walk long after the age at which it should do so.
Paraplegia implies paralysis of the lower extremities ; in the great majority of instances it arises from a local or general disease or injury of the spinal cord. A localized transverse myelitis will interrupt the motor and sensory paths which connect the brain with the spinal grey matter below the lesion ; thus fracture, dislocation and disease of the spinal column (e.g., tuber cular caries, syphilitic disease of the membranes, localized tumours and haemorrhages) may cause compression and inflammatory softening, and the result is paralysis of the voluntary muscles, loss of sensation, loss of control over the bowel and bladder, and a great tendency to the development of bedsores. The muscles do not waste except from disuse, nor undergo electrical changes unless the disease affects extensively the spinal grey matter or roots as well as the cerebral path. When it does so, as in the case of acute spreading myelitis, the symptoms are usually more severe and the outlook is more grave.
In focal myelitis from injury or disease, a good measure of recovery may take place by keeping the patient on his back in bed, daily practising massage and passive movements, and so managing the case as to avoid bedsores and septic inflammation of the bladder.
Paralysis may also result from acute inflammatory affections of the spinal cord involving the grey and white matter—myelitis (see NEUROPATHOLOGY).
were given before the true nature of the disease in the spinal cord was known ; the same affection may occur, however, in adults. The medical name is acute anterior poliomyelitis, because the anterior grey matter of the spinal cord is the seat of acute inflammation, and destruction of the spinal motor nerve path to the muscles. The term atrophic spinal paralysis is sometimes employed as indicating the wasting of muscles that results.
Infantile paralysis often commences suddenly, and the paralysis may not be observed until a few days have elapsed; the earliest symptoms are fever, convulsions and sometimes vomiting ; and, if the child is old enough, it may complain of pains or numbness or tingling in the limb or limbs which are subsequently found to be paralysed. It is characteristic, however, of the disease that there is no loss of sensation in the paralysed limb. The whole of the limb is not necessarily paralysed, often it is only a group of muscles, and even if the paralysis affects both legs or the arm and leg on one side, it generally fails in the uniform distribution of paraplegia or hemiplegia. The affected muscles rapidly waste and become flaccid, the electrical reactions change, and finally the muscles may cease to respond to electrical stimulation alto gether. In the less severe cases (and they are the most common) only a group of muscles undergo complete paralysis and atrophy, and there is always hope of some return of power in a paralysed limb. Associated with the withered condition of the limb due to the muscular atrophy is an enfeebled circulation, rendering the limb cold, blue and livid; the nutrition of the bones and other parts is involved, so that a limb paralysed in early infancy does not grow and is shorter than its fellow. Deformities arise, some the result of failing muscular support ; others due to permanent changes in the position of the limbs, for example clubfoot. There is absence of bladder and bowel troubles, and bedsores do not occur; the disease itself is rarely, if ever, fatal. About a month after onset of the disease every effort should be made by massage, by suitable positions and passive movements to promote the circu lation and prevent deformities in the affected limbs. Should these measures fail, surgical aid should be sought.