An acute infectious inflammation of the anterior horns of the gray matter of the spinal cord, a rare illness in the U.S. since the introduction of effective polio vaccines. In this disease, paralysis may or may not occur. In the majority of patients, the disease is mild, being limited to respiratory and gastrointestinal symptoms, such constituting the minor illness or the abortive type, which lasts only a few days. In the major illness, muscle paralysis or weakness occurs with loss of superficial and deep reflexes. In such cases characteristic lesions are found in the gray matter of the spinal cord, medulla, motor area of cerebral cortex, and cerebellum.
An infectious disease, characterized, when fully developed, by muscular paralysis. Although no age is immune it was called infantile paralysis because early in this century its maximal incidence was among two and three year old children. The young are still mostly attacked, but at present the biggest risk appears to be in the five to ten year old group and the young adult. Infants under one year seem to be completely immune. There appear to be three degrees of poliomyelitis: abortive cases, called the “minor illness”; nonparalytic and preparalytic; and paralytic. While this classification is justifiable and useful on practical grounds there are no actual subdivisions in disease, as the three degrees may shade off imperceptible one into the other. The “minor illnesses”: these cases occur sporadically, being particularly plentiful during epidemics. The symptoms are easily confused with those of influenza or the early stages of an infectious fever such as measles or glandular fever, and consist of a feeling of being unwell, with headache, mild gastrointestinal upset, but at this stage or in this condition there is no muscular paralysis. Non-paralytic and preparalytic poliomyelitis: the symptoms are essentially the same as the “minor illness” but tend to be more intense and prolonged. The onset is often abrupt and a high temperature is almost invariable, usually lasting from two to four days and then gradually subsiding, though there may be secondary rise for a few days before paralysis appears. Back and limb pains are more severe and flexing the spine is painful. Vomiting and loss of appetite are common and there is often slight diarrhea. After a day or son the headache becomes intensified at the back of the head, and is associated with classical symptoms of brain irritation-irritability, neck stiffness, and photophobia. The back and limb muscles are often tender and may show tremors and loss of reflexes. Such a picture in a young adult or child in summer or early autumn is extremely suggestive of poliomyelists. Paralytic poliomyelitis: in these cases muscle paralysis usually appears at the height of the general body disturbance and may be confined to muscles which receive their nerve supply from the spinal cord, the “spinal form” as it is called, or affect muscles which receive their nerve supply direct from the brain, the so-called “bulbar poliomyelitis.” In spinal poliomyelitis, the paralysis occurs usually between the second and fifth days of the illness but may be delayed as long as the tenth day if the fever persists. It usually reaches its height within 24 hours, but in rare cases it may continue to progress for several days. In the gravest cases all four limbs become completely paralyzed very quickly and the patient is at once engaged in a life and death struggle in order to breathe. At the other end of the scale are cases so mild that the paralysis is not apparent until the patient tries to walk. Generally speaking, the legs and lower trunk muscles suffer more frequently and severely than the upper parts of the body, especially when diarrhea has been a feature of the early stages. Bulbar poliomyelitis commences with mental confusion and drowsiness, rapidity and irregularity of the pulse, irregularity of breathing, flushing, and congestion of the skin and eyes. There may be paralysis of the throat and gullet, making it difficult or impossible to swallow. The larynx, tongue, and palate may become paralyzed, causing nasal speech and regurgitation of fluids down the nose. Paralysis of one side of the face may occur, and occasionally the patient cannot keep the jaw shut. In this type of poliomyelitis the prognosis is always very grave, but if the patient survives the cranial nerve paralysis he usually makes a remarkably complete recovery. Now that protective inoculation against “polio” is available, it is an astonishing fact that those who seek it are but a small proportion of those who actually need it. The present practice is to give two inoculations at monthly intervals, followed by a third after some months and a fourth injection a year later. There is a move, however, to go over to oral vaccine (three doses at monthly intervals), and research is being made to find a vaccine to include diphtheria, whooping cough, and polio and so cut down the number of injections that have to be given to children. Also called infantile paralysis, polio.