Convulsion, in Medicine, is sometimes used of any involuntary contraction of the voluntary muscles of the body; but especially of seizures in which the body is thrown into violent spasmodic contractions, the sensibility and voluntary motion being for a time suspended. In adults convulsions almost always indicate the presence of grave disease, either of the brain (particularly Epilepsy, q.v.) or of the kidneys. In children, especially before the age of three years, they are of much more common occurrence, and, though serious in themselves, may be due to temporary and comparatively trifling causes. The following description applies chiefly to the convulsions of children. A fit of convulsions may last from a few minutes to some hours, and may readily prove fatal, if not relieved within a short period. The first symptom observed is often a twitching of particular muscles or groups of muscles, and a change in the habitual expression or colour of the face, with distension of the features, and turning of the globes of the eyes suddenly upwards. The fingers are sometimes clenched in the palm, and the feet turned inwards; sometimes, however, convulsions occur absolutely without warnings of this kind, and even in the midst of perfect apparent health. Their cause is usually to be found in some source of irritation, especially in the digestive organs; as, for instance, disordered dentition, worms in the intestine, indigestible or unsuitable food, &c. Most epidemic fevers are also apt to be attended, in children, by convulsions in their early stages, and if severe, particularly in the case of whooping-cough, during their progress as well; and diseases of the brain and its membranes at every stage. Convulsions are greatly promoted by bad ventilation and injudicious feeding, with deficient exercise; and a great part of the cure consists in discovering and removing the causes of the disease.
When a child is suddenly seized with a tendency to spasm, such as twitching of the features, or contractions of the fingers and toes, it should be placed at once in a very free current of air, with its feet towards the fire; the extremities should be kept warm, and a cold lotion may be applied to the head, especially if there is much flushing of the face; a little castor-oil may be given unless the bowels are loose; and if there is flatulence, the belly may be rubbed with a warm hand, or with some simple stimulating liniment, such as camphorated oil. If an actual convulsion occur, the feet, or if possible the whole body, should at once be put in hot water to which a little mustard has been added, and cloths wrung out of cold water frequently applied to the head. If there is any suspicion that worms or undigested food may be the cause, a purgative Clyster (q.v.) should be given; and aperient medicine by the mouth as well, if the child be able to swallow. Nothing more should be attempted without medical advice. The further treatment generally consists in the administration of nerve sedatives, especially bromide of sodium or potassium and chloral, and in obstinate cases chloroform, with careful attention of course to any cause of irritation that may be present.
Convulsions are rare amongst horses and cattle. In young dogs, however, they frequently occur from intestinal worms, disordered digestion, or in connection with distemper or other debilitating diseases: they usually disappear when their special causes are removed.