ST.VITUS'S DANCE or CHOREA,a disorder of the nerv ous system characterized mainly by involuntary jerking move ments of the muscles throughout almost the entire body (see NEUROPATHOLOGY). This name was originally applied to epidemic outbursts of mental and physical excitement which occurred among the inhabitants of some parts of Germany in the middle ages. Sufferers from this dancing mania were wont to resort to the chapels of St. Vitus (more than one in Swabia), the saint being believed to possess the power of curing them.
Chorea occurs particularly between the ages of nine and twelve and is twice as frequent in girls as in boys. Fright, ill-usage, insuffi cient feeding, overwork or anxiety, are among the most common exciting causes especially when associated with family tendency to nervous disease ; occasionally it complicates pregnancy. The connection of chorea with rheumatism is now universally recog nized, and is shown by its frequent occurrence before, after or dur ing attacks of fever in young persons, and by the liability of the heart to suffer in a similar way in the two diseases.
The symptoms sometimes develop suddenly but are usually pre ceded by changes in disposition and general health. The first thing indicative of the disease is awkwardness or fidgetiness of manner together with restlessness. In walking, too, slight dragging of one limb may be noticed. The convulsive muscular movements usually first show themselves in an arm or a leg, and may remain localized ; in all cases the disorderly symptoms are more marked on one side than on the other. The child with fully developed chorea, when awake, is never still, but is constantly twitching the body, limbs or face. These symptoms are aggravated when pur posive movements are attempted or when the child is watched. When the tongue is protruded it comes out in a jerky manner and is immediately withdrawn, the jaws at the same time closing sud denly and sometimes with considerable force. Speech, swallowing
and locomotion suffer from muscular incoordination. In short, the whole muscular system is deranged in its operations, and the term "insanity of the muscles" not inaptly expresses the condition. The involuntary muscles appear scarcely affected in this disease ; the rhythmic movements of the heart, for example, are not as a rule impaired. But the heart may suffer from conditions similar to those in rheumatism.
This disease occasionally assumes a very acute and aggravated form, in which the disorderly movements are so violent as to render the patient liable to be injured, and to necessitate forcible control of the limbs, or the employment of anaesthetics. Such cases are very grave, if, as is common, they are accompanied with sleeplessness, and they may prove rapidly fatal by exhaustion.
It is doubtful whether any drug has much control over the disease, which under suitable hygienic conditions tends to recover of itself after one or two months or perhaps longer. Ruhrah, recognizing the importance of rest, recommends a modified Weir Mitchell treatment. Of medicinal remedies the most serviceable appear to be zinc, arsenic and iron, especially the last two, which act as tonics to the system and improve the condition of the blood. In view of the connection of chorea with rheumatism, salicylate of soda in large doses has been recommended. In long-continued cases much benefit will be obtained by change of air and moderate gymnastic exercises. Massage and electricity may be beneficial.
In the acute form of chorea, where the convulsive movements are unceasing and violent, the only measures available are the use of chloral or chloroform inhalation to produce insensibility and muscular relaxation, but the effect is only palliative.