CHORDITIS VOCALIS. See LARYN GITIS.
CHOREA.—From the Greek: zopEia. Synonym.—St. Vitus's dance.
Some confusion arises from the fact that under the name "chorea" are in cluded several forms of nervous disease and degeneracy having as their com mon and characteristic symptom jerky, arhythmic, involuntary, inco-ordinate, muscular movements, while differing widely from one another in nature, causa tion, pathology, prognosis, and general symptomatology. This confusion is further added to by the varying opinions held by those who write upon the sub ject as to what conditions shall and what shall not be included among the choreas.
The following forms are described:— 1. Sydenham's chorea. With several varieties, as "chorea insaniens," "liemi chorea," etc.
2. Endemic chorea.
3. Electric chorea.
4. Hysterical chorea.
5. Saltatory spasm.
G. Oscillatory spasm.
Tic co-ordine, or "habit spasm." 8. Post-hemipleg,ic chorea.
9. Chronic adult chorea.
10. Huntington's chorea.
Of these, the first in order is the com mon St. Vitus's dance, chorea minor, or acute curable chorea, and much the most common and important of the choreoid diseases. It is the form meant when the word chorea is used without qualifica tion. Those included from the 'second to the seventh belong to the functional neuroses, and may be regarded as ex pressions of neurodegeneracy. The eighth, ninth, and tenth are attended by aegenerativc changes tne cortex cere bri or spinal cord, or both.
Definition.—This is the well-known "St. Vitus's dance," an acquired func tional neurosis, occurring during the middle and later periods of childhood, being rarely seen before the age of five years and after puberty; it is more com mon in females than in males, is more frequently met with in urban than in rural populations, and during the spring months.
Symptoms.—The onset of the disease is often foreshadowed by symptoms cov ering a prodromal period of a few days to a few weeks. These premonitory symptoms consist in general nervousness, a, tendency to fidget and uneasiness, a change in disposition; irritability and emotional weakness, headache, vague pains, some impairment of general health, and possibly the occurrence of some one of the acute diseases or unfav orable circumstances enumerated below as exciting causes of the disorder. The disease always develops gradually and with varying rapidity in different cases, the onset being marked by the appear ance of the characteristic choreic move ments. These are peculiar, jerky, often lightning-like, clonic spasms, involving the muscles of the face and head, neck, trunk, and extremities, usually more pro nounced. in the face and arms, and often
more pronounced in one lateral half of the body ("hemichorea," when typically shown). The movements are sudden in onset and as suddenly cease; they are irregular in force and direction, markedly inco-ordinate, and differ in character from any other form of abnormal motor discharge known. They result in sudden grimaces and facial twitchings; sudden closure and opening of the eyes or mouth; sudden seizure and immediate dropping of any object it is attempted to grasp; twisting- movements of the arms; pe culiar dancing and bobbing movements of the feet, all of these movements seem ing at times semipurposeful, leading to the idea on the part of the onlooker that they are due to bad habit or awkward ness, and could be prevented.
The movements vary in intensity from slight, scarcely-noticeable twitchings of co-ordinate groups of muscles, occurring at intervals, to violent and almost con tinuous clonic spasmodic contractions of nearly or quite all of the voluntary, mus cles of the body, resulting in writhings and contortions which completely inca pacitate the patient and render neces sary confinement to bed. The move ments may occur when the muscles are at rest, but they are often precipitated or intensified by voluntary muscular effort of any kind. They are increased by efforts to prevent them and by anything which directs attention to them. They cease entirely during sleep. In many cases speech is affected in consequence of implication of labial muscles and tongue, giving rise to peculiar jerking out of words, explosive utterances, hesi tation, or indistinctness of articulation which may in some cases amount to en tire inability to talk. The lips are occa sionally bitten; the tongue rarely. The muscles of respiration may become in volved, in which event there will be un even, irregular respiratory movements, with, possibly, sighing, moaning, or other involuntary inarticulate sounds. Deglu tition in severe cases is also more or less interfered with, and the patient natu rally finds difficulty in feeding himself, on account of the inco-ordinate action of the muscles of the arms and hands. The urine and aces may pass involuntarily. The gait is, in all well-marked cases, altered, and is usually shuffling and slow, the steps being unequal in length and in time, with difficulty in progress ing in a straight line.