Chorea is sometimes confined to a single muscle or group of muscles. When limited in this way it is generally in the head, face, or perhaps in the shoulder. These cases of localized chorea have been spoken of by Mitchell as habit chorea.21 They are often very obstinate in resisting treatment, and sometimes last during life.
21 Lectures on Nervous Diseases, p. 146.
PARALYSIS.—Not infrequently in chorea there is paralysis to a greater or less extent. It is generally one-sided, and most often involves the upper extremity. The limb affected is the one in which the movements were most violent. The arm may hang entirely powerless or it may be only enfeebled, and feeling to the patient like a dead weight. The paralysis always recovers with the chorea or soon after.
POST-PARALYTIC CHOREA.—Under this term Mitchell and Charcot have described a variety of chorea which is seen in patients after an attack of hemiplegia. The movements are chiefly on voluntary effort, and are those of inco-ordination. They come on from one to several months after an attack of unilateral paralysis, and are sometimes seen in cases in which almost complete recovery has taken place. Mitchell has reported22 a case which was under my care for several years, and which he saw in consultation with me. This patient had two attacks of left hemiplegia, the last being fatal. After the first attack there was great gain of power to use the arm and leg, but the movements were performed awkwardly and with an irregular jerking movement. A post-mortem examination revealed a spot of softening the size of a filbert in the left corpus striatum, which was apparently recent, and a point of red degeneration in the right crus cerebri. The vessels at the base of the brain were extensively atheromatous.
22 American Journal of the Med. Sci.
Of the electrical condition of the muscles in chorea but little is known. Rosenthal23 found increase of faradic contractility in three cases of hemichorea, and the galvanic test showed a high degree of excitability, demonstrated by the fact that weak currents gave contractions at cathodic closure, or even tetanic contractions, and also contractions were produced at cathodic opening.
23 Ziemssen's Cyclopædia, loc. cit., p. 434.
The affection of speech which is so common in chorea is due to disordered action of the laryngeal muscles, or it may be from choreic action of the abdominal muscles. Sometimes it is chiefly from the awkwardness of the tongue. The usual form of trouble is that the patient speaks in a staccato manner and the syllables seem as if they were driven out. When the chorea is in the laryngeal muscles, the tone and pitch of the voice are altered.
Chorea of the heart is sometimes spoken of, but it has never been satisfactorily demonstrated that there is any real disorder of cardiac rhythm in chorea. It is not unusual in chorea to meet with over-action or palpitation of the heart, but these conditions do not necessarily depend on the disease.
Valvular murmurs are often met with from the beginning of an attack. In some instances they are the result of an endocarditis, but frequently they are functional or anæmic. They are usually heard at the apex. Sometimes there is a reduplication of the first sound, giving the idea of a want of synchronism in action of the two sides of the heart; but this is probably not the result of chorea of the heart. I recall one patient, a child of seven or eight years, in whom the reduplication of the first sound was very distinct during an attack of St. Vitus's dance. She was brought to me at the beginning of a second attack a year later, and the reduplication of the cardiac sounds was heard again, so it is likely that it had continued during the interval, and was probably a congenital condition.