A specific microbic origin has been suggested, but is, as yet, not demon strated.
Hints at the possibility of an infectious origin for chorea. Report of a case of chorea insaniens in a woman of 27, who had had two attacks of rheumatism, and, with the second, had had delirium and irregular movements of the limbs. The autopsy showed an acute endocarditis, abF,cess of the parotid. and catarrhal pneumonia of both lungs. No special germ, however, could be discovered. Chorea is a general systemic affection, acting with greatest intensity upon the vascular system and the leptomeninges; its cause is to be sought for in a special bacillus. Berkley (Johns Ilopkins Hosp. Rep., Aug., '91).
Autopsy of a case in which micro scopical examination showed a conspicu ous chronic leptomeningitis involving the vertex of the brain; a proliferating proc ess, without exudation or inuch cell infiltration. In the superficial layer of the cortex there was cellular infiltration with degenerative changes. At this point a diplococcus was found. The micro-organisms were observed'only in the deep layer of the pia and the super ficia,1 part of the cortex. Dana (N. Y. Med. Jour., Aug. 19, '93).
Study of GOO cases. The toxin of chorea may be a, glyeocin, for which reason micro-organisms will not be found in the blood. No light thrown upon the connection of arthritis and chorea nor any explanation advanced why the toxin settles in the brain when chorea occurs in rheumatic subjects. Failed to find any cases of rheumatism caused by fright or any of chorea primarily induced by chill. Churton (Med. News, Dec. 4, '97).
Stndy of choreics bacteriologically, and discovery of a la,nceolate encapsulated diplococcus extremely pathogenic to guinea-pigs, in which it determines an luemorrhagie hypert-emia with diminished fibrin and no (edema. The histological lesions in the nervous system of patients and in the viscera of the guinea-pigs showed that the effect was more toxic than septic, with an elective action on the vessels. The findings appear to sus tain Leroux's theory that chorea is a syndrome determined by some infective or toxic agent on a, soil prepared by an inheritance of neurotic and arthritic tendencies. Mei (Gaz. degli Osp. et dello
Clin., Aug. 22, '97).
Conclusions regarding etiology of chorea are (1) rheumatic chorea is in fective, and depends on the action of toxins of micro-organisms on the nervous system; (2) staphylococci are the chief source of infection, in that they have been found twice as often as all the other organisms put together. Isdaragli (Centralb. f. innere xx, p. 459, '99).
While the importance of the pyogenic micro-organisms in relation to chorea is generally recognized, recent bacteriolog ical examinations of the spinal fluid of choreic patients go to show that the relation is a closer one than is usually I supposed. Staphylococci found in the I eerebro-spinal fluid in two personal cases. In a third ease of erysipelas, which was folh»vcd by chorea of a se vere type, not only had lumbar pnlicture a favorable therapeutic effect on the movements and the sleeplessness, but also streptococei were demonstrated in the fluid. In both the blood and urine of this case streptococei were also found. The statistics of Triboulet show that a third of all chorea cases furnish a his tory of an antecedent febrile attack, of which the most common are scarlatina. measles, and erysipelas. In all cases of chorea the eerebro-spinal fluid should be examined. Fornaca (Riforma Medica, No. 74, 1901).
Chorea is not infrequently an infec tious disease; it is, therefore, necessary to ma,ke a bacteriological examination of the blood in every case. Not rarely the disease is of streptococcic origin. In polyvalent antistreptococcic serum we possess a, rational remedy for the treatment of appropriate cases of this disease. P. A. Preobrazshensky (Aledi einskoje Obozrenijo, vol. lviii. No. 21, 1902).
Other suggested causes are cerebral hypermmia, capillary thrombosis, and prolonged arterial spasm; but none of these theories offer so rational an ex planation of the observed symptoms as that which attrilmtes the choreiform movements to inherent instability in sensorimotor sphere, together with a tox mmia or a shock sufficient to disarrange the customary association- or contact areas in cortex, basal ganglia, and cord.