CONVULSION AND SPASM.
Convulsion or spasm are terms used to define uncontrolled ac tions of the muscles. In convulsion the contraction of the mus cles alternates with relaxation, and opposing muscles contract one after the other, so that active movements of the limbs or other parts, over which the affected muscular organs are distributed, take place. In spasm the muscles are held in a state of perma nent contraction, one set of muscles, or, it may be, opposing sets of muscles, being in some instances equally affected at the same time. Convulsion is contraction of muscle with alternate relaxa tion. Spasm is contraction long continued, until either the mus cle or nervous stimulus is exhausted. Cramp is spasm of an ex treme kind, prolonged, rigid, and acutely painful, but usually confined to one part, as the calf of the leg. The voluntary as well as the involuntary muscles may be affected by spasm.
There are many varieties of spasmodic disease, of which the following are the more striking: Laryngeal spasm, laryngismus stridulus or spasmodic croup. —A spasm of the muscles of the glottis or opening into the windpipe, by which a crowing or croupy cough is produced, with hard or stridulous breathing. It is a disease often fatal to young children, and due to some surface irritation reflected to the ner vous centres which form the muscles of the glottis.
Intestinal spasm. Colic. Spasm of the intestines. It is due to irritation from improper food; or to cold; or to the action of some poisons, especially lead; hence the term "lead colic." Chest spasm. Angina pectoris. A sudden and painful spasm of the muscles of the chest, including the heart, and seizing the sufferer with such sudden violence that the term "breast pang" has been employed to express the paroxysm.
Chorea. St. Vitus' Dance.
A disease in which the muscles of the voluntary order are in frequent motion without either the direction or the control of their possessor. In some instances single tracts of muscles are affected, in others all the large tracts of voluntary muscular fibre. The disease might be called a paralysis or palsy of intellectual direction of muscles, the nervous stimulus flowing, if I may so express it, of its own accord into the muscular organs without any individual controlling power being exerted over it. The phe nomena present themselves at all ages, and the affected seeming to move constantly are said to have a dancing disorder, choros, a dance. Recovery sometimes occurs. The disease is technically divided into two varieties, (a) acute, (b) chronic.