Apoplexy, a word the meaning of which it is not easy to define; it is used in varying senses by different authorities, and much confusion has in consequence resulted. In its original use it denoted simply a "stunning" or "stupor" produced by internal disease. The old physicians recognised a form of seizure in which disablement of body, mind, or both suddenly supervened, usually in persons who had passed the prime of life, and altogether apart from injury, poisoning, epilepsy, or other known causes of such a condition. To this class of cases the term "stroke," "apoplectic stroke," or simply "apoplexy" was applied. It was subsequently discovered that one of the commonest causes of such a seizure was the rupture of an artery within the brain, leading to effusion of blood into the cerebral substance. Hence apoplexy came to signify an extravasation of blood, and by an unfortunate extension of its meaning (in defiance of the etymology of the word) it was applied indiscriminately to any such extravasation, in whatever part of the body it might occur. Thus arose the terms cerebral apoplexy, pulmonary apoplexy, and the like.
In cerebral apoplexy the symptoms are very variable, differing according to the part of the brain which is affected. There is usually sudden loss of consciousness, accompanied by hemiplegia (or paralysis of one side of the body). The state of stupor may become more and more pronounced, with stertorous breathing, and may end in death; or recovery of consciousness may take place, though in that event loss of power of movement, loss of speech or some other defect usually remains.
Rupture of a cerebral artery is due to degeneration of the arterial coats; it is particularly liable to occur in the subjects of the disease known as chronic interstitial nephritis (q.v.). The old notions that stout, short-necked persons are especially liable to apoplexy rests on no secure foundation.
A patient who has had one apoplectic attack is always liable to another. Popular pathology says that "the third "stroke" is always fatal; this is, however, by no means necessarily the case.