Paralysis
Collier's New Encyclopedia (1921)
the loss of the natural power of sensation or motion in any part of the body. It is owing to some diseased condition of the nervous system, either of the brain or spinal cord, or of the nerves. If the nerves of sensation or their centers be affected, there will be loss of sensation; if of motion, then loss of motion; to the latter of which the term paralysis is by some exclusively applied. The most usual form is when one side or half of the body is deprived of sensation or motion, or both, called hemiplegia; paraplegia is when the lower part of the body is paralyzed, while the upper retains both sensation and motion; and general paralysis is when the loss of nervous power extends over nearly every part of the body. In hemiplegia, the seat of the disease is one side of side of the brain, usually that opposite to the affected side of the body; in paraplegia, the lesion is within the spinal cord; and when more limited in extent, the disease usually arises from some abnormal state of a particular nerve. Paralysis frequently follows apoplectic attacks, and this usually in its most severe and dangerous form. The prognosis must be looked on as extremely unfavorable when the attack is sudden, the paralysis extensive and complete, and the loss of consciousness protracted; while, on the other hand, when the paralysis advances gradually, there is more reason to hope for prolonged life, if not for a complete restoration of health. Among the other causes that may give rise to paralysis are various injuries and diseases of the brain or spinal cord; as tumors, inflammation, external injuries, etc. When paralysis takes place without any previous vious apoplectic attack, the premonitory symptoms are a general torpor or lassitude, occasional giddiness, or a sense of weight and pain in the head, and loss of memory. When it is the result of injury of the spinal cord, then, of course, the paralysis takes place instantly. Paraplegia sometimes lasts for many years without greatly interfering with any function except locomotion; but when it occurs during fevers and advances rapidly, it is of very sinister augury, especially if it involves the sphincter muscles of the anus and bladder. Paralysis is not a disease of itself, but only a sign of some disorder of the nervous system, probably at a distance from parts affected.
What Has Changed in the Last Century
The clinical map Collier's drew in 1921 — hemiplegia from a lesion on the opposite side of the brain, paraplegia from damage in the spinal cord, and the insistence that "paralysis is not a disease of itself, but only a sign" — is still what medical students are taught. What has changed is the ability to see the lesion and sometimes undo it: CT and MRI scanning, from the 1970s and 1980s, show the damaged tissue directly instead of leaving it to be inferred, and clot-dissolving treatment for ischaemic stroke (tPA, approved in the United States in 1996) can reverse a sudden hemiplegia if given within hours. Two of the great causes of paralysis in 1921 have all but vanished: "general paralysis" was late-stage syphilis, curable after penicillin came into use in the 1940s, and poliomyelitis was driven out of most of the world by the Salk and Sabin vaccines of the 1950s. Severed spinal cords remain beyond repair, but the prognosis Collier's called "extremely unfavorable" now means decades of life with ventilators, catheters, wheelchairs and rehabilitation rather than an early death from bedsores or urinary infection.
Written for this edition, 2026.