Paraplegia (Gr.) is usually confined to the two lower extremities, but the muscles of the lower part of the trunk and of the bladder and rectum are sometimes affected. There are at lest two distinct forms of paraplegia, viz., (1) pataplegia dependent on primary disease of the spinal cord or its membranes, and especially on myelitis (q.v.); and (2) reflex paraplegia, i.e.. paraplegia consequent on disease of the kidneys, bladder, urethra, prostate, womb. etc. These two forms of paraplegia differ in many of their phenomena, and the most important of these points of difference have been arranged in a tabular form by Dr. Brown Sequard in his Lectures on Paralysis of the Lower Ertremi ties, to which we must refer for the hest information on this form of palsy. Paraplegia usually comes on slowly, with a gradual increase of its symptoms. The reflex form is, of course, by far the most favorable, us it usually abates spontaneously on the sub sidence of the primary disease.
Facial palsy, although locally affecting only a small part of the body, is a disorder of sufficent importance to require a definite notice. In this affection there its a more or less perfect loss of power over all the muscles supplied by the portio dura, or facial nerve. The following graphic account of the appearance of the patient is condensed from Dr. Watson's Lectures on the Practice of Physic. From one-half of the counte nance ail power of expression is gone; the features are blank, still, and unmeaning; the eyelids apart and motionless. The other half retains its natural cast, except that, in some cases, the angle of the mouth on that side seems drawn a little awry, in conse quence of the want of counterpoise from the corresponding muscular fibers of the palsied side. The patient cannot laugh, or weep, or frown, or express any feeling or emotion with one side of his face, wale the features of the other may be iu full play, nor can he spit or whistle properly. One-half of the aspect, with its unwinking eye, its fixed and solemn stare, might be that of a dead person; the other half is alive and merry. To those who do not comprehend the possible extent of the misfortune, the whimsical appearauee of the patient is a matter of mirth and laughter; while, on the other hand, his friends imagine that he has had a stroke, and that he is in a very dangerous state. The nerve may be unable to discharge its duties in consequence of disease within the cavity of the skull, and in that case there is very serious danger; but iu the great majority of cases the nervous function is interrupted in that part of the portio aura which lies encased in the temporal bone, or in the mac exposed part which issues in front of the car; and hence this form of palsy is generally unattended with any danger to life. It may arise from various causes. Sometimes it is the consequence of mechani
cal violence, sometimes of tumors pressing on it in the region of the parotid gland, and it very frequently arises from the mere exposure of the side of the some time to a stream of cold air.
It yet remains to notice certain kinds of paralysis which differ either in their char acters, or in their causes, from those which have been already described—viz.. shaking palsy, or paralysis ayitans; and the palsies induced by various poisons. Shac'ng palsy has been defined as "involuntary tremulous motion, with lessened muscular power in parts not ill action, and even when supported; with a propensity- to bend the trunk forwards, and to pass from a walking to a running pace; the senses and intellect being uninjured." It is chiefly an affection of old age, and often goes uo further than to cause an unceasing nodding and wagging of the head in all directions. Somewhat analogous to this form of palsy is that peculiar kind of trembling which is often tiotWd in persons who are much exposed to the vapor of mercury; 1/tenurial tremor, as it is termed by the physicians, and the treadles, as the patient usually calls it. It consists in a con vulsive agitation of the voluntary muscles, especially when an attempt is made to cause them to act under the influence of the will; a patient with this affection walks with uncertain steps, his limbs trembling and dauciug as if they had been hung upon wires. AVhen sitting down he exhibits little or no indication of his disease, but he cannot hold his legs steady, nor direct them with precision; and in severe eases lie falls to the ground if not supported. The arms are similarly agitated. and the tongue is usually so tremulous as to render the articulation hurried and unnatural. The disease is especially common in artisans employed in the gilding of metals, and particularly of silver, by means of heat; it is also frequent among the workers of quicksilver mines, in which the crude metal is purified by heat. The time required for the production of the disease varies extremely in different cases (according to Dr. Watson, from two years to five-and-twenty). The duration of the complaint is considerable; it may last. two or three months, or longer, but it is seldom fatal.
The palsy arising from the absorption of lead has been already noticed in the article