PARALYSIS, or PALSY, the loss of the power of muscular action due to some interruption to the nervous mechanism by means of which such action is excited (see " Nervous System " in PHYSIOLOGY). In its strict sense the term might include the loss of the influence of the nervous system or any of the bodily functions, the loss of common sensation or of any of the special senses; but other terms have come to be associated with these latter conditions, and the word " paralysis" in medical nomenclature is usually restricted to the loss or impairment of voluntary muscular power. Paralysis is to be regarded rather as a symptom than a disease pier se, and is generally connected with some well-marked lesion of some portion of the nervous system. According to the locality and extent of the nervous system affected, so will be the form and character of the paralysis. It is usual to regard paralysis as depending on disease either of the brain, of the spinal cord, or of the nerves distributed to parts and organs ; and hence the terms cerebral, spinal, and peripheral paralysis respectively. The distribution of the paralytic condition may be very extensive, tending to involve in greater or less measure all the functions of the body, as in the general paralysis of the insane (see INSANITY) ; or again, one half of the body may be affected, or one or more extremities, or it may be only a certain group of muscles in a part sup-plied by a particular nerve. Reference can be made here only to the more common varieties of paralysis, and that merely in general terms.

1. Paralysis due to Brain Disease.—Of this by far the most common form is palsy affecting one side of the body, or Hemiplegia. It usually arises from disease of the hemi-sphere of the brain opposite to the side of the body affected, such disease being in the form of hemorrhage into the brain substance, or the occlusion of blood-vessels, and consequent arrest of the blood supply to an area of the brain; or again it may be due to the effect of an injury, or to a tumour or mor-bid growth in the tissues of the brain. The character of the seizure and the amount of paralysis vary according to the situation of the disease or injury, its extent, and its sudden or gradual occurrence. The attack may come on as a fit of apoplexy, in which the patient becomes suddenly unconscious, and loses completely the power of motion of one side of the body; or a like result may arise more gradually and without loss of consciousness. In either case of " complete " hemiplegia the paralysis affects more or less the muscles of the tongue, face, trunk, and extremities. Speech is thick and indistinct, and the tongue, when protruded, points towards the paralysed side owing to the unopposed action of its muscles on the unaffected side. The muscles of the face implicated are chiefly those of mastication. The paralysed side hangs loose, and the corner of the mouth is depressed, but the muscles closing the eye are as a rule unimpaired, so that the eye can be shut, unlike what occurs in another form of facial paralysis (Bell's palsy). The muscles of respiration on the affected side, although weakened, are seldom wholly paralysed, but those of the arm and leg are completely powerless. Sensation may at the first be impaired, but as a rule returns soon, unless the portion of the brain affected be that which is connected with this function. Rigidity of the paralysed members is occasionally present as an early or a late symptom. In many cases of even complete hemiplegia improvement takes place after the lapse of weeks or months, and is in general first indicated by a return of motor power in the leg, that of the arm following at a longer or shorter interval. Such recovery of move-ment is, however, in a large proportion of cases only partial, and the side remains weakened. In such instances the gait of the patient is characteristic. In walking he leans to the sound side and swings round the affected limb from the hip, the foot scraping the ground as it is raised and advanced. Besides this the evidence of the " shock " is felt more or less upon the system generally, the patient rarely (though occasionally) recovering his nervous stability. The paralysed parts retain as a rule their electric con-tractility, but they are apt to suffer in their nutrition both from disuse and also from certain degenerative changes which the interruption of nervous influence is apt to exer-cise upon them.

It is to be observed that in many instances the hemi-plegia is only partial, and instead of the symptoms of complete paralysis above described there exist in varied combination only certain of them, their association depend-ing on the extent and locality of the lesion in the brain. Thus there may be impairment of speech and some amount of facial paralysis, while the arm and leg may be unaffected, or the paralysis may be present in one or both extremities of one side while the other symptoms are absent. Further, the paralysis may be incomplete throughout, and the whole of the side be weak, but not entirely deprived of motor power. To partial paralysis of this latter description the term " paresis " is applied.

Besides hemiplegia, various other forms of paralysis may arise from cerebral disease. Thus occasionally the paralysis is crossed, one side of the face and the opposite side of the body being affected simultaneously. Or again, as is frequently observed in the case of tumours of the brain, the paralysis may be limited to the distribution of one of the cranial nerves, and may produce an association of phenomena (such as squinting, drooping of the eyelid, and impairment or loss of vision) which may enable the seat of the disease to be accurately localized.

2. Paralysis due to Disease of the Spinal Cord.—Of paralysis from this cause there are numerous varieties depending on the nature, the site, and the extent of the disease. Some of the more important only can be noticed.





Paraplegia, paralysis of both lower extremities, including usually the lower portion of the trunk, and occasionally also the upper portion—indeed the whole parts below the seat of the disease in the spinal cord—is a form of paralysis which is a not unfrequent result of injuries or disease of the vertebral column; also of inflammation affecting the spinal cord (MYELITIS, q.v.), as well as of haemor-rhage or morbid growths involving its substance. When due to disease, the lesion is generally situated in the lower portion of the cord. The' phenomena necessarily vary in relation to the locality and the extent of the disease in the cord. Thus, if in the affected area the posterior part of the cord, including the posterior nerve roots, suffer, the function of sensation in the parts below is impaired because the cord is unable to transmit the sensory impressions from the surface of the body to the brain. If on the other hand the anterior portion of the cord and anterior nerves be affected, the motor impulses from the brain cannot be conveyed to the muscles below the seat of the injury or disease, and consequently their power of movement is abolished. In many forms of this complaint, particularly in the case of injuries, the whole thickness of the cord is involved, and both sensory and motor functions are arrested. Further, the functions of the bladder and bowels are apt to suffer, and either spasm or paralysis of these organs is the result. The nutrition of the paralysed parts tends to become affected, and bed-sores and wasting of the muscles are common. Occa-sionally, more especially in cases of injury, recovery takes place, but in general this is incomplete, the power of walking being more or less impaired. On the other hand the patient may linger on for years bedridden, and at last succumb to exhaustion or to some intercurrent disease.

A form of spinal paralysis, often showing itself as paraplegia, occasionally occurs in children, and is termed—

Infantile or Essential Paralysis.—It is caused by an inflammatory affection limited to the anterior portion of the grey matter of the spinal cord throughout a greater or less extent, and affects therefore the function of motion, leaving that of sensation unimpaired. This disease is most common during the period of first dentition (although a similar affection is sometimes observed in adults). The commencement may be insidious, or there may be an acute febrile attack lasting for several days. In either case paralysis comes on, at first very extensive, involving both upper and lower extremities, but tending soon to become more limited and confined to one or other limb or even to a group of muscles. The affected muscles lose their electric contractility and are apt to waste. Hence limbs become shortened, shrivelled, and useless, and deformities such as club foot may thus be readily produced. In many instances fortunately recovery is complete, and the pro-spect of amendment is all the greater if the muscles snow any reaction to electricity. There is throughout an absence of some of the more distressing of the phenomena of paraplegia, such as disturbances of the bladder and bowels or extensive bed-sores, and in general the health of the child does not materially suffer.

Progressive Muscular Atrophy or Wasting Palsy is a disease usually occurring in early or middle life. It is characterized by the wasting of certain muscles or groups of muscles accompanied with a corresponding weakness or paralysis of the affected parts, and is believed to depend on a slow inflammatory change in the anterior cornua of the grey matter of the spinal cord. It is insidious in its onset, and usually first shows itself in the prominent muscular masses in the palm of the hand, especially the ball of the thumb, which becomes wasted and deficient in power. The other palmar muscles suffer in like manner, and as the disease advances the muscles of the arm, shoulders, and trunk become implicated if they have not themselves been the first to be attacked. The malady tends to spread symmetrically, involving the corresponding parts of the opposite side of the body in succession. It is slow in its progress, but, notwithstanding it may occasion-ally undergo arrest, it tends to advance and involve more and more of the muscles of the body until the sufferer is reduced to a condition of extreme helplessness. Should some other ailment not be the cause of death, the fatal result may be due to the disease extending so as to involve the muscles of respiration.

Another form of paralysis in certain respects resembling the last, and supposed by some to be due to a similar cause, is Pseudo-hypertrophic Paralysis, a condition occur, ring most frequently in male children, in whom in such cases there exists at first a remarkable enlargement of certain muscles or groups of muscles, followed sooner or later by wasting and paralysis. The enlarged muscles are chiefly those of the calf and hips, and their abnormal size is caused by an over-development of their connective tissue, and is therefore not a true hypertrophy. The child acquires a peculiar attitude and gait. He stands with his legs widely separated, his body arched forward, and in walking assumes a rocking or waddling movement. Later on the enlarged muscles lose their bulk, and at the same time become weakened in power, so that walking becomes impossible, and the child is completely paralysed in the limbs and all other affected parts. In most instances death takes place from some intercurrent disease before maturity.

Paralysis Agitans or Trembling Palsy is a peculiar form of paralysis characterized chiefly by trembling movements in certain parts, tending to become more widely diffused throughout the body. It is a disease of advanced life. The symptoms come on somewhat insidiously, and first show themselves chiefly by involuntary tremblings of the muscles of the fingers, hand, arm, or leg, which are aggra-vated on making efforts or under excitement. These trembling movements become more marked and more extensive with the advance of the disease, and along with the tremors there generally occurs increasing weakness of the affected muscles. This is very manifest in walking, the act being performed in a peculiar tottering manner with the body bent forward. The trembling movements cease during sleep. This disease is a chronic one, and is intractable to treatment, but life may be prolonged for many years.





Glosso-labio-laryngeal Paralysis is a form of paralysis affecting, as its name indicates, the functions of the tongue, lips, and larynx (besides others), and depending upon disease of certain localities in the medulla oblongata from which the nerves presiding over these functions arise. The symptoms come on slowly, and are generally first manifested in some difficulty of speech owing to impaired movements of the tongue. Associated with this there is more or less difficulty in swallowing, owing to paralysis of the muscles of the pharynx and soft palate, by which also the voice is rendered nasal. With the advance of the disease the paralysis of the tongue becomes more marked. It cannot be protruded, and frequently undergoes atrophy. Certain of the facial muscles become implicated, especi-ally those in the neighbourhood of the mouth. The features become expressionless, the lips cannot be moved in speaking, the mouth remains open, and the saliva flows abundantly. The muscles of the larynx may also be involved in the paralysis. In the later stages of the malady the power of speech is completely lost, the difficulty in swallowing increases to a degree that threatens suffoca-tion, the patient's condition altogether is one of great misery, which is in no way mitigated by the fact of his mental power remaining unaffected. Complications con-nected with the respiratory or circulatory functions, or disease affecting other parts of the nervous system with which this complaint may be associated, often terminate the patient's sufferings, and in any case life is seldom pro-longed beyond two or three years.

3. Peripheral Paralysis, or local paralysis of individual nerves, is of not unfrequent occurrence, The most com-mon and important examples of this condition can only be briefly referred to.

Facial Paralysis, Bell's Palsy, are the terms applied to paralysis involving the muscles of expression supplied by the seventh nerve. It is unilateral, and generally _occurs as the result of exposure of one side of the head to a draught of cold air which sets up inflammation of the nerve as it passes through the aqueductus Fallopii, but it may also be due to injury or disease either affecting the nerve near the surface or deeper in the bony canals through which it passes, or in the brain itself involving the nerve at its origin. Here the paralysis is manifested by a marked change in the expression of the face, the patient being unable to move the muscles of one side in such acts as laughing, whistling, &c, or to close the eye on that side. The mouth is drawn to the sound side, while, although the muscles of mastication are not involved, the food in eating tends to lodge between the jaw and cheek on the palsied side. Occasionally the sense of taste is impaired. In the ordinary cases of this disease, such as those due to exposure, recovery usually takes place in from two to six weeks, the improvement being first shown in the power of closing the eye, which is soon followed by the disappearance of the other morbid phenomena. When the paralysis proceeds from disease of the temporal bone, or from tumours or growths in the brain, it is more apt to be permanent, and is in many cases of serious import. Throughout there is no diminution of sensibility in the paralysed muscles; but they early lose their reaction to faradization, retaining that to galvanism.

Lead Palsy is a not uncommon form of local paralysis. It is due to the poisonous action of lead upon the system, and, like the other phenomena of lead poisoning, affects chiefly workers in that metal (see LEAD). The pathology of this disease is still unsettled, but it is believed to depend upon the local effect of the lead upon the nerves of the part rather than to any disease, at least in the first instance, of the nerve centres. The paralysis in this case is as a rule confined to the muscles of the forearm which extend the hand, and as they lose entirely their power the hand cannot be raised when the arm is held out, which gives rise to the condition termed " wrist drop." The paralysis may come to affect other muscles of the arms as well as certain of those of the legs and trunk, and along with the paralysis there occurs wasting of the affected muscles and loss of their electrical reactions. Occasionally in severe cases other nervous phenomena, such as convul-sions, delirium, &c, may become superadded. The symp-toms usually disapjjear on the removal of the patient from the source of lead contamination, along with the applica-tion of the treatment appropriate to poisoning with this metal,-—and all the more speedily if the case has not been of long duration and the affected muscles have not under-gone atrophic change.

A form of peripheral paralysis not unlike the last occasionally results from chronic alcoholism. The paralysis occurring after diphtheria, another example of the peri-pheral variety, has been already referred to (see DIPHTHERIA).

Treatment.—It is impossible in a general notice like the present to refer at any length to the treatment of paralysis. The conditions of the disease in any particular case and its associations are so manifold that they can only be fully understood and appreciated by the medical expert under whose direction alone treatment can be advantageously carried out. It may be stated generally, however, that, since paralysed muscles tend to undergo certain degenera-tive changes (see PATHOLOGY), it becomes an object in treatment to endeavour to maintain as long as possible their molecular integrity. With this view, when pain and other acute symptoms which may be present have ceased, the use of nervine tonics such as iron, quinine, and strych-nine, and the suitable dieting of the patient, are the best constitutional remedies; while of local applications fric-tions or massage, but more particularly the employment of electricity, will be found of service, the latter agent often yielding markedly beneficial results. (J. O. A.)


Footnotes

From _______, to relax. Wiekliffe has palesy, and another old form of the word is parlesy



The above article was written by: J. O. Affleck, M.D.