PARALYSIS AGITANS.
BY WHARTON SINKLER, M.D.
SYNONYMS.—Parkinson's disease; Shaking palsy; Trembling palsy; Senile chorea; Chorea festinans. The first name is due to the fact that the disease was first fully described by Parkinson in a book published in England in 1817.
Paralysis agitans is a neurosis, chronic in its forms and characterized by a tremor which gradually increases in extent and severity. The tremor is not increased by voluntary muscular movements. A peculiar manner of walking, known as festination, comes on later in the disease, and there are also alterations in the attitude of the head and trunk.
It is a disease which belongs to middle age, being rarely seen before forty years, although cases are quoted by Charcot as early as twelve and sixteen years. Constant and prolonged exposure to dampness and cold seems to bring on the disease, and it is sometimes caused by sudden emotion, like fear or distress. The following case is an instance of the latter:
Case I.—Mr. A. M——, æt. fifty-two years, consulted me Oct. 1, 1883. He is a bookbinder by occupation. His habits have been good. He had a chancre in 1861, but had no secondary troubles. He was in the army from 1861 until 1866. In 1866 he went into business for himself, and, although his business was large, he had no great anxiety or worry. His general health has been good, and he has had no illness except an attack of malarial fever about six years ago. In May, 1883, he was standing by an elevator door on the fourth floor of his place of business, and, seeing that the elevator was caught by something, released it. It immediately fell with a crash to the second floor, and as there were two or three persons on it, Mr. M—— thought they must have been killed or severely injured. He was greatly excited and alarmed, and soon after he had assured himself that none of the occupants of the elevator had been hurt, discovered a trembling of the right hand. The tremor has continued ever since, and has extended to the arm and leg.
On examination there is seen a coarse tremor of the right arm and leg while the limbs are at rest. A voluntary muscular movement stops the tremor, and it also ceases during sleep. When he makes an effort with the right hand, as, for instance, in squeezing the dynamometer, the tremor ceases in the arm, but becomes greatly exaggerated in the right leg. While occupied in doing anything he does not notice the tremor, and it stops when he is lying down.
The dynamometer shows, right hand 150°, left hand 120°. After two years have elapsed the disease has gradually progressed in severity.
SYMPTOMS.—The course of the disease has been divided into three stages—the period of invasion, the stationary period, and the terminal period.1
1 Lectures on Diseases of the Nervous System, by J. M. Charcot.
Period of Invasion.—There are several modes of invasion, but the most frequent by far is slow in its onset. The disease comes on gradually, first showing itself as a slight tremor in the hand or fingers while the part is at rest. It is not constant, and ceases as soon as the patient's attention is called to it. There is sometimes preceding the tremor rheumatic or muscular pain in the affected arm. The tremor may first occur in the foot. Should the disease begin in the hand—and this is most common—the movements are peculiar. They may consist of a fine rhythmical tremor, or the fingers move in a methodical way over each other. Charcot speaks of the thumb and forefinger being rubbed together as if the patient were spinning wool. While this movement of the thumb and finger is going on the wrist is being flexed by jerks. During the early stages of the disease the tremor is observed only at intervals. It comes on intermittently when the patient is not thinking of it and while the limb is at rest, and ceases as soon as any voluntary muscular effort is attempted. The act of grasping the hand or taking up an object is enough to check it for the time. In a patient now under my care I have often noticed during the early stages a well-marked tremor of the right hand while it was lying in her lap, but it would at once cease when I called attention to it. As soon as the mind of the patient was diverted to some other subject the tremor would begin again.
As the disease progresses voluntary effort no longer controls the tremor, or if it does at all it is only for a few seconds, when it begins again. As the tremor increases in violence it extends to other parts of the body. At first it may have been confined to the hand; now it extends to the arm, a little later to the foot and leg on the same side. Then the other arm will be affected, and finally all of the limbs will succumb to the tremor.
Charcot speaks of decussated invasion—that is, the disease begins in the right upper extremity, for example, and next passes to the left lower extremity. This is a rare form; it is much more frequent to see the hemiplegic type, which may persist for some time, or the paraplegic type, when both legs are affected.
There is a progressive form of invasion when the tremor is not the first symptom. The patient has neuralgic or rheumatic pains in the limbs, which are afterward affected with tremor. Sometimes there is some mechanical injury of the limb, which subsequently is the seat of pain and tremor. The general health of the patient is at the same time more or less impaired. There is a sense of general weakness and lassitude; the temper is irritable, and there may be some vertigo. The features and countenance are characteristic even at the earliest periods of the disease. There is an absolute absence of expression, and the features are fixed. The face looks like a mask, and although the patient may smile or laugh, immediately after the features return to the original blank expression. Amidon showed two cases of paralysis agitans to the American Neurological Society in 1883, in which there was no tremor whatever, but all the other features of the disease were present.
After a great mental or moral shock the trembling begins suddenly, abrupt invasion, as in Case I., or the case described by Charcot, where the wife of a gendarme, seeing her husband's horse return riderless to the barracks, received a shock of great severity, which was followed on the same day by tremor. The tremor is at first confined to one limb. It may even disappear for a time, but gradually and slowly extends to the other limbs, and takes the same progressive course.
Period of Stationary Intensity.—After the disease has become fully developed the tremor is incessant. The intensity is not the same all the time. It may be augmented by cold, over-excitement, or voluntary effort, and is lessened by repose and sleep. The trembling ceases during anæsthesia.
During this time all the characteristic movements are at their height. The moving of the thumb and finger, already referred to, is present, and seems like a partly co-ordinated movement. Charcot describes these movements as being in some cases like the rolling of a pencil or a paper ball between the thumb and finger, and in others the movements, he says, are more complicated, and are like what occur in crumbling a piece of bread.
The handwriting is almost illegible, and every letter shows the excessive trembling of the hand, most marked in the up strokes of the pen. All this time the head and neck are unaffected. There is no nodding or shaking of the head to be observed on the closest inspection. This is an important fact to bear in mind, for it is a distinguishing feature between the disease under consideration and disseminated sclerosis. There is no nystagmus, and the muscles of the jaw are unaffected by tremor. The tongue, however, while lying on the floor of the mouth undergoes tremor, and this is increased when the organ is protruded.
The speech is slow and jerky, and the patient usually speaks in a low tone of voice. He eats his food without difficulty, but in advanced cases the saliva sometimes escapes from the mouth during deglutition. A characteristic symptom of the disease is a rigidity of the muscles of the extremities, trunk, and of the neck. When the muscular stiffness first begins the patient complains of cramps followed by a sense of rigidity. The flexor muscles are first affected. This stiffness causes peculiarities in the patient's attitudes. The head and neck are usually bent forward, and seem fixed in that position. The body is inclined slightly forward in standing. The elbows are held somewhat away from the chest, the forearms are flexed on the arms, and the hands are flexed on the forearms. The thumb and forefinger are extended and brought together as if holding a pencil. The other fingers are also flexed. The attitude of the hand and the prominence of the knuckles make it closely resemble the hand of rheumatoid arthritis. In paralysis agitans, however, there are no bony deposits in the joints, and no cracking is heard on bending the knuckles.
In the lower extremities there is often intense rigidity. Contractions occur, and the legs are strongly flexed. The feet often are extended in the position of equinus. It is this rigidity which causes the difficulty in walking (Charcot).
The gait of the patient now becomes very striking. He gets up from his seat slowly and with difficulty; hesitates a moment before starting to walk; then, once having made a few steps, goes at a rapid pace. The tendency is to fall forward; in order to preserve his equilibrium the patient hurries forward as if to catch up with his centre of gravity. This gait has been called paralysis festinans—festination or propulsion.
Although propulsion is the usual form the gait assumes, sometimes there is a tendency to fall or run backward. This tendency is not always apparent even when it exists. Charcot has a method of showing its existence which is very successful: when a patient is standing he pulls her slightly backward by the skirt, and this is sufficient to start a movement of retropulsion.
Propulsion and retropulsion are not necessarily always present. Many cases progress to the end without these symptoms.
As the disease advances the muscles become more rigid and the patient is confined to bed. He is, however, restless from a sense of prostration and fatigue. He is unable to turn himself, and often calls to his attendant to change his position. The sufferers from this disease, although not having actual pain, complain of disagreeable sensations. There is a constant sense of excessive heat whether the temperature of the room be high or low. In winter they cannot bear much bed-clothes at night, and prefer to wear very light clothing. Associated with this sensation of heat is often profuse perspiration (Charcot). Notwithstanding all these troublesome sensations the sensibility of the skin is not changed. Heat and cold are readily felt, and there is no anæsthesia or analgesia.
Terminal Period.—The duration of paralysis agitans is generally great. The disease may extend over many years—even as long as thirty years in some cases. As the tremors and rigidity increase in intensity the patient becomes obliged to sit all day in a chair or is confined to bed. Occasionally the tremor becomes less while the rigidity increases. The nutrition suffers, and the muscles especially become greatly wasted. Up to a certain point the intellect remains unaffected, but late in the disease the mind fails. General prostration of the whole system sets in, bed-sores occur, the urine and feces are passed unconsciously, and the patient dies of exhaustion. It is not often that the end comes in this way. It is much more frequent that some intercurrent disease, like pneumonia, ends the life of the patient. The disease is undoubtedly a most painful and trying one to both patient and physician. It lasts for years, and there is no prospect of relief. Charcot says that he has seen the terminal period last for three or four years. The following case is a fair example of the disease:
Case II.—Margaret Hays, aged fifty-four, single, applied for treatment at the Infirmary for Nervous Diseases, Oct. 9, 1882. She is housekeeper for her brother, who keeps a restaurant. She has had to be up late at night, and has had very much washing to do for many years. The kitchen in which she is most of the time is damp, and opens into a yard into which she has often to go. About two years ago she thought that she hurt herself in lifting something, and soon after this, on putting her hands from hot into cold water, suddenly felt a numbness in both forearms. One year ago she noticed tremor in both hands and both legs. The tremor interfered with her work, and has increased. She also felt as if there were loss of power.
Present Condition.—The face is expressionless and looks as if it were a mask. She articulates without using her lips to any extent, and speaks in a low tone, scanning the syllables. The head is held stiffly, and the attitude of the whole body is peculiar.
The tremor is fine, and is constant while the hands are at rest. On voluntary effort the tremor ceases. On examination with the dynamometer, right hand 95°, left hand 80°. She feels weak generally, and says she cannot use her hands even to button her clothes or to dress or undress without aid. She performs all movements slowly and with great deliberation. The patellar reflex is not excessive.
Sensation.—She has lost the sense of numbness she used to have, but says she cannot feel a needle between the fingers when she attempts to sew. There is loss of sensation in the finger-ends; the compass points are not felt at less than three lines.
Her walk is slow and deliberate like all her movements, and there is no festination. Her eyes were examined, and there was no decided change in the fundus and vision was about normal. Pupillary reflexes good.
This patient was under observation for several months, and steadily grew worse. One peculiar feature was observed, however: it was that at one time the tremor almost ceased, although all of the other symptoms were worse.
ETIOLOGY.—As already mentioned, the causes which have been observed are fright or sudden grief and prolonged exposure to cold and dampness. A number of cases of the former are mentioned by Charcot, and a case which I have related above is a good illustration of paralysis agitans produced by fright. When caused in this way the disease does not present any peculiar features in its progress or termination. I have seen many cases in which the disease had been preceded by more or less exposure to dampness. One of my patients had worked in a basement room which was damp; another (Case II.) was a great deal of the time in a kitchen which opened on a wet yard, and she was constantly going in and out of doors, getting her feet wet frequently. Sometimes irritation of a peripheral nerve seems to have been the origin of the trouble. Charcot quotes several cases of this kind.
Sex does not appear to exert any special influence in the production of the disease. Some writers assert that it is more common in males than in females, but Charcot in his large experience at La Salpêtrière has not found this to be the case.
MORBID ANATOMY.—A number of autopsies have been made in cases of paralysis agitans without any constant lesion of the nervous system having been discovered. Charcot refers to three cases in which he made careful post-mortem examinations in which the results were negative. Parkinson and Oppolzer each report one case in which was found induration of the pons, medulla, and cervical portion of the cord. More recently, however, Charcot and Joffroy have examined cases in which microscopic examination revealed blocking up of the central canal of the cord by increase of the epithelium of the ependyma and pigmentations of the ganglion-cells.
Leyden has reported a case in which the disease was confined to the right arm, and on post-mortem examination a tumor of the left optic thalamus was found.2
2 Quoted by Hamilton, Diseases of the Nervous System, p. 500.
Dowse and Kesteven found degeneration of the nerve-cells of the anterior pyramids, changes in the olivary body, nucleus of the ninth nerve, laminæ and corpus dentatum of the cerebellum and of the anterior cornua of the spinal cord. Also cortical sclerosis of the right lateral column of the cord and miliary changes in the white matter of the corpus striatum and hemispheres.3
3 Ross, Diseases of the Nervous System, vol. ii. p. 797.
In this disease, as in chorea, there must be two classes of cases—those in which there is no lesion to be discovered after death, and others in which there are changes throughout the brain and spinal cord more or less widespread. The cases in which the disease comes on suddenly from some moral shock probably belong to the former class; while in cases which have come on gradually during senility one would expect to find organic changes in the nervous system. Ross4 suggests that the cause of the tremor is probably a diminution in the conductivity of the fibres of the pyramidal tract, which prevents impulses from the cortex reaching the muscles in sufficiently close proximity to produce a continuous contraction. This, however, does not explain the cause of the tremor in the cases where it began suddenly from fright.
4 Op. cit., p. 798.
DIAGNOSIS.—The only diseases with which paralysis agitans may be confounded are disseminated sclerosis, senile tremor, and chorea in the aged. From senile tremor it may be distinguished from the fact that it begins before old age—that the tremor is more excessive and the gait and facial expression are distinctive. Chorea in old persons resembles paralysis agitans, but is not progressive, the tremor is not lessened as a rule by voluntary effort, and the peculiar gait and expression of the face are wanting.
There are many points of difference between paralysis agitans and disseminated sclerosis, as can be seen below:
| PARALYSIS AGITANS. | DISSEMINATED SCLEROSIS. |
| Tremor ceases on voluntary effort, or is not increased by it. | Tremor induced by muscular effort, and ceases during repose. |
| Tremor regular and fine. | Coarse tremor, becoming more so during voluntary effort. |
| Face expressionless; tremor of face rare. | Facial muscles affected; nystagmus frequent. |
| No tremor of head. | Tremor of head generally present. |
| Belongs to advanced age. | Usually comes on before middle age. |
| Propulsion (festination) and retrogression. | Staggering walk. |
TREATMENT.—The results of treatment are not encouraging. Cases have been reported in which cures were effected, but it is doubtful if they were true instances of paralysis agitans. Hyoscyamus and conium have been given with temporary relief to the tremor. Trousseau recommends strychnia, but Charcot declares that it aggravated the cases in which he gave it. Hammond advises the use of galvanism, at the same time giving strychnia or phosphorus. I have seen one case in which decided relief was obtained from arsenic hypodermically, and another in which the patient was benefited for a long time while taking small doses of strychnia combined with iron and quinine, and at the same time static electricity was applied.