FIG. 29.
Spasm of flexors
Occasionally one finger will become rigidly extended during telegraphing, and any attempt to prevent this will bring on great discomfort and greater disability. When, more rarely, it is the flexors which are affected, the key is depressed with undue force at the wrong time, and a dash is made where a dot was intended, or an extra dot or so introduced, or the proper spacing of the characters prevented, thus rendering the message unintelligible.
The telegraph operators who experience the most difficulty in transmitting usually have a cramp of the extensors, and those having the most difficulty in receiving (writing) usually have a cramp of the flexors, although the reverse is occasionally seen.
In some cases of the spastic form of copodyscinesia the contraction almost becomes tetany; thus there may be a contraction of the flexors of the wrist, which comes on whenever any attempt is made to use the hand, although the fingers may be entirely unaffected, or there may be a more or less constant contraction, greatly exaggerated on any attempt at motion.
Lock-spasm, as described by Mitchell,35is a rare form of this affection: in this the fingers or hand become locked, so to speak, in a strong contraction, even stronger than the patient could ordinarily produce by an effort of will; this lasts for a considerable time, and after its disappearance the customary work may be resumed. Duchenne36likewise reports some curious cases of functional spasm analogous to the foregoing.
35Loc. cit.
36Duchenne (de Boulogne), “Note sur le Spasm functionnel, etc.,”Bull. de Thérap., 1860, pp. 146-150.
II. Paresis or Paralysis (Paretic Form).—More or less weakness of some of the muscles of the hand or arm is frequently seen in cases of copodyscinesia; this is, however, less common than the spastic form, and, like the latter, is preceded or accompanied by other symptoms. This form occasionally follows the spastic, or it is seen in those cases where the cause of the trouble has been a preceding neuritis, or it may be due to professional muscular atrophy as described by Onimus,37where, contrary to the ordinary rule, excessive use of a muscle or set of muscles produces, instead of hypertrophy, a condition of considerable atrophy, usually of the larger muscles first, which is preceded for some time by pain and cramp in the affected parts, with fibrillary twitchings; this is amendable rather rapidly under appropriate treatment, and thus differs from progressive muscular atrophy, with which it is apt to be confounded.
37E. Onimus, “On Professional Muscular Atrophy,”Lond. Lancet, Jan. 22, 1876.
Some of the cases of this group may be confounded with those of the former, as there may be an apparent cramp or spasm of the unopposed healthy muscles. Zuradelli38considers this condition to be the one ordinarily found in this disease.
38Crisanto Zuradelli,Gaz. Med. Ital. Lomb., Nos. 36-42, 1857; alsoAnn. Universali, 1864.
A paretic condition of one muscle may coincide with a spastic condition of another not its opponent, the paralyzed muscle being the one first affected.
When a patient with paresis or paralysis as the most prominent symptom attempts to write, an intense feeling of fatigue usually appears, and the writing becomes difficult or impossible—not from a too ready response and spasm, but from an inability of the muscles to obey the will; the pen-holder is held in a feeble manner, and sometimes falls from the grasp. There may be a sense of utter weakness and powerlessness, the arm feeling as if glued to the table.
Duchenne39calls attention to this form of trouble, which he styles paralysie functionelle, and states that it is much less common than functional spasm.
39Loc. cit.
New methods of holding the pen are as constant in this form as in the spastic, as it is as necessary in one as in the other to avoid as much as possible the use of the affected muscles. A carpet-weaver, seen by myself, was obliged to tie the knots in the warp on the distal extremity of the second phalanx of the thumb, as the extensor secundi internodii pollicis was partially paralyzed, so that he was unable to keep the distal phalanx extended. This condition came on when he was a compositor, and compelled him to change his trade. A condition of spasm had preceded the paralysis.
The first dorsal interosseus muscle is frequently the seat of paresis; this is readily discovered by measuring the power which the patient has of lateral movement of the index finger and comparing it with that of the sound hand.
III. Tremor (Tremulous Form).—Trembling or unsteadiness of the fingers is occasionally seen, usually most marked in the fore finger when the hand is at rest with the fingers slightly separated. In some cases this may be sufficient to cause unsteadiness in work, prolonged work and over-fatigue being most apt to produce it; as previously mentioned, this is one of the premonitory symptoms of professional muscular atrophy.An oscillatory trembling, due to implication of the supinators and pronator, is described by Cazenave,40which interfered greatly with the act of writing. Tremor is of itself rarely complained of by those affected with copodyscinesia, unless it becomes sufficiently marked to cause interference with work.
40“Observations de Tremblements oscillatoires de la Main Droite,”Gaz. méd. de Paris, 1872, pp. 212-215.
A peculiar form of nystagmus occasionally seen in miners may be considered as belonging to this category. According to Nieden of Bochum41it is caused by eye-strain in the defective illumination of the mines, and consists not of a spasm, but of a defective innervation, like the tremor of old persons. C. B. Taylor42of Nottingham and Simeon Snell43also speak of this as a fatigue disease.
41“The Pathogenesis and Etiology of Nystagmus of Miners,”Am. Journ. Med. Sci., Oct., 1881.
42Quoted by Poore,loc. cit.
43“Miners' Nystagmus,”Brit. Med. Journ., vol. ii., 1884, p. 121.
IV. Pain, or Some Modification of Normal Sensation.—Every case of copodyscinesia, without exception, has at one period or another of the disease some modification of normal sensation in the hand or arm. Usually the very first symptom that attracts the patient's attention is a sense of fatigue or tire in the hand or arm, which at first appears only after a considerable amount of work; if rest is taken now, the part regains its normal condition, but if the work is continued the sensation increases, and the amount of labor necessary to cause the disability gradually grows less and less until any attempt suffices to produce it. A painful sensation or a sense of heat may be experienced in the shoulders or in the cervical or upper dorsal spine at the time the foregoing symptoms are felt.
These symptoms are due to chronic fatigue in many instances, this being an important factor in the causation of these troubles. An expression frequently used by those affected is that the hand or arm becomes lame; this sense of tire may be slight or may be of an intense aching character, almost unendurable.
Should spasm supervene, then there will be a sense of tension and pain in the rigid bellies of the muscles. When a subacute neuritis is present, as frequently occurs, all the symptoms common to that condition appear—viz. pain over the various nerve-trunks and at the points of emergence of their branches, either spontaneous or only solicited on pressure; areas of hyperæsthesia or anæsthesia; a sense of itching or tingling or pricking in the arm or hand; or a sense of numbness, causing the part to fall asleep.
As previously mentioned under Etiology, pain may be absent in some cases of subacute neuritis. Occasionally, the distal phalanx of the fore finger or thumb becomes exquisitely sensitive to pressure, and there may be a burning or stinging pain under the nail, severe enough to make the patient think local suppuration is about to take place.
Sensory disturbances in the region of the hand supplied by the radial nerve are quite common, less so in the region supplied by the median, and least of all in the ulnar distribution. This last having never been seen by Poore, although, as pointed out by him, the muscles supplied by the nerve are those most frequently implicated in this disease when it affects scriveners, his explanation is that the deep motor branches arewidely separated from the sensory branches of the nerve, while this is not true of the radial.
One case of impaired sensation affecting the ulnar distribution, and consisting of slight numbness of the palmar surfaces of the ring and little fingers, has come under my observation. The patient was a young woman affected with pianists' cramp, having as its foundation a subacute neuritis of the musculo-spiral and ulnar nerves; the trouble had lasted five years.
A curious form of pain, as of a bar thrust diagonally through the hand, has been complained of; again, the arm, hand, or fingers may be the seat of a subjective sensation of weight, so that one arm will feel very much heavier than its fellow, or the hand may feel as heavy as lead. A soreness and sense of tightness, as of a band around the wrist, a throbbing and pulsation, or a tense feeling as if the skin would burst when the hand was closed, have been noticed occasionally.
V. Vaso-motor and Trophic Disturbances.—Among the rarer symptoms seen are vaso-motor and nutritional changes; these never occur alone, but are accompanied by cramp and fatigue or by some evidence of nerve-lesion.
When a patient with this symptom attempts to perform the task which produces the disability, in addition to the fatigue, spasm, or pain the veins on the back of the hand and fingers will be seen to slowly enlarge; this may gradually increase until it extends over the whole arm, the parts becoming more or less turgid with blood, the temperature at the same time being somewhat increased. A marked sensation of throbbing accompanies these symptoms.
Other parts more distant may become affected, the face becoming flushed, palpitation of the heart and profuse perspiration, either local or more or less general, ensuing, followed by exhaustion.
When there is a marked hyperæsthesia of the distal phalanges of the fingers, there may be a glossy appearance of the skin, or the parts may appear inflamed and as if about to suppurate, or there may be chilblains. A rare symptom is change in the character of the nails, which become brittle and crack off like shell, either spontaneously or when an attempt is made to cut them.
GENERALSYMPTOMS.—Besides the various symptoms above enumerated, there may be others more general in character, such as intense headache and great general nervousness, the emotional character being generally well marked, as is shown by the disability being greatly increased when the patient knows some one is watching and criticising. There may be also vertigo and sleeplessness. When there is an associated spasm of the analogous muscles of the other arm and hand, although there is no apparent trouble in the arm which is being used, it shows that the hitherto almost automatic act is losing some of its automatism: this, although rare, is an important premonitory symptom.
A rare symptom, which, as far as my knowledge allows me to say, is confined to telegraph operators, is an inability to mentally grasp the proper number of dots and dashes composing certain Morse characters: this usually coincides with the difficulty experienced in making those characters after they have been thought of, and also makes it difficult for them to recognize them by sound even when properly made by anotherperson. The characters composed entirely of dots seem to cause the most trouble in this way.
Electrical Reactions.—In those cases where spasm of one or more muscles is a more or less marked symptom electrical examination shows, both to the faradic and galvanic current, a quantitative increase in the reaction, both in the nerves and muscles; with the galvanic current the cathodal closing contraction is more marked than the anodal closing contraction, as in health (KaSZ > AnSZ); only this formula is most marked in the affected arm. When paresis is present there will be a quantitative decrease in the reaction, the formula still being KaSZ > AnSZ. In the same arm some muscles may show a quantitative increase and others a quantitative decrease. Where there is a neuritis present the electrical examination will show a quantitative increase, but where the disease has advanced to degeneration of the nerve the reaction of degeneration will be found, and the formula will be AnSZ > KaSZ; there is, therefore, a qualitative change, but this must be looked upon as rather uncommon in this class of diseases.
Poore44is of the opinion that increased irritability shows an early, and decreased irritability a late, stage of the same condition. According to his tables, but very few of his 75 cases of impaired writing-power showed this quantitative increase, while every case showing the least evidence of cramp that has come under my observation has shown it in one or more muscles; in a few cases the antagonistic muscles showed a decrease. Increased sensitiveness to both currents is sometimes noticed.
44“Writers' Cramp and Impaired Writing-power,” by C. V. Poore, M.D.,Medico-Chirurgical Trans., vol. lxi, 1878.
COURSE.—The course of the disability is slow and, unless appropriate treatment is instituted, progressive, although at times there are periods during which the symptoms ameliorate without assignable cause, thus giving rise to false hopes. The usual history is that group after group of muscles becomes implicated as these are in turn used to relieve those first affected, the left arm, should this be used, becoming disabled in the same manner as the right, and the unfortunate sufferer is then compelled to give up his calling or else to lessen very materially the amount of his labor.
DURATION.—As might be inferred from what has been written, those who have suffered for years with this affection may expect it to continue for the remainder of their days; but the later investigations upon this subject give rise to much hope that in future the duration of this troublesome complaint will be materially shortened when the disease is recognized early and treatment instituted at the very first symptom.
DIFFERENTIALDIAGNOSIS.—Although many of the cases of copodyscinesia are diagnosed with comparative ease, there are others which require much study, as there are several disorders which are apt to mislead by the similarity of symptoms.
Any affection of the finger-joints or of the muscles of the hand or arm, or any disease of the nerves or of the spinal cord, from which these nerves arise, or of the corresponding part of the brain, will necessarily interfere more or less with the finer movements of the hand, and yet all these, manifestly, cannot be considered cases of this affection.
Where the symptoms are undoubtedly caused by over-use of a part, by the constant repetition of the same muscular act, although the lesionsmay vary considerably in the different cases, they may be classed with propriety under the above head; but there is a second class which cannot be so considered, in which there has been a central lesion which has arisen entirely independently of the occupation which has become difficult to perform, and which disability is only one of the many symptoms that have arisen on account of the aforesaid lesion: these are the cases that it is important to differentiate from cases of true copodyscinesia.
When a patient is suffering from a difficulty in performing a fine act of co-ordination where previously there had been no trouble, much information as to the cause may be gained by examining critically the method in which that act is attempted to be carried out; thus, if the patient has a difficulty in writing, his method of holding the pen and his style of writing may throw some light upon the diagnosis; if he holds his pen too firmly or if the down strokes are too heavy, or the writing gradually grows smaller and smaller toward the end of the line, there is a spasm of the flexor muscles; if, on the contrary, the down strokes are imperfectly made or the thumb rises upon the holder, or one finger shows a tendency to straighten itself, the extensors are at fault. Each muscle should then be examined. By asking the patient to make the different movements possible with the fingers and hand of the affected side, and comparing them with those of the sound side, a feebleness of one or more muscles may be detected. The offending muscle may also be detected by electrical examination—by its reacting more or less strongly than its fellow on the other side to the faradic current or showing a quantitative change to the galvanic current.
By stripping the patient to the waist, or at least the arms, and making a careful examination, atrophy or local lesions may be detected that will aid in clearing up the diagnosis.
In telegraphers the mode of manipulating the key should be noted if possible, and the faults made in the different Morse characters studied; this will show as much in this form of the trouble as the mode of writing does in scriveners' palsy.
The condition described by Mitchell45as post-paralytic chorea may easily be mistaken for these affections, especially where the cerebral lesion was coincident with much manual work (as writing or telegraphing), and was so slight in extent that the paralysis was transient and overlooked, the choreoid movements appearing later, and affecting, as they may do, only the hand. Of this condition Mitchell states “that it may exist in all degrees, with partial loss of power and with full normal strength—that it may consist in mere awkwardness, or exist to the degree of causing involuntary choreoid movements of the parts.”
45“Post-paralytic Chorea,” by S. Weir Mitchell,Am. Journ. Med. Sci., Oct., 1874.
The diagnosis can, in most cases, be satisfactorily arrived at by careful consideration of the history of the case, the mode of onset, the presence of some other signs of cerebral lesion, and the examination of the heart and of the urine.
Some cases of paresis of the arm or hand from lesions of slight extent affecting the arm-centres in the brain (minute emboli, disease of the finer vessels, etc.) might possibly be mistaken for the paretic form of copodyscinesia. Two cases46will illustrate this point:
Case I.—Mr. G.——, æt. 58, dentist. A great writer, although writing was always a difficult task and soon fatigued him. One day, after excessive writing the day previous, he awoke with a loss of power to write from an inability to properly co-ordinate his muscles; his hand was not unsteady, motion was apparently unimpaired, and his power good, but after laboring for ten or fifteen minutes he would drop the pen. He was treated for writers' paralysis, and gradually improved. One year later he was seized with aphasia and entire loss of power in the right arm and leg. His further history is that of right hemiplegia, and not interesting in this connection.
Case II.—Mr. W——, civil engineer, æt. 54. Until July, 1881, he considered himself a healthy man, although very excitable; he was then engaged in calculating and writing almost steadily for one week, which exhausted him exceedingly; following this, he was engaged in an abstruse calculation lasting another week, and at the end of this period he awoke to find himself powerless to extend or flex his wrist, and, to use his expression, his thumb would gravitate into his palm. The movements of the shoulder and arm were comparatively unimpaired, and with the exception of occasional dimness of vision of the right eye there was no other symptom noticed. In one week he considered himself well again. In July, one year later, after again passing through a period of exceedingly hard work, he awoke to find that he had lost sensation on the right side and had some difficulty in articulating (muscular). Although thus warned, he worked steadily for twelve hours the next day, in consequence of which he completely broke down. After this he would occasionally write down a wrong word or put down a wrong figure in calculating, etc. One month later he had a transient attack of loss of power in right leg and other signs of partial right hemiplegia, which was in all probability due to an embolus, as there was a marked aortic systolic murmur.
46From S. Weir Mitchell's notebooks.
The point brought forward by Axenfield47that the paralysis in brain lesions manifests itself equally in all movements of the fingers, while in writers' cramp, etc. there is integrity of all movements except those necessary for the special act, cannot be accepted as diagnostic.
47Des Névroses, par le Docteur Axenfield, Paris, 1864, p. 389.
Progressive muscular atrophy, as previously mentioned, bears a close resemblance to professional muscular atrophy (Onimus), which may be considered one of the forms of copodyscinesia. The resemblance, together with the few points of difference, may be best seen in the form of a table, thus:
The ordinary course of symptoms in this disease is not always followed out, and occasionally the resemblance of the initiatory symptoms to one of the forms of copodyscinesia is great; the following is a case in point:
W. F. G——, æt. 34, clerk, at one time an excessive smoker and a steady writer. In the autumn of 1883 he noticed a numbness on the ulnar side of the tip of the right index finger and on the radial side of the middle third of the right middle finger, at about the points touched by the pen-holder, which he held between these two fingers; this was soon accompanied by a hyperæsthesia to light touches, and the two together seriously interfered with pen-prehension; he then changed the pen to the left hand, and soon noticed a numbness on corresponding points on the left fingers. Any sudden extension of the right arm would cause a thrill to shoot down into the fingers. Weakness of the right opponens pollicis was present at the same time. These symptoms caused the first physician consulted to make a diagnosis of writers' palsy, but the later manifestations of the disease, six weeks subsequently, soon showed its true character: these were marked atrophy of the external portion of the thenar eminence (opponens pollicis) and weakness and partial atrophy, and finally total loss of power, of the anterior group of muscles of right leg (tibialis anticus, extensor proprius pollicis, and extensor longus digitorum); numbness and hyperæsthesia, as in the hand, appeared over instep. Fibrillary twitchings were absent. The affected muscles did not respond to the faradic current, while to the galvanic current there was a quantitative lessening, the reaction still being normal in kind—viz. KaSZ > AnSZ.
Paralysis agitans and multiple sclerosis both interfere with writing on account of the tremor of the muscles; the latter disease markedly so, as voluntary effort increases the trembling.
According to Sigerson,48the flexors are the least affected in the former disease, and the extensors most so, especially the interossei, which are the earliest involved; the down strokes of the writing will therefore be made with comparative firmness, while the up strokes will show the tremor.49
48Lectures on the Diseases of the Nervous System, by J. M. Charcot, trans. Philada., 1879, foot-note by Sigerson, p. 113.
49Ibid., p. 112.
The writing in multiple sclerosis is much more wavy and irregular, although the same tendency to firmness in the down strokes may still be seen.50
50Ibid., foot-note by Bourneville, pp. 153, 154.
Both these diseases, when well pronounced, should occasion no trouble in diagnosis, but there are cases where the symptoms are not typical, and where the sclerotic change is slight in amount and principally limited to the arm-centres in the cord, or at least to the anterior columns, the symptoms being confined to the finer movements of co-ordination of the hand and arm, and necessarily interfering with such occupations as writingmuch more than with those which only necessitate coarser movements. The following cases illustrate this point:
Case I.—J. S——, æt. 67, male. Two relatives had paralysis agitans (?). Previous health good; present trouble began nine years ago. Tremor first noticed in writing, and only then, but later any voluntary effort of right arm was accompanied by a fine tremor, which became particularly noticeable when the arm was semiflexed. This is now equal in both arms. When patient writes slowly and with great attention to each movement, he can write fairly for a short time; but if he attempts to write quickly, there is a marked tremor which renders the letters sometimes almost illegible. The up strokes show the most tremor. There is no festination, no change in voice, no loss of power over the sphincters, and no loss of reflexes; the reaction to the galvanic current is normal.
Case II.—W. H——, æt. 58, male. For fifty years the patient has been a hard writer, first as an editor and later as a cashier. In 1882 he noticed difficulty in raising arm to put away papers in pigeon-holes above his head; this movement caused pain in shoulder and arm. Shortly after this he found that his hand became tremulous when he attempted to write, and later any voluntary effort was sufficient to cause the tremor. There has been no cramp. The grip of both hands is good, nor is there any wasting of the muscles. Standing with eyes closed causes no swaying, although there are occasional vertiginous attacks. While walking he has noticed that the right arm does not swing with its usual freedom. No ataxic pains are present. Reflexes of right arm and shoulder are very much exaggerated; there are no changes in nutrition or sensation. Galvanic reaction normal and alike in both arms. The urine is non-albuminous.
The following case is in all probability one of diffused sclerotic changes in the right lateral half of the cord, where the disease has apparently ceased advancing:
Case III.—T. L——, æt. 45. In 1880, three years ago, patient noticed occasional formication in various parts of the right face, hand, and leg, which ceased after he suspended the use of tea and coffee; soon after this he noticed that his writing began to lack ease and that the letters became crowded toward the end of the line; later, a fine tremor appeared in the fingers of the right hand; crampy sensations then appeared in the hamstring muscles of right leg, chiefly while sitting with the knee bent at right angles; writing with the right hand was sufficient to cause, or at least aggravate, this. In 1882 the right arm lost its automatic swing during walking, although holding the left arm still would enable the right arm to swing automatically. Lately the symptoms have ceased advancing, and some seem to improve. His present condition is an inability to write with right hand without paying great attention and making each letter separately, and a trembling of fingers during excitement of any kind. Coarse movements of co-ordination can, as a rule, be well performed; there is no increase of reflexes, nor are they absent; there is no ataxic gait, and there are no trophic changes. Galvanic reaction is normal, and alike on both sides. There is no history of hereditary disease or of venereal taint.
In this connection it is proper to mention tremor mercurialis andtremor saturninus, which might possibly lead to mistake should proper attention not be paid to the history and to the symptoms. Paul51reports a case of the former affection, and gives a specimen of the handwriting of the patient.
51C. Paul,Bull. et Mém. de la Soc. de Thérap., Paris, 1881, xiii. pp. 129-131.
Traumatisms, etc. of the various nerves of the arm usually interfere with the proper play of the muscles supplied by them, and although certain of the milder forms of inflammation or of congestion, as previously mentioned, are sometimes present in cases of copodyscinesia, it is manifestly improper to include all cases of impairment of hand-and-arm movement from nerve-injury under this head.
Palsy from pressure, as from sleeping with the head resting upon the arm or with the arm hanging over the back of a chair, is a frequent cause of paresis or paralysis of the muscles supplied by the musculo-spiral.
Tumors pressing upon the nerves in any part of their course, or neuromata, may be mentioned among the more ordinary affections that possibly might mislead.
Tenosynovitis which is described by Hopkins52as a congestion of the tendinous sheaths in the forearm, with insufficient lubrication of the same, causing pain and interfering with motion, might be mistaken for the disease in question, especially as it occurs in many of the same occupations which furnish cases of copodyscinesia.
52Wm. Barton Hopkins, “Tenosynovitis,”Med. News, Philada., July 15, 1882.
The exciting cause of tenosynovitis is “usually the resumption of work to which the individual is thoroughly accustomed after a shorter or longer interval when he is out of practice,” and not the monotonous repetition of the same act. The differential diagnosis should occasion no difficulty, as there is soreness amounting to positive pain upon motion or pressure along the course of the affected tendons, and the peculiar creaking which is communicated to the finger on palpation.
PATHOLOGY ANDMORBIDANATOMY.—Unfortunately for correct determination of the pathological conditions underlying these neuroses, there have been no reported examinations of the spinal cord and nerves in subjects affected with copodyscinesia dying from intercurrent diseases, although it is probable that no macroscopic lesion would be discovered.
Solly53reports the post-mortem appearance in a case of impaired writing-power in which he found a granular disintegration of the cervical portion of the cord; but this case, from his description, was evidently one in which the impairment of power was merely one of the numerous symptoms dependent upon disease of the cervical cord from degenerative changes, and not a true case of writers' cramp. If such a condition underlaid these neuroses, the cures occasionally reported and the relief frequently felt after the use of the galvanic current could not be explained.
53London Lancet, vol i. p. 113.
In default, then, of positive information upon this point, conclusions must be drawn from a study of the symptoms, the course, and the behavior of these diseases under treatment. An affection of such protean aspect is not likely to have one settled pathological condition underlying it.
Many affections considered hitherto purely functional have under ourmore advanced knowledge been found to have as a basis a positive organic change.
On the subject of fatigue, Poore54concisely states that the symptoms “are referable to the muscles, but we must always bear in mind that muscles and motor-nerve are one and indivisible, and that recent experiments have given great probability to the idea that every muscle is connected with a definite spot in the brain; when, therefore, we speak of a sense of fatigue, we must necessarily be in doubt, notwithstanding the fact that the symptoms are referred to the muscles, whether brain, nerve, or muscle, one or all of them, be really at fault.”
54“On Fatigue,”London Lancet, vol. i., 1875, p. 163.
There is a certain limit to which exercise of a given group of muscles may be carried without producing fatigue and local congestion, or perhaps even inflammatory results; this varies greatly in different individuals, but if it is continually and uninterruptedly overstepped, and insufficient time given for rest and recuperation, the centres in the spinal cord which regulate the action of the various muscles implicated become overstimulated, and the result is an undue amount of nervous energy induced by the peripheral excitation, or there is a distortion of the central impulses in passing through these centres: a perturbation of the co-ordinating power ensues and inco-ordination is the result. Under rest and appropriate treatment these symptoms may pass away, but if the part is continuously used it is highly probable that nutritive changes will be produced in that part of the spinal cord from which the nerves supplying the overtaxed muscles proceed.
In some cases of hemiplegia there is produced during gaping and sneezing an automatic movement of the paralyzed arm; this was noticed as early as 1834 by Marshall Hall,55and in 1872, Onimus56noticed that movements of the hand and fingers of the non-paralyzed arm produced similar movements in the paralyzed side.
55Quoted by Charcot,Diseases of Spinal Cord, transl. by Comyges, Cincinnati, 1881, p. 110.
56Ibid.
Erb57states that these movements in certain spinal troubles are partly owing to the establishment of conditions of irritation in the neighborhood of the lesion.
57Ziemssen's Cyclopædia, Amer. ed., vol. xi. p. 409.
Hitzig58states that in certain pathological conditions where the ganglionic elements (in the cord) are superexcitable, the least disturbance produced on one side, and which determines there a voluntary movement, may be communicated to the other side, and provoke, according to the case, either movements similar to a voluntary one or a spasmodic movement which is really a contraction; and also in certain cases relations of the same nature may be established among cellular groups quite distant from each other; and we can comprehend that in these cases the voluntary movements executed by the sound side may be re-echoed in that which is diseased.
58Quoted by Charcot,loc. cit., p. 124.
This apparent digression bears an important relation to the pathology of copodyscinesia, and lends force to the view that the associated movements which occur in the well arm, or in the affected arm when the sound side is used, or even in the face and legs, and which are quite often seen in these affections, are due to the fact that there is a central change.
Mitchell,59in speaking of functional spasms, states that it will be foundin all these cases that when an ordinary functional motor act gives rise to spasms elsewhere, these occur in muscles which have physiological, and therefore anatomical, relations to the muscles which by their normal use give rise to the morbid activities. He considers that there is a hypersensitizing of the sensory centre which takes record of the activities of the affected muscles.
59“Functional Spasms,”Amer. J. Med. Sciences, Oct., 1876.
The fact that the left hand becomes implicated in some cases where it is used to relieve the right should be mentioned in this connection as lending weight to this hypothesis, especially as in a few cases of telegraphers' cramp the left hand has been found implicated in the very first attempt to use it in telegraphing.
Poore60considers this transfer as no evidence that the change is central, and is one of the few who consider the pathological conditions as purely peripheral in character. Hamilton61and De Watteville62also consider the peripheral hypothesis the correct one.
60Loc. cit.
61Nervous Diseases, Philada., 1881.
62“The Cure of Writers' Cramp,”Brit. Med. Journ., 1885, vol. i. pp. 323-325.
Fritz63(and after him Poincaré64) considers the disease a reflected neurosis, due to a perversion of the muscular sense. Onimus and Legros65incline to the same opinion.
63Oesterr. Jahrb., März u. April, 1844.
64Le Système nerveux-péripherique, Paris, 1876.
65Traité d'Electricite médicale, Paris, 1872, p. 327.
The older theory that the disease is solely central in its pathology is advocated by Duchenne,66Solly,67Reynolds,68Althaus,69Wood,70Vance,71Erb,72Dally,73Axenfield,74Whittaker,75Waller,76Gowers,77Hammond,78Romberg,79Cederschjöld,80Robins,81Ross,82and some others. Roth83considers that there are two entirely separate classes, the central and the peripheral or local.
66De l'Électrisation localisée, 3d ed., pp. 1021et seq.
67London Lancet, Jan. 28, 1865.
68System of Medicine.
69Julius Althaus,London Mirror, vol. vii., Aug. 1, 1870; also, pamphlet,Scriveners' Palsy, London, 1870.
70Practice of Medicine.
71Reuben A. Vance,Bost. Med. and Surg. Journal, vol. lxxxviii. p. 261.
72Ziemssen's Cyclopædia, vol. xi. p. 355.
73Journal de Thérapeutique, Paris, 10 Fév., 1882.
74Des Névroses, Paris, 1864.
75Cincinnati Lancet and Clinic, 1880, N. S., vol. iv. p. 496.
76Aug. Waller,Practitioner, 1880, vol. ii. p. 101.
77W. R. Gowers,Med. Times and Gaz., 1877, vol. ii. p. 536.
78Treatise on Dis. of Nervous System, 6th ed., New York, 1876.
79Manual of Nervous Dis. in Man, Sydenham Society, vol. i.
80Gustaf. Upsala läkarefören, förhandl. xv., 3 och. 4, S. 165, 1880, review inSchmidt's Jahrb., Bd. clxxxvii., 1880, p. 239.
81“Writers' Cramp,”Amer. Journ. Med. Sci., April, 1885, pp. 452-462.
82A Treatise on Diseases of the Nervous System, London, 1881, vol. i. pp. 464-469.
83The Treatment of Writers' Cramp, by Roth, London, 1885.
The later theory, that the disease is at first peripheral, but that by abuse may become central (spinal), is advocated by Beard,84Liebman,85Bartholow,86Frazer,87and a few others. The latter theory, and not the idea that it is a disease of the co-ordinating centres in the brain or of the spinal centres only, best explains, in my opinion, the various symptoms encountered.
84New York Med. Record, 1879, p. 244.
85Maryland Med. Journ., June, 1880-81, vol. vii.
86Medical Electricity.
87Glasgow Med. Journ., 1881, vol. xv. p. 169.