Chapter M: M——, was a stout Irish woman about forty years of age. She had (2)

The following figures are of interest as proving the great superiority, in point of strength, of the flexor over the extensor muscles of the wrist and fingers. The measurements were made by the dynamometer of V. Burq, great care being taken to apply the instrument upon corresponding points of the palmar and dorsal surfaces of the hand. The grasp of the average man, which includes all the flexor muscles of the fingers and thumb, equals 125 pounds, while the power of the flexors of the wrist, exclusive of the fingers, equals 40 pounds. In marked contradistinction {510} to this the extensors of the wrist register 35 pounds, and the extensors of the fingers only 7. The total power of all the flexors is therefore 165 pounds, and that of the extensors 42 pounds, nearly four times less (3.92). In women the ratio is the same, although the number of pounds registered is about half.

From the foregoing enumeration of the muscles used in writing and telegraphing it may be seen that the brunt of the work does not fall on the same muscles in the two acts, so that operators are seen utterly unable to telegraph more than a few words intelligibly who can still write a fluent hand. The two forms of neuroses often coincide in the same subject, as all telegraphers are of necessity scriveners; in fact, the majority suffer from both forms, and as a rule the most difficulty is experienced in telegraphing, and not in writing, although the reverse is frequently seen. But rarely does one see an operator who, unaffected as far as telegraphing is concerned, has difficulty in writing on account of this curious neurosis.

Of the muscles enumerated in the foregoing discussion, six are supplied, either wholly or in part, by the ulnar nerve—namely, the first two interossei, adductor pollicis, flexor brevis pollicis (inner half), flexor carpi ulnaris, and flexor profundus digitorum (inner part); and seven by the median nerve wholly or in part—namely, the opponens and abductor pollicis, flexor brevis pollicis (outer half), flexor longus pollicis, flexor profundus digitorum (outer part), flexor carpi radialis, and flexor sublimis digitorum.

The remaining important muscles are supplied by the musculo-spiral and its branches, except the biceps, which is supplied by the musculo-cutaneous.

The ulnar nerve supplies fifteen of the muscles of the hand; many of these are not prominently brought forward in writing, but are more or less used in keeping the hand in the required position.

Poore, after a careful study of 32 cases of undoubted writers' cramp, found the muscles affected in the following proportions:

Interossei (supplied by the ulnar nerve) 18 times.
Extensors of the thumb ( " " " musculo-spiral) 10 "
Flexor brevis pollicis ( " " " median and ulnar) 7 "
Abductor " ( " " " median) 7 "
Flexor longus " ( " " " " ) 4 "
Adductor " ( " " " ulnar) 3 "
Opponens " ( " " " median) 2 "
All the muscles of the forearm, more or less, 2 "

—showing that the muscles supplied by the ulnar nerve were affected more often than those supplied by the others.

The musculo-spiral and its branches supply the extensors of the thumb, fingers, and wrist, besides the two supinators; and by referring to the muscles most called into action in the act of telegraphing it will be seen that the majority are supplied by this nerve and by the median, which supplies the majority of the flexors. This statement explains to a great extent the fact that telegraph operators may be unable to telegraph and yet be able to write, as the muscles most important in the two acts have not the same nerve-supply.

The integrity of these nerves is therefore of the first importance in all {511} cases requiring the use of the fingers and forearm, and many cases of copodyscinesia undoubtedly have a subacute inflammation of these nerves, or at least a congestion of the same, as their foundation, the neuritis or congestion being overlooked, owing to its mild type.

S. Weir Mitchell[12] states that subacute neuritis is often incapable of distinct clinical discrimination when of a mild type and when there is an absence of traumatic cause. Mills[13] states that “a lesion of the sensitive fibres profoundly affecting this power of conducting impressions may not cause pain, and that pain is not a necessary symptom of inflammation of a mixed nerve: this is an important fact, as I think too much stress is often laid on pain as a symptom of neuritis, leading to error in diagnosis and treatment.”

[Footnote 12: _Injuries of Nerves, and their Consequences_, by S. Weir Mitchell, M.D., Philada., 1872.]

[Footnote 13: F. T. Mills, M.D., “On Two Cases of Neuritis of the Ulnar Nerve,” _Maryland Med. Journ._, vol. viii. p. 193, 1881.]

Other Forms of Copodyscinesia.—In violin-playing the bow is held steadily between the fingers and thumb for long periods at a time, and the left arm is forcibly held in supination in order to bring the fingers upon the strings—actions well calculated to cause trouble if persisted in, not taking into account the rapid movements of the fingers which are necessitated in playing and the movements of the arm in bowing. The violinist is therefore liable to suffer in both arms, but in a different manner in each, as different muscles are used in bowing and in fingering.

The other musical instruments necessitating great education in the movements of the fingers and wrist are also liable to cause these neuroses, but this is not true of those wind instruments which require education of the movements of the lips and tongue. Piano-playing is a frequent cause of these troubles, which have been known to appear quite suddenly during the practising of some difficult piece.

In fact, all occupations which require a muscle or a group of muscles to be kept in a constant more or less firm contraction, together with fine movements of co-ordination in themselves and in the neighboring muscles, may be expected to furnish cases of this class of disease; the muscles affected necessarily varying with the work done, mere routine work being more liable to cause trouble than that which is new and original, as in the latter case time has to be taken to elaborate it, thus giving temporary rest to the muscles.

Besides the forms already mentioned these neuroses have been known to effect compositors, engravers; seamstresses, tailors, from using the needle or scissors; cobblers; bricklayers, from using the trowel; artificial-flower makers; weavers; milkers; painters; dentists; ballet-dancers, from standing on their toes; blacksmiths and those using the hammer; carpenters, from using the saw and screw-driver; electrical-instrument makers, from winding coils; turners; watchmakers; fencing-masters; cigar-makers; makers of photographers' gelatin plates; knitters and those using the crochet-needle; billiard-players; counters of money; dressers of hides; pedestrians; and a few others.

Writers, telegraph operators, and musicians are those which by far are the most frequently affected, the others being almost curiosities. Among the latter may be mentioned the case, recently coming under my notice, of pain in the right forefinger and arm, with cramp in the former, upon {512} any prolonged attempt to read with this finger the raised letters of the alphabet of the blind. The patient was a blind woman depending for her living upon crocheting, which occupation was also seriously interfered with by this trouble.

After inquiring, in factories, etc., I find that the disease is by no means a recognized one among the workmen. Among telegraphers, however, it is so well known that they have called it the loss of grip, while in France it is known among them as le mal télégraphique.

Gardner,[14] after a careful investigation, finds no proof that physical disease originates in, or is even aggravated by, the use of the sewing-machine, and he has “never even heard of a case of cramp.” He comes to this conclusion after having visited many large factories where sewing-machines are used and worked by foot-power; his remarks apply to those machines where the feet are worked together, and not alternately, which last has been known, according to Down,[15] to cause serious troubles, of an entirely different kind, however, from the one under consideration, and with which this subject has nothing in common.

[Footnote 14: A. K. Gardner, M.D., “Hygiene of the Sewing-Machine,” _Am. Med. Times_, Dec 15-29, 1860.]

[Footnote 15: “Hygiene of the Sewing-Machine,” _London Lancet_, 1866, vol. ii. p. 447.]

PREDISPOSING CAUSES.—Tobacco and Alcohol.—Both of these articles exert a powerful effect upon the nervous system, tobacco particularly being a factor in the causation of many cases of neurasthenia. The first effect of tobacco and alcohol in small doses on the brain and spinal cord is, according to Boehm and Von Boeck,[16] that of an excitant; subsequently it acts as a depressant. Eulenburg[17] mentions tremor as of very frequent occurrence, and states that he has frequently noticed it in young cigar-makers who smoke to excess.

[Footnote 16: _Ziemssen's Cyclopædia_, Amer. ed., vol. xvii.]

[Footnote 17: _Ibid._, vol. xiv.]

Cigarettes are more injurious than other forms of tobacco used in smoking, as the smoke is nearly always inhaled, a greater effect being thus produced by a given amount of the drug. Besides this, cigarettes contain a large amount of other substances deleterious in their effects. Trembling of the fingers and hand is frequently seen in those smoking cigarettes freely.

The majority of the cases of copodyscinesia that are in the habit of using either of these articles acknowledge that their use increases their disability; in very exceptional cases the moderate use of tobacco appears to soothe and quiet, and thus relieve some of the symptoms.

Age.—Copodyscinesia is a disease of early adult life; it is rare in old age. In 39 out of 43 cases of telegraphers' cramp coming under my notice the age of the patient at the outset of the disorder could be accurately determined. The average was 23.94 years. The average age of all cases of the various forms of copodyscinesia seen by me up to the present time (1886) is 25.96 years.

Sex.—The influence of sex as a predisposing cause of these affections has not been studied with sufficient care, although a few authors allude to it.

Onimus[18] states that women are more frequently affected than men with telegraphers' cramp. Erb[19] states that writers' spasm is met with more {513} frequently in men, much more rarely in women, and that pianoforte-players' spasm occurs more frequently in women, and particularly in neuropathic persons who belong to nervous families. Hasse[20] and Romberg[21] consider that writers' cramp especially occurs in men, women being affected very rarely. Of the 75 cases of impaired writing-power reported by Poore,[22] only 17 were women, while of the 31 cases of undoubted writers' cramp included in the 75, all were men.

[Footnote 18: _Loc. cit._]

[Footnote 19: “Writers' Cramp and Allied Affections,” _Ziemssen's Cycl._, Amer. ed., vol. xi.]

[Footnote 20: _Loc. cit._]

[Footnote 21: _Nervous Diseases_, vol. i. p. 320.]

[Footnote 22: _Loc. cit._]

It may be seen that the male sex has been employed far more frequently than the female in most of the occupations previously mentioned, so that a larger percentage of men would naturally be affected; but now that women are being employed more generally a larger number of the female sex may be expected to suffer in this way.

Whether sex, per se, has much influence as a predisposing cause is difficult to say, as statistics are wanting, but it is probable that with the same amount of work given to each sex a large proportion would be found among women.

Women are being employed to a considerable extent in telegraphy, and although I have been able to collect but 4 cases of this form of copodyscinesia affecting women out of a total of 43, I have reason to believe it is quite common among them, my mode of collecting statistics (soliciting replies to printed questions) being much more likely to give a larger percentage of answers from men.

Hereditary Influence and Nervous Temperament.—Both of these factors seem to play an important rôle as predisposing causes to these affections. Cases are on record where several members of the same family were the subjects of writers' cramp. The statement made by Erb (vide supra), that neuropathic persons and those who belong to nervous families are more subject to these affections than others, seems to me to be true, at least to a great extent, for a careful inquiry into the history of cases coming under my knowledge has quite often elicited the statement that migraine, functional spasm, epilepsy, hay fever, neuralgia, writers' cramp, telegraphers' cramp, or general neurasthenia has existed either in the immediate family or in the patients themselves. Hasse[23] is also of the same opinion.

[Footnote 23: _Loc. cit._]

Whittaker[24] states that many of the cases coming under his notice, if not the majority, occurred in individuals of irritable nervous temperament, subject themselves to, or the descendants of parents afflicted with, migraine, chorea, epilepsy, paralysis, or some form or other of neurosis, but that a certain contingent of the minority of cases occurred independently of any neurosis or any abuse of alcohol or sexual excess.

[Footnote 24: _Cincinnati Lancet and Clinic_, N. S., vol. iv. p. 496, 1880.]

Fritz,[25] after studying 25 cases of writers' cramp, found 7 who either stuttered, squinted, or had choreoid movements or œsophageal spasm at the same time; but it is probable that a few of these cases at least were due to some central lesion (post-paralytic chorea?).

[Footnote 25: “Ueber Reflexionsfingerkrampf,” _Oesterr. Jahrb._, März u. April, 1844, quoted by Hasse, _loc. cit._]

Beard[26] holds an opinion directly the reverse of the vast majority of the authorities upon this subject, and states that this disease occurs mostly in {514} those who are of strong—frequently of very strong—constitution, and that it is quite rare in the nervous and delicate; and when it does occur in those who are nervous it is easier relieved and cured than when it occurs in the strong.

[Footnote 26: G. M. Beard, M.D., _loc. cit._]

That in the majority of the cases there is an emotional factor is evident to every one who has seen a considerable number, the knowledge that some one is looking on and will notice the disability being almost sure to aggravate the symptoms. This is frequently noticed among telegraph operators, and is well exemplified in the following answer made by a female operator: “If I am working with a disagreeable or fault-finding operator, who I know will make unpleasant remarks about my sending, and break me (break the circuit) on certain difficult letters, it is almost impossible to make those letters correctly with either hand.” Again she says, “If I come to the difficult letters without thinking about them, I can make them much easier than if I look ahead in the message and see them; for instance, some time after I had ceased using my right hand on account of the cramp, an outside occurrence made me very angry; just then a message was placed on my desk, and with my mind fully occupied with my grievance I sent the message with my right hand very easily and quickly.”

Wasting Diseases.—These favor the production of these affections in those predisposed to them by occupation or otherwise, by the constant drain upon the system. Numbness of the fingers and stiffness are occasional symptoms of renal disease, and would naturally aggravate any difficulty of writing and so-forth that the patient might have. Mitchell[27] reports two cases of writers' cramp dependent upon or coincident with albuminuria, which were treated in vain until the condition of the kidneys was discovered: under appropriate treatment for this condition one recovered entirely from the cramp and the other improved greatly.

[Footnote 27: S. Weir Mitchell, M.D., “Nervous Accidents in Albuminuria,” _Philada. Med. Times_, Aug. 1, 1874, p. 691.]

Traumatism, etc.—Injuries, etc. occasionally act as predisposing causes; thus cases are on record where the starting-point seemed to have been an ingrowing thumb-nail, and others where it was the pressure of large sleeve-buttons upon the ulnar nerve; and tight sleeves seem to have been the starting-point of inflammatory troubles ending in writers' cramp. An inflammation of the periosteum of the external condyle (node) and a painful ulcer upon the forearm are reported by Runge[28] as giving rise to symptoms closely allied to this affection. Seeligmüller[29] mentions a case where the symptoms came on after an insignificant grazing bullet-wound of the knuckle of one of the fingers.

[Footnote 28: “Zür Genese u. Behandlung des Schreibekrampfes,” _Berl. klin. Wochensch._, x. 21, 1873.]

[Footnote 29: Adolph Seeligmüller, “Lehrbuch der Krankheiten der Peripheren Nerven, etc.,” _Wreden's Sammlung, Kurzer Med. Lehrb._, Band v. p. 29.]

SYMPTOMATOLOGY.—Owing to the fact that various causes give rise to these affections, and that the different groups of muscles implicated differ with the varying occupations of those suffering, no one stereotyped set of symptoms can be described as applicable to each case, and no one symptom can be looked upon as diagnostic.

The symptoms most frequently seen may be classified under five heads—viz.: I. Cramp or spasm; II. Paresis or paralysis; III. Tremor; IV. {515} Pain or some modification of normal sensation; V. Vaso-motor and trophic disturbances.

These may, and generally do, exist in various combinations, and they may be accompanied by other symptoms of nervousness; they are not of necessity confined to the hand or arm, but may become more or less general. At first they are usually only seen after long continuance of the occupation which produced them, but later any attempt to perform this act will cause their appearance, although it may not be noticed in any other of the daily avocations.

In some of the rarer cases the neurosis makes its appearance suddenly after a prolonged siege of work. It has been generally stated that writers' cramp, for instance, only manifests itself on attempting to write, but this is due to the fact that there is no other occupation which exactly needs the same co-ordination of the muscles, for others can be substituted in the place of those affected. This is particularly seen in the early history of the cases, but when it has become pronounced in character any analogous movement, such as holding a spoon or fork or paint-brush, will be sufficient to produce it. Difficulty in buttoning the clothes with the fore finger and thumb is frequently noticed.

I. Cramp or Spasm (Spastic Form).—The first form of this disease to be considered is that in which cramp or spasm is present. This is one of the most frequent symptoms, and when present usually attracts the most attention. In most of the articles written upon these affections great importance has been given to this symptom, which, however, may be absent during the whole history of the case, but when it does appear it usually indicates an advanced stage. The term writers' cramp is an evidence of the widespread opinion of the importance of this symptom.

The cases that present themselves to the physician have usually been affected for some time, and where cramp is present an earlier examination would probably have resulted in the discovery of premonitory signs before the appearance of the spasm or cramp; and in fact it may be stated that this symptom is always preceded, or at least accompanied, by one or two more. The muscular contraction may be so slight as to amount to a mere occasional awkwardness, in writers' cramp an abnormal grasp of the pen-holder being all that is noticed; or it may be so severe as to cause a tonic contraction of the muscles affected, which may continue for some time after the exciting cause has been removed, as in the cases reported by Poore[30] and S. Weir Mitchell.[31]

[Footnote 30: _Electricity in Medicine and Surgery_, London, 1876, p. 209.]

[Footnote 31: “Functional Spasm,” _Amer. Journ. Med. Sciences_, Oct., 1876, pp. 322, 323.]

As might be supposed, these spasms affect most usually the upper extremities, although they may affect the lower, as is occasionally seen in workers on the lathe and in pedestrians. Other muscles than those necessary to perform the act that has become difficult may also be seized with spasm coinstantaneous with the spasm of the affected part; thus the left arm may be the seat of associated movements while the right is being used: these are, however, most frequently seen in the affected arm when the other is being used to relieve it; they may also be noticed in the legs, although much more rarely.

Gallard[32] reports a case of a street-pavior who had associated spasm of {516} both sterno-cleido-mastoid muscles, which came on only when using the instrument to settle the stones. Dally[33] reports a case of a woman who had spasm of the left sterno-cleido-mastoid muscle at the time the right hand was seized with cramp in writing. More rarely all the muscles on one side of the body may be affected. Reynolds[34] reports such a case.

[Footnote 32: “Crampe des Écrivains,” _Progrès médical_, v., 1877, p. 505.]

[Footnote 33: “Traitement des Spasms professionnels,” _Journ. de Thérapeutique_, No. 3, 10 Fèvrier, 1882.]

[Footnote 34: _System of Medicine_, “Writers' Cramp,” vol. ii. p. 287.]

In the spastic form of the disease an early investigation usually shows a rigidity or spasm of one or more of the fingers, coming on when an attempt is made to perform the act which originated the trouble, and occasionally only on performing that act; but this statement, so strongly insisted upon by some authors as a diagnostic symptom, does not universally obtain.

The contraction may affect either the extensors or the flexors; in the former case—in writing, for instance—the pen can with difficulty be kept upon the paper, and the stroke movement is interfered with; if the spasm is of the flexors, which is of the most common occurrence, it usually affects the fore finger and thumb; the pen is then forced downward, and upon attempting to make the upward movement catches in the paper; besides, there may be with this a flexion and adduction of the thumb, which causes the pen-holder or pencil to be twisted from the grasp, occasionally with sufficient force to throw it to some distance. The other fingers may be similarly affected. The supinator longus is quite a common seat of spasm, the pen being thereby drawn from the paper by a partial supination of the forearm.

Sometimes the character of the spasm cannot be described, the hand seeming to run away with the pen.

The patient who feels these spasms or contractions coming on soon changes the manner of holding the pen-holder, so as to relieve the affected muscles and to use those which are but slightly or not at all affected. Many grotesque manners of writing may thus be encountered. One sometimes employed by those seriously affected is to grasp the holder in the closed hand, holding it nearly at a right angle to the forearm, all movements being made with the whole arm, thus relieving the finger-muscles. The diagram on p. 457 shows the method of writing adopted by a patient who has a marked spasm of the flexors of the fingers and thumb, preventing his writing in the ordinary manner; he is also the subject of telegraphers' cramp.

These means, however, give but temporary relief, as, sooner or later, if writing is persisted in, the muscles of the arm and shoulder become implicated.

In telegraphers the extensors of the wrist are frequently affected, so that the operator is unable on account of the spasm to depress the key of the instrument with sufficient force to close the circuit, the signals being made, so to speak, in the air, or else a dot (.) is made in place of a dash (—). The extensor spasm seems to be the most frequent form of the cramp among telegraphers, many of them saying that they are unable to keep their fingers upon the key-knob. It will generally be found that the characters that are the most difficult to make are those which are composed entirely of dots, such as _h_ (....), _p_ (.....), _6_ (......), or those {517} ending with dots, such as _b_ (—...), _d_ (—..), _8_ (—....). Some of the spaced characters are also difficult to make, such as _z_ (... .), _&_ (. ...), _y_ (.. ..).

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,[35] is 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. Duchenne[36] likewise reports some curious cases of functional spasm analogous to the foregoing.

[Footnote 35: _Loc. cit._]

[Footnote 36: Duchenne (de Boulogne), “Note sur le Spasm functionnel, etc.,” _Bull. de Thérap._, 1860, pp. 146-150.]

{518} 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,[37] where, 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.

[Footnote 37: E. 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. Zuradelli[38] considers this condition to be the one ordinarily found in this disease.

[Footnote 38: Crisanto Zuradelli, _Gaz. Med. Ital. Lomb._, Nos. 36-42, 1857; also _Ann. 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.

Duchenne[39] calls attention to this form of trouble, which he styles paralysie functionelle, and states that it is much less common than functional spasm.

[Footnote 39: _Loc. 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. {519} An oscillatory trembling, due to implication of the supinators and pronator, is described by Cazenave,[40] which 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.

[Footnote 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 Bochum[41] it 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. Taylor[42] of Nottingham and Simeon Snell[43] also speak of this as a fatigue disease.

[Footnote 41: “The Pathogenesis and Etiology of Nystagmus of Miners,” _Am. Journ. Med. Sci._, Oct., 1881.]

[Footnote 42: Quoted by Poore, _loc. cit._]

[Footnote 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 are {520} widely 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.

GENERAL SYMPTOMS.—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 another {521} person. 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.

Poore[44] is 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.

[Footnote 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.

DIFFERENTIAL DIAGNOSIS.—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 lesions {522} may 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 Mitchell[45] as 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.”

[Footnote 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 cases[46] will illustrate this point:

{523} 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.

[Footnote 46: From S. Weir Mitchell's notebooks.]

The point brought forward by Axenfield[47] that 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.

[Footnote 47: _Des 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:

PROGRESSIVE MUSCULAR ATROPHY. | PROFESSIONAL MUSCULAR ATROPHY.
|
1. Heredity in 24.63 per cent. | 1. Heredity not marked.
(Roberts). |
|
2. Affects adult males | 2. Affects adult males
principally. | principally.
|
3. Frequently follows exhausting | 3. Always follows exhausting
muscular activity. | muscular activity.
|
4. Atrophy a cardinal symptom. | 4. Atrophy a cardinal symptom.
|
5. When it affects the upper | 5. The muscles first affected are
extremities, the interossei and | generally the largest ones,
the thenar and hypothenar | particularly those in the
eminences are the first | neighborhood of the
affected. (Eulenburg says in his | shoulder-joint. The muscles of
experience the first dorsal | the hand may be affected first.
interosseus is always first |
attacked, and the others later.) |
|
6. Fibrillary twitchings | 6. Fibrillary twitchings
frequent. | frequent.
| {524}
7. Premonitory pains rare. | 7. Pains and cramps at the onset
| in the affected parts a
| distinctive sign.
|
8. Diminution of electrical | 8. (?).
reactions to both faradism and |
galvanism. Reaction of |
degeneration occasionally a late |
symptom. |
|
9. Prognosis generally | 9. Rapid amendment under rest and
unfavorable: as regards perfect | the use of constant and
restoration of muscles, almost | continuous electric currents.
hopeless. |

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,[48] the 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]

[Footnote 48: _Lectures on the Diseases of the Nervous System_, by J. M. Charcot, trans. Philada., 1879, foot-note by Sigerson, p. 113.]

[Footnote 49: _Ibid._, 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]

[Footnote 50: _Ibid._, 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 writing {525} much 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 and {526} tremor saturninus, which might possibly lead to mistake should proper attention not be paid to the history and to the symptoms. Paul[51] reports a case of the former affection, and gives a specimen of the handwriting of the patient.

[Footnote 51: C. Paul, _Bull. et Mém. de la Soc. de Thérap._, Paris, 1881, xiii. pp. 129-131.]