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.

46 From S. Weir Mitchell's notebooks.

The point brought forward by Axenfield47 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.

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

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.