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
48 Lectures on the Diseases of the Nervous System, by J. M. Charcot, trans. Philada., 1879, foot-note by Sigerson, p. 113.
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
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 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.