bilateral from the start, but commonly it is more marked on one side than on the other, and may be monoplegic or more often hemiplegic for several years, eventually showing a tendency to be diplegic in distribution. Often it is steadily preceded in its advance by the rigidity, or the rigidity may be generalized and of long standing before tremor appears in the hands. It affects the distal portion of the extremities most. In the hands, where it customarily first appears and is most developed, it causes a rhythmical, alternating flexion and extension of the fingers, mainly at the metacarpal joints. The tremor may be limited to the index and thumb, or affect the interossei mainly, causing rolling of the fingers upon their long axes. The patient appears to be constantly rolling some small object, as a pill or a pencil, between his fingers and the opposed thumb. Sometimes flexion and extension of the wrist are added, and very rarely we encounter movements of pronation and supination. As a rule, the arm and shoulders are unaffected. the lower extremity the tremor predominates at the ankle, causing the foot to drum on the floor as if with clonus. The toes are less evidently involved, but the muscles of the thigh often participate in the tremor.

It is pleasant.

Fig. 208.-Handwriting in Parkinson's disease, with former style below.

In

In

The muscles at the back of the neck, the shoulders, and the dorsum of the body are seldom affected. The abdominal muscles invariably escape. In the great majority of cases the head does not tremble, or only does so by movements communicated to it from a distance. very rare cases, however, there is a rhythmic nodding, shaking, or rotation of the head that persists even when the patient is recumbent. The eyelids exceptionally are affected, while the lips and lower jaw not rarely show a tremor synchronous with that in the hands.

The great peculiarity of this tremor is its occurrence while the patient is at rest, during repose, and while the parts are supported. It ceases during sleep. Usually it subsides momentarily on voluntary motion. In early cases, and particularly in cases presenting marked antecedent rigidity, the tremor may only appear on voluntary and sustained motion, as in reaching to the back of the neck or into a distant pocket, and must be carefully sought. The tremor is a slow one, of from four to eight oscillations in a second. Usually, they are more rapid if of limited extent, as when confined to the fingers, and grow slower as they involve larger muscles and a wider distribution. When both upper

or all four extremities are involved by the tremor, there is a practical synchronous uniformity of rhythm at all points. The character of the tremor shows distinctly in the handwriting. The letters are formed slowly and are of fair proportions, but all the lines are tremulous, both upstrokes and stems. The writing tends to become cramped and small. Sometimes a lens is required to detect the tremor thus graphically demonstrated.

The palsy never reaches a complete degree, and the paresis may be extremely slight. While patients may bitterly complain of a feeling of weakness and stiffness, they often show a normal amount of strength, even when the rigidity and tremor are very well developed. In advanced cases, however, there is customarily some weakness, and this may even be extreme; but these patients, as a rule, are loath to make exertion of any sort.

Sensory Disturbances.-The general sensibility is objectively intact, but Parkinsonians frequently complain of subjective feelings of heat, more rarely of cold. These sensations may be accompanied by vasomotor disturbance, showing itself in elevated local temperature, in profuse sweats, and in flushing. Sometimes they seek cool rooms and throw off heavy clothing and bed-covering, even in winter. In some cases there is great restlessness, apparently due to the discomfort arising from muscular rigidity. The hands may be frequently moved or the patient insists upon the limbs being rubbed and moved about every few minutes. Muscular atrophy only appears in advanced cases but even then is not extreme. There are no electrical changes or sphincter weakness. As this is a disease of the involutional period of life, we may find all the disturbances of senility, but they are coincidental accessories.

The mental state is likely to be mistaken for one of dementia, but, as a rule, these patients enjoy all their mental powers. There is, however, the same inertia in the mental processes that marks the muscular state. They shun exertion, are chary of their thoughts, talk little, appear indifferent, and often require the incentive of strange faces or extraordinary circumstances to arouse them to a show of mental activity. This, taken with their inexpressive faces, is easily misleading.

Course. The disease is essentially chronic and progressive. The onset, insidious, as a rule, may be abrupt, following some mental or physical storm. The duration is from ten to forty years. In the extremely protracted cases the patients become more and more helpless, fall into a senile dementia, and die from intercurrent disease, usually pneumonia. Varieties have been described, but they are usually limited and undeveloped cases. Thus, the monoplegic and hemiplegic forms, the form without tremor, the form without rigidity, and the form showing extension are named. The prognosis is bad, but there may be remissions.

Diagnosis. In typical cases the diagnosis is almost made at a glance. In early and undeveloped cases Parkinson's disease may be mistaken for posthemiplegie trembling, but lacks the history of a stroke. Senile trembling usually first affects the head and does not present the facies and rigidities, but intermediate cases may be found and both may

coexist. Multiple sclerosis has its increased reflexes and intention tremor, hysteria its stigmata.

Treatment. If seen early, the cases should be treated as those of cerebral arteriosclerosis (see p. 193). In several instances this plan of treatment has seemed to retard the development of the disease. Symptomatic medication is practically useless. Opium, hyoscin, and cannabis indica, if given freely, temporarily control the tremor, but at the expense of the general health and welfare. Massage, electricity, and strychnin give a little help for the time being in some cases. Mental and physical fatigue must be avoided. Charcot noticed that the vibrations experienced in carriage- and car-riding mitigated the tremor, and treated many cases by means of a jolting or vibrating chair with temporary benefit.

THOMSEN'S DISEASE (MYOTONIA).

In 1876 Thomsen, himself subject to the disease, fully described a muscular condition later called myotonia congenita, family myotonia, etc. It is a disorder manifest in the voluntary muscles, which show a stiffness and rigidity upon attempted use after a period of repose, and certain peculiarities of mechanical and electrical irritability. It is a rare disease, numbering not more than fifty recorded cases.

Etiology. The salient etiological feature of the infirmity is heredity. Most of the known cases have been in family groups, sometimes extending over several generations and through several collateral branches. Occasionally the disorder has passed over a generation and again appeared. With and without direct heredity the family history is commonly surcharged with neuroses and psychoses. Males are apparently the more commonly affected.

Morbid Anatomy.-Various observers, upon examination of excised fragments of the affected muscles, have recognized a hypertrophy of the protoplasm and nuclei and a deficiency of striation in the enlarged muscle-fibers, usually with slight but insignificant increase of interstitial tissue. This constitutes, according to Deleage, a persistence of embryonal conditions. Jacoby 1 insists that this appearance is an artifact that is not found if the tissue removed during life is not allowed to contract. Babes and Marinesco have noted deformity or maldevelopment of the terminal motor-nerve plaques. In the only autopsy yet recorded, Déjerine and Sottas2 found no changes in medulla, cord, or peripheral nerves. It is as yet impossible to say whether we have to deal with a pure myopathy, a trophoneurosis, or a congenital defect in the trophic and motor apparatus of the cord.

Symptoms. The awkwardness caused by the fixity of the muscles upon attempted use is noticed in infancy, or may appear at any time up to the twentieth year, or perhaps even later. In typical cases, when the subject desires to execute some movement, a more or less marked 1"Jour. Nerv. and Mental Dis.," July, 1898.

2 "Revue de Méd.," March, 1893.

and prolonged contraction fixes the muscles in question. This gradually subsides and the movement is accomplished. Repetitions occur with less force and duration for the particular action, and finally cease to appear, but any change in the character or even in the rhythm of the movements may reinstate the muscular fixation. Thus, in rising from a chair the legs and thighs are held rigidly. Once erect, the first step is impeded, the second less so, and finally steps are taken with natural ease, but a halt, a sharp turn, or even a change of speed may again set up the spasm. All the voluntary muscles may be affected, even to those of the thorax, eye, and tongue, but usually the myotonia is most marked in the lower extremities, and in some cases the face and upper extremities escape. The congenital paramyotonia of Eulenberg, in which symmetrical groups of muscles are affected mainly on direct exposure to cold, appears to be a limited form of Thomsen's disease. The sphincters and unstriped muscles escape, and in the case mentioned the heartmuscle was normal. Gaping, sneezing, cold, wet, fatigue, and emotional excitement provoke the spasms, while warmth, moderate exercise, repose, and quietude diminish their intensity. They are in some measure relative in intensity to the vigor of the attempted movement.

Commonly, the affected muscles are of unusual firmness and increased bulk, but of lessened power, giving an appearance of athletic development at variance with the actual weakness. They are perfectly supple to passive movements. The reflexes are normal, but a tap on the tendon is likely to produce a spasm in the anterior femoral group, modifying the usual response. Electrical and mechanical excitations of the motor nerve-trunks produce perfectly normal responses, or they are, if anything, somewhat diminished. In the muscles it is very different. A slight blow, as with a percussion hammer, produces a persisting welt from localized muscular swelling or myoidema. The galvanic current produces sluggish, prolonged contractures upon closure almost equally with either pole. Anodal or cathodal closing tetanus may often be secured with the continuous passage of five to ten milliamperes of current. The strong faradic current produces undulatory contractions in many muscles, and these sometimes attend the passage of the continuous current. Repeated electrical or mechanical stimulation of the muscles, like volitional use, gradually exhaust the myotonic responses.

As varieties, Jacobi 1 would limit the term congenital myotonia to cases (1) presenting a hereditary etiology either as a direct transfer from the ascendant, or by inherited disposition; (2) manifesting the myotonic disorder of movement-namely, intention spasm; (3) showing the myotonic reaction, which he describes as made up of normal mechanical and faradic excitability of the nerves and increased mechanical and faradic excitability of the muscles, anodal and cathodal contractions being equal and the response always being tonic and prolonged ; (4) persisting hypertrophy of the enlarged muscles; and (5) absence of symptoms pointing to gross involvement of the nervous system. Other varieties of myotonia he would denominate myotonia aquisita, as

1 Loc. cit.

describing those acquired subsequent to birth, and myotonia transitoria for the cases due to exposure to cold, etc.

Psychic disorders are frequently associated, but not necessarily present. The malady once developed persists for life, which it does not abridge. It is an incurable infirmity, but sometimes shows arrest or amelioration.

Diagnosis. The myoidema and myotonic electrical reactions, taken with the intention spasm, if the term may be used, make the diagnosis easy. Tetany has its distinctive signs in the phenomena of Trousseau and Chvostek. Pseudohypertrophic paralysis has peculiar deformities, contractures, and weakness without intention cramps. It subsequently shows atrophies and has no myotonic reactions.

Treatment. The causes which provoke the myotonic cramps, such as overexertion, fatigue, exposure to cold, and excitement of all sorts, must be avoided. Massage, reasonable exercise, electric baths, and cerebral galvanization have been recommended.1

CHAPTER IV.

FATIGUE NEUROSES.

MANY occupations requiring the constant repetition of certain precise muscular movements may, eventually, through overuse and fatigue, give rise to disturbances of muscular control for the manoeuver in question. The condition may be manifest as pain, tremor, weakness, or cramp, but usually these are variously combined in different cases. This group of motor disturbances is also called occupation spasms or occupation neuroses. Many of them are described under terms indicating their particular avocational association, as scriveners' palsy, pianoplayers' cramp, seamstresses' spasm, etc. We may take writers' cramp, the most commonly encountered one, as a type, and then only an enumeration of the other forms will be needed. The more delicate and highly differentiated the functional movements, the more readily does their repeated overfatigue set up this inhibitory condition. No definite anatomical changes have been found, but it is highly probable that improved methods will demonstrate morphological alteration of the nuclear gray. Vigouroux2 claims to have found changes in nerves and muscles in many cases, and supposes them to be present in all.

1 W. von Bechterew, "Neurolog. Centralbl.," Nov., 1897.

2" Progrès Médicale," quoted in "Amer. Medico-Surg. Bulletin," Jan. 25, 1897.