CHAPTER XVI

DIAGNOSIS

TICS AND STEREOTYPED ACTS

We have already, on more than one occasion, drawn attention to the phenomena known as stereotyped acts, demonstrating their intimate kinship with the tics and the frequent difficulty of establishing a differential diagnosis. To ensure precision of ideas and of terminology, we must restrict the expression to motor disturbances in which the characters of the muscular contraction are identical with those of normal acts. On this view many motor reactions are really classifiable as stereotyped acts, and among them are those denominated by Letulle "habit tics."

Stereotyped acts occur in normal individuals, and it may fairly be said there is no one but has his habitual gesture, his movement of predilection. As a matter of fact, a certain number of what Letulle calls co-ordinated tics belong to the group under consideration; others, no doubt, are genuine tics, and between the two may be found innumerable intermediate varieties.

From the diagnostic standpoint the stereotyped acts that occur in the course of mental disease, of which a conscientious study has recently been made by Cahen,[168] are highly instructive. He defines them as non-convulsive, co-ordinated attitudes or movements, resembling intentional or professional acts, repeated at frequent intervals and always in the same fashion, till their conscious and voluntary performance is replaced by a degree of subconscious automatism. In the case of the insane they are secondary to some delusion, and persist though the latter may disappear. Hence the patient may be incapable of explaining his movements and attitudes, however much he may persevere in their automatic execution--an evolutionary process akin to that of the tics.

A typical instance may be quoted from Séglas:

B. passed under observation in 1891, suffering from delusions of persecution, and not long afterwards it was noticed that from time to time he used to come to a halt in the courtyard, gaze at the sun, and rotate his hands round an imaginary axis. The reply he vouchsafed to interrogation on this point was that he was effecting the sun's revolution. At present, however, he has sunk into a state of dementia, and while the gesture continues he is unable to furnish any explanation of it.

Of course it is inadmissible to apply the term to co-ordinated acts that are neither conscious nor voluntary, such as the teeth grinding of the general paralytic, or the body oscillation of the idiot. Similarly one must differentiate them from impulsive seizures, abrupt irresistible motor explosions neither frequent nor prolonged.

A distinction has been drawn between _akinetic_ (attitude) stereotyped acts and _parakinetic_ (movement) stereotyped acts. As instances of the former we may give the following:

A woman reclines continuously in bed because she believes she has an infernal machine in her abdomen.

Another patient sits on the ground all day long, buttoning and unbuttoning his clothes.

An old gymnast maintains while he stands a professional attitude in which his head is raised, his right fist closed on his hip, his right leg crossed in front of the left, and his right foot elevated vertically.

Conditions such as these present the most intimate analogies to our attitude tics, though in the case of the latter there is always a more or less pronounced exaggeration of muscular contraction, a certain degree of tonic convulsion.

Parakinetic stereotyped acts are of common occurrence, and embrace every variety of movement or gesture.

A former acrobat leaps staircases, climbs railings, exercises his arms rhythmically and regularly, etc.

A patient promenades untiringly in the same corner and at the same pace.

An old engraver, now a dement, passes the day in reproducing in a more or less modified form certain actions associated with his former profession.

Alike in tics and in stereotyped acts, a time comes when the motor habit establishes itself, for no apparent reason or purpose; hence the co-existence of the two classes in chronic delusional insanity, in dementia precox, in catatonic states, in systematised mental disease of other forms, and in general paralysis.

Stereotyped acts may be the embodiment of ideas of persecution and of grandeur, or the outcome of mystical, hypochondriacal, and other states. A patient with delusions of persecution writhes because he is being "electrified." A hypochondriac rests motionless because he believes himself made of glass. A mystic maintains an attitude of genuflexion for hours at a time.

Obsessions also play a part in the genesis of the acts we have under consideration, but of all delusional ideas those of defence are the most fertile in this respect.

A patient under the care of A. Marie used to carry a fragment of glass between his teeth and other pieces beneath the soles of his feet, the idea being that they formed insulating cushions whereby to protect himself from the electricity of his enemies.

The suggestion was thrown out by Bresler that the movements of tic are often of a defensive character--that the disease, in fact, is a sort of "defence neurosis" linked to hyperexcitability of psychomotor centres. This theory is not unlike the view of hysteria taken by Brener and Freud, and as the movements themselves are usually of the nature of mimicry, Bresler has proposed the term _mimische Krampfneurose_.

In some cases of mental torticollis, the attitude assumed may be considered as a stereotyped act. Martin has recorded an example of torticollis in relation to melancholia. Another of his patients suffered from rotation of the head to the left, a position which could easily be rectified by asking the man to make the sign of the cross. The moment he put his finger on his forehead the displacement of the head was corrected. If, however, he were requested to look straight in front of him, he remained incapable of altering the vicious attitude, the reason he advanced being that he could no longer see the sun.

One cannot but be struck with the remarkable analogies to the cases given by Cohen. And it is worth remembering further, that sometimes mental torticollis degenerates into actual dementia.

TICS AND SPASMS

Nothing is more arduous, at first sight, than the differentiation of a tic from a spasm, the similarity of their external forms being a fertile source of confusion. Yet the establishment of a correct diagnosis is of prime importance, since in their case prognosis and treatment alike are diametrically opposed.

Tic is a psychical affection capable of being cured, if one can will to cure it: at the worst we may fail, but there is no idea that it is indicative of a grave organic lesion prejudicial to life. A spasm, on the contrary, though it appear in almost identical garb, is excited by a material lesion on which depends the degree of its gravity. The focus of disease may disappear, no doubt, but it is only too likely to persist and to occasion other disorders. Hence the desirability of making sure of one's diagnosis--a proceeding not necessarily of insuperable difficulty. If we apply the principles of diagnosis enunciated by Brissaud, to which our attention has already been directed, we shall not find the task beyond our powers.

Let us take a concrete instance.

Here is a cabman, forty-nine years of age, the left half of whose face is the seat of convulsive twitches. These commenced eighteen months ago by brief insignificant contractions of the left orbicularis palpebrarum, which have gradually spread to the whole of the muscular domain supplied by the left facial nerve. Their momentariness and rapidity, their apparent independence of extraneous stimuli, their indifference to treatment and resemblance to the twitches produced by electrical excitation, their occurrence in sleep, the fact of voluntary effort, of attention or distraction, serving so little to modify their range and intensity--all make clear the spasmodic nature of the condition.

The motor manifestation is the consequence of irritation at some point on a bulbo-spinal reflex arc; its abruptness and instantaneousness negative the possibility of recognising in it any sign of functional systematisation. It is not a co-ordinated act of a purposive nature, but a simple, unvarying, constant motor reaction to a particular stimulus. That its intensity should be in direct proportion to the intensity of the latter, changing from feeble contractions to a state of transient tetanus, is further proof of its spasmodic origin. When the excitation is at its maximum, there is sometimes involvement of the opposite side of the face, by virtue of the law of the generalisation of reflexes.

It is true there is no association of pain with his attacks, as in so-called tic douloureux, but the spasm is heralded by a tingling sensation below and to the inner side of the outer corner of the eye. This sensation, "like an electric battery," persists during the spasm and disappears in the intervals. Its occurrence suggests that the ascending branch of the infraorbital nerve, springing from the trigeminal, is affected, and indeed pressure over its point of emergence evokes a certain amount of pain. Moreover, there is occasionally a flow of tears when the spasm is at its height. It may be difficult to decide whether this is the result of mechanical compression of the lachrymal gland or an exaggerated secretion of tears under the influence of stimulation of the lachrymo-palpebral twig of the orbital nerve. In any case the pathogeny of this facial spasm is entirely comparable to that of tic douloureux of the face, and it is quite within the bounds of possibility that a minute hæmorrhage--for the patient is of a very florid type--somewhere on the centrifugal path of the trigemino-facial reflex arc, may be giving rise to the phenomena.

What we wish to insist on, however, is the dissimilarity between this facial spasm and tic. In the movements we have been describing we fail to distinguish any purposive element, any co-ordination for the fulfilment of a particular function: they are not imitative in character, nor do they express any sentiment; no impulse precedes their execution, no satisfaction follows.

The patient's mental state presents no peculiarities, as far as we have been able to discover. There is no volitional debility or instability; if he cannot control the convulsions, it is to be remarked that he cannot control them even for a moment, whereas all sufferers from tic are capable of inhibiting it for a longer or shorter period by an effort of the will, by concentrating their attention on it.[169]

The following remarks on this case are due to Professor Joffroy:

If the patient be asked to open his mouth, the spasm of the left cheek remains in abeyance at long as it is open, but the platysma of the same side then begins to twitch spasmodically. Or if he be requested to shut his eyes, so long as they continue closed the cheek is quiescent; but, on the other hand, both orbiculares palpebrarum, as well as the pyramidal muscles and the adjacent fibres of the frontalis, are seen to contract irregularly. There is a sort of transference of spasm, and this is of peculiar interest, inasmuch at it affords evidence that the lesion is not so restricted as one might suppose.

The explanation no doubt is to be sought in the law of the diffusion of reflexes, confirming the diagnosis of an irritative lesion at some point on the trigemino-facial reflex arc.

In the differential diagnosis of spasm assistance may be obtained by a consideration of the following points:

The extreme abruptness of the movement recalls the contractions produced by electrical stimulation.

There is no purposive or co-ordinated feature in the spasm, which is confined to some nerve area anatomically limited.

Volition, attention, distraction, emotion, all fail to effect any modification of the phenomena.

No irresistible impulse precedes their manifestation, nor is it succeeded by a feeling of satisfaction. Sometimes the spasm is accompanied by severe pain.

As a general rule the patient's mental state does not present the anomalies met with so frequently among those who tic.

Important information may be gleaned from a scrutiny of the condition during sleep. Should the convulsive movement persist, it may be said with confidence to be a spasm; whereas if it completely disappear, it is probably a tic. Whether a spasm may vanish in sleep, however, is another question, which clinical observation has not yet satisfactorily answered, and if no other indication of organic disease be forthcoming, the problem must in the present state of our knowledge be left unsolved.

A. Tic or Spasm of the Face

In cases where the face is the seat of the convulsive movements this problem of diagnosis becomes one of the utmost nicety. That a distinction may be drawn, however, is universally admitted. Hallion,[170] for instance, specifically separates clonic spasms due to structural changes from the "nervous movements" of neuroses such as chorea or tic. Facial spasm is rigorously limited to the distribution of the nerve, and is commonly the result of some alteration in it effected by causes similar to those that occasion facial paralysis.

Clonic spasms of the face are occasionally a sequel to local traumatism--that is to say, they are the result not of direct but of reflex excitation of the facial nerve. Tic douloureux belongs to this class. Tic non-douloureux also is sometimes merely a simple reflex spasm.

One of the most pregnant of Brissaud's lessons is devoted to the elucidation of this part of our subject, and we have already made several quotations from it. In many cases he is forced to say, "I decline to hazard a diagnosis when etiology is silent." We too have been face to face with this diagnostic difficulty on several occasions, and it may be instructive to give the details of one or two cases where no definite conclusion could be arrived at.

A man thirty-seven years of age had been suddenly seized with facial paralysis on the left side thirteen years before, accompanied after an interval of eight days by bilateral fronto-temporal cephalalgia, nausea, vomiting, and disturbances of vision. These attacks recurred irregularly during the next four years, since when they have ceased, although the palsy persists. Recently the patient woke up abruptly in the middle of the night to find that the left side of the face was in a state of spasmodic contraction, a condition which has continued absolutely without intermission. There is no pain in relation to the spasm, merely a peculiar sensation at the site of the muscular twitches. Of what nature are they?

If we analyse the muscular play somewhat more closely, we observe that with the exception of the frontalis all the muscles of the left face, including the platysma, contribute. On a background of more or less permanent contraction are outlined short, incomplete, greatly varying twitches, affecting one muscle after another, and sometimes only a few fibres, in a highly erratic way. The march of the movements obeys no law, either of space or time, nor is there any co-ordination in their activity. That the condition is one of tic, therefore, is scarcely conceivable. No purposive element is discoverable in the phenomena, no systematisation, no expression of emotional excess. All is disorder, confusion, contradiction.

We should, accordingly, be content to make a diagnosis of spasm, but an examination of the patient's mental condition must not be neglected, and in this particular case it is very instructive.

It appears that his imagination has always been singularly fertile, amounting indeed to eccentricity. The picturesque description he furnished of the unusual sensations in face and neck lent support to the view that his muscular activity was intended, consciously or unconsciously, to free himself from their insistence, so that his grimacing may have been but a gesture of defence.

But however much his lack of psychical equilibrium may favour the relegation of his affection to the category of tic, certain considerations make one question the validity of the hypothesis.

In the first place, it is rather an uncommon functional adaptation of the facial muscles to utilise them in an attempt to disembarrass oneself of disagreeable sensations; and in the second it is no less uncommon for the sufferer from tic to be unable to restrain his muscles even momentarily, as our patient appears to be. The actual time of onset of the movements is significant enough, but of supreme importance is the fact of their supervention in an area previously the seat of paralysis. To our mind this is more than a coincidence; from the history supplied by the patient it is plain that the paralysis was peripheral and that the lesion involved the facial trunk somewhere in its intracranial course after its emergence from the side of the pons. Thirteen years later, convulsive movements appear in the same domain. Taking all the circumstances into consideration, we think the hypothesis tenable that the trigeminal is implicated in the pathogeny of the spasm, although the condition is not strictly comparable to the classic tic douloureux.

The exact nature of the lesion is more difficult to determine. A review of the details of the facial palsy suggests its vascular origin, to which theory the headache, nausea, and photophobia of succeeding days and months--indicating, as they do, a circulatory disturbance in the basilar region--lend support. With the gradual restoration of vascular equilibrium the migrainous attacks lessened in frequency and severity, though the facial trunk remained compressed, till the spasm appeared, no less suddenly than had the paralysis. It is feasible that the former, too, is the derivative of a minute hæmorrhage irritating either the centrifugal or the centripetal arm of the facial reflex arc, probably the latter, which would explain the paræsthesiæ.

The possibility of this explanation being accurate is confirmed by a case reported by Schültz, where facial spasm of ten years' duration was shown at the autopsy to have been caused by an aneurism of the left vertebral artery impinging on the facial nerve in the neighbourhood of the basilar trunk.

The arguments, therefore, which plead in favour of the spasmodic nature of the condition seem to us so cogent that the hypothesis of tic must be rejected. We ought not to forget, on the other hand, that a spasm, of whatsoever origin, may be transformed into a tic by the perpetuation of a morbid habit.

Let us take a second case, no less instructive than the preceding.

Madame L. was sent to one of us by Professor Pierre Marie. She had always been nervous, impressionable, and high-spirited, but had never suffered from fits. At the age of eight years, during convalescence from one of the exanthemata, she got a chill, and the very next day developed an acutely painful torticollis, the head resting on the right shoulder and the chin touching the left clavicle. A complete cure ensued, but from that time a certain degree of facial asymmetry was remarked. At the age of eight and a half menstruation commenced, and it still continues, at the age of fifty-nine.

From youth she had at intervals been stricken with pains in the limbs, and with recurrent bilious attacks. Two years ago the death of her husband was the occasion of great mental strain and distress. Sixteen months ago she noticed a curious sensation in the right eye, not painful, accompanied from time to time by blinking of the lids. Very gradually the convulsive movements spread over the whole of the right face, and for the last month their frequency and intensity have been such that rest is an impossibility.

When she came under observation what impressed the mind first was the remarkable asymmetry of her figure: the right side of the face was smaller than the left, the right eye appeared to be at a lower level than the other, while the mouth was strongly deviated to the right and the chin twisted in the same direction. For a minute or two the facial contortion held sway, disappearing only to reappear quickly.

Not solely to the old torticollis was the facial asymmetry attributable, but also to the convulsive movements of the right half of the face. The effect of these was to close the right eye, deflect the nose to the same side, drag the mouth in a similar fashion, and wrinkle the skin of the chin and neck. Hence was evolved a unilateral grimace quite unlike any ordinary expression, resembling rather the facies in contracture secondary to facial paralysis.

During the next few months there was a gradual change from this tonic to a clonic stage, in which the movements were of less frequent occurrence, but more rapid. In repose there was no further indication of the old facial palsy than the flattening of the facial lines on the right. Under the influence of any emotion, or any passing contrariety, or in the course of an animated conversation, or if circumstances call for their repression, the spasms increase in number and degree, whereas solitude and tranquillity favour their subsidence.

A recent development has been the discovery of a means of checking the spasm--viz. by compressing the larynx with the fingers of the two hands. Madame L. admits the illogical nature of the manOEuvre, but extols its efficacy. As a matter of fact, it sometimes fails of its object.

How, then, is this localised convulsive movement to be designated? Is it a tic or is it a spasm?

The march of the disease, its painlessness, the absence of any reaction in sleep, the success of the little laryngeal trick, the inhibitory effect of the will, the definite influence of attention, distraction, in short of the psychical condition of the moment--all plead in favour of its classification in the former category. On the other hand, we cannot shut our eyes to the fact of the pre-existence of specific organic disease, and, moreover, the spasm is strictly confined to the anatomical distribution of the facial nerve. Even in periods of repose there is a certain amount of fibrillation on that side. On these counts are we to hazard the diagnosis of facial trophoneurosis?

A subsequent opportunity of examining the same patient served to confirm the diagnosis of spasm secondary to facial dystrophy, and treatment failed to make any impression on the condition.

Our object in giving these cases has been to point out the difficulties in the way of diagnosis, especially where spasm is superadded to a mental state that itself predisposes to tic. The wisest plan in many instances is to confine oneself to a description of the symptoms and to tabulate the arguments for and against a particular view, without perpetrating the error of committing oneself.

Many cases labelled convulsive tic might be quoted where the expression of so definite an opinion ought to have been reserved, as in one reported by Mayer[171] under the title of convulsive tic consecutive to infraorbital neuralgia:

A man, thirty-two years of age, had suffered from a severe infraorbital neuralgia of some weeks' duration, apparently attributable to a chill. The pains recurred at intervals till their substitution five years later for slight spasmodic twitches of the left eyelid, which gradually developed into violent convulsions of the whole of the left half of the face. These spasms were preceded by a sensation of numbness in the left ear, while during repose no modification of facial expression was to be remarked.

Further, there was a history of exactly similar neuralgia and spasm in the mother of the patient, although in her case the latter had been the first to appear, and had been replaced after a six years' interval by left facial neuralgia, which resection of the nerve failed to relieve.

In these cases the condition is undoubtedly one of painful facial spasm, inaccurately and unfortunately styled "tic douloureux."

Bruandet[172] has recorded a typical example of right facial hemispasm consequent on facial neuralgia, in which, however, no certain macroscopical or microscopical lesion was detected, in either cortex or bulb. But the mere fact that no structural alteration was discovered post-mortem cannot invalidate the diagnosis; the imperfection of our methods of investigation suffices to explain the negative results of such researches.

B. Tic or Spasm of the Neck--Torticollis Tic and Torticollis Spasm

To make a diagnosis of torticollis, it is essential to satisfy oneself of the integrity of the bones, muscles, and articulations of the cervico-scapular region, previous to directing attention to the psychical state of the patient. In regard to the latter point, the question of heredity must not be neglected. If personal and hereditary defects are prominent, the presumption is in favour of mental torticollis; and if the convulsive movements present the characters of tic, the diagnosis is practically certain.

In three cases under the observation of Fornaca,[173] for instance, there is no room for doubt. Not merely was there no sign of irritation from peripheral sources, but also no one of the three was psychically normal.

Nevertheless we frequently find ourselves confronted by the question: is the movement a tic, or is it a spasm? For, strictly speaking, there are both a torticollis tic and a torticollis spasm, and their separation one from the other is often a matter of the greatest perplexity.

We must refer the reader to the chapter devoted to mental torticollis for a consideration of the features of that condition, and we need not dwell on those cases of spasmodic torticollis that are obviously occasioned by irritative lesions of nervous centres or conductors. In this latter category may be placed the case put on record by Oppenheim, where torticollic spasms were produced by pressure of a cerebellar tumour on the cranial nerves.

But in the affection known as hyperkinesis of the accessory of Willis we have little doubt both tics and spasms have been included. Apart from the cases of spasmodic torticollis, so called, which Babinski has published and to which reference has already been made, we may be allowed to cite one or two more, in order to exemplify the differences of interpretation to which they are liable.

At the Congress of Toulouse two patients were shown by Desterac,[174] both of whom had suffered since the age of eight from a disease akin either to Friedreich's disease or to hereditary cerebellar ataxia.

They presented the spastic gait of the former with the involuntary movements of the latter, in addition to spasm of the hand in writing, spasmodic movements of the trunk, and spasmodic torticollis. Both had club foot and scoliosis, and one was afflicted with spasm of the face and left arm. In his case, further, there was nystagmus, together with loss of reflexes and difficulty in articulation, while fibrillary contractions were to be observed in his muscles. The other patient's reflexes were exaggerated, and he showed a double extensor response.

In Desterac's opinion their spasmodic torticollis was dependent on this congenital constitutional affection, which might be regarded as a _fruste_ form of one of the diseases above mentioned.

Through the kindness of M. Desterac the opportunity has been granted one of us of examining the two patients, and we should like to point out why we think his interpretation of their symptoms must be considered with reserve.

Speaking generally, we thought the cases closely resembled those in which a long-standing mental torticollis is accompanied with convulsive movements of the limbs. The scoliosis was not permanent, the deformation of the foot could be overcome, and at the same time we failed to convince ourselves of the presence of nystagmus and the absence of the knee-jerks. Moreover, we happened to observe one of the patients in the street unawares, and remarked how between two phases of bizarre contortions his vicious attitudes and convulsive gestures almost entirely vanished. In fact, the clinical picture seemed to us to be quite other than that associated with organic disease such as Friedreich's disease or hereditary cerebellar ataxia.

Another case recently brought before the Neurological Society of Paris by Marie and Guillain[175] serves even better to illustrate the intricacies of diagnosis.

The patient was a man of fifty-eight, who for years had exhibited certain movements apparently of an athetoid nature. His head was extended and rotated to the right synchronously with elevation and eversion of the left shoulder, then it passed into flexion. Except for a few odd movements of the tongue, the face conserved immobility. In the arms the localisation of the contractions was mostly proximal, though there were alternating flexion and extension movements of the fingers which suggested athetosis. Flexion, inversion, and adduction of the thighs also occurred. The recti abdominis were similarly involved.

Under the influence of emotion the movements were increased, but they could not be inhibited by an effort of attention. Their rate was too slow for chorea. Ordinary voluntary movements were performed without apparent trouble; the patient was able to dress himself, and to drink without spilling the liquid. Diminution of the knee-jerks was noticed, with what seemed to be an extensor response. Slight scoliosis of the vertebral column and a misshapen right foot recalled Friedreich's ataxia. There was nothing to justify a diagnosis of hysteria.

This curious condition dated from the year 1874, when the patient had a febrile attack, in the course of which pain and tingling appeared in the toes of the right foot, followed by involuntary movements of the same member. Analogous symptoms were not long in appearing in the left arm. Two months later the condition had become general, but from that time no special modification took place.

In the subsequent discussion it was remarked by Souques that the case resembled one recorded by Chauffard[176] as Friedreich's disease with athetotic attitudes, where the patient was a child with club foot, diminution of the knee-jerks, and generalised athetotic movements.

Notwithstanding our inability to assign a definite nosographical position to examples of this kind, we think it desirable to make some reference to them, in the hope that further observations will aid in their diagnosis. They at least remind us that convulsions occurring in the course of organic disease may be simulated by the manifestations of certain motor neuroses.

TICS AND CHOREAS

A. Sydenham's Chorea

It would be difficult to find a better description of chorea minor than that given originally by Sydenham himself:

The dance of Saint Guy, chorea Sancti Viti in Latin, is a sort of convulsion whose incidence is greatest, in both sexes, between the age of ten and puberty. Its onset is characterised by weakness of one limb, which the patient drags behind him, and soon the arm of the same side is affected in the same way. He finds it impossible to maintain the same position of the arm for two consecutive moments, however great be his efforts to attain this object. Before he can bring a full glass to his lips he makes innumerable gestures and antics, as the convulsive moments of the limb deviate it from one side to the other, until at length he has piloted the glass opposite his mouth, when he empties it at a gulp.

If we were to confine ourselves to this description by Sydenham, which so far as typical cases of the disease are concerned is perfectly accurate, differentiation between tic and chorea would not be a matter of any complexity. Unfortunately, however, the varieties of this form of chorea are legion, and in practice one constantly meets with conditions suggesting alike the gesticulations of chorea and the convulsive reactions of tic. Moreover, it has been pointed out by Oddo[177] that the fact of the habitual exaggeration of tic during the very years when chorea is liable to appear is calculated to confuse the issue.

He has attempted, however, to specify certain factors in the differential diagnosis. In the first instance, the form of the movements is of significance: there is no co-ordination in the muscular play of the choreic; it is amorphous, indefinable, and erratic, whereas the gestures of tic are purposive, and may be said to have a shape. One never sees in chorea a succession of similar movements, but though a patient be suffering from several tics, each of them is reproduced always in the same fashion. Unilaterality of distribution is more common in chorea than in tic; in other words, chorea, more or less, follows anatomical lines in the regions it affects, whereas the incidence of tic is physiological.

Both are arhythmic in their manifestation; nevertheless the repetition of tic is noteworthy for its regularity as compared with the changing mode and rate of the other. Noir emphasises the diagnostic value of its frequency, abruptness, and reiteration of identical movements. In a majority of cases the interference of the will is futile as far as chorea is concerned, while the victim to tic is usually capable of restraining his muscular activity at least for a space. The choreic exhibits his movements in public, but the _tiqueur_ seeks the seclusion of his own room. The association of tic with obsessional ideas is frequently encountered, but there is no similar connection between obsessions and chorea. In addition, the myasthenia, pains, and alterations in the reflexes that often characterise chorea are awanting in the other affection.

It cannot be gainsaid, however, that the frequency with which atypical varieties of chorea occur is inimical to a ready diagnosis, and the onerous nature of the task is not lessened by the circumstance that many choreics are the offspring of neuropathic parents and reveal psychical anomalies comparable to those of the subjects of tic.

In a disease such as variable chorea, which has features in common both with tic and with chorea properly so called, the problem of diagnosis is still more complicated, though excellent hints for its solution have been furnished by Brissaud.[178]

However frequently and warmly the theory of the origin of chorea in a neuropathic predisposition was advocated by Charcot, the fact of its usual evolution consecutive to some toxic or infective process is no less certain. Its incidence is greatest in children and the adolescent; it runs a regular course of increase and decrease; and the circumstances which cause the symptoms to vary during this cycle are never sufficiently potent to bring about even transitory suppression of them.

It is true that changes in the intensity of the symptoms seem to confer a remittent character on the affection, but there is nothing at all comparable to the sudden and unexpected waxing and waning of the form of chorea at present under consideration. None of the pathological attributes just mentioned concerns variable chorea, which, in addition, differs from Sydenham's chorea in two points--the multiplicity of the types of movement, and the fact that the patient can voluntarily check his involuntary actions. For these reasons, assimilation of the two clinical varieties is impossible, and the confusion of the two in practice need never occur.

A form of chorea entitled "habit spasm" by Gowers, and "habit chorea" by Weir Mitchell, has been the subject of further study by Sinkler,[179] but in all probability the cases of this description reported are instances of the variable chorea of Brissaud.

B. Huntington's Chorea

In spite of the preponderating etiological significance of heredity and the constancy of psychical imperfections in the chronic chorea of Huntington, its confusion with tic is not at all likely to occur. Difficulties might arise in distinguishing chorea major from variable chorea, however, and here we have the views of Brissaud to help us.

True chronic chorea is an incurable neurosis, of life-long duration. We have no trouble in pronouncing a diagnosis of chronic chorea if the symptoms date back five, ten, or twenty years, but they must have had a commencement, and the whole problem is to foretell the course of a chorea as yet only a few weeks or months old.

The involuntary movements of chronic chorea, like those of Sydenham's chorea, are illogical, but they are combined in a co-ordinate manner--that is to say, certain functionally associated muscular groups act simultaneously as for a particular end: the patient shrugs his shoulders, closes his fists, cracks his fingers, utters cries, he swallows, sniffs, sucks in his breath, makes the sound of kissing, etc, in all of which actions orderly participation of the musculature in a foreordained way is evident. Slight twitching of individual muscles and parts of muscles also occurs.

There is no limitation of the movements to a special division of the body; on the contrary, they spread from one muscle to another, and from one segment to another, rapidly and arhythmically. The gait is by turns skipping, dancing, or stumbling, interrupted by falls or by abrupt jerks of the loins. Speech is uncertain or monotonous; writing is incorrect and badly formed, sometimes illegible. A fact of the utmost importance is that all these involuntary movements may be modified, abated, relieved, so to speak, by voluntary movements in an inverse direction. In some cases the power of willing is still sufficiently developed to permit of the patient's following his occupation.

The steadily progressing increase in the seriousness of the motor trouble, paralleled by progressing mental deterioration, is one of the most significant factors in the differential diagnosis. It is precisely the variability of the symptoms that distinguishes variable chorea.

C. Hysterical Chorea

The conditions to which the name of hysterical chorea is applied may assume two forms, the commoner being known as rhythmical chorea, the other as arhythmical chorea. In the former case the convulsive movements are usually unilateral, being confined sometimes to a single limb, and reproducing, for instance, the actions of dancing (saltatory chorea), or of swimming (natatory chorea), or such professional movements as those of the blacksmith (_chorée malléatoire_). Occasionally there is a more or less faithful reproduction of deliberate and purposive acts in the form of attacks of varying duration, recurring, moreover--and this is their cardinal feature--at equal intervals.

Under the title of disease of the tics two cases have been published by Nonne,[180] the first consisting of rhythmical twitches in a man of forty years, secondary to a head injury, the other presenting similar appearances, but concerning a young girl of eighteen years who had sustained a shock. In neither was there any sign of hysteria. The reporter animadverts on the designation "rhythmical chorea," and protests that the systematisation and co-ordination of the movements are very different from the clinical picture of Sydenham's chorea, while their rhythmical nature does not allow of their being classified as tic.

Sometimes hysterical chorea is arhythmical--that is to say, the movements are irregular and contradictory, as in ordinary chorea. True chorea in cases of hysteria comes under this heading, as well as those cases where hysterical patients imitate the movements of chorea. The presence of the distinctive characters of hysteria makes a diagnosis of tic improbable.

The separation of hysterical from variable chorea may be peculiarly perplexing, as in one of Brissaud's cases, where the patient's extraordinary mental instability was such as is encountered only in advanced hysteria, while her disorders of motility were highly characteristic of what is known as variable chorea.

The condition described as chorea gravidarum may be placed at one time in the category of hysterical chorea, at another in that of ordinary chorea. In it there is intense motor restlessness, and accompanying mental symptoms are not awanting in a majority of instances.

D. Electric Chorea, Bergeron's Chorea, Dubini's Chorea, Fibrillary Chorea of Morvan

To render the study complete, we may remind ourselves of those still imperfectly differentiated forms known as electric chorea (Hénoch-Bergeron) and Dubini's chorea.

Bergeron's chorea affects children chiefly, and is characterised by the suddenness of its onset and the rapidity with which it attains its maximum. The movements are abrupt and brief, as though produced by an electric discharge at regular intervals, but their intensity does not hinder the execution of voluntary acts. They are sometimes confined to the head and limbs, most commonly they are generalised, and during sleep they disappear.

In the opinion of many, Bergeron's chorea is secondary to gastric disturbance. A cure may be regarded as certain, and indeed frequently follows the administration of an emetic. Sometimes the effect of the latter seems to be purely psychical.

Pitres thinks that this condition, as well as the electrolepsy of Tordeus, is simply a manifestation of infantile hysteria. According to Noir, there is an affinity between tic and electric chorea, and Ricklin is inclined to consider the two identical, but further study of the question is desirable.

Dubini's chorea is ushered in by pains and aches in the region of the head, neck, and sometimes the loins, and these are succeeded by electric-like twitches in the segment of a limb, which quickly become general. Severe convulsive attacks also occur, without loss of consciousness, entailing actual paresis of the limbs. The duration of the disease may be days or months, and 90 per cent. of the cases have a fatal issue. Confusion with tic is impossible.

We need not concern ourselves with so-called paralytic chorea, or with the fibrillary chorea of Morvan, which is a disease of adolescence, characterised by fibrillary contractions in the calves and thighs, passing thence to the trunk muscles and even to the arms; the face and neck, however, are spared, and during voluntary movement the fibrillation vanishes. Probably it is merely a variety of the paramyoclonus of Friedreich.

TIC AND PARAMYOCLONUS MULTIPLEX--TIC AND MYOCLONUS

It is not our intention here to seek to provide a differential diagnosis between tic and the various conditions usually classed as myoclonus, and that for two reasons: in the first place, we cannot admit that the latter form a distinct clinical or nosographical entity, since the term myoclonus seems simply to be an abbreviation for clonic muscular convulsion, and is a symptom rather than a clinical syndrome; secondly, the fact that the tics themselves have been incorporated with myoclonus involves the investigation of all the published cases with a view to their critical sifting. This task we have pursued for our own edification, but to enter on it here would serve no useful purpose, and we shall rest content with examining succinctly several recent cases described as myoclonus, in the hope that the prosecution of further research will introduce order into what is at present chaos.

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Among the various forms of myoclonus there is one which presents a certain individuality, and which was described originally by Friedreich under the name of paramyoclonus multiplex.

This disturbance of motility supervenes, in patients with a neuropathic heredity, after some psychical accident such as a sudden fright or emotion, and consists in clonic muscular convulsions affecting the body generally, with the exception of the face. The contractions appear without obvious cause in one or in several muscles, are instantaneous, involuntary, and usually bilateral, but their most important feature is their inequality and irregularity. They may or may not effect displacement of the limbs; in any case they compose neither gesture nor gesticulation. Volition occasionally seems to have some transient inhibitory influence over them; they are exaggerated by cold and by emotion, and usually disappear in sleep.

It is obvious that this account of a typical case precludes the possibility of any confusion with tic, but the published cases are not always in conformity with it.

In 1892 Lemoine[181] reported a case where the movements of paramyoclonus multiplex were accompanied with echolalia and psychical changes. Raymond quotes an instance of the disease being preceded by facial tic, and another associated with tremor and choreic movements.

D'Allocco[182] has recorded twenty-four cases of differing forms of myoclonus, of which nineteen occurred as a family disease, in conjunction with stigmata of degeneration, epilepsy, and hysteria.

In a patient, aged twenty-six, suffering from general paralysis, Hermann[183] noted the presence of abrupt, irregular, myoclonic twitches in the sternomastoids, recti abdominis, adductors, and in some of the toes and fingers, first on one side and then on the other, also in both legs, and subsequently in both arms, the face being unaffected.

Jancowicz considers diagnosis possible only in typical cases, and expresses the opinion that paramyoclonus is a syndrome common to many affections. Further, Schupfer makes the perfectly justifiable remark that under this denomination have been included cases of chorea, tic, hysteria, and rhythmic spasm; others have been secondary to organic disease of the cerebro-spinal axis, such as rolandic lesions, spinal muscular atrophy, chronic poliomyelitis, syringomyelia. Others, again, depend on one or other of the psychoses, others on infective conditions such as malaria, diphtheria, typhoid, or on intoxications such as uræmia, mercurialism, or lead poisoning. Only a few recorded cases cannot be attributed to any of the conditions enumerated above, hence Schupfer's objection to the promiscuous classification of them all as paramyoclonus multiplex is quite warranted, in the absence of a uniform etiology and symptomatology.

Schultze[184] has suggested the term monoclonus for the tics, and he distinguishes monoclonus, polyclonus, and paraclonus. Embraced in the last of these is the paramyoclonus of Friedreich, which, according to Schultze, is usually unilateral, voluntary action diminishing the intensity of the involuntary movements, whereas the converse is the case in tic or monoclonus. Mixed forms are met with, however, and Schultze himself mentions one in which the movements were bilateral and increased with voluntary activity.

Heldenberg[185] applies the term intermittent functional myoclonus to twitches occurring from time to time in antagonistic muscles during voluntary movement, twitches exaggerated by excitement and diminished with rest. They occur in combination with well-marked vasomotor phenomena.

The myokymia of Kny and Schultze is characterised by fibrillation, pain, hyperidrosis, and changes in electrical excitability.

A case which seemed to be a combination of paramyoclonus with Thomsen's disease has been reported by Hajos[186] under the title myospasmia spinalis.

There cannot possibly be any hesitation in arriving at a diagnosis between tonic tic and Thomsen's disease, a condition consisting in slowness of relaxation of a strongly contracted muscle, and conceivably due to defective metabolism or organic change in muscular tissue.[187]

Examples such as the above, culled at random from an abundant medical literature, and variously entitled, will serve to demonstrate the protean nature of what the medical world is content to call myoclonus, and if from this collection of motor disorders we may hope to extricate the tics, there will remain still no inconsiderable labour of differentiation for the student.

TIC AND ATHETOSIS

The athetotic movements that may accompany hemiplegia are scarcely likely to be confused with those of tic, but difficulties may arise where the athetosis is double.

It has been universally remarked that athetotic movements of the face reproduce the expression of emotions, such as admiration, astonishment, sorrow, gaiety, etc. Of course the same may be said of the grimaces of chorea; the latter, however, are usually more abrupt and pass less readily one into the other. The gesticulations of athetosis are undulatory, so to speak, and their excess leads to deformities principally in the direction of forced extension. The musculature is often rigid, and the reflexes are increased in activity. Sometimes there is a considerable degree of mental disturbance.

Now, it is precisely in cases where mental deterioration is a prominent feature that "nervous movements" have been described resembling those of athetosis, for which the term pseudo-athetosis has been coined. Two examples may be quoted from Noir.

E. is a girl of eleven years. Her expression is grimacing; her tongue is often protruded, but never bitten; her head is regularly flexed or extended, or rotated rhythmically to left or right. The arms are moved spasmodically at shoulder and elbow, while the hands are the seat of athetotic movements. She walks curiously, throwing her feet out in advance without bending her knees. She has a silly smile, and her mouth almost invariably hangs open. On request she can keep her hands quite steady, but one observes at once the effort this entails in the sudden seriousness of her expression. The ordinary acts of every-day life are performed satisfactorily enough: she can dress and undress, use a knife and fork, thread a needle, sew, etc.

J. is eleven years old also. She puckers her lips, contracts her eyebrows, elevates her alæ nasi; at the same time she exhibits pseudo-athetotic movements of her fingers which are entirely under voluntary control.

The question may indeed be asked whether pseudo-athetosis and variable chorea are not really identical. Further, all sorts of combinations of athetosis and myotonia have been noted,[188] but more light must be shed on the subject before any further classification can be attempted.

The following case has recently been published by Marina[189]:

A blacksmith, aged seventeen years, already treated three times for recurrent chorea, suffered from slow contractions of the shoulder muscles, involving the elevators and internal and external rotators successively, and accompanied by movements of the head and arm, and by twitches of the quadriceps. Nothing seemed to have any influence over these movements except sleep. The faradic excitability of the shoulder muscles was augmented, the galvanic excitability diminished. Application of the constant current to the head and back sufficed to effect a cure in three weeks.

Marina proposes the term athetotic myospasm for these incessant slow alternating contractions, impulsive myospasm being employed to signify convulsive movements of more than one muscular group, purposive yet irresistible, as in tic and chorea major. Simple myospasm consists of single twitches in individual muscles, recalling those produced by electrical excitation. If several muscles are implicated, the condition is one of multiple myospasm or myoclonus.

TICS AND TREMORS

All tremors, whether they occur during muscular repose or muscular activity, are distinguished by the relative restriction of their range and the regularity of their time. The tremors of paralysis agitans, disseminated sclerosis, senility, toxæmia, hysteria, ex-ophthalmic goitre, etc., are not liable to be mistaken for tic.

It is true, of course, that tremor is sometimes combined with choreiform or athetotic movements in patients with psychical stigmata.[190] A proposal, too, has been made to unite hereditary and functional tremor and to describe them as a tremor neurosis.[191]

However simple be the diagnosis between tremor and tic, it is worth while to note in passing the etiology they may have in common. In a case recorded by van Gehuchten an intention tremor of the right arm co-existed with a tic of the right sternomastoid.

A sudden twitch of the whole body Letulle particularises as a "tic of starting," and Noir too thinks that a start of this nature may constitute a tic, but we are inclined to consider it a generalised reflex.

TICS AND PROFESSIONAL CRAMPS

We have already had occasion to enlarge on the distinguishing features of professional or occupation cramps, spasms, or neuroses. Writers, pianists, violinists, flutists, dressmakers, telegraphists, watchmakers, milkers, knackers, blacksmiths, shoemakers, tailors, dancers, embroiderers, barbers, etc., etc., are all liable to suffer from occupation cramps. In every case the condition is one of inability to perform the professional movement, and that alone.

Grasset proposes to separate intra-professional from post-professional spasm, the former consisting in the impossibility of making the necessary professional movements, the latter in the involuntary over-reproduction of the familiar act. Properly speaking, the post-professional spasm is a tic.

We need not do more than remind the reader of the close affinities we have already seen to exist between tics and professional cramps, and of the mental instability which both classes of patient present.

L. supplies an instance of variable hemichorea followed by writers' cramp and later by mental torticollis.

When L. was eight years old choreiform movements of the right arm began to appear, and soon rendered writing an impossibility. The disease continued for so long a time that one might not unreasonably expect to find considerable actual impairment of her caligraphy. As a matter of fact, it is scarcely affected: the patient can make her letters correctly, but after each letter she lifts her pen to allow her fingers to perform an abrupt movement, then she proceeds.

It cannot therefore be considered a true writers' cramp, but when she had learnt to write with the other hand it was not long ere that became the seat of a genuine cramp. The moment she attempted to make the pen move over the paper her grasp of it tightened and her fingers stiffened; her wrist would no longer answer her. To obviate the trouble she used a pencil, at first with complete success; but the cramp occurred afresh, and she gave up writing altogether. Prolonged holidaying, however, and respite from the exercise, had a salutary effect, and to-day there is no trace of former mischief.