CHOREA:

A STUDY IN CLINICAL PATHOLOGY.

BY

H. C. WOOD, M.D., LL.D.

REPRINTED FROM THE THERAPEUTIC GAZETTE, MAY, 1885.

DETROIT, MICH. :

GEORGE S. DAVIS, PUBLISHER.1885.

CHOREA:A STUDY IN CLINICAL PATHOLOGY.

PRECISELY as at one time paralysis wassupposed to be a disease, so at a later

period was chorea believed to be a distinctaffection. Indeed, many of the professionstill use the term as though it were the nameof a distinct ailment, and most of the treatisesupon nervous diseases have a chapter uponchorea as a separate affection. It is, however,perfectly clear that the word should be em-ployed as analogous to, or having equal rankwith, paralysis or tremor. The term choreicmovements is unnecessary; or, if it still beused, the term chorea should be consideredto represent that condition in which choreicmovements occur.

Of the various diseases or conditions inwhich choreic movements occur, I shall firstspeak of that which is known as post-para-lytic chorea, or sometimespost-hemiplegic chorea,and begin by a brief record of a case nowunder my care.

Miss W., aged 29. At nine months of age,probably after improper feeding, she was seizedwith a violent convulsion. These convulsionsrecurred at brief intervals until she was aboutfive years old, when she had an exceedinglybad one, lasting all night. During this timecomplete right-sided hemiplegia appeared.Three or four months afterwards she began tohave movements in the right arm. These havecontinued ever since. She had convulsionsafter this frequently, until about the age offifteen, when, menstruation setting in, the con-vulsions became more infrequent, and she hasnot had one since 1875.

Present condition, a well-nourished, healthy-looking woman. Right side of the face some-what smaller than the left side of the face, andthe left angle of mouth, on smiling, going upvery distinctly more than the right. Everytime she winks there is a very curious localspasm, covering about the size of half a dol-

lar, in the right side of the chin. Occasion-ally a slight tremulousness about the rightcorner of the mouth. The spasms are chieflyin the arm, causing the hand to vibrate rap-idly. There are also spasms of the forearm,causing disorderly movements of the fingers;right hand registered on the dynamometer 45,left hand 75 ; while the right-arm muscles areapparently bigger than the left. There is aperpetual perspiration on the right arm. Thedeltoid muscle evidently takes part in thespasm, and is exceedingly large. There isslight loss of sensation in the right arm. Byfixing the hand against the body, immediatelyunder the right breast, she is able to do suchwork as crochetting. Complains much of painin the upper arm, especially in the region ofthe deltoid. This pain is worse on gettingup in the morning. She does not know aboutspasms during sleep, but generally lies on herarm. General intelligence and health perfect.

This case is especially interesting on ac-count of the co-association of winking with avery peculiar local spasm involving only a fewfibres of the facial nerve. In some way theoculo-motor centres have become linked witha few cells of one facial nucleus, so that onereflex nerve-discharge influences the threecentres, a combination very difficult to ex-plain.

This case illustrates many of the peculiari-ties of this so-called post-hemiplegic chorea,but it seems to me as absurd to speak of thiscondition as a distinct affection as it wouldbe of contractures occurring after an apo-plexy. There are, however, certain verycurious facts connected with the affectionworthy of here being noted. Very generallythere is associated with it a loss of sensibility ;

then again the movements are almost alwaysconfined to the upper extremities. Although

CHOREA—A STUDY IN CLINICAL PATHOLOGY.2

in some of the reported cases there was alack of control over- the movements of theleg, I cannot recall a single instance in whichthere were in the leg decided spasmodic move-ments such as occur in the arm of Miss W.

The following case of chorea now under mycare at the University Hospital is in many re-spects closely allied to the cerebral chorea ofearly childhood, and seems worthy of beingnoted, although the history of it is very im-perfect. The patient is a young man 19years of age, well nourished, muscular, whofor the last three years has followed the oc-cupation of driving trotting-horses, both intraining and races. He states that his presentdifficulty began when he was four years of age,and that two years since the movements weregreater than they are at present; except for themovements, the health is perfect, and the mus-cular power of the whole body is much abovethe average. The movements are confined tothe upper extremities, including the group ofshoulder muscles; they are worse in the rightthan in the left arm; are constant during theday; do not interfere with his going to sleep,and always cease at such time. They aregreatly increased by excitement, or when heattempts any movement with his arms underobservation. They are much lessened by anysteady muscular act, such as driving a hard-mouthed horse or firmly grasping a chair.They are mostly typical choreiform move-ments, but at times when he is very muchexcited become so marked as to appearalmost like voluntary movements. The pa-tella reflexes are very active, and there is inthe right arm a slight but distinct finger-reflexwhen the tendons on the wrist are tapped.

The following extract from my note-bookshows that the loss of sensibility is very slight,and I am not sure whether the lesion is spinalor cerebral, although inclined to the latterview. “ Lowest point of separation of points.Right ar7n—back and front of forearm, 7.5cm. ; palm, 0.6 cm. ; tips of fingers, 0.4 cm. ;

back of fingers, 0.5 cm.; region of biceps andof deltoid, 7 cm. Left arm—upper and fore-arm as on other side ; tips of fingers, 0.2 cm. ;

back of fingers, 0.5 cm.”

There are two classes of these cases, onein which the choreic movements develop atthe same time as the palsy, or even before it,and one in which they first appear long afterthe loss of power. It is very desirable thatclose microscopical examinations should bemade in the latter class of cases, as it is verypossible that the symptoms may be connected

with secondary degenerations. Such connec-tion is established for post-paralytic contrac-tures, and there is reported in the HospitalGazette (vol. iv. p. 366) a case in which suchcontractures co-existed with choreic move-ments, and in which there was almost certainlysecondary degeneration of the nerve-centres.

The seat of the lesion in post-hemiplegicchorea, as first stated by Charcot, and espe-cially developed in the thesis of his pupil, Ray-mond, is in the posterior part of the internalcapsule, in the immediate neighborhood ofthe lenticular nucleus and optic thalamus.The immediate band of fibres of the coronaradiata especially involved is in front of thatconnected with and covering the posteriorend of the optic thalamus. This region, itwill be remembered, is a very distinct one,having its own artery, the posterior optic.Although in many cases of post-hemiplegicchorea the lesion is located in the spot desig-nated by the great French neurologist, suchlocation is not invariable. M. Demange{Rev. de Med., March, 1883, p. 377), afterreporting a case with Charcot’s lesion, recordsone in which there was violent post-hemiple-gic chorea, and in which the lesion was situ-ated in the convolutions. It is a very inter-esting feature in this case that the choreicmovements were preceded by epileptiformcrises, which ceased when the choreic move-ments developed. The choreic movementsthemselvesalso disappeared before death. Intwo cases of cerebral syphilis, with presumablycortical lesion, I have seen a violentchoreiformspasm of the face replace epileptiform con-vulsions, and there is a close analogy betweenpost-hemiplegic chorea and Jacksonian epi-lepsy. Dr. Demange reports a case in whichhemiplegia was associated with severe trem-blings, like those of paralysis agitans, andthe lesion was situated in the lenticular nu-cleus. This form of tremor may, however,be considered distinct from true post-hemi-plegic chorea, but in the Bulletin of the Ana-tomical Society of Paris, 1879 (vol. liv. p.748), is recorded a case in which a true post-paralytic chorea was found to depend upona softening of the brain on the level of thefirst convolution, involving the whole thick-ness of the external capsule, as the sole lesion.This case separates itself from those of Char-cot in the complete preservation of sensibility,and as the choreic movements developedmonths after the coming on of the paralysis,it is fair to suspect the presence of an unob-served secondary degeneration.

A very important fact in the natural history

CHOREA—A STUDY IN CLINICAL PATHOLOGY. 3

of post-hemiplegic chorea is that it may existin its most typical form without organiclesion, as is shown by the case reported inthe Bulletin of the Anatomical Society (vol.Iv. p. 150). A woman, aged 49, with a pasthysterical history, and also one of chroniciritis and arterial atheroma, but who deniedsyphilis, suffered paresthesias in the right armand leg, with vertigo, lasting for some days.She then had a sudden right hemiplegia,without loss of consciousness. The paralysiswas at first complete, but eight days later shebegan to walk a little. Two months afterthis she had a second attack. Several monthssubsequent to this she entered the hospital.At that time she had complete right-sidedhemiplegia both of common sensibility and ofthe special senses, and a partial right motorhemiplegia, with very marked choreic move-ment of the right arm. Neither the right legnor the left side were in movement. Shedied of an intercurrent pneumonia, and afterdeath a very careful microscopic examinationof the brain failed to detect any lesion.During life a murmur of an aortic insuffi-ciency had been heard, and after death theappropriate lesion was found. It seems tome that the reporter of this history is correctin affirming that during life it was impossibleto determine that the case was not one ofcerebral disease. This case brings up clearlythe possibility that in some even of theseprolonged post-paralytic choreas there maybe no organic affection.

Not only may post-hemiplegic, but alsoother forms of chorea be imitated by hysteria.I have not rarely seen cases offering the or-dinary manifestations of Saint Vitus’s danceof childhood in extremely hysterical youngfemales, and believe them to be of pure hys-terical origin.

The so-called electric chorea of Frenchwriters is evidently, in many cases, hysterical.It consists of very rapid, rhythmical movementsof the head or other portions of the body, oc-curring at intervals, as though in a series ofshocks. A very interesting case is reportedin the Thesis of Andrd Guertin, Paris, 1881,which shows that this electric chorea may co-exist with general choreic movements, exactlyresembling those of the Saint Vitus’s dance.In some cases of hysteria the movements areentirely rhythmical, and it is perfectly evidentall forms of choreic spasms may be producedby hysteria.

The truth of the following propositions maybe considered established by facts which havebeen already adduced :

First. —Choreic movements may be the re-sult of organic brain-disease.

Second.—Choreic movements exactly simu-lating those of organic brain-disease may oc-cur without any appreciable disease of thenerve-centres.

Third.—General choreic movements, as wellas the bizarre forms of electric and rhythmicalchorea, may occur without any organic diseaseof the nervous system.

To these propositions may be added afourth, viz.: Choreic movements may be theresult of a peripheral irritation, or, in otherwords, may be reflex.

As proof of the last proposition, I wouldcite the following cases :

Dr. C. Fischer reports (Zeitschrift f. Wund-arzte, 1853, Bd. 6, p. 89) the case of a youngpeasant girl, who suffered from a violent peri-odontitis, and a futile attempt at a removal ofthe tooth. The operation was followed by theformation of an abscess, and marked unilat-eral chorea, which lasted two years, when Dr.Fischer removed the roots of the tooth, andthe movements ceased at once.

Dr. R. Fischer (Oester. Med. Wochenschrift,

1841, p. 46) reports a case in which a generalchorea ceased at once upon the expulsion of atapeworm. Dr. Edmond Censier records acase similar to this in the Gaz. Med.-Chir. deToulouse, 1877, p. 43. The chorea was soviolent as to threaten life, and had persistedseveral months, notwithstanding treatment.Amelioration began five days after the expul-sion of the parasite, was very rapid, andresulted in complete cure.

In the Journ. de Mdd. et de Chirurg., Paris,1841, is the record of a case in which choreaof one month’s duration was immediately ar-rested by the expulsion of lumbricoid worms.

M. Borelli reports (.Bulletin de la Soc. de Chi-rurgie, 1852, p. 292) the case of a boy thirteenyears old, in whom a violent chorea, which hadresisted all treatment for six months, was curedby the removal of a neuromatous tumor frombeneath the foot. The movements becameless the day after the operation, and by thefourth day had ceased entirely.

Further citations of cases might readily bemade, and especially an abundance of opinionbe obtained from recognized authorities, asshowing the occasional dependence of choreaupon the presence of intestinal worms ; but Ithink enough has been here said for the pur-pose. The chorea which occurs during preg-nancy is also probably of reflex origin.

There is a form of chorea which is not un-

CHOREA—A STUDY IN CLINICAL PATHOLOGY.4

common in the young of certain of our car-nivorous domestic animals. I have neverseen a case in herbivora; but Prof. Huide-koper, of the Veterinary Department of theUniversity of Pennsylvania, informs me thathe has treated the disease in calves.

The relations of this disease with the choreaof childhood have been considerably discussed,with difference of conclusions. I shall post-pone the consideration of this question untilafter a study of the animal chorea, of which Ihave seen a number of examples. It is im-

Chauvet {Mem. et Compt. Rend. Soc. de Sci.Med. de Lyoti). I have never seen this paper,but it is quoted as affirming that the move-ments persist in the hind legs after section ofthe spinal cord.

In April, 1869, M. Carviler presented tothe Societe de Biologic {Compt. Rend. Soc.Biolog., 1869, p. 154) an account of some ex-periments upon a choreic dog, with persist-ence of movements after section of the cordin the middle dorsal region. The peculiarityin this report is the assertion that after sec-

Tracing 1.—A, the point where the drum was stopped and allowed to again revolve whenetherization was complete.

Tracing 2. —A, the point where drum was started so soon aseffect of ether had passed oft.

Tracing 3.—A, the point where drum was stoppeduntil the effect of shock had entirelypassed by, showing that the movements of the feet were much greater after thanbefore the section. Compare with Tracing x.

possible to experiment, except within very nar-row limits, upon human beings, and hence it isonly by the light of investigations upon thelower animals that we can hope to come toany very definite conclusions. In such inves-tigations, the points to be inquired into are asto the seat and nature of the lesion, and as tothe effect of external irritations upon thesymptoms themselves.

The first study of this affection directed to-wards the discovery of the seat of the lesionof which I have knowledge is that of Prof.

tion of the cord the movements of the face,front and hind legs were perfectly isoch-ronous. It seems to me that it is scarcelypossible for such isochronous movements tooccur when the spinal cord has been com-pletely severed, as the simultaneousness ofmovement could only depend upon nerve-waves running down an uninterrupted cord.It is therefore a natural suspicion that thecord was not entirely divided.

The most elaborate study of the subject isthat of Legros and Onimus {Journ. del'Anal.

CHOREA—A STUDY IN CLINICAL PATHOLOGY. 5

et de la Physiolog., 1870-71,p. 403). These ob-servers found that the movements are not syn-chronous with the beat of the heart, and donot varypari passu with the cardiac pulsation;that they are not arrested by section of thespinal cord, but are to a certain extent by theaction of thecerebrum, for a sudden loud noisewould for a time cause them to cease; thatthey are very sensibly affected by chloral;that division of the sensitive roots of an iso-lated section of the cord lessens, but does notarrest, the movements; and that a galvaniccurrent passed down the spinal cord greatlydiminished the activity of the movements, butwhen passed up the cord increased the ampli-tude and rapidity of the choreic vibrations.

movements was longest put off. In the secondexperiment, the section was practised verylow down and the hind legs were inordinately

Tracing4.—Showingthe

inhibitionof

movementby

the

galvanizationofthesciaticnerveaftersectionofthe

spinalcord.

Dr. Hughlings Jackson also noticed thepersistence of the choreic movements aftersection of the spinal cord (.London Lancet,

1875, vol. i.), but Dr. James J. Putnam [Bos-ton Med. and Surg. Journ., 1879, vol. ci. p.690) failed to obtain the movements after sec-tion of the cord in a choreickitten. There canbe no doubt that this failure was due, as Dr.Putnam himself suggests, to the kitten beingkilled too soon after the section of the cord.My own experiments prove that when the di-vision is made low down, the shock of theoperation prevents the reappearance of themovements for a considerable period after therecovery of consciousness.

In the first case in which I experimented (asshown in the tracing herewith submitted), themovements were arrested by ether, and afterdivision of the cord in the upper dorsal regiondid not reappear for over a quarter of an hourafter complete recovery of consciousness.They first made their reappearance in thehind legs, and afterwards in the front legs.The movements were finally much more vio-lent in the hind legs than they had been be-fore section; but all synchronism between thefront and hind legs was completely set asideby the section.

In the second experiment the movementswere rhythmical, and, as is often the case, weremost marked in the opposing front and hindlegs. They were, as in the first case, immedi-ately stopped by ether. The cord was cut inthe lower dorsal region, and the movementsreoccurred in the front leg so soon as the effectof the ansesthetic had gone off, but did notcome back in the hind legs for over an hourafter the return of consciousness. It is plain tomy mind that the shock of section of the cordhas an effect upon these movements. In thefirst experiment, the front legs were nearestthe seat of section, and recurrence of their

influenced. In the choreic dog, as in thechild, the movements can certainly be inhib-ited temporarily by the cerebrum.

6 CHOREA—A STUDY IN CLINICAL PATHOLOGY.

This cerebral inhibition is readily explainedupon the theory of Setschenow’s centre in thebrain, but inhibition may certainly occur inde-pendent of any cerebral action. The cord wasthoroughly cut in the second animal experi-mented upon, as was proven not only by theparalysis of the hind legs, but also by the factthat no pain was caused by very powerfulirritation of an exposed sensoryVerve of thelargest size. Under these circumstances, thechoreic movements were very markedly in-hibited by galvanization of the sciatic nerve,as is shown by the photographic reproductionof the tracing made. (See tracing No. 4.) Theupper line represents the writing of the move-ments of the right leg, the lower line the timeof application of the current. This experi-ment affords direct proof that there are in-hibitory centres in the cord, or else that theganglionic motor cells of the cord are directlyinhibited by peripheral impulses.

From a pathological point of view, the ex-periments upon the section of the cord justdetailed are of great importance as fixing theseat of the lesion. They have been so oftenrepeated with such concordant results, thatwe must consider it settled that the move-ments in the choreic dog originate in thespinal cord, and that the spinal cord is theseat of the lesion ; of course the observedfacts do not prove that the brain ganglioniccells are in a normal condition ; indeed, theactions of the choreic dog indicate that theyshare the abnormal condition of the spinalcells.

In 1875 (■London Lancet, vol. i. p. 610), Dr.Gowers examined the spinal cord of a choreicdog and found no structural alteration. Twoyears subsequently, however, Drs. Gowersand Sankey {Medico-Chirurgical Transactions

,

London, 1877) determined the presence oflesions in the cord of another animal. Theygive of it the following account:

“ The most conspicuous change was the in-filtration of limited areas with small round‘ lymphoid’ cells, which varied in size, theaverage being .0075 mm. In most cells nonucleus was visible, but in some a large roundnucleus occupied about half or two-thirds ofthe area of the cell. These cells were notuniformly infiltrated in the affected areas. Inthe white substance they aggregated in tracts,often branching and extending through part orthe whole of the affected column. When theinfiltration affected the gray substance it wasmore uniform ; but here, also, the corpuscleswere aggregated in masses as well as scattered.The aggregations in both gray and white

matter corresponded to the course of vessels.Whenever a section divided such a tract trans-versely, a vessel could always be detected inits centre. Where the infiltration was ex-tensive, the corpuscles were so densely massedthat the individual cells could scarcely be dis-tinguished ; but where it was slighter, a vesselcould often be seen to be encrusted with alayer of such cells. In some places a fewonly lay in the perivascular sheath, but inother places similar corpuscles lay outsidethe perivascular sheath and in the adja-cent tissue. In the white substance in theneighborhood of these tracts similar cells layamong the nerve-fibres, and in some placeswere so numerous as to occupy a larger areathan the nerve-fibres. In some places, indeed,the nerve-elements appeared to have beendestroyed.

“These cells were deeply stained with car-mine, and still more deeplyby logwood. Theyresemble closely white blood-corpuscles insize and appearance. (The measurementsgiven above correspond closely to those ofwhite blood-corpuscles in hardened tissues.)They were identical in appearance with thewhite blood-corpuscles which were seen hereand there among the blood-disks within thevessels. In some sections the walls of thevessels appeared to contain similar cells, asif in the process of diapedesis. From theseappearances we are inclined to regard thesecells as being actually white blood-corpuscles,and the morbid change as a leucocytal infil-tration."

In 1879, Dr. J. J. Putnam {Boston Med.and Surg. Journ., vol. ci. p. 691) exam-ined very carefully the nervous system of twokittens which had suffered from chorea. Inneither of these animals were there any alter-ations at all similar to those described byGowers and Sankey. There were no abnor-mal leucocytes in any of the nerve-centres. Inone kitten no change whatsoever could befound in any of the nerve centres. In thesecond there was a marked injection of theblood-vessels, and the ganglion-cells in thespinal cord, as well as those in the brain, failedto imbibe the staining fluids, and even mglycerine could not be satisfactorily studied.

I have examined the spinal cord of fourdogs. Three of the dogs were killed whilestill able to go about. Two of them sufferedfrom typical rhythmic chorea, one from achorea with movements exactly simulatingthose of a child, and associated with greatweakness. The fourth animal died of thedisease, after having completely lost control

CHOREA—A STUDY IN CLINICAL PATHOLOGY. 7

of his hind legs. In each of these cases therewere numerous lymphoidal cells in the graymatter, very few, if any, of them appearingin the white matter. The cells were mostlyscattered, but sometimesoccurred in groups ofeight or more. They were distinctly granular,and some of them were nucleated. The nu-clei were usually small, but in some cases werelarge, nearly filling the cells. In none exceptdog No. 4 could any connection whatever bemade out between these cells and the blood-vessels, the perivascular spaces being entirelyfree. In the dog that died of the disease, thecells were more numerous than in the others,and could in some instances be found in theperivascular spaces. In no instance, however,was there any such outpouring of leucocytesas is described by Gower and Sankey.

Normal cord.

scurely arranged in three groups. Just pos-terior to the spinal canal, and at a little dis-tance laterally from it, is a small group ofvery large cells. In the extreme anterior por-tion of the gray matter is a much larger groupof similar cells, whilst in the lateral peripheralportions of the gray matter are numerouscells, mostly smaller than those just spoken of.Whilst this general topographical descriptionis the most correct that can be made, I havefound that the position of the cells reallyvaries very much, not only on different levelsof the cord, but in the two sides of the samesection.

In my paraplegic dog the group of spinalganglion-cells nearest the spinal canal was themost profoundly affected. As seen with a lowpower, the cells could not be discovered ; but

Choreic cord, paraplegia.Figs, x and 2 are reproductions of camera drawing with low power, to show disappearance of ganglion-cells.

The outline below is of edge of spinal canal.

An examination of healthy dogs shows thatthese lymphoidal cells are to be found in thenormal cord. They are, however, not so nu-merous as in the severe cases of chorea ex-amined ; but I could not make out any con-gestion of the blood-vessels or other lesionswhich seemed to indicate that the outpouringof these leucocytes was the cause of the symp-toms. On the other hand, my studies haveclearly shown that the ganglionic cells of thecord are profoundly affected.

It has already been stated that Dr. Putnamnoticed in one of his kittens that the gangli-onic cells would not take the staining fluid.This represents the earliest alteration that isto be distinctly recognized. In my dog thatdied with paraplegia the change was morepronounced and widespread than in either ofthe others.

The motor cells in the dog’s cord are ob-

when the higher powers of the microscopewere used, it was found that their positionwas occupied by irregular, globose, crumpled-looking masses, without sharp outline, andtaking the staining very faintly. No granula-tions, no nuclei, no processes were apparent.These masses certainly represent the cells inthe last stages of degeneration, and were ofvarious sizes. The cells of the other groupwere plainly altered. They took the stainingvery faintly. In a large proportion of themno nuclei could be found, and in quite anumber about one-fourth of their contentswas occupied by a large mass, having a sharpdefinite outline, free from granular contents,and having the appearance of a vacuole.Within this body was a nucleus or nucleolus,so that the body itself was probably an alterednucleus, but I have never seen anything likeit in the normal cord. In many cases the pro-

CHOREA—A STUDY IN CLINICAL PATHOLOGY.8

cesses were gone, and the irregular borders ofthe cells were completely wanting in definite-ness. In some instances globose masses ofdegenerated protoplasm, similar to those de-scribed a few lines above, occupied the placesof some of the cells.

In the dog which had the choreic move-ments like those of St. Vitus’s dance therewere cells which had undergone extreme de-generation, but they were not so numerous asin the preceding case. In the sections ex-amined it was also the peripheral cells whichwere most affected. It is probable that thislocation varies, and that more numerous sec-tions of the two cords than I examined wouldshow in some place in each cord one group,in other places other groups .of cells were themost severely attacked.

In the milder cases of the disease, when theanimal had been killed in the early stages, theonly changes in the cells were the very fre-quent absence of the nuclei, the failure ofgranulations in the protoplasm,, the loss ofpower to take staining fluids, and rarely theoccurrence of sharply-defined vacuoles.

The evidence which we now have concern-ing the changes of the nervous system incanine chorea is sufficient to establish definiteconclusions. The lesion which was found byGowers and Sankey is evidently an accidentalone, as it has not been present in one caseexamined by Dr. Gowers himself, and in halfa dozen cases examined by other equallycompetent observers. This infiltration withleucocytes may be viewed as the result of a

congestion of the part. Now it is well knownthat when functional excitement arises fromcongestion, the congestion precedes the func-tional excitement; and if the congestion werein the dog the cause of the choreic move-ments, it ought always to be discovered sosoon as the latter were fairly established. Onthe other hand, functional excitement pro-duces congestion, and in such cases the con-gestion follows the functional excitement, andvaries very much in different cases, even whenthe excess of functional activity is apparentlythe same. If, then, the infiltration observedby Gowers and Sankey was the result of afunctional excitement of the motor cells ofthe spinal cord, its absence in other cases isno more than ought to be expected.

It seems to me clear that the basal lesionof canine chorea is a peculiar condition-ofthe motor cells of the spinal cord, which con-dition is at first, and may long continue tobe, functional, but which finally may developinto organic change. It must be remembered

that the distinction between functional andorganic disease is a purely arbitrary one.Functional movements are the results of nu-tritive changes, and a functional disorder isone in which the nutritive changes have oc-curred, but have not sufficiently advanced tobe recognized by our comparatively grossmethods of study. The structure of the gan-glionic nerve-cells is so complex in its ultimatenature, and yet so simple in its microscopicappearances, that it may be permanently andvery seriously altered without leaving a phys-ical trace which we can recognize. The firstchange in canine chorea is an altered nutri-tion, i.e., functional excitement (or depres-sion), of the multipolar cells of the spinalcord. This altered nutrition may continueuntil the structure of the cells is entirely de-stroyed, but it may never go beyond the con-dition of change so non-apparent as to beunappreciable to us. The studies of Dr.Putnam show that the cells of the brain inthe kitten are in a similarly altered conditionto those of the spinal cord, and it is mostprobable that although the movements origi-nate in the altered nutrition of the spinal cells,yet throughout the nervous system the gan-glionic nerve-masses suffer, so that the dis-order is really a condition affecting notmerely the spinal, but rather the wholenervous system.

It is a matter of great interest to decidewhether the canine chorea is the same diseaseas the St. Vitus’s dance of children. Exceptin the case of contagious diseases, it is im-possible to determine with absolute positive-ness that a certain disease in the animal rep-resents a certain disease in the man, but tomy mind it is plain that if canine chorea benot the same disorder as St. Vitus’s dance ofchildhood, it is very closely allied to it.

It is true that the movements in caninechorea are usually rhythmical, whilst the move-ments in the child are ordinarily not so, andmuch has been made out of this difference.I have, however, seen dogs in which themovements were not rhythmical, but had allthe gaucherie of the chorea of childhood, andin some cases of children the choreic move-ments do approximate the rhythmical type.

The points of resemblance in the two affec-tions are very close and striking. In eachdisease it is the young which are especiallyattacked ; in each the chief symptoms are thoseof disordered motion; each affection is con-nected with a constitutional disorder (rheuma-tism in the child and distemper in the dog); ineach case the movements can be temporarily

CHOREA—A STUDY IN CLINICAL PATHOLOGY. 9

inhibited by the will, are not accompaniedwith disorder of sensation, and are associatedwith loss of power and lowered general nervetone; finally, in each disease arsenic is recog-nized as the standard remedy.

Even if canine chorea be considered essen-tially distinct from the St. Vitus’s dance ofchildhood, it cannot be denied that the lawswhich preside over the nervous system of thedog are essentially the same as those whichrule the human nervous system, and the fol-lowing proposition must apply to man as wellas to the dog:

Fifth.—Choreic movements may dependfor their origin upon a diseased condition ofthe motor cells of the spinal cord, which dis-eased condition may not impair the structuresufficiently for the alteration to be recognizedby our instruments, and hence may be functional ; or may go on to the production ofmarked change in the ganglionic cells, oreven to their total destruction, when it is en-titled to rank as an organic affection.

When we approach immediately the discus-sion of the nature of St. Vitus’s dance ofchildhood, we find that numerous post-mortems have been made upon this diseasewith very varying results. In my opinionthe older autopsies ought to be disregarded.The means of investigation were so imperfect,and were so imperfectly used, that the dangerof being misledby these observations is greaterthan the chance of receiving enlightenment.Nevertheless, it seems to me that, after throw-ing overboard much rubbish, there remaincertain cases, in which after properly con-ducted autopsies no appreciable lesion couldbe found. The positive results which havebeen reached in other cases are best glancedat under two heads: First, brain alteration.Secondly, alteration of the spinal cord.

Among the most remarkable papers uponthe brain-lesions of chorea is that of Dr.Broadbent, who has demonstrated that thecorpus striatum and thalamus opticus are insome cases the location of the lesion. Dr.B. states that a variety of morbid conditionsof these ganglia may produce chorea, but themost frequent alteration in his cases was acapillary embolism of the corpus striatum,thalmus opticus, and their vicinity. A num-ber of autopsies have been made confirmingthe existence of capillary embolism in thebrain in fatal chorea, and it would seem asthough there was an intimate relation betweenchorea and this condition of the brain. Theassociation is too frequent and too peculiar

to be merely the result of a chance. On theother hand, it is perfectly evident that in manycases of chorea no such lesion exists. It isabsurd to suppose that the chorea which isproduced in a few hours by a fright, and iscured in a few days by arsenic, is the resultof so serious an organic lesion as that indi-cated. Moreover, there have been an abun-dance of autopsies in which capillary embolismdid not exist. Again, as in the case reportedby Tuckwell, other changes in the brain havebeen noted besides those of embolism. Itmust, therefore, be concluded that an acutechorea may be intimately associated withminute cerebral embolism and also with otherlesions of the brain; among which lesionsmay be especially mentioned the peculiaralteration of the ganglionic cells of the brainnoted by Meynert as pervading the wholeorgan in a case of chorea.

In regard to the spinal cord, the followingparagraph from the article of Von Ziemssenin his Encyclop3edia expresses the evidence tothe date of its writing, 1877: “In the spinalcord alterations have been repeatedly found,namely, hyperaemia of the medulla and themembranes, softening of the cervical and alsoof the dorsal medulla (Romberg, Ogle, Gray,Golgi, De Beauvais, Hine, Brown-Sequard,Lockhart-Clarke); interstitial proliferation ofnuclei and hyperplasia (Rokitansky, Steiner,Meynert, Elischer), and sometimes serousexudation in the central canal, proliferationof nuclei in the adventitia of the vessels, andregressive metamorphosis in the ganglion-cells (Elischer).” Since this paragraph waspenned spinal lesions have been discoveredin chorea by Dr. Dickinson, by Dr. Bury, andby Dr. James Ross. According to Dr. Dick-inson, the part of the cord especially affectedin the disease is “the central portion of eachlateral mass of gray matter comprising theroot of each posterior horn.”

Dr. Ross says of a case, “ I was struck withthe alteration presented by the accessory cellsof the anterior gray horns ; they appearedshrivelled, their protoplasm was granular, theirnuclei were obscured, and many of their pro-cesses were indistinct or absent.”

Without indulging in further quotations, itmay be stated that we have the evidence ofat least five or six different observers as tothe alterations of the spinal ganglionic cellsin acute human chorea, and that in numerouscases these alterations in all probability ex-isted, but were not noted simply because theywere overlooked. I do not mean to assert thatan appreciable lesion of the spinal cells is

CHOREA—A STUDY IN CLINICAL PATHOLOGY.

always to be found in St. Vitus’s dance; in-deed, I am quite confident that the diseasemay prove fatal without such lesion. Never-theless, I am well assured that such alterationsare very frequent in fatal cases, and have innot a few instances been overlooked becausenot appreciated and sought for.

The marked tendency of the choreic move-ments to affect one side of the body or one limbhas led many observers to confine their care-ful examinations to the brain, this hemi- ormonoplegic tendency being believed to showthat the movements originate in the brainand not in the spinal cord. A clinical studyof the various human affections of the motorganglia of the cord shows, however, that insuch disorders spinal monoplegias are not atall uncommon, and that in some cases hemi-plegias may be seen. In many cases of choreaof the dog this localization of the movementsin one limb or in one side of the body is quitepronounced ; indeed, this was the case in dogsin which I positively determined the spinalcord to be the seat of the lesion ; it cannotthereforebe considered that a hemiplegic muchless that a monoplegic chorea is necessarily ofbrain origin.

It is plain that the similarity of the lesionswhich have been recently noted in the gan-glionic cells of the spinal cord in fatal cases ofhuman chorea with those which I have foundin the dog is very apparent, and increases theprobability that the two affections are essen-tially the same disorder. Whether this be soor not, considerations previously detailed (seeproposition five) show that choreic movementsin the child, as in the dog, may originate from adiseased conditionof the ganglionic spinal cell.Further, as a diseased condition of the spinalganglionic cells has been found in severalcases of human chorea, it must be allowed thatsuch diseased state is at least one of the funda-

mental pathological alterations of humanchorea. It is perfectly clear, on the otherhand, that the disorder is not confined to thesemultipolar cells. The researches of Dr. Put-nam, already quoted, show that in the catalterations may be found, at least in somecases, in the brain ganglionic cells, and everyclinician knows that the cerebral functions areoften profoundly affected in the choreic child.The will, the intellectual and the emotionalfaculties are all prone to show the presenceof an abnormal influence in chorea, and itseems, therefore, that we must consider thatin the choreic child the ganglionic cells in thewhole cerebrospinal system suffer, and that thisalteration is the base of the disease: or, in otherwords, the morbid pathology of chorea, or St.Vitus's dance of childhood, may be said to bea diseased condition of the ganglionic structuresof the cerebrospinal axis, which abnormal statemay exist without alterations of structure suffi-cient to be determinedby the microscope, or maygo on until it is accompanied with marked struc-tural lesions. Further, this condition must belooked upon as one of lowered tone, and itmust be allowed that it may be produced byvarious causes, but is little prone to occur inpersons of robust nervous system. The vitalchoreic depression of the nerve-cells may bethe result of emotional disturbance, as in thechorea produced by fright. It may be theresult of the influence of the rheumatic dia-thesis or poison upon the affected tissues. Itmay be the result of the partial occlusion ofthe circulation by cerebral capillary throm-bosis or embolism, and there are probablyother efficient causes in its production. Thecourse of a chorea, as well as the severity ofthe symptoms, very naturally depends uponthe cause of theabnormal condition, and hencewe have the varieties so plainly marked in thisso-called disease.