Pain in its neuro-pathological, diagnostic, medico-legal, and neuro-therapeutic relations

II

CONSULTANT IN NERVOUS DISEASES TO ST. FRANCIS HOSPITAL, ST. MARY'S HOSPITAL,

THE HACKENSACK HOSPITAL, ETC. ; FELLOW OF THE NEW YORK ACADEMY OF MEDICINE; MEMBER OF THE NEW YORK NEUROLOGICAL SOCIETY, THE MEDI- CAL SOCIETY OF THE COUNTY OF NEW YORK, AND THE MEDICAL SOCIETY OF THE STATE OF NEW YORK, ETC.

AUTHOR OF "A TREATISE ON HEADACHE AND NEURALGIA," " BRAIN-EXHAUSTION, WITH SOME PRELIMINARY CONSIDERATIONS ON CEREBRAL DYNAMICS," "LOCAL ANESTHESIA," " A TREATISE ON HYSTERIA AND EPILEPSY," " BRAlN-REST : BEING A DISQUISITION ON THE CURATIVE PROPERTIES OF PRO- LONGED SLEEP," ETC.

ILLUSTRATED.

t

PHILADELPHIA

J. B. LIPPINCOTT COMPANY. /^

S> c*

Copyright, 1894,

BY

J. B. Lippincott Company.

Printed by J. B. Lippincott Company, Philadelphia.

TO MY MATERNAL UNCLE,

FREDERICK DEMING,

AS A TOKEN OP ADMIKATION AND AFFECTION.

Preface

11 Pains are the correlatives of actions injurious to the organism, while pleasures are the correlatives of actions conducive to its welfare." — Herbert Spencer, Principles of Psychology.

11 The phenomena of feeling constitute the true basis of all that part of philosophy which at all involves the interest of man." — Lester F. "Ward, Dynamic Sociology.

There is no department of neurology a knowledge of which is so essential to the physician as that which deals with pain. As an aid to diagnosis the importance of this symptom is unique; while to relieve it requires discernment and ingenuity of a high order.

Nor is its ethical significance less apparent; for surely there is nothing in all the world so conducive to an active sympathy with mankind as the habitual relief of suffering.

Since, during the past ten years, the author has devoted much time to the study of pain, he is led to hope that in presenting this volume he may be able to advance in some degree the cause of scientific medicine.

53 West Thirty-eighth Street, New York. March 1, 1894.

1* 6

Concerning Pains located in Definite Nerve-Areas — Neuralgia . 62

CHAPTER IV. Pain associated with the Rheumatic and Gouty Diathesis 70

8 CONTENTS.

CHAPTEK V. page

Pains which have their Seat in the Structures contained within the Cavities of the Body — Intracranial Pains (Headache) — "Spinal" (Medullary) Pains— Abdominal and Thoracic (Visceral) Pains . 80

CHAPTEE VI.

The Diagnostic Value of Pain 92

CHAPTER VII.

The Clinical and Medico-Legal Significance of the Phenomena evoked by Pain — Objective Method of diagnosticating Pain 108

CHAPTER VIII.

The Medico-Legal Relations of Pain — Spinal Concussion 117

CHAPTER IX.

Of the Insomnia and Melancholia of Pain 128

Part II. The Special Therapeutics Of Pain

CHAPTER X.

Concerning the Importance of Rest in the Treatment of the Nervous Symptoms engendered by Prolonged and Severe Pain 140

CONTENTS. 9

CHAPTEK XL PAGE

Op Internal Eemedies which are either directly or indirectly Applicable in the Treatment op Pain 165

CHAPTEK XII.

Op other and More Kecent Eemedies which have been employed in the treatment of pain 189

CHAPTEK XIII.

Summary op other Important Facts Kelative to the Action of Remedies on the Nervous System .... 198

CHAPTER XIY.

On the Author's Methods of employing Remedies so as to Increase the Certainty and Duration of their Action on the Peripheral Nerves — Other Measures which have been proposed 206

CHAPTER XV.

Surgical Expedients 227

CHAPTER XVI.

Local Medication of the Spinal Cord and Cauda Equina, Author's Plan— Other Measures 241

CHAPTER XVII.

The Use of Compressed Air in conjunction with Remedies which tend to diminish the Acuity op Perception, Author's Plan. . 256

CHAPTER XVIII.

Reflex and Spurious or Imaginary Pains— Hypnotism 304

10 CONTENTS.

CHAPTER XIX. p AGE

Concluding Observations on the Prevention of Relapse — The Prophylaxis of Pain 313

CHAPTER XX.

Supplementary Observations on Torture, or the Infliction of Pain as a Judicial Punishment or for the Purpose of extorting a Confession of Guilt . 318

PART L

PHYSIOLOGICAL, PATHOLOGICAL, AND CLINICAL.

CHAPTER L

THE PHYSIOLOGY OF PAIN — CONDUCTION — DEFINITION.

Definition of Pain. — Various attempts have been made to define pain. Cicero looked upon it as a disagreeable movement within the body, independent of the senses. According to others, it is a species of sensation which may emanate from both internal and external regions of the body, in which are distributed nerves, " whose office it is to transmit to the brain all impressions." Sauvage calls it a disagreeable perception, originating from any lesion of the nerve-fibres ; Gaubius regards it as a sensation which the mind "would rather not experience" (!); while Bilon is discontented with all definitions, and believes the word pain to be so universally descriptive in itself as to enable one to dispense with

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all definitions. 1 More recent authors have, nevertheless, persisted in further attempts to define it. Thus Valentin 2 perceives in pain " sensory impressions which, on account of their too great intensity, become disagreeable;'' "Wundt 3 calls it "a feeling that accompanies all powerful or intense stimuli," while Eulenburg 4 defines it as " a gradual increase of the feeling that accompanies every sensory process."

To my mind, the views of Erb 5 regarding the nature of pain are among the most comprehensive which have been recently expressed. " We hold," he says, " that every increase of ordinary sensory stimuli is capable of producing pain, as soon as it attains a certain intensity. Every excitation, the intensity of which exceeds certain limits, every molecular change of the centripetal series, induced by an abnormally strong stimulus, is perceived as pain. Very simple experiments, as, for example, pressure or temperature gradually increased till pain

1 Dictionnaire des Sciences Medicales, vol. x. p. 179, Paris, 1814.

2 Physiologische Pathologie der N erven, vol. i. p. 240.

3 Lehrbuch der Physiologie des Menschen, p. 503, 1874.

4 Functionelle Nervenkrankheiten, p. 31. Vide also Diseases of the Peripheral Cerebro-Spinal Nerves, by Wilhelm Heinrich Erb, Ziemssen's Cyclopaedia, vol. xi. p. 14.

5 Op. et loc. cit.

is produced, show that, with very gradual increase in the strength of the stimulus, a limit is at length reached beyond which the excitory process is accompanied by pain, yet no sharp line of demarcation can be traced denning the point at which the sensation of pressure or temperature ceases and the sensation of pain commences."

Regarding, then, the phenomena concerned in their broadest aspect, I would define pain as the feeling (perception) evoked by over-stimulation of the nerves of special and common sensation. By over-stimulation is meant, of course, a degree of stimulation which exceeds the physiological limit.

We have thus a clue to the genesis not only of those pains which originate in over-stimulation of the nerves of common sensation, with which we are most frequently called upon to deal, but of those likewise which have their origin in an exaggerated stimulation of the nerves of special sense ; for do we not know that intense light and loud inharmonious noises produce sensations which are described by those subjected to them as veritable pains ?

In view of these facts, nothing can be more inconsistent — to give it no stronger name — than the attempts of those extremists whom Brown-Sequard has facetiously alluded to as the " cluster localizers" to ascribe the perception of pain to a limited area

14 PAIN.

of the cortex. Clearly, a hypothetical spot of this kind could by no possibility serve as the rendezvous for the pain-concepts of both special and common sensation.

Such a centralization of heterogeneous functions is physiologically, not to say anatomically, unthinkable.

From all this it is evident, then, that the modification engendered in the perceptive mechanisms of common and special sensation by excessive stimulation is the principal, if not the only, prerequisite to the development of pain.

As regards those fine molecular perturbations originating in the nerve and transmitted thence to the sensorium, — perturbations which are evidently the ultimate and essential element of pain, — we are still, and doubtless are destined in future to remain, entirely in the dark. Although we are thus debarred, on account of the crudity of our physiology, from penetrating the final mystery of pain, we are, nevertheless, enabled to adopt proper means for its arrest when once established.

As the argument proceeds, we shall find that, in combating pain, we are compelled to invoke the aid of a wide range of agents ; and thus it happens that chemistry, thermo-dynamics, physics, and even surgery have all rendered important assistance.

Finally, we must not forget to mention a very recent theory regarding the mechanism underlying the pains occurring along the course of nerves. According to Prus, 1 who is the promulgator of this theory, there are filaments in the sheaths of nerve-trunks the irritation of which gives rise to the painful points found in neuralgic affections. These filaments, the presence of which was made known by careful microscopical examination, have received the somewhat ponderous appellation of nervi nervorum periphericorum.

It is, of course, impossible at present to prophesy with any degree of certainty what part these structures are destined to play in the physiology and pathology of the future. Perhaps autopsies conducted with a special view to further enlightenment on this point may afford assistance ; but it is hardly to be anticipated that we shall derive much help from experimentation.

The Transmission of Painful Impressions from the Periphery to the Perceptive Mechanism. — The next question which naturally suggests itself is, how do painful impressions reach the higher centres of the brain ? or, in other words, along what paths do such impressions travel in their journey from

1 Archives Slaves de Biologie ; also Brain, vol. x. p. 657.

PAIN.

the periphery to the mechanism (" centre") of conscious perception ?

It is much to be regretted that only a partial answer can be given to this important question.

About all we know of the matter is soon told. In the first place, as every one knows, the trans-

FlG. 1.

AN TER10RH0RH mission of painful sensations from the periphery to the spinal cord is accomplished through the instrumentality of the sensory nerves. The course pursued by such painful impressions through the cord is more obscure. Some physiologists believe that, after crossing to the opposite side of the cord, they are transmitted wholly through the gray substance ; others, again, assign special importance to the sensory conducting paths of the posterior columns;

Fig. 2.

while a third class of observers believe that sensations of pain may be transmitted both through the gray substance and the white substance of the posterior and lateral columns.

But while the direction pursued by the sensory pathway after crossing in the cord is not altogether clear, the decussation itself seems adequately demonstrated. Evidence of this intersection of the fibres is afforded by the fact that, when one lateral half of the cord is divided transversely by traumatism or disease, the parts below it on the same side are paralyzed, while sensation is lost in the corresponding parts on the opposite side.

Thus it is that sensory fibres from the right half of the body cross the median line and ascend in . the left half of the cord, while those from the left half of the body decussate and pass upward on the right side of the cord. The decussation of the sensory fibres in the cord is indicated in the diagrams, — Fig. 1, transverse, and Fig. 2, longitudinal, section. b 2*

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Our knowledge of the route pursued by the sensory fibres through the medulla oblongata and the pons is quite indefinite, and the same may be said of the relation which these tracts sustain to the gray matter of those regions. From the data available, it would seem, however, that sensation is transmitted onward through the tegmentum to the hindermost portion of the posterior limb of the internal capsule, and thence, by way of the corona radiata, to the cerebral cortex. At its point of transit through the internal capsule the sensory pathway seems to lie in close proximity to the fibres destined for the conduction of the impressions of the special senses.

The Sensory Regions of the Cortex. — The evidence that the nerves of special sense are connected with definite areas of the cerebrum may be thus summarized :

Certain fibres of the olfactory tract have been traced to the hippocampal gyrus in the temporal lobe; and it has been observed that keenness of the sense of smell is materially lessened after lesion of the hippocampus. The so-called " taste centre" has been located in the temporal lobe in the vicinity of that of smell ; but the .evidence in favor of assigning it to this locality is inconclusive. Nor is the location of the auditory centre altogether certain, in spite of the attempts to associate it with the superior temporal convolution. Some of the phenomena bearing on the question are, however, sufficiently interesting to deserve mention.

In the first place, it has been observed that, after destruction of the internal ear, the median corpus geniculatum and posterior corpus quadrigeminum atrophy ; and, secondly, atrophy of the nuclei may be induced by destroying the superior temporal convolution. Additional experiments and pathological investigations are required to establish this somewhat complicated connection.

The cortical area concerned in visual perception — the so-called optic centre — is much more definitely located than any of those previously considered. It seems, indeed, exceedingly probable, to say the least, that that portion of the occipital lobe called the cuneus is intimately associated with visual perception ; for when, for example, the right occipital lobe is removed or rendered inoperative by disease, left hemiopia results, and vice versa, while the obliteration of both occipital lobes gives rise to total blindness.

There are other collateral facts bearing on the question, such as the secondary atrophy of the pulvinar of the thalamus, the lateral corpus geniculatum, and the median corpus quadrigeminum

PAIN.

after extirpation of the occipital cortex, but the essentially practical scope of this work precludes their consideration.

An immense amount of discussion has been lavished on the question as to what portions of the cerebral cortex are associated with cutaneous sensation. In my opinion, the evidence at present available — though certainly to some extent con-

Fig. 3.

flicting — goes to show that the so-called "sensory centres" are distributed throughout the "motor area," if indeed they do not extend beyond it.

It is a well-known fact that irritation of the sensory nerves of the skin may produce several kinds of sensations ; or what amounts to the same thing, these nerves are endowed with different kinds of sensibility.

Thus, we have a sense of locality, tactile sensibility, sense of temperature, " sense of pain," and sense of pressure, according to the mode of action of the peripheral irritant.

In certain diseases of the nervous system some or all of these powers of discrimination may be im-

Fig. 4.

paired or lost; so that from a diagnostic point of view the investigation of cutaneous sensibility is a matter of importance. Whether — as has been alleged and as some facts tend to show — each variety of cutaneous sensibility is provided with a

22 PAIN.

separate and distinct pathway is, however, still an open question.

The regions previously discussed are shown in the annexed diagrams. The hypothetical areas (" centres") of vision, smell, and taste, as viewed from the mesial aspect of the brain, are shown in Fig. 3, while the sensori-motor region and the locality supposed to be associated with hearing are indicated in Fig. 4, representing the right cerebral hemisphere.

Identity of the Processes in Motor and Sensory Nerves. — It has often been asked, as a matter of theoretic interest, whether the processes accomplished in a motor nerve differ radically from those occurring in a sensory nerve. On this point, Radclilfe, in concluding an elaborate argument, observes, " that there is reason to believe that there is no essential difference between the action which issues in sensation and the action which issues in muscular contraction." As a corollary to this proposition, he adds: "that the production of sensation and the production of muscular contraction only differ in this, — that the electrical discharge, analogous to that of the torpedo, which is developed in and near the nerve in the state of nervous action, happens to tell upon sensorial ganglionic cells in the one case, and upon muscular fibres in the other."

Of course to speak of the electricity evolved during the action of a nerve as though it were the nerve-force concerned in the production of sensation or motion is a mistake. In other respects, the figure is an apt one.

It may be of interest, in this connection, to consider the experiments which have led Radcliffe and others to these conclusions. Undoubtedly the researches of Du Bois Reymond and Matteucci have had a powerful influence in shaping opinion.

The principal experiment of Du Bois Eeymond consists in pouring hot water upon the leg of a frog, the nerve of the same being connected with a galvanometer. When this is done, the galvanometer shows a cessation of the electrical current, — a phenomenon which is observed almost as soon as the water touches the integument. This observation in conjunction with the well-known fact that there is also a decrease, amounting sometimes to almost entire absence of " natural electricity," during the action of motor nerves, led Du Bois Reymond to the inference that in sensory as well as motor nerves there is a loss of electricity when the nerves pass from rest into a state of action.

Matteucci's experiment, performed upon a rabbit, consisted in dissecting out the upper portion of the sciatic nerve and in irritating it with the galvanic

24 PAIN.

current. When the current was closed the animal screamed loudly, but when it was opened there was no sign of pain.

The resemblance of the phenomena evoked by the galvanic current in sensitive and motor nerves has led to the inference that the change in a sensory nerve when sensation is produced by the action of voltaic electricity, and the change in a motor nerve when muscular contraction is produced by the same means, are, as Radcliffe puts it, exact equivalents.

Such, then, are the principal facts which have been assumed to prove the identity of the processes underlying the actions of motor and sensory nerves. While, however, the relation of the two kinds of nerves to the galvanic current points to the truth of this proposition, it is, of course, self-evident that the final result of the action differs radically in each kind of nerve. In the case of the motor nerve, action results in contractions, due to the excitation of the contractile substance of the muscle ; in the case of the sensory nerve, on the other hand, action is translated into perception, through the instrumentality of the central ganglionic apparatus in the cortex.

So much for the fundamental features of the argument.

Concerning the Correct and Erroneous Reference of Painful Sensations. — While all are aware of that remarkable attribute of the perceptive mechanism which usually enables the individual to refer with great exactness both agreeable and disagreeable sensations to their point of origin at the periphery, few comparatively have given thought to the anatomical arrangement underlying this phenomenon; and fewer still are able to account for those apparent paradoxes, which obscure the physiology involved and tend to discredit its application in the clinic. Hence we shall not, I believe, misuse our time if we devote a few paragraphs to a review of the more important points connected with referred sensations.

In the first place, then, it must be remembered that a sensory nerve supplies a certain area of the body and transmits to the brain only such impressions as emanate from that area. In other words, there is no physiological anastomosis, however much the fibres may interlace or run together. To prove this, it is only necessary to divide a sensory nerve and irritate its distal end, when we find that no sensation is perceived, thus demonstrating that there is no collateral communication whatsoever. As a matter of course, irritation of the proximal or central portion of the nerve — that part which B 3

26 PAIN.

is connected with the nerve-centres — gives rise to distinct sensation.

In the same way, if we divide the spinal cord of an animal transversely, so as to sever the sensory conducting paths, and irritate the nerves which join the cord below the incision, no sensation will be perceived; but if we stimulate the nerves which enter the cord above the incision, we shall have every evidence that the sensation has been perceived. Precisely the same sort of phenomena may be observed in human beings who by reason of injury or disease have suffered a solution of the sensory conducting paths of the cord.

Another important fact is, that an impression made upon any point in the course of a sensory nerve may be perceived by the mind as though it were made not only upon the point in question, but also upon the part to which the fibres of the nerve are distributed. "We have, therefore, under such circumstances, practically the same effect as if the irritation were applied to the regions supplied by the branches of the nerve.

An explanation is thus afforded of the fact that when the sensibility of a part is abolished by compression or division of the nerve which supplies it, irritation of the central portion may still give rise to sensations which are felt as though they emanated from the parts below the point of interruption, — i.e., from the parts to which the peripheral terminations of the nerve are distributed. Thus, when a nerve is divided for the cure of an intractable form of neuralgia, it sometimes happens that pain still persists. This is undoubtedly due to the fact that the division of the nerve has not been made near enough to the nerve-centres to include the entire affected portion, and hence the continued irritation of the central portion causes pain, which, in accordance with the law under consideration, is felt as though it emanated from the peripheral parts of the nerve. Another illustration of the same thing is found in those paralyses in which the limbs are quite insensible to such external stimuli as pricking, pinching, and burning, and yet are believed by the patient to be the seat of severe pain. Still another example of erroneously referred pains is seen in persons who have suffered amputation of a limb. When the divided nerves of the stump are inflamed, or otherwise irritated, nothing is more common than to hear the subject complain that he experiences pain which appears to be located in the part of the limb which has been removed.

Such facts as these might, on a superficial examination, lead one to suppose that there was little or no benefit to be anticipated from local therapeutic

28 PAIN.

measures addressed to the affected nerve itself in cases of pain. It must be remembered, however, that by the aid of chemicals we are in many cases able not only to temporarily cut off the peripheral portion of an affected nerve from its central connections, but also to modify the abnormal condition of the nerve itself, thus accomplishing an abolition of pain which is often permanent. From this it follows that we can deal much more effectively with circumscribed neuritis and congestion by the aid of local remedies than with diffuse inflammation of the nerves, which can only be reached by remedies acting through the general circulation.

CHAPTER II.

THE PATHOLOGY OF PAIN— NEURITIS, OR INFLAMMATION OF THE NERVES.

As inflammatory conditions of the nerves constitute the most prolific source of pain, it is necessary to possess a general knowledge of the more common, and hence important, forms of neuritis.

General Considerations. — The whole subject of neuritis, and particularly the part of it which relates to multiple neuritis, has received a vast deal of attention during the last few years. These studies — many of them at least — are important, not only on account of their immediate clinical bearing, but also because of the light which they have already shed and are destined in future to shed upon many disputed points in neuro-pathology. Let me illustrate this point. Up to a comparatively recent period most of the text-books contained a more or less elaborate description of a form of paralysis the chief features of which are a motor paralysis which usually begins in the legs and spreads rapidly over the trunk to the arms. As a rule the medulla ob-

3* 29

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longata is involved, and there is usually, though not invariably, more or less fever. General sensibility and the functions of the bladder and rectum are but slightly affected ; there is no notable atrophy of the muscles, and consequently no diminution in the electrical excitability. !Nbw, this acute ascending paralysis, or "Landry's paralysis," as it has often been called in recognition of the accurate description which this writer was the first to publish, was for a considerable time almost universally classified among the diseases of the spinal cord, and this in the face of the fact that pathology afforded little or no justification for such a step. It is not to be wondered at, therefore, that in default of tangible changes in the cord pathologists should ultimately have sought elsewhere for lesions of sufficient extent to account for the symptoms. Nor is it surprising that they should have turned their attention to the nerves, since by assuming a more or less general disturbance of these organs the symptoms — or at least most of them — might be logically accounted for. Thus it happened that as soon as the etiology and symptomatology of neuritis, and more especially general neuritis, had become more thoroughly understood, neurologists were not slow to perceive the parallelism which exists between this affection and the group of symptoms heretofore known as

Landry's paralysis. So impressed is Ross with this resemblance that he has undertaken a most exhaustive study of all the cases of Landry's paralysis to be found in literature. From an analysis of these cases (ninety-three in number) he concludes that Landry's paralysis is simply a variety of multiple neuritis. In this he agrees with the general deductions of Barth and Nauwerck, who have also conducted some important studies in the same field. The literature of the subject has also received copious additions from other sources.

Before, however, pursuing this subject of multiple neuritis further I shall take the liberty of offering a few remarks on the simple or local form of nerve inflammation.

Simple Neuritis. — The most frequent causes of this local form of neuritis are wounds, inflammatory conditions in the vicinity of the nerve-stem, rheumatic influences culminating in thickening of the sheath, and tumors pressing upon the nerve. Severe compression of the nerve, caries of neighboring bones, and bruises may also give rise to it. To sum up the whole question of etiology, it may be stated that the restricted form of neuritis is more apt to be due to local than general causes ; while of multiple or general neural inflammations the reverse is true ; for toxic agents acting

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more or less extensively throughout the organism play a prominent part in their causation.

Symptoms. — The duration and course of simple neuritis is subject to a certain degree of variation. Usually, however, the onset is quite abrupt, although a gradual beginning is occasionally observed. An initiatory chill and fever are a feature in some cases, but the majority begin without these warnings.

Whatever the precise mode of onset may chance to be, the first symptom to excite the apprehension of the patient is pain. This pain is usually severe, and is felt more or less throughout the distribution of the affected nerve. On applying gentle pressure along the course of the nerve, the latter is found to be extremely sensitive; and after the trouble has continued a certain length of time, it is often possible to feel the nerve — which has become considerably thickened — through the integument.

Though the pain is more or less persistent, it sometimes abates, but only to return again with renewed intensity.

I have under my care at this time a patient in whom the intermittent and severe type of neuritic pain is well illustrated. The patient, a lady of high social position, was recently referred to me by Dr. M. S. Ayers, of New Jersey, for severe brachial neuralgia. On examination, I found the region along the course of the brachial plexus exceedingly sensitive to the touch, and the whole right arm hypersesthetic.

Desiring to ascertain a possible cause for the neuritis, I investigated the case with considerable care, the patient herself aiding me in every way by her prompt and intelligent replies. Without entering into unnecessary details, let me say that my attention was early directed to a swelling situated in the space above the clavicle immediately adjoining the neck. This tumor was somewhat compressible ; there was pulsation, — whether external or internal I could not tell, — and the region round about, and more especially at the anterior border of the enlargement, was quite tender to the touch. The point of interest, however, from an etiological point of view, was the fact that whenever the tumor was pressed upon, even to a moderate degree, the most excruciating pains were evoked in the region of the brachial plexus, and indeed throughout the entire arm. This left no doubt in my mind that the neuritis had been set up by the pressure of the tumor. Being in doubt, however, as to the nature of the latter, I called in consultation my friend Dr. John A. Wyeth, who, after a most thorough examination, expressed the belief that the tumor was either a subclavian aneurism or a malignant tumor.