NEURALGIA OF THEUTERUS ANDOVARIES.—Attention has repeatedly been called to the fact that affections of these organs may excite neuralgias in distant parts of the body or in the lumbo-abdominal nerves; but besides these the uterine and ovarian nerves themselves sometimes are the seat of neuralgia, and it is claimed that menorrhagia and metrorrhagia may occur as a consequence.
The other abdominal organs and the testis are occasionally the seat of neuralgic pains, and attacks which involve the liver may be followed by swelling of the liver and by jaundice.
It is not always easy to assert with confidence whether an attack of abdominal neuralgia affects the external or the visceral nerves.
NEURALGIA OF THEANUS ANDRECTUMis a well-marked and painful affection, and the tendency to it may be hereditary. The seizures themselves may come on spontaneously, especially after fatigue, or may be excited by slight irritations, such as the passage of hardened feces, or may follow seminal emissions. The pain may be accompanied by quick, clonic spasm of the perineal muscles.
The rapid injection of hot water into the rectum often at once relieves the attack.
We have not space to discuss at length the neuralgiform affections of the joints and muscles and those due to the metallic poisons and other causes which do not follow the course and distribution of special nerves.
In accordance with the belief which we have expressed, that neuralgic attacks are not always of the same nature, but are the manifestations of many different conditions, we should be inclined to include many of these irregular affections under the neuralgias instead of classifying them apart, as Anstie and most writers have done. Thus, a patient of the writer, a gentleman of middle life, who has had migraine since childhood and belongs to a neuropathic family, suffers on the slightest exertion from violent pain in both thighs, which comes on very gradually, beginning at the knees and spreading upward, eventually passing away after a night's rest. One might diagnosticate this as myalgia if he confined himself to topographical considerations, but the history of the patient and the regular march of the attacks point to a different conclusion.
BYM. ALLEN STARR, M.D., PH.D.
BYM. ALLEN STARR, M.D., PH.D.
DEFINITION.—In the term vaso-motor and trophic neuroses it is intended to include a number of forms of disturbance of circulation and nutrition which are caused by disorders of the nervous system. Such disturbances may occur in any part of the body. They are not to be regarded as distinct diseases, but rather as symptoms of lesions in the peripheral or central nervous system. They may present themselves in various forms, as hyperæmia or anæmia or instability of vascular tone, as atrophy or hypertrophy or disintegration of normal tissue. Their consideration cannot, however, be assigned to any previous department of this volume nor relegated to various divisions of it; partly because in some cases they are to be traced to lesions of the sympathetic system, not elsewhere considered; partly because of our ignorance as to the exact location in many cases of the lesion of which they are manifestations.
It is probable that at a future time this chapter will disappear from a system of medicine, as the chapter on ascites has disappeared, and that the symptoms under consideration will be distributed among various departments as symptoms of ascertained lesions in various organs. For the present, however, they demand a separate discussion.
It is not possible to distinguish accurately in all cases between the vaso-motor and the trophic neuroses, for while in many features they are distinct, in a large proportion of cases they occur together. But it is not possible to ascribe all trophic changes to vascular disturbance, nor all vaso-motor changes to a defect or excess of trophic action. Hence a separate consideration of these allied subjects must be given. It is always to be remembered, however, that each may give rise to the other, and that in their pathology they are closely connected. Vaso-motor disturbances manifest themselves (1) by a dilatation of the vessels, producing redness, heat, and rapid metabolism in the part affected; or (2) by a contraction of the vessels, causing pallor, coldness, and malnutrition; or (3) by an alternation of these conditions and consequent temporary disturbance of function. Trophic disturbances may occur in consequence of such increase or decrease of blood-supply, or independently of any vascular change, causing (1) an abnormal production of tissue in an organ, or (2) a decrease in the size and number of its constituent cells, or (3) an actual degeneration of the elements which make it up, after which their place may be taken by another kind of tissue. Under all these circumstances the function of the part affected will be disturbed, and symptoms will be produced which will vary with the tissue or organ involved. Hence ageneral consideration of these symptoms must be given. Before proceeding to a detailed consideration of these neuroses it is necessary to review the physiology of the vaso-motor and trophic systems, in order to make clear the manner in which they perform their functions. And inasmuch as the pathology of these affections is best understood by comparison with experimental lesions made by physiologists in investigating their function, it will be treated together with their physiology.
FIG. 56.
Nerves and ganglia accompanying arterioles
Vaso-motor Nerves and Ganglia accompanying the Arterioles in a Frog (Gimbert):C, arterioles;N, vaso-motor nerve;G, ganglion, from which nerves issue, situated at the point of anastomosis of several capillaries;R, fibre of Remak.
PHYSIOLOGY.—Local Vascular Tone.—Since changes in the force and frequency of the heart's action, and variations in the total amount of blood in the body, affect the body as a whole, the state of circulation in any one organ or part must be dependent upon the degree of contraction or dilatation of its own vessels. This is known as the local vascular tone. It is under the control of a system of nerve-ganglia with their subservient fibres which are found in the middle coat of all arterioles (Fig. 56). The energy expended by these ganglia is manifested by a constant moderate contraction of the circular muscular coat of the artery—a contraction which is as constantly opposed by the dilating force of the blood-pressure within the vessel. An exact equipoise between these two forces never occurs, since each varies constantly, but in a state of health one never becomes permanently excessive. Considerable variations, however, in the localvascular tone are frequently observed. Thus each organ is influenced to a certain degree by every other, since an increase of blood in one part must involve a decrease in all other parts, the total amount of blood in the vessels being constant. Alteration in the heart's action is felt more quickly in some organs than in others, and thus the general blood-pressure by its variations may cause secondarily a disturbance of local vascular tone. The variations now under consideration, however, are not of this kind. They are such as are produced by influences acting directly upon the ganglia in the vessel-walls.
Local irritation is such an influence, and it may excite the ganglia to increased activity, so producing a contraction of the vessel and consequent pallor; or it may suspend the action of the ganglia, so producing a dilatation of the vessel and consequent flushing.
Another influence is irritation acting from a distance and conveyed to the local ganglia by nerve-fibres. These nerve-fibres can be distinguished from all others by their structure, being non-medullated, and by the fact that they have an indirect course, passing from the central nervous system to the sympathetic ganglia, and from these to the local ganglia in the vessels. The impulses sent along these nerves may affect the local ganglia in one of two ways, and either cause contraction by exciting the ganglia, or dilatation by inhibiting the action of the ganglia. The result produced has determined the names given to the impulse, to the fibre transmitting it, and to the centre whence the impulse proceeds, and hence vaso-constrictors and vaso-dilators are distinguished from one another.
The history of the development of the sympathetic nervous system,1as well as its gross anatomy, affords distinct proof that it is not an independent system, as Bichat supposed, but is closely connected in its physiological action with the spinal cord and brain. Impulses which reach the sympathetic ganglia from a distance along the vaso-constrictor or vaso-dilator fibres originate in the central nervous system. The nervous mechanism which controls the local vascular tone is therefore a complex one, consisting not only of the set of local ganglia connected with larger sympathetic ganglia, but also of centres in the spinal cord connected with higher centres in the brain. The brain-centres in turn are complex, consisting of an automatic mechanism in the medulla regulating the action of all the subordinate parts below it, and of a series of cortical centres whose function it is to stimulate or inhibit the medullary mechanism. It therefore becomes evident that local vascular tone may be modified by local causes acting on the ganglia in the vessels—e.g.cold or heat; by changes in the sympathetic ganglia—e.g.the hyperæmia of the face in lesions of the cervical ganglia; by reflex action through the spinal cord—e.g.pallor produced by pain; by reflex action through the medulla oblongata—e.g.glycosuria following sciatica; or by conscious or unconscious impulses coming from the cortex—e.g.the blush of shame, the vaso-motor paralysis of hemiplegia.
1W. R. Birdsall, “Embryogeny of the Sympathetic System,”Arch. of Med., vol. i. where a bibliography of the subject is to be found.
Vaso-constrictors.—Such a mechanism, however complex in structure, would be easily comprehended if the constant manifestation of energy in the maintenance of arterial tone had its only source in the action of the local ganglia in the vessels, and was affected only occasionally by impulsesfrom a distance, as has been thus far supposed. This, however, is not the case, as has been demonstrated by a series of experiments beginning with the brilliant researches of Claude Bernard. The classical experiments of the French physiologist were made upon the sympathetic cord in the neck of a rabbit. Division of this was found to produce a dilatation of the vessels of the ear. Irritation of the peripheral end of the divided cord produced a contraction of the vessels. Division of the spinal nerves connected with the cervical sympathetic and of their anterior roots, or irritation of the cut ends, produced effects similar in character to those caused by division or irritation of the cervical sympathetic. Destruction of the spinal cord in the lower cervical region, or division of the cord at any higher level up to the medulla, was followed by dilatation of the vessels. If the segment of the divided cord just below the section was irritated the vessels contracted. Destruction of the medulla at the calamus scriptorius and above it for three centimeters produced a general dilatation of all the vessels in the body, but division above this level had no effect. The initial congestion produced by these various experiments was accompanied by a rise of temperature in the part. It was followed after a time by a partial recovery of vascular tone, which was more complete the farther the division from the local ganglia. These facts warranted the conclusion that the energy expended by the local ganglia in holding the vessels in a state of constant moderate contraction is derived from the central nervous system, primarily from the automatic centre in the medulla, which in turn is reinforced by each of the secondary centres in the spinal cord and sympathetic ganglia; and also that while the medullary centres control the entire body, the cord and sympathetic centres control only those parts with which they are especially related. In order, therefore, to the maintenance of normal vascular tone the local ganglia must be intact, and they must be in connection with the sympathetic ganglia; these must be active, and must be connected with the spinal cord; the cord must be normal, and its tracts from the medulla must be capable of conduction; the medullary centre must be active, and not hindered or spurred by cortical impulses of a conscious or unconscious nature. Any injury to one or more of these parts will produce a vascular dilatation by interfering with the transmission of vaso-constrictor impulses from within outward, and any irritation of one or more of these parts may cause a contraction of the vessels by increasing the normal stimulus sent to the local ganglia by the vaso-constrictors.
Vaso-dilators.—The action thus far considered has been wholly of a vaso-constrictor kind, and the dilatation which has been mentioned has been due to cessation of the constrictor energy normally passing outward. This may be termed a passive dilatation. It is the kind produced by division of any one of the sympathetic ganglia or cords. But further experiments have shown that another kind of dilatation may be produced, traceable not to a mere cessation of constrictor impulses, but to an impulse of a positive kind sent to the local ganglia and resulting in a sudden suspension of their activity. Such an impulse is really an inhibitory impulse arresting the action of the ganglia in spite of the continued stimulus sent to them from the central nervous system. Its result is a dilatation of the arteries, produced by the blood-pressure within them, which may be termed an active dilatation. Thus, Bernardfound that irritation of the chorda tympani caused an immediate flow of blood to the submaxillary gland because of the dilatation of its vessels. And Dastre and Morat2have demonstrated a similar effect in the head and extremities after irritation of portions of the cervical sympathetic and of the peripheral nerves.
2SeeArchives de Physiologie, “Vaso-dilateurs,” 1879, 1880, 1882;Comptes rendus de l'Academie des Sciences, 1880, pp. 393 and 441.
Much confusion has arisen from the use of the term active dilatation, and many explanations of its mechanism have been offered. At first it was supposed that a system of longitudinal fibres in the vessel-wall acted as opponents to the circular constrictor fibres. This theory, originating with Stilling and Duchenne,3has been lately revived by Anrep and Cybulski.4They hold that since a vessel elongates as well as dilates with every heart-beat, its total distension is the result of two factors—viz. transverse and horizontal distension. If one of these is neutralized, they claim that the other will be increased. Longitudinal fibres in the wall by preventing elongation may thus allow the entire force of the heart to be expended in dilating the vessel. This theory has not, however, been accepted, and with that of Schiff, that contractile elements of the connective tissue surrounding the vessel-walls could pull outward the walls and thus dilate the vessel, has lapsed, because of lack of demonstration of the necessary anatomical structure in all arterioles. Another theoretical explanation, that dilatation of the arteries is caused by contraction of the veins damming back the blood, is disproved by the fact proven by Dastre and Morat, that blood-pressure increases instead of diminishing in the veins during vaso-dilator action. Legros5and Onimus,6noticing the normal occurrence of a peristaltic motion of centrifugal direction in the arteries of the retina, which if increased produced a certain degree of hyperæmia, attempted to explain the phenomena of dilatation by supposing a sudden increase of peristalsis. But Vulpian has proved that the peristalsis is both too slight and too slow in its effects to account for the rapid action of the vaso-dilators, and Dastre and Morat have shown that the peristalsis, not being synchronous with the heart-beat, really impedes the flow of blood. The last theory to be mentioned has a chemical basis, and is known as the theory of attraction (Brown-Séquard, Severini.) According to this, the organs, when active, manifest increased metabolism, to maintain which the blood is drawn toward them by the chemical changes in progress. This theory was based on the fact that irritation of the chorda tympani causes an increased secretion of saliva as well as a congestion of the submaxillary gland. It is now known, however, that these two acts are independent of each other, as either can be suspended while the other continues. Hence this theory too has lapsed.
3Von Recklinghausen,Handbuch der Pathologie des Kreislaufs und der Ernahrung, 1883, where a full bibliography is to be found.
4St. Petersburg Med. Wochenschrift, 1884, i. 215.
5Des Nerfs vaso-moteurs, Thèse de Concours, Paris, 1873.
6Des Congestions actives, Paris, 1874.
The view already stated, that vaso-dilators act by inhibiting local ganglia which cause contraction, is now accepted, especially since it is found that such inhibitory activity is constantly displayed by other parts of the nervous system, and is competent to explain the facts. The active dilatation produced by the inhibition of the action of the local ganglia istherefore to be clearly distinguished from the passive dilatation caused by the cessation of normal tonic impulses sent to them from higher centres. The former is a positive active vaso-dilator phenomenon. The latter is a negative paralytic vaso-constrictor phenomenon. The former is more effective, the dilatation being greater in degree and more permanent than the latter, and resembles exactly the dilatation produced experimentally by exhaustion of the activity of the local ganglia by over-stimulation of the constrictors.7
7Goltz,Arch. f. d. gesammt. Physiol., xi. 92.
An important point of contrast which has been established between vaso-constrictor and vaso-dilator impulses is that while the former are constant the latter are intermittent. Hence they cannot be regarded as opponents of one another. In a normal quiescent state vaso-constrictor energy is always being supplied to counteract the continued intravascular pressure ever renewed with the cardiac systole. The vaso-dilators are inactive. In an organ thrown into functional activity an increased flow of blood at once takes place, proportionate to the work being done by the organ. Such a functional hyperæmia might be produced either by a cessation of constrictor impulses or by an inhibition of their effects. It is by the latter means and through the vaso-dilators that it is produced, and it is probably the chief function of the vaso-dilator nerves to regulate the blood-supply in accordance with the need of a part. For this reason these nerves have been supposed to pass with the motor nerves to the muscles. As few organs exist without a possible use, it is probable that vaso-dilators pass to all parts of the body, as Vulpian asserts, though they have not been demonstrated in every organ or every part.
Like the vaso-constrictors, the vaso-dilators can be traced to the spinal cord, and their centres there are governed by a general centre in the medulla, which in turn may be affected by impulses from the cortex. A destructive lesion in any part of the vaso-dilator system does not produce as marked effects as one involving the vaso-constrictor system, since the symptoms of such a lesion will only appear when the vaso-dilators are called into play. When the vaso-dilator nerve to the submaxillary gland is cut, no change is observed until by some sapid substance put in the mouth its function should be excited, when the gland is no longer found to flush with blood as in the normal state. It is by means of the vaso-dilators that erectile organs become engorged with blood. Eckhard has shown the nervi erigentes of the penis to be vaso-dilator nerves. If they are destroyed, the organs will not respond to the wonted stimulus—a symptom which, however, would only be noticed at intervals. An irritative lesion of the vaso-dilator system may produce permanent congestion of an organ or part, but this seems to be rather more rare than a congestion from paralysis of the constrictors. It is seen in injuries of the peripheral nerves.
Origin of the Vaso-motor Nerves.—The exact course of the vaso-constrictor and vaso-dilator nerves has been traced from various parts into the central nervous system by the careful experiments of Dastre and Morat,8and more recently by Gaskell.9It is now established that theyexist as separate nerves, although they often run together, and that they usually enter the spinal cord at different levels.
8SeeComptes rendus Soc. de Biologie, andArch. de Physiol., 1879-84.
9W. H. Gaskell, “On the Structure and Function of the Nerves which Innervate the Vascular System,”Journ. of Physiol., Jan., 1886.
If the various spinal nerves be cut singly from above downward, and the effects noted, and if the peripheral ends be irritated and the effects noted, and if with proper care the results be analyzed and compared, it will be found that the anatomical connections of the segments of the spinal cord with the sympathetic ganglia, which are so evident at each level, are not the ones by which physiological impulses pass out at that level. The vaso-constrictors of the head, which can be traced to the superior cervical ganglion, do not come from the upper cervical region of the cord, as might be supposed from the connections of that ganglion, but from the first three dorsal nerves. They reach the ganglion through the sympathetic cord in the neck, having traversed the inferior cervical ganglion on the way. There are vaso-constrictors in the cranial cavity which accompany the third, fifth, seventh, and twelfth nerves to the eye, face, and mouth. It is still undecided whether they originate in the cord and medulla, issue in the spinal accessory nerve, and with it enter the cranium (Gaskell), or reach those nerves by way of the carotid and vertebral plexus from the inferior cervical ganglion (Dastre and Morat). The vaso-constrictors of the arm, which can be traced to the inferior cervical and upper thoracic ganglia and to the thoracic sympathetic cord, are derived from the seven upper dorsal nerves. It is true that division of the roots of the brachial plexus causes a slight dilatation of the vessels of the arm, but this is so much increased when the dorsal nerve-roots are divided that it is evident that it is through them that the constrictor fibres chiefly pass. The vaso-constrictors of the leg, which can be traced into the second and third lumbar ganglia and lumbar sympathetic cord, are derived from the five lower dorsal and first lumbar nerves, and only join the crural and sciatic nerves after passing through the abdominal sympathetic. The thoracic viscera are probably supplied partly through the branches of the inferior cervical and thoracic ganglia, and partly through the pneumogastric, the latter statement being disputed by Gaskell. The abdominal viscera are supplied partly through the splanchnic nerves, which are made up of fibres issuing from the cord in the fifth to the twelfth dorsal nerves inclusive, and partly through the pneumogastric. Thus the dorsal region of the cord is the origin of the majority of vaso-constrictor fibres in the body.
The origin of the vaso-dilators is also to be traced to the dorsal cord. The vaso-dilators of the bucco-facial region come from the second to the fifth dorsal nerves, whence they pass to the first thoracic ganglion, and thence by the annulus of Vieussens into the cervical sympathetic cord. Those of the eye, head, and ear come from the same ganglion, but have their spinal origin in the eighth cervical and first dorsal nerves. Those of the arm are traced into the upper thoracic sympathetic cord, which they reach from the five upper dorsal and last cervical nerves. Those of the leg are traced to the first and second lumbar ganglia and the lumbar sympathetic cord, which they reach from all the dorsal nerves from the sixth downward. Gaskell holds, however, that the vaso-dilators of the extremities pass out of the cord in the cervical and lumbar plexuses and accompany the cerebro-spinal nerves. The vaso-dilators of the thorax andabdomen are supposed to pass in the pulmonary plexus and splanchnic nerves, but this is not yet fully determined.
Gaskell10believes that vaso-motor nerves can be distinguished from motor and sensory nerves in the spinal nerve-roots by the smallness of their calibre. He finds such fine fibres only in the spinal nerve-roots between the second dorsal and second lumbar segments of the cord (in the dog), and in the three upper roots of the spinal accessory nerve. According to his account, the vaso-constrictors issue from the spinal cord in both anterior and posterior nerve-roots as medullated fibres, and pass to the sympathetic ganglia lying on the vertebræ (proximal or lateral ganglia); there they lose their medullary sheath, and either end in cells whence new fibres issue, or more probably pass directly onward as non-medullated fibres, having a connection with the unipolar cells of the ganglia only for purposes of nutrition. The number of fibres issuing from any one ganglion is much greater than the number entering it from the cord; hence it is supposed that each medullated fibre splits up into a group of non-medullated fibres; which is possible, as the researches of Ranvier have shown that each axis-cylinder is made up of numerous fibrils. Leaving these ganglia, the nerves pass either to the second series of ganglia (distal or collateral ganglia), whence they issue in plexuses to enter the vessels, or to the vessels directly, where they divide in plexuses. It is in the meshes of the plexus that the local ganglia of the vessel-walls are found. The vaso-dilators are thought to differ from the vaso-constrictors in passing directly to the distal ganglia as medullated fibres, not being connected in any way with the proximal ganglia. Gaskell makes no statement regarding their limits of origin from the cord, except to state that the nervi erigentes issue with the sacral nerves. He agrees with the view that the vaso-dilators act as inhibitory nerves upon the local ganglia.
10Journal of Physiology, Jan., 1886.
Vaso-motor Reflexes.—Thus far, reference has been made only to fibres whose direction of transmission is centrifugal, and whose exit from the spinal cord is by the anterior nerve-roots. There are other fibres, however, through which centripetal impulses pass, and these enter the spinal cord with the posterior nerve-roots. The function of these fibres is to transmit sensory impulses inward to reflex centres, and thus set in action motor mechanisms of a vaso-constrictor or dilator kind whose effects are produced at the periphery. There are, therefore, vaso-motor reflexes, as well as skin and tendon reflexes, whose centres are in the spinal cord. These reflex acts may be excited by impulses reaching the centre not only through the vaso-motor centripetal nerves, but also through the sensory nerves of the cerebro-spinal system. The effect of changes of temperature on the circulation in the skin (if the right hand be plunged in cold water there is a fall of temperature in the left hand), the effect of pain upon the color of the face and the size of the pupil, the red cheek on the affected side in pneumonia, the occurrence of glycosuria during sciatica,—are all instances of such reflex acts. Many vaso-motor affections are produced by irritation causing reflex effects at a distance from the seat of irritation—a fact always to be kept in mind. The utility of counter-irritation to the surface in diseases of the internal organs is explained by supposing that vascular changes are produced in thoseorgans through reflex mechanisms set in action by the local irritation. While some of these reflexes may have their central mechanism in the local ganglia, it is probable that the majority are to be traced to the spinal cord. It is believed that the sympathetic ganglia are not the seat of reflex centres.
FIG. 57.
Action of counter-irritants to chest
Diagram to represent the Mode of Action of Counter-irritants applied to the Chest (Lauder Brunton). The irritation of the afferent nerves by the blister on the chest wall gives rise to a vaso-constrictor reflex in the vessels of the lung.
Since the vaso-motor nerves are connected almost exclusively with the dorsal portion of the spinal cord, it is very natural to conclude that the vaso-motor reflex centres are situated in this region; and the hypothesis has been advanced by Jacubovitch, and strongly urged by Gaskell,11that the cells of the vesicular columns of Clarke, which are peculiar to this region, are the seat of these reflex mechanisms. This hypothesis gains some support from the pathology of syringo-myelia. In this disease the gray matter surrounding the central canal and the vesicular columns are destroyed. The characteristic symptoms are vaso-motor and trophic disturbances, consisting of changes in the vascular tone, changes of local temperature, and various eruptions, in some cases going on to ulceration in the skin and mucous membranes. It is, however, undecided whether the vaso-motor centres of the cord are limited to the columns of Clarke, or are situated in the gray matter surrounding the central canal, since both these parts are destroyed in this disease.12That they are not located in the anterior or posterior gray cornua is determined by the fact that diseases limited exclusively to these areas do not cause vaso-motor disturbances. The situation of the various reflex centres for the various parts of the body is at different levels of the cord, as has been determined by the experiments already cited to establish the level of origin of the vaso-motor nerves. The exact location of the vaso-constrictor and vaso-dilator reflex centres for definite parts is yet to be ascertained.
11Loc. cit.
12See Fürstner,Arch. für Psych., xiv. 422.
Vaso-motor Tracts.—These reflex centres are connected with the medulla by tracts which lie in the lateral columns of the spinal cord,13although it is not determined in which part of these columns. It is not possible as yet to separate the constrictors from the dilators in this tract, nor to determine whether it transmits impulses in both directions or only from above downward. Nor is the course of associating fibres between reflex centres at different levels known. In cases of transverse myelitis the control of the medulla is removed from the vascular centres below the lesion, and the lack of vascular tone seen in the paralyzed limbs, together with the susceptibility to local irritation, is the result of this division of the vaso-motor tracts.
13“Owsjanikow and Tschirijew,”Bull. de l'Acad. de St. Petersbourg, xviii. 18.
Medullary Centres.—It has been stated already that a general vaso-motor centre with both constrictor and dilator powers is situated in the medulla. This lies in two divisions on each side of the middle line, in or just beneath the floor of the fourth ventricle, from the calamus scriptorius up to the level of the sixth nerve-nucleus. Each division governs the vascular tone of its own side of the body,14and lesions in its region in man produce unilateral vaso-motor symptoms.15This centre can be excited to reflex action by strong irritation locally or through the blood, in which case a general constriction or dilatation of the vessels of the entire body will ensue. It seems probable, however, that the general centre in the medulla is made up of a number of special centres, each of which governs a definite set of organs. The vascular tone of the thoracic and abdominal viscera is certainly regulated by a series of such centres. Brown-Séquard and Schiff have produced hemorrhages in the lungs, pleura, stomach, intestines, and kidneys at different times by destructive lesions of the medulla, and the well-known experiments of Bernard, in which by puncture of the medulla local hyperæmia of the liver or kidneys was caused, producing glycosuria or polyuria, confirm this view. Lesions of these parts in man produce similar effects. Charcot has shown that in cerebral hemorrhage ecchymoses may be found in the stomach, pleura, and endocardium, and that pneumonia is especially frequent upon the paralyzed side. De Jonge16has been able to collect thirteen cases of diabetes mellitus in which a lesion of the medulla (hemorrhage or tumor) was found after death; and Flatten17has proven the existence of similar lesions in diabetes insipidus. The connection of these centres with the liver and kidneys has been traced elsewhere.18The medulla contains a special centre for the vaso-motor nerves of the abdomen, which are in the domain of the splanchnic nerves. This centre is excited reflexly by impulses reaching it through the depressor nerve of Cyon from the heart; so that when that organ is overburdened it may be relieved by a fall of arterial pressure produced by dilatation of the abdominal vessels. Whether the connection of the medulla with the centres in the semilunar ganglion which preside directly over these vessels is made by way of the spinal cord or by way of the pneumogastric nerve is still undetermined, though the researches of Gaskell favor the former view. Gastric and intestinal disturbances are certainly produced by nervous lesions in the medulla, but whether they are due to vascular changes is uncertain. The vomiting of mucus and blood, and the large watery evacuations which accompany mental shock or anxiety, as well as the polyuria associated with mental effort, have been ascribed to irritation of local centres in the medulla governing the gastro-intestinal and urinary organs by impulses received from the cortex above. The spleen is under the control of vaso-motor centres, since section of the splenic branches of the semilunar ganglia will produce a great enlargement of the organ, and irritation of the cut end of these branches will producecontraction.19The medulla also contains a vaso-dilator centre for the erectile tissues of the genital organs, irritation of which by mental action or local disease causes impulses to pass to the nervi erigentes by way of the spinal cord, resulting in a flow of blood to the parts. Although a centre has been thought to exist controlling the circulation in the lungs, whose paralysis has been supposed to explain the occurrence of sudden pulmonary œdema without other known cause, no definite facts regarding it are known. That the action of the heart is under the control of the medulla is a fact too well known to require more than a mention. The physiology of the nervous control of the heart cannot be discussed here.
14Owsjanikow,Arbeiten aus d. Physiol. Instit. zu Leipzig, 1871.
15M. A. Starr, “Sensory Tract in Central Nervous System,”Journ. Nerv. and Ment. Dis., July, 1884, pp. 396-398.
16Arch. f. Psych., xiii.
17Ibid.
18See Tyson, “Diabetes Mellitus,”Pepper's System of Medicine, Vol. I. p. 195; Edes, “Diabetes Insipidus,”ibid., Vol. IV. p. 30.
19Tarchanoff,Pflüger's Arch., viii. p. 97; Ross,Diseases of the Nervous System, vol. i. p. 225.
While these medullary centres are certainly influenced by impulses reaching them from the cerebral hemispheres, as is evident from the vaso-motor symptoms produced by mental action—e.g.pallor from fright, blushing, etc.—it is impossible to state in what portion of the hemispheres in man the higher vaso-motor centres lie. Eulenburg and Landois locate them in the motor area in animals.20They are certainly beyond control of the will, and are wholly reflex in their action, a purely mental act in this case being the excitant of a purely physical result.21
20Arch. f. Path. Anat., Bd. lxviii. p. 245.
21In addition to the articles already cited the reader is referred to Landois'sPhysiology, to Duval's article, “Vaso-moteurs,” in theDictionnaire de Médecine et de Chirurgie, vol. xxxviii. (1885), for a summary of vaso-motor physiology, and to Gerhardt's “Ueber Angio-neurosen,”Volkmann's Sammlung klin. Vorträge, No. 209. Gaskell's researches, published in theJournal of Physiology, are the most recent and satisfactory.
PATHOGENESIS.—From this review of the physiology of the vaso-motor system it becomes evident that disturbances of vascular tone may be produced by many different causes acting upon many various parts. They may be due to local affections of the part in which the symptoms are present, as in the case of erythema22after burns or frost-bite, or congestion of any organ after injury. They may be due to affections of the vaso-motor nerves passing to the part affected, as in the case of vascular changes due to peripheral nerve lesions.23They may be due to affections of the sympathetic ganglia connected with the part affected, as in the case of migraine,24sudden flushing of one ear, certain cases of polyuria,25and Basedow's disease.26They may be due to lesions in the spinal cord affecting the vaso-motor centres27or compressing the nerve-roots on their way to and from the sympathetic ganglia,28as is the case in the various forms of myelitis and in Raynaud's disease or symmetrical gangrene, and in meningitis, tumors of the cord, or Pott's disease. They may also be caused by such conditions in the cord as cut off the vaso-motor centres from the medullary centres, such as transverse myelitis from compression or traumatism.29They may be due to lesions of the medulla oblongata,30as is seen in some cases of polyuria and glycosuria,31and in cases of universal erythema32following acute fevers. They may be due to diseases of the cerebral hemispheres, as is evident from the vaso-motor symptoms occurring in hemiplegia and hysteria. Finally, they may be of a reflexorigin, dependent upon some obscure source of irritation in a part quite distant from the region in which the symptoms appear.33
22Vol. IV. p. 511.
23Vol. V., “Neuritis.”
24Vol. V., “Migraine.”
25Vol. IV., “Polyuria.”
26Vol. III. p. 761.
27Vol. V., “Syringo-myelitis.”
28Vol. V., “Meningitis Spinalis.”
29Vol. V., “Transverse Myelitis.”
30Vol. V., “Medulla.”
31Vol. I., “Diabetes Mellitus.”
32Vol. IV. p. 512.
33Vol. V. p. 205.
TheDIAGNOSISof the seat of the lesion in many cases of vaso-motor neurosis may be made if the organ or the exact limitation of the area affected be ascertained, and the history of the case, together with the concurrent symptoms of other kinds, be considered. In some cases no organic cause can be found, and in these a reflex cause should be diligently searched for.
SYMPTOMS.—A vaso-motor affection may manifest itself either by a spasm or a paralysis of the vessels. In angiospasm the part affected becomes pale, and irritation no longer causes a vaso-motor reflex. It looks shrunken, and if the skin over it is loose it may be thrown into folds or shrivelled, presenting the appearance seen in the hands after long immersion in hot water. The lack of blood in the part arrests the processes of metabolism which are normally constant, and if the condition continues this may result in such a disturbance of nutrition that ulceration, or even gangrene, may ensue. The local anæmia, combined with the cessation of metabolism, produces a fall of temperature in the affected part, which is then more easily affected by the temperature of the air than in a normal state, so that exposure to cold is very liable to cause freezing. These conditions necessarily produce an impairment of function, so that if the affection is located in the extremities, as the fingers, they are soon rendered useless. The term digiti mortui has been applied to this state. In the surface of the body angiospasm causes cutis anserina, pallor, numbness, tingling, slight anæsthesia, and analgesia. If it occurs in a limb, the finer motions are imperfectly performed, and in time the nutrition of the muscles may be so impaired as to produce atrophy and paresis. It may even lead to gangrene. Nothnagel has recorded34five cases of sciatica in which the pain produced a reflex spasm of the vessels of the leg, which, persisting, resulted in partial paralysis, atrophy, lowering of temperature, pallor, and sensory disturbances. Ross mentions35the sudden appearance of circumscribed patches on the hands and forearms of washerwomen, in which there is a pallor, coldness, and partial anæsthesia. These may be limited to the distribution of a single nerve, and may be accompanied by trophic affections.
34Arch. f. Psych., v.
35Vol. I. p. 221.
Spasm of the veins may occur as well as of the arteries,36or independently of them. In the latter case the blood will not pass out of the capillaries. The part will then be blue, swollen, œdematous, and painful; the temperature will be lowered by increased radiation of heat, and all the sensations and functions be impaired in greater or less degree. If this continues, nutrition may suffer, and in the end gangrene develop, which will take its course and lead to the throwing off of the part. Grainger Stewart has described such a condition occurring in both hands and feet.37It may be likened to a severe form of Raynaud's disease.
36Weiss, “Symmetrische Gangrän,”Wiener Klinik, 1882.
37Grainger Stewart,An Introduction to the Study of Nervous Diseases, p. 138.
Angio-paralysis is more frequent than angiospasm, and may be due either to paralysis of the vaso-constrictors or to excitement of the vaso-dilators. It shows itself by a bright-red or mottled appearance of the skin, and increase of local temperature, and more rapid processes ofnutrition, together with an increase of secretion if the part is a gland or a mucous membrane, and an increase of sweat if it is the skin. In the latter case an increased sensitiveness to changes of temperature, a subjective sensation of heat, and hyperæsthesia and hyperalgesia may occur. The hyperæsthesia on the paralyzed side which is present in hemiparaplegia spinalis is ascribed to the vaso-motor paralysis. But these symptoms soon give place to others. The dilatation of the vessels, which at first caused an increased flow of blood to the part, produces a slowing of the blood-current in the part, just as a river runs less rapidly where it becomes wider. The slowing of the current in the skin allows of a more complete cooling of the part as the radiation of heat and the evaporation of moisture are increased, and the slowness of the renewal of blood impairs the processes of nutrition, so that to the first stage of redness, heat, and increased metabolism there ensues a stage of blueness, cold, and defective nutrition, and the function of the part may be impaired. In this stage it usually presents a mottled appearance, and may be slightly swollen and œdematous, and the continued increase of perspiration gives it a clammy coldness to the touch. In all of these conditions severe pain, sometimes of a burning character, is a very distressing symptom (causalgia). These conditions are seen in peripheral nerve-lesions, and give rise to the appearances which have been so admirably described by Weir Mitchell.38
38Injuries of Nerves.
A peculiar combination of symptoms may be mentioned here, to which Weir Mitchell has given the name of erythromelalgia.39This disease begins with tenderness and pain in the soles of the feet, which are soon followed by a marked distension of the capillary vessels. The congestion is attended by a sensation of burning pain similar to that produced by a blister. The surface is at first of a dull dusky-red color; later it appears purple. The redness is not uniformly distributed over the sole, but occurs in patches of irregular shape, being especially frequent over prominent parts exposed to pressure and friction, and the attacks seem to be brought on by long standing or walking. At first there is a rise of temperature in the affected surface, the arteries pulsate visibly, the veins are swollen, and there may be some œdema. Later, the foot is cold and pale. Sensations of touch and temperature are normal, but the part is so extremely tender that walking is impossible. There is no paralysis. One or both feet may be affected, but the patches of redness are rarely symmetrical. The hands are occasionally affected. The condition may occur in paroxysms or may remain for some time. It resists all known methods of treatment, although applications of cold relieve the burning pain to some extent and the tenderness enforces rest.
39Amer. Journ. of the Med. Sci., July, 1878.
With angio-paralysis may be classed the taches cérébrales of Trousseau no longer considered diagnostic of meningitis, but denoting a weakened condition of vaso-constrictor action in the local ganglia of the vessel-wall which may occur upon local irritation of the skin in any severe disease affecting the nutrition of the general nervous system.
Actual rupture of the capillaries in the course of vaso-motor diseases is rarely observed, although the stigmata appearing in hysterical and cataleptic patients may be ascribed to this cause. In this connection tabetic ecchymoses may be mentioned, which appear suddenly without local injury,and resemble an ordinary bruise, running a similar course. They occur only in the course of locomotor ataxia.40
40Straus,Arch. de Neurologie, tome i. p. 536.
In addition to these forms of vaso-motor affections there is a condition of instability of vascular tone which manifests itself by sudden transient changes in the circulation of various organs. This is a functional affection, usually due to malnutrition. It is seen in many cases of neurasthenia and hysteria, and manifests itself by sudden flushes or pallor, alternations of heat and cold, local sweating, attacks of mental confusion, and inability to use any organ continuously from disturbance of the power of the vaso-dilators to maintain a condition of functional hyperæmia.41Little is actually known about the causes of this state of the vascular system, although much has been written about it. (For a fuller description the article on Neurasthenia may be consulted.)
41Anjel,Arch. für Psychiatrie, xv. 618.
Many functional derangements of the internal viscera have been ascribed to such vaso-motor instability with more or less probability,42but hypothesis of this kind, however plausible, is evidently beyond confirmation. It is especially in affections of this kind that causes of reflex irritation are to be carefully sought. Cutaneous angio-neuroses, such as have just been described, may affect any part of the body. They usually appear suddenly, producing much discomfort and an impairment of function in the part if it is an extremity. They disappear as rapidly as they come. The duration of such attacks varies from a few minutes to several days. They are very liable to recur. If it is the vessels under the control of the cervical sympathetic which are affected, the symptoms will be those of migraine or of lesion of the ganglia.43If it is the vessels in the extremities which are involved, the condition of digiti mortui or erythromelalgia or symmetrical gangrene44may be produced.
42Fox,The Influence of the Sympathetic System in Disease, London, 1885.
43See p. 1263.
44See p. 1257.
A singular epidemic occurred in France in 1828 and 1830 which was termed acrodynia. Many persons were suddenly seized with vomiting and purging, and soon after the onset the extremities became red or mottled in blotches, swollen and œdematous, and hot, painful, and tender. The attacks lasted from a few days to two months, and during this time the skin became thick and hard, the muscles weak and subject to spasms, and the general health was impaired. Relapses occurred in many cases, but all finally recovered, and hence the exact nature of the disease was not ascertained.
COURSE.—In any case of vaso-motor neurosis the course of the disease and its termination will depend chiefly upon its cause. If the cause is some permanent lesion of the nervous system, the condition will remain, and in this case the termination will depend upon the severity of the symptoms. Angiospasm may be so severe as to lead to gangrene ana the separation of the part affected, or may be so slight as to cause only subjective discomfort and a little pallor. Angio-paralysis may lead to an extreme degree of congestion, which is attended by heat and pain at first, later by paræsthesia and coolness, with increased liability of the part to be affected by changes in the surrounding air. This stage is succeeded by one of less marked dilatation of the vessels and a spontaneous partialrecovery, although the more moderate symptoms may continue indefinitely and seriously impair the function of the part. If the cause is a temporary derangement of function in the vascular mechanism, is reflex irritation which can be removed, or is a curable organic disease, the symptoms will subside rapidly or gradually and perfect recovery may follow. If the condition is one of irritability in the vaso-motor centres, producing alternations of flashing or pallor, such as is observed in nervous exhaustion, it may recur irregularly for a considerable length of time until the causative condition can be removed.
PROGNOSIS.—The prognosis must be determined in each case by a consideration of the cause of the affection, of the nature of the symptoms, of the severity of the disease, and of the possibility of success in both symptomatic and causative treatment. In the angio-paralytic cases an eventual spontaneous relief from much of the discomfort may be promised, although the duration of the symptoms cannot be predicted.
TREATMENT.—Treatment must be directed primarily to removing or diminishing the severity of the cause. A review of the section on Pathogenesis will indicate how wide a field this may include, and the reader must be referred to the special articles which are alluded to in that place for therapeutic measures. Special diligence is to be shown in searching for a source of reflex irritation. When the cause cannot be reached, and when the symptoms are of such severity as to demand immediate attention, treatment may be directed to them.
In all conditions of vaso-motor disease it is important to shield the part from external injury; for if the vessels are dilated they are liable to rupture, and any abrasion of the surface may produce serious inflammation and ulceration; and if the vessels are contracted any injury will be repaired slowly and imperfectly on account of the anæmia, and may even hasten the approach of gangrene.
Perfect rest, bandaging with cotton, and even the application of a light splint to the extremities will be advisable in cases of angiospasm. It is desirable to retain the animal heat, inasmuch as its supply is deficient. In angio-paralysis rest in a somewhat elevated position and applications of mild evaporating lotions are indicated in the early stage; later, the limb may be bandaged. It is not advisable to attempt by tight bandaging to counteract the effect of the vascular paralysis, for the nutrition of the limb is liable to suffer and gangrene may be induced.
Massage of a part affected with vaso-motor symptoms is of great service, since the circulation can be increased in the veins, and thus indirectly in the capillaries, and the nutrition of the part can thus be favored. It is more efficacious in angio-paralysis than in angiospasm. Too rough rubbing is of course to be avoided, lest the skin be injured. All counter-irritation is to be strictly forbidden.
Electricity has been used with varying results. According to Erb,45moderate faradic applications contract the vessels; strong faradic applications, especially with the brush, dilate the vessels. The galvanic current at first contracts the vessels, but this is followed by a secondary dilatation, which will be greater and occur more rapidly the stronger the current used.46Cathodal closures contract the vessels; the anodalcontinuous current dilates them widely. Stabile continuous currents through a nerve dilate the vessels which the nerve supplies. Inasmuch as vaso-constrictors and vaso-dilators pass together in many nerves, and are found together in all parts, it is impossible to apply electricity to either alone. In those cases, therefore, in which it has been ascertained which set of vaso-motors is affected, it is not always possible to produce a direct effect upon that set by electrical treatment. Erb recommends, in conditions of vaso-motor spasm a trial of the galvanic current, the cathode on an indifferent point, the anode being applied over the vaso-motor centres governing the part, and also over the area of the body which is affected, and held there while a moderate continuous current is passing, interruptions being avoided; or, the cathode being placed on the neck, the anode may be applied to the nerves passing to the affected part; or a strong continuous current may be sent through the nerve, its direction being changed several times during a moderately long application. Finally, the faradic brush applied to the part or a strong faradic current sent through its nerve may relax the spasm. In any case, all these methods should be tried before electrical treatment is abandoned.
45Electrothérapie, 562.
46To this statement Lauder Brunton assents—Pharmacology, p. 250.
In vaso-motor paralysis other methods are used. The cathode is placed on the part congested, and a weak galvanic current is employed with frequent interruptions or even with changes of the pole; or the cathode may be moved about upon the reddened skin while a mild continuous current is passing. A very weak faradic current with wet electrodes, or even a weak faradic current applied with a brush, may be of service. Here, again, various methods may be tried.
If the extremities are affected, it may be well to immerse them in a basin of water which is connected with one pole of the battery, and the current directed in the manner just described, according to the case. It must be confessed that no definite results can be predicted from the use of electricity in these cases, and much more experience is needed before definite rules can be laid down. The records show that in apparently similar cases opposite methods of application have produced favorable effects, while in other cases all methods have failed. Too much reliance should not be placed in electrical treatment. Erythromelalgia is an obstinate affection, and symptomatic treatment, directed chiefly to quieting the pain by opium and allaying the sensation of burning by cool baths, must be resorted to.
Internal remedies may be tried appropriate to the condition present. In angiospasm nitrite of amyl inhaled, or nitro-glycerin1/100gr. t. i. d., may give considerable relief, although both of these drugs are to be used with caution. Chloral hydrate is also of some service, and where the patient is in pain and suffers from insomnia this may fulfil several indications. In angio-paralysis ergot has been used with advantage. Oxygen inhalations are of service. Chloride of potassium may also be tried. It is evident, however, that such remedies, acting as they do upon the general arterial system, are not to be depended upon in the treatment of local conditions, since they have no selective action upon the affected part. The majority of the drugs known as sedatives and antispasmodics have been used in these conditions, but the records of individual cases show that they are not of much avail. Theoretical therapeutic measures based uponexperimentation on animals have been fully discussed by Lauder Brunton,47but practical experience has not yet been sufficiently extensive to warrant any further statements.
47Pharmacology, Therapeutics, and Materia Medica, pp. 229-360. Lea Bros., 1886.