Neuralgia and the Diseases that Resemble it

Such is the description given by Valleix; for my own part, I cannot say that I have seen enough cases to test its accuracy. I believe it to be generally correct, yet it may fairly be doubted whether the author might not have revised his description had the natural history of myalgic affections been as carefully investigated as it has since been. The hypogastric foci of pain of which he speaks are at least open to considerable suspicion, as it will be shown, in the chapter on Myalgia, that an extremely common variety of the latter affection is situated in this region, and the severity of the pain which it often produces might well cause it to be mistaken for a genuine neuralgia.

I have, however, seen three or four cases in which the very complete intermittence of the paroxysms, without any perceptible relation to the question of muscular fatigue, left no doubt in my mind of the really neuralgic character of the malady. In one of these instances, oddly enough, the exciting cause appeared to be fright; and this was as severe a case as one often sees. The patient was a woman of middle age, and much depressed by the long continuance of a profuse leucorrhœa. As she was walking along the street, a herd of cattle, in a somewhat irritable and disorderly condition, came suddenly toward her; she immediately began to suffer pain just above the crest of the ilium, and at the lumber region, and, most acutely, in the labium majus of one side; and then pain returned daily, about 10 a. m., lasting for half an hour with great severity. This woman's family history was remarkable: her mother had been paraplegic, her sister was a confirmed epileptic, and two of her children had suffered from chorea.

In two other cases of lumbo-abdominal neuralgia which were under my care, there were also very painful points in the spermatic cord and in the testicle. One of these cases will be referred to under the head of Visceral Neuralgia. Another case, in which severe quasi-neuralgic pain was referred to the groin, will be described in the chapter on the Pains of Hypochondriasis.

(f) Crural Neuralgia.– This appears to be rare as an independent affection occurring primarily in the crural nerve. Valleix had only seen it twice in all his large experience, and I have never seen it myself. Neuralgic pain of the crural nerve is almost always a secondary affection arising in the course of a neuralgia, which first shows itself in the external pudic branch of the sacral plexus; or else occurring as a complication of sciatica. A remarkably severe example of the latter occurrence was observed in an old man who still occasionally attends the Westminster Hospital. He has been a martyr to the most inveterate bilateral sciatica for between two and three years; and, within the last three months, it has extended itself into the cutaneous branches of the curval nerves of both thighs. So great an aggravation of the pain is produced by any muscular movement, that the patient can only walk at the slowest possible pace, moving each foot forward only a few inches at a time. The bilateral distribution of the pain is remarkable in this case; but there can be no doubt of its really neuralgic character, from the truly intermittent way in which it recurs, and the absence of any history whatever to point in the direction of rheumatism, gout, or syphilis.

The nervous supply to the skin of the anterior and external portion of the thigh includes: (1) The middle cutaneous, (2) the internal cutaneous, and (3) the long saphenous branch of the anterior crural nerve; (4) the cutaneous branch of the obturator; and (5) the external cutaneous nerve, derived from the loop formed between the second and third lumbar nerve. The sensitive twigs derived from the two latter sources, equally with the branches of the anterior crural, are liable to be secondarily affected by neuralgia, which commences in the lumbo-abdominal nerves; but it must be a rare event for them to be the seat of a primary neuralgia. The only occasion on which I have seen anything which looked like the latter was in the case of a porter, who, in straining to lift a very heavy load, ruptured some part of the attachment of the tensor vaginæ femoris. But the susceptibility of all the nerves of the front of the thigh to secondary or reflex neuralgia receives numerous illustrations. The extremely severe pain at the internal aspect of the knee-joint, which is such a common symptom in morbus coxæ, is evidently a reflex neuralgia of the long saphenous nerve, the ultimate irritation being situated in the branches of the obturator nerve which supply the hip-joints. For some reason unexplained, it happens that this saphenous nerve is specially liable to be affected in a reflex manner: for instance, this happens in a considerable number of cases of sciatica. I have a lady now under my observation, in whom the secondary neuralgia of the saphenous nerve has become even more intolerable than the pain in the sciatic, which was the nerve primarily affected. The pain in these cases very frequently runs down the inner and anterior surface of the leg to the internal ankle. Sometimes the branches of the anterior crural become the seat of intensely painful points in the course of a long-persisting sciatica. A patient at present under my care has a spot, about the size of a shilling, just at the emergence of the middle cutaneous branch from the fascia lata, which is intensely and persistently tender to the touch, and the skin here is so exquisitely sensitive to the continuous galvanic current that the application of moistened sponge-conductors, with a current of only fifteen Daniell's cells, causes intolerable burning pain; whereas at every other part of the limb the current from twenty-five cells can be borne without much inconvenience.

(g) Femoro-popliteal Neuralgia, or Sciatica.– This is one of the most numerous and important groups of neuralgia; but, notwithstanding that there are plenty of opportunities for studying it, I venture to think it is very commonly mistaken for different and non-neuralgic diseases, and they for it. The rules of diagnosis which will be laid down for all the neuralgiæ would nevertheless prevent these errors, if carefully attended to.

Sciatica is a disease from which youth is comparatively exempt. Valleix had collected one hundred and twenty-four cases, and in not one was the patient below the age of seventeen, only four were below twenty. In the next decade there were twenty-two; in the next, thirty; and the largest number of cases, thirty-five, occurred between the ages of forty and fifty. This completely tallies with my own experience, and appears to afford some support to a suspicion I have formed, that the chief exciting cause of sciatica is the pressure exercised on the nerve in locomotion, and that this cause exercises its maximum influence when the period of bodily degeneration commences. It is further remarkable that, in elderly persons (whose habits of locomotion are of course more limited), the proportion of fresh cases rapidly diminishes; and also that above the age of thirty the number of male patients greatly exceeds that of female patients attacked. All this seems to point in the same direction.

According to my observation, there are three distinct varieties of sciatica. The first of these is obscure in its origin, but may be said, in general terms, to be connected with a nervous temperament of the highly impressible kind, which is more or less like what we call "hysteric," not only in the female, but also in male patients. The subjects of this kind of sciatica are mostly young persons, and hardly ever more than middle-aged; they are generally found to be liable to other forms of neuralgia; and the actual attack of sciatica is produced by some fatigue or mental distress, which at other times might have brought on sick headache, or intracostal neuralgia, etc. Very many of these patients are anæmic; and chlorotic anæmia seems specially to favor the occurrence of the affection. The greater number of the victims are females, and in very many, whether as cause or effect, there is impeded, or at least imperfect, menstruation. This kind of sciatic pain is not usually of the highest degree of intensity, but it generally spreads into a great many branches, both in a direct and a reflex manner. It is probable that this variety of the disease is, at least very often, dependent upon, or much aggravated by, an excited condition of the sexual organs; certainly, I have observed it with special frequency in women who have remained single long after the marriageable age, and in several male patients there has been either the certainty or a strong suspicion of venereal excess. Sciatica of this kind also occurred in the case of a single woman aged about thirty, who to my knowledge was excessively addicted to self-abuse.

The second variety of sciatica occurs for the most part in middle-aged or old persons who have long been subject to excessive muscular exertion, or have been much exposed to damp and cold, or who have been subject to the combined influence of both these kinds of evil influence. One must also include, I think, in this group a considerable number of cases where the age is not so advanced, but the patient has been obliged, by the nature of his business, to maintain the sitting posture daily, for hours together, exercising pressure on the nerve; this is especially liable to happen in these persons.

The sufferers from this variety of sciatica are mostly, as already said, of middle age or more; but this statement must be understood to be made in the comparative sense, which refers rather to the vital status of the individual than to the mere lapse of years. Many of these people have hair which is prematurely gray, and in some the existence of rigid arteries, together with arcus senilis, completes the picture of organic involution, or senile degeneration. In particular cases, where depressing influences have been at work for a long time, or unusually active, these appearances rectify the false impression we should otherwise derive from learning the mere nominal age of the person; this is especially often the case with regard to patients who have for a long time drunk to excess. The prematurely and permanently gray hair (it will be seen hereafter that permanency of grayness is an important point), together with well-marked inelasticity of arteries, very often tells a tale which is most useful in informing us, not only of the vital status of the patient, but of the kind of sciatica under which he labors; and also influences our prognosis seriously. There is otherwise a somewhat deceptive air about the appearance of many of these degenerative cases; for instance, a ruddy complexion is not uncommon, nor the retention of considerable, or even great, muscular strength. It is probable that these appearances deceived Valleix and many others, or they could hardly have failed, as they have, to observe the frequency of the degenerative type among the most numerous group of sciatic patients, namely, those between thirty and fifty years of age. These persons are not truly "robust," although at a hasty glance they might at first seem to be so. It would be a serious mistake to omit the search for the important vital evidences which have been referred to, since these therapeutic and prognostic indications are of the highest value.

A prominent feature in this kind of sciatica is its great obstinacy and intractability. Another, equally marked, is the tendency to the development of spots around the foci of severest pain which are intensely and permanently tender, and the slightest pressure on which is sufficient to set up acute pain. This is a symptom much less developed, if developed at all, in the variety of sciatica which we first discussed. The places which are especially apt to present this phenomenon of tenderness are as follows: (1) A series, or line of points, representing the cutaneous emergence of the posterior branches, which reaches from the lower end of the sacrum up to the crista ilii; (2) a point opposite the emergence of the great and small sciatic nerves from the pelvis; (3) a point opposite the cutaneous emergence of the ascending branches of the small sciatic, which run up toward the crista ilii; (4) several points at the posterior aspect of the thigh, corresponding to the cutaneous emergence of the filets of the crural branch; (5) a fibular point, at the head of the fibula, corresponding to the division of the external popliteal; (6) an external malleolar, behind the outer ankle; (7) an internal malleolar.

I have already mentioned that in sciatica the pain frequently spreads in a reflex manner to nerves which are connected, by their origin from the plexus, with the sciatic. It will be remembered, also, that I related cases in which the formation of tender points, in the course of the nerves thus secondarily affected, was even more distinct and remarkable than anywhere in the branches of the sciatic itself.

Another circumstance which distinguishes the form of sciatica which we are now describing is, the degree in which (above all other forms of neuralgia) it involves paralysis of motion. [The subject of the complication of neuralgia will be treated in a general manner farther on; but it seems necessary to note here the special liability of sciatic patients to this and to the most material complications]. By far the largest part of the motor nervous supply for the whole lower limb passes through the trunk of the great sciatic; it might therefore be naturally expected that a strong affection of the sensory portion of the nerve would produce, in a reflex manner, some powerful effect upon the motor element. This effect is most frequently in the direction of paralysis. Complete palsy is rare, but in a large proportion of cases which have lasted some time there will be found, independently of any wasting of muscles, a positive and considerable loss of motor power. It is of course necessary to avoid the fallacy which might be produced by neglecting to observe whether movement was restricted merely in consequence of its painfulness. Not long since, I had occasion to test the electric sensibility in a case of sciatica, in which there was extremely severe pain, affecting chiefly the peroneal region of the leg, and great weakness of the leg, amounting to inability for walking. The gastrocnemius could hardly be got to contract at all, when the most powerful Faradic current was directed upon the nerve in the popliteal space of the affected limb, though the muscle of the sound side reacted with great vigor.

Anæsthesia is also a common complication of sciatica, far commoner, I venture to think, than it has been represented either by Valleix, or Notta. It is necessary, however, to be explicit on this point. In the early stages, both of this form of sciatica, and of the milder variety previously described, there is almost always partial numbness of the skin previous to the first outbreak of the neuralgic pain, and during the intervals between the attacks. By degrees this is exchanged, in the milder form, for a generally diffused tenderness around the foci of neuralgic pain, while other portions of the limb remain more or less anæsthetic. In the severer forms it sometimes happens that, besides an intense tenderness of the skin over the painful foci, there is diffused tenderness over the greater part or the whole of the surface of the limb. But it is important to remark that both in the anæsthetic and the hyperæsthetic conditions (so called) the tactile sensibility is very much diminished. I have made a great many examinations of painful limbs, in sciatica, and have never failed to find (with the compass points) that the power of distinctive perception was decidedly lowered.

Convulsive movements of muscles are met with in a moderate proportion of cases of sciatica in middle and advanced life, in which affection they are entirely involuntary. They differ from certain spasmodic movements not unfrequently observed in the milder form (and especially in hysteric women), for these are more connected with morbid volition, and are in truth, not perfectly involuntary. In several cases of inveterate sciatica I have seen violent spasmodic flexures of the leg upon the thigh. Cramps of particular muscles are occasionally met with. I have seen the flexors of the toes of the affected limb violently cramped, and in one case there was agonizing cramp of the gastrocnemius. It is chiefly at night, and especially when the patient is falling asleep, that this kind of affection is apt to occur.

A third variety of sciatica is the rather uncommon one so far as my experience goes, in which inflammation of the tissues around the nerve is the primary affection, and the neuralgia is mere secondary effect, from mechanical pressure on the nerve, which, however, is not apparently itself inflamed. I believe that these cases are sometimes caused by syphilis, and sometimes by rheumatism. One of the most violent attacks of sciatic pain which ever came under my notice was in a syphilized subject, a discharged soldier, who had been the victim of severe tertiary affections, and had been mercilessly salivated into the bargain. This unfortunate man suffered dreadful agony, which was aggravated every night, but was never totally absent. The pain started from a point not far behind the great trochanter: pressure here caused intolerable darts of pain, which ramified into every offshoot of the sciatic nerve, as it seemed, and made the man quite faint and sick. Large doses of iodide of potassium, together with the prolonged use of cod-liver oil, completely removed the pain and tenderness. It need hardly be said that cases of this kind are essentially different, and require perfectly different principles of treatment from neuralgias in which the disturbance originates within the nervous tissues themselves.

The chronic rheumatism does also, occasionally, affect the sheath of the nerve in such a manner as to produce a deposit which sets up neuralgic pain, must also be admitted, although I believe the number of such cases to be preposterously over-estimated by careless observers. It has several times happened that a patient has come under my care with so-called "rheumatic affection of the nerves" of the thigh and leg, and that on examination one has found all the symptoms and clinical history of a neurosis, but not the slightest valid argument for a diagnosis of the rheumatic diathesis. Indeed, upon this point, I think it is time that a decided opinion should be expressed. I firmly believe that a large number of sciatic patients have their health ruined by treatment directed to a supposed rheumatic taint which is purely imaginary. The state of medical reasoning, suggested by the way in which too many practitioners decide that such and such pains are rheumatic in their origin, is a melancholy subject for reflection. Nearly always it will be found, on cross-examination, that the state of the urine has been made the basis of a confident diagnosis; the practitioner will tell you that the urine was loaded, i. e., with lithtaes. He ignores the fact that nothing is more common, in neurotic patients who are perfectly guiltless of rheumatic propensities, than a fluctuation between lithiasis and oxaluria, neither of which phenomena, under the circumstances, indicates any more than a temporary defect of secondary assimilation of food, produced by nervous commotion. I may perhaps find room, on a future page, for a few further remarks on the subject; at present I only put in a caution against too ready an acceptance of the rheumatic hypothesis.

II. Visceral Neuralgias.

Uterine and Ovarian Neuralgia.– This is an important group of neuralgic affections, and one which I cannot help thinking is strangely misappreciated, very often, in a therapeutic point of view. In one aspect these affections possess a special interest, namely this, that they are more frequently dependent on peripheral irritation for their immediate causation than any other group of neuralgias. If we consider the great copiousness of the nervous supply to the uterus and ovaries, and the powerfully disturbing character of the functional processes which are periodically occurring in these organs, we shall be at no loss to understand how this may be. The amount force of the peripheral influence and which are brought to bear upon the central nervous system by the functions of the uterus and ovaries are greater than any that emanate from the diseases and functional disturbances of any other organ in the body.

The most common variety of peri-uterine neuralgia is that which attends certain kinds of difficult menstruation. It would be hardly correct to give the name of neuralgia to the pain existing in these very numerous cases of dysmenorrhœa in which the suffering is apparently altogether dependent on the mere retention or difficult escape of the menstrual fluid, although the character of the pain often resembles the neuralgic type. There is another group of dysmenorrhœal affections however, in which the pain may fairly be called neuralgic, since it is apparently independent of the circumstances of the discharge of menstrual fluid, and simply attends the process, seemingly on account of a naturally-exaggerated irritability of the organs concerned. There is a large class of young women in whom, and more especially before marriage, the time of menstruation is always marked by the occurrence of more or less severe pain. Formerly I used to believe that this pain was relieved on the occurrence of the discharge, but I have seen too many cases of a contrary nature to retain this opinion. I now believe that the subjects of the kind of menstrual pain to which I am referring are naturally endowed with a very irritable nervous apparatus of the pelvic organs, and that there is a certain character at once of immaturity and excitability in their sexual organs, especially in the virgin condition. So far from these females being disposed to sterility, as is too often the case with those dysmenorrhœal subjects whose troubles depend upon occlusion, distortion, or narrowing of the outlets, they are often extremely apt to the generative function; and, what is more, the full and natural exercise of the sexual function appears necessary to the health of their organs, as is shown by the fact that these menstrual pains lose their abnormal character, completely or in great part, after marriage, and especially after child-bearing. The contrast between the two types of dysmenorrhœal patients is sharply brought out by the two following cases:

Case I. – S. M., a housemaid, aged twenty-three when first under my notice, was the picture of physical health and strength, very intelligent, and a girl of excellent character and most industrious habits. At every menstrual period, however, she suffered, for some hours previously to the occurrence of the flow, from severe pain in the uterine region, which was tumefied and tender. Hot hip-baths gave some relief, apparently by hastening the discharge; as soon as the latter was established, the pain rapidly subsided. This young woman married a healthy and vigorous young man, but has never had any children, and at the date of my last inquiries still suffered periodically from her old troubles.

Case II. – Mrs. B. was married at the age of twenty-six. Up to the date of her marriage she used to suffer the most severe pain at every menstrual period; the pain, however, bore no relation to the freedom of the discharge, but always lasted about the same length of time, under any circumstances, or was only less or more according as the general bodily vigor was greater or less at the moment. From the date of marriage these troubles steadily declined; a child was born at the end of twelve months, and the menstrual troubles have never resumed a serious shape up to the present time, a period of nearly nine years. This lady is herself a neuralgic subject, liable to migraine in circumstances of fatigue, and suffering horribly from it during her pregnancies; and she comes of a family in whom the nervous temperament is strongly developed.

It must not always be concluded, because the menstrual pain is very severe before the discharge and is relieved at or soon after its appearance, that the case is one of occlusion, and not of neuralgia. There is a class of cases in which the affection appears to be a very severe ovarian neuralgia, attended with a vaso-motor paralysis which causes great engorgement of the ovary and consequent difficulty of "ovulation." I have seen several instances which I could not explain in any other way.

Case III. – One patient I particularly remember, from the fact that she was always attacked with dreadful pain, which was sometimes seated in one groin and sometimes in the other, but was regularly attended with large and palpable tumefaction of the ovary, which began to subside when the discharge commenced. This woman married rather late, but her menstrual troubles immediately became less, and she became pregnant and was happily delivered, nearly as soon as was possible. She, too, was a decidedly neuralgic subject, independently of her tendency to dysmenorrhœal ovarian pain.