Neuralgia and the Diseases that Resemble it

The final characteristic common to all neuralgias is that fatigue, and every other depressing influence, directly predispose to an attack, and aggravate it when already existing.

Varieties.– It is possible to classify neuralgias upon either of two systems: first (a), according to the constitutional state of the patient; and, secondly (b), according to the situation of the affected nerves. It will be necessary to follow both these lines of classification, avoiding all needless repetition.

(a) In considering the influence of constitutional states upon the typical development of neuralgia, it will be convenient to commence with the group of cases in which the general condition of the organism produces the least effect. This is the case when the pain is the result of direct injury to a nerve-trunk, whether by external violence, by the mechanical pressure of a tumor, or by the involvement of a nerve in inflammatory or ulcerative processes originating in a neighboring part. As regards the development of symptoms, the important matters are, that the pain in these cases commences comparatively gradually, that the intermissions are usually more or less complete, and that the pain is far less amenable to relief from remedies, than in other forms of neuralgia. The little that can be said about the form which is dependent upon progressively increasing pressure, or involvement of a nerve in malignant ulcerations, caries of bones or teeth, etc., falls under the heads of Diagnosis and Treatment, and need not detain us here. The clinical history of neuralgia from external violence, however, requires separate discussion:

1. Neuralgia from external shock may be produced by a physical cause (as by a fall, a railway collision, etc.), which gives a jar to the central nervous system; or by severe mental emotion, operating upon the same part of the organism. Under either of these circumstances the development of the affection may occur at once, but by far the most frequently it ensues after a variable interval, during which the patient shows signs of general depression, with loss of appetite and strength. Sometimes vomiting, and in other instances paralysis, of a partial and temporary kind, occur. When once developed, the neuralgic attacks do not differ from those which proceed from causes internal to the organism. In the greater number of instances, so far as my experience goes, it is the fifth cranial nerve which becomes neuralgic from the effects of central shock. Illustrative cases will be given in the section on Local Classification. Meantime the important facts to note, in relation to the influence of constitutional states, are these: In the first place, the tendency of such accidents to excite neuralgia varies directly with the hereditary predisposition evinced by the liability of the sufferer's family to neuralgic affections and to the more serious neuroses. Secondly, the likelihood of a neuralgic attack is indefinitely increased if he has already had neuralgia. Thirdly, although debility from temporary and special causes can rarely be sufficient to insure a true neuralgic access after a severe shock, it probably heightens, indefinitely, the tendency in a person otherwise predisposed. Delicate women are many times more liable to experience such consequences, from a physical or mental shock, than men of tolerably robust constitution.

2. Neuralgia from direct violence to superficial nerves is produced by cutting or, more rarely, by bruising wounds. Cutting wounds may divide a nerve-trunk (a) partially, or (b) completely.

(a) When a nerve-trunk is partially cut through, neuralgic pain occurs, if at all, immediately, or almost immediately, on the receipt of the injury. One such instance only has come under my own care, but many others are recorded. In my case the ulnar nerve was partly cut through, with a tolerably sharp bread-knife, not far above the wrist; partial anæsthesia of the little and ring fingers was induced, but at the same time violent neuralgic pains in the little finger came on, in fits recurring several times a day, and lasting about half a minute. Treatment was of little apparent effect in promoting a cure; though opiates and the local use of chloroform afforded temporary relief. The attacks recurred for more than a month, long after the original wound had healed soundly; and, for a long time after this, pressure on the cicatrix would reproduce the attacks. A slight amount of anæsthesia still remained, when I saw the patient more than a year after the injury.

(b) Complete severance of a nerve-trunk is a sufficiently common accident, far more common then is neuralgia produced by such a cause; indeed, so marked is this disproportion between the injury and the special result, that I have been led to infer that a necessary factor in the chain of morbid events must be the existence of some antecedent peculiarity in the central origin of the injured nerve. This opinion is rendered the more probable because the consecutive neuralgia is in some cases situated, not in the injured nerve itself, but in some other nerve with which it has central connections. Two such cases are recorded in my Lettsomian Lectures, [Lancet, 1866], in which the ulnar nerve, and one in which the cervico-occipital, were completely divided; in all three the resulting neuralgia was developed in the branches of the fifth cranial. Here we may suppose that the weak point existed in the central nucleus of the fifth; and that the irritation, or rather depression, communicated to the whole spinal centres by the wound of a distant nerve, first found, on reaching this weak point, the necessary conditions for the development of the neuralgic form of pain, which therefore would be represented to the mental perception as present in the peripheral branches of the fifth nerve. In all the cases which have come under my notice, the neuralgia set in at a particular period, namely, after complete cicatrization of the wound, and while the functions of the branches on the peripheral side of the wound were partly, but not completely, restored. The same obstinacy and rebelliousness to treatment are observed as in other instances of neuralgia from injury.

One of the cases above referred to may here be briefly detailed, as it shows very completely the clinical history of such affections. C. B., aged twenty-four, an agricultural laborer, applied for relief in the out-patient room of Westminster Hospital, suffering from severe neuralgic pains of the forehead and face of the left side. Then pains were felt in the course of the supra-orbital, ocular, nasal, and supra-trochlear branches, and also in the cheek, appearing, there, to radiate from the infra-orbital foramen. They had commenced about three weeks previously to the patient's first visit to the hospital, and about six weeks after the accident which appeared to have started the whole train of symptoms. This was a cutting wound, evidently of considerable depth as well as external size, toward the back of the neck, and so situated that it must have divided the great occipital nerve of the left side: and, from the man's account of the numbness of the parts supplied by the nerve which immediately followed the wound, there could be no doubt that this had occurred. There was no acute nerve-pain, either during the healing of the wound, which was rapid, or subsequently, until more than three weeks from the date of the injury; at this time there was still a considerable sense of numbness in the skin of the occipital and upper cervical region; but there now commenced a series of short paroxysms of pain in the forehead of the same side. These at first occurred only about twice daily, at regular intervals; the pain was not very sharp, and only lasted a minute or two. The attacks rapidly increased in frequency and duration, however, and extended their area. At the time when I first saw the case the pain was very formidable, it recurred with great frequency during the day, but would sometimes leave the patient free for several hours together. The site of the wound was occupied by a firm cicatrix of about a line in breadth and an inch and a quarter in length; pressure on this excited only a vague and slightly painful tingling in the part itself, but severely aggravated the trigeminal pains, or reproduced them if they happened to be absent. The regions supplied by the great occipital nerve were still very imperfectly sensitive. This patient gave me a great deal of trouble. He continued for many weeks under my care, and I can scarcely flatter myself that any of the numerous remedies which I administered internally, or applied locally, had any serious effect in checking the disorder. The subcutaneous injection of morphia gave some relief, as it always does, but this seemed to be perfectly transitory; and, although when the patient ceased to attend the hospital he was decidedly better, I cannot imagine that there was anything in it except the slow wearing out of the neuralgic tendency, very much without reference to the administration of any remedies.

The description of neuralgia from injury would be incomplete without some special words on a variety of this affection which has only very recently been described with that fulness which it deserves. I refer to the pains which are produced by gunshot injuries of nerves, received in battle, of which no sufficient account had been given until the publication of the experience of Messrs. Mitchell, Moorehouse, and Keen, in the late American civil war.3

From the interesting treatise of the above-named writers it appears that not merely is neuralgia of an ordinary type a frequent after-consequence of wounds, but that certain special pains are not unfrequently produced. In the more ordinary instances, pain is of the darting, or of the aching kind; and all writers on military surgery, who have recorded their experience of the results of wounds received in battle, have spoken of affections of this kind, for the most part singularly severe and obstinate, and in not a few recorded instances clinging to the patient during the remainder of his life. These pains may at times leave the sufferer, but they infallibly recur when from any cause his health is depressed, and it is an especially common thing for them to be evoked in full severity under the influence of exposure to cold, and particularly to damp cold.

But the American writers introduce us to another and more terrible neuralgia which is a, fortunately, less frequent result of serious injuries to nerves. They speak of it as a burning pain of intense and often intolerable severity; they believe that it seldom if ever originates at the moment of the injury, but rather at some time during the healing process; and it is especially noteworthy that it is sometimes felt not in the nerve actually wounded, but in some other nerve with which it has connections. After it has lasted a certain time, an exquisite tenderness of the skin is developed, and a peculiar physical change of skin-tissue occurs; it becomes thin, smooth, and glossy. It is a remarkable fact that these burning pains which are so definitely linked with a nutrition-change of skin are never felt in the trunk, and rarely in the arm or thigh, not often in the forearm or leg, but commonly in the foot or hand; and the nutrition changes of the skin are generally observed on the palm of the hand, the palmar surface of the fingers, or the dorsum of the foot; rarely on the sole of the foot or the back of the hand. It is very interesting to remark that these skin-lesions correspond very nearly, not only to those observed in the cases of nerve-injury reported by Mr. Paget,4 in which actual neuralgia was present (though the kind of pain is not exactly specified), but also very nearly with the nutritive changes observed by Mr. Jonathan Hutchinson in a number of cases of surgical injuries of nerves.5 The tendency of neuralgic pain accompanied by nutritive lesions of the skin and nails to seat itself in the hands and feet will be hereafter noted in connection with the subject of the pains of locomotor ataxy and of those produced by profound mercurial poisoning. And it will be seen in the section on Pathology, that very important conclusions are suggested by the coincidence.

Joined with the burning pains, and the altered skin-nutrition, in the cases of gunshot injury of nerves which we are considering, there is nearly always a marked alteration in the temperature of the parts, either in one direction or the other. In the great majority of instances of ordinary neuralgia after wounds, this alteration is a very considerable reduction of the temperature of the parts supplied by the painful nerves; a change which corresponds with what appears in the vast majority of all cases of division of sensitive nerves, whether pain be set up or not. But, in all examples of the burning pain after injury, Messrs. Mitchell, Moorehouse, and Keen found the temperature of the painful parts notably elevated.

It would appear that there is no form of neuralgia more dreadful, and scarcely any so hopeless, as this burning pain coming on as a sequel to severe nerve injuries. It exercises a profoundly depressing effect upon the whole nervous tone; the most robust men become timid and broken down, and their condition is compared by the American writers to that of hysterical women.

There is another peculiar nutritive affection, first recognized as an occasional consequence of nerve injuries by Messrs. Mitchell, Moorehouse, and Keen, namely, an inflammation of joints, and, although we have no concern here with this symptom, it will be referred to hereafter as throwing interesting light on certain questions of pathology. Certain lesions of secretion will also be specially referred to under the heading of Diagnosis.

II. Neuralgias of Intra-nervous Origin. – As regards the constitutional conditions with which the several varieties of neuralgia that arise independently of external violence, or disease of extra-nervous tissues, are respectively allied, the following preliminary subdivisions may be made:

1. Neuralgias of malarious origin.

2. Neuralgias of the period of bodily development.

3. Neuralgias of the middle period of life.

4. Neuralgias of the period of bodily decay.

5. Neuralgias associated with anæmia and mal-nutrition.

1. Neuralgias of malarious origin were formerly far more prevalent than they are at present, within the sphere of the English practitioner of medicine; with the general decline of malarial fevers, consequent on improved drainage and cultivation of lands, they have become constantly more scarce. The districts in which they still are found to prevail with any frequency are carefully specified in the interesting report of Dr. Whitley to the Medical Officer of the Privy Council, in the Blue-Book for 1863.

Of course, however, there are a considerable number of persons continually returning to England from countries where malarious diseases are common; and these often bear about with them the effects of paludal poisoning which occasionally exhibits itself in the form of neuralgia. Till very lately, however, I had not happened to come across such cases, although at one time and another I have seen and treated a good many persons returned from India and Africa, whence I judge that neuralgia with this special history is less common than many seem to think. In former times, on the contrary, malarioid neuralgias were so common that they forced themselves on the notice of every practitioner. The term "brow-ague," to this day applied by many medical men to every variety of supra-orbital neuralgia, is a relic of the older experience on this point, as is also the very common mistake of expecting all neuralgic affections to present a distinctly rhythmic recurrence of symptoms.

In the year 1864 I published the statement6 that, "in a fair sprinkling" of the cases of neuralgia which present themselves in hospital out-patient rooms, ague-poisoning may be suspected; but I was then speaking rather from hearsay than from my own experience, which, in fact, had yielded no clear cases of this sort of neuralgia, and was till just recently unable to reckon up more than two undoubted and one doubtful case of the affection, in all of which the fifth cranial nerve was unattacked. The periodicity in one of the genuine cases was regular tertian, in the other regular quotidian. A semi-algide condition always ushered in the attacks; but this was gradually exchanged, as the pain continued, for a condition in which the pulse was rapid and locomotive, but compressible, and the strength was further depressed. In both these cases there was unilateral flushing of the face, and congestion of the conjunctiva, to a slight degree, during the attack of pain. The pain became duller and more diffused contemporaneously with the lowering of arterial pressure; and, after the disappearance of active pain, moderate tenderness over a considerable tract round the course of the painful nerves remain for some time. There was no distinct development of painful points in the situations described by Valleix; but it should be remarked that the cases were rapidly cured with quinine, which very probably accounts for this circumstance.

Till lately I had not witnessed neuralgia as an after-consequence of tropical malaria-poisoning, although I have had many cases of other diseases, the relics of hot climates, under my care; but within the last year I have seen a case of extremely severe intercostal neuralgia of a perfectly periodic type occurring in a patient whose constitution had been thoroughly saturated with tropical marsh poison, and in whom the spleen was still much enlarged. The neuralgia was so terrible, and accompanied by such severe algide phenomena at the beginning of the attacks, and such a sense of throbbing as the pain developed, as to lead to serious suspicions of hepatic abscess, for the moment; but the course of events soon corrected this idea.

2. Neuralgias of the Period of Bodily Development.– By the "period of bodily development" is here understood the whole time from birth up to the twenty-fifth year, or there-abouts. This is the period during which the organs of vegetative and of the lower animal life are growing and consolidating. The central nervous system is more slow in reaching its fullest development, and the brain especially is many years later in acquiring its maximum of organic consistency and functional power.

That portion of the period of development which precedes puberty is comparatively free from neuralgic affections. At any rate, it is rare to meet in young children with well-defined unilateral neuralgia, except from some very special cause, such as the pressure of tumors, etc. Such neuralgias as do occur are commonly bilateral, and are connected either with the fifth cranial or the occipital nerves.

I must here mention an affection which was quite unknown to my experience, but was brought under my notice by the late Dr. Hillier, who kindly called my attention to the notes of two cases which were published in his interesting work on "Diseases of Children." The cases are those of two female children, aged nine and eleven respectively, in whom the principal symptom was violent and paroxysmal neuralgic headache. In both of these children the existence of cerebral tubercle was suspected, but this proved to be a mistake. In both there were intolerance of light, vomiting, tonic contraction of the muscles of the neck, and occasional double vision; but no impairment of intelligence, no amaurosis, and no paralysis or rigidity of the limbs. Each of these children died rather suddenly, after a violent paroxysm of pain. The main, indeed almost the only characteristic post-mortem change was a marked loss of consistence of tissue, in one case in the pons varolii, in the other in the pons, the medulla oblongata, and the cerebellum. These cases are of the highest possible interest, as are also several other instances of headache in children recorded by Dr. Hillier; notably one in which severe paroxysmal pains were attended with general impairment of brain-power, and, on the occurrence of death from exhaustion, the autopsy revealed an amount of degeneration in the cerebral arteries (as also in the general arterial system) which was astonishing, considering that the child was only ten and a half years old. This case, the full significance and interest of which will be better seen when we come to discuss the subject of pathology, is an example of physical changes in the nervous system, which are usually delayed to an advanced period of life, occurring altogether prematurely, and bringing with them a kind of neuralgic pain which is far more common in the decline than in morning of life. It will be seen presently that functional derangements may be in like manner precociously induced, with the parallel effect of inducing such pains as are ordinarily the product of a later epoch.

From the moment that puberty arrives all is changed in the status of the nervous system. In the stir and tumult which pervade the organism, and especially in the enormous diversion of its nutritive and formative energy to the evolution of the generative organs and the correlative sexual instincts, the delicate apparatus of the nervous system is apt to be overwhelmed, or left behind, in the race of development. Under these circumstances, the tendency to neuralgic affections rapidly increases. It will, however, be seen later that there is a great preponderance of particular varieties of the disease during this time. This period is above all things fruitful in trigeminal neuralgias, especially migraine.

There remains to be noticed the fact that sexual precocity sometimes very much anticipates the peculiar characteristics of the period after puberty. It is well known that in too many instances children are led, by the almost irresistible influence of bad example, to indulge in thoughts and practices which are thoroughly unchildish, and which exercise a powerfully disturbing influence upon the nervous system. A child before the age of puberty ought to be distinguished (if moderately healthy in other respects) by the absence of any tendency to dwell upon his own bodily health. Under the influence of precocious sexual irritation he becomes hypochondriacal and self-centred, and often suffers, not merely from fanciful fears and fanciful pains, but from actual neuralgia, which is sometimes severe. The attacks of migraine which are a frequent affection of delicate children whose puberty occurs at the normal time, are a much earlier torment with children who have early become addicted to bad practices. It is an anticipatory effect upon the constitution, strictly analogous to the production of the so-called "hysteria" in little girls under similar circumstances; and I suppose there is no physician who has not once or twice, at least, met with cases of the latter kind. The existence of any severe neuralgic affection in a young child, if it cannot be traced to tuburcle or other recognizable or organic brain-disease is prima-facie ground for suspicion of precocious sexual irritation; though, as Dr. Hillier's cases show, it is occasionally produced otherwise. Usually, there are other features which assist in the discovery of precocious sexualism, when it exists; there is a morbid tendency to solitary moping, and a moral change in which untruthfulness is conspicuous.

3. Neuralgias of the Middle Period of Life.– By this period is meant the time included between the twenty-fifth and about the fortieth or forty-fifth year. It is the time of life during which the individual is subjected to the most serious pressure from external influences. The men, if poor, are engaged in the absorbing struggle for existence, and for the maintenance of their families; or, if rich and idle, are immersed in dissipation, or haunted by the mental disgust which is generated by ennui. The women are going through the exhausting process of child-bearing, and supporting the numerous cares of a poor household, in some cases; or are devoured with anxiety for a certain position in fashionable society for themselves and their children; or again, they are idle and heart-weary, or condemned to an unnatural celibacy. Very often they are both idle and anxious.

It must not be supposed that there is a sharp line of demarcation between this period and the last; nevertheless, there are certain well-marked differences, both in their general tendencies, and as regards the local varieties which are commonest in each. We shall discuss the latter point farther on. At present, it is interesting to remark on the general freedom of the busy middle period of life from first attacks of neuralgia. A person who has had neuralgia previously may, and very likely will, during this epoch, be subject to recurrence of the old affection under stress of exhaustion of any kind. But it is very rare, in my experience, for busy house-mothers or fathers of families to get first attacks of neuralgia during this period of life. It is not the way in which a still vigorous man's nervous system breaks down, if it breaks down at all. Men frequently do break down, of course, at an age when their tissues generally are sound enough, and there is no reason, except on the side of their nervous system, why they should not remain in vigorous health for years. But it is greatly more common for the nervous collapse to take the form of insanity, or hypochondriasis, or paralysis, then that of neuralgia. If a man has escaped the latter disease during the period when the growth of his tissues was active, it is not very often that he falls a victim to it till he begins, physiologically speaking, to grow old.