Chapter LXXX: Introduction: This disease remained unnoticed until twenty years ago, (4)

These changes may be transient, or, if a neuralgia is long continued and severe, they may pass into a series of more lasting and deeper affections of the nutrition.

The skin and subjacent tissues, including the periosteum, from being simply swelled or œdematous may become thickened and hypertrophied. The writer has known a case of supraorbital neuralgia, at first typically intermittent, to lead to a thickening of the periosteum or bone over the orbit, which even at the end of several years had not wholly disappeared.

Neuralgias of the fifth pair, which are as remarkable in their outward results as they are in their severity and their relation to other neuroses, are said to give rise to clouding and ulceration of the cornea, to iritis, and even to glaucoma.

Herpetic eruptions on the skin sometimes occur, of which herpes zoster is the most familiar instance.

Muscular atrophy is very common, especially in sciatica, and in some cases this occurs early and goes on rapidly, while in others it may be only slight and proportioned to the disease and relaxation of the muscles, even where the neuralgia has lasted for weeks or months.

Neuritis of the affected nerve is a common result or attendant of neuralgia, and may remain behind for an indefinite period after the acute pain has gone, manifesting itself by subjective and objective disorders of sensibility, by occasional eruptions on the skin, or by muscular atrophy.

It is plain that in this list of symptoms a variety of conditions have been described which would never all be met with in the same case, and which, as will be shown in the section on Pathology, are probably due to different pathological causes.

{1215} Neuralgia of the Viscera.

These neuralgias are less definitely localized by the sensations of the patient than those of the superficial nerves, and it is not definitely known what set of nerves are at fault.

They are deep-seated and are referred to the general neighborhood of the larynx, œsophagus, heart, or one of the abdominal or genital organs, as the case may be.

The pain is usually of an intense, boring character, and does not dart like the pain of superficial neuralgia, but is either constant or comes in waves, which swell steadily to a maximum and then die away, often leaving the patient in a state of profound temporary prostration.

Deep pressure often brings relief. A patient of the writer, who is subject to attacks of this kind in the right hypochondrium, will bear with her whole weight on some hard object as each paroxysm comes on, or insist that some one shall press with his fists into the painful neighborhood with such force that the skin is often found bruised and discolored.

The functions and secretions of the visceral organs are apt to be greatly disordered during a neuralgic attack, and it is often difficult or impossible to tell with certainty which of these conditions was the parent of the other. Undoubtedly, either sequence may occur, but the pain excited by disorder of function, or even organic disease of any organ, is not necessarily felt in that immediate neighborhood. Thus I have known the inflammation around an appendix cæci, of which the patient shortly afterward died, to cause so intense a pain near the edge of the ribs that the passage of gall-stones or renal calculus was at first suspected.

There seems to be as much variation as to modes of onset and duration among the visceralgias as among the superficial neuralgias, but the tendency to short typical attacks of frequent recurrence seems to be greater with the former.

The visceral neuralgias are quite closely enough related to certain of the superficial neuralgias to show that they belong in the same general category. The two affections are often seen in the same person, and not infrequently at the same time or in immediate succession. Thus in the case of the patient just alluded to above, the attacks of deep-seated neuralgia in the neighborhood of the right flank are at times immediately preceded by severe neuralgia of the face or head. Similarly, intercostal neuralgia may occur in immediate connection with neuralgias of the cardiac or gastric nerves.

The phenomenon of tender points is not entirely wanting in the visceralgias, though less constant and definite than in the superficial neuralgias.

The liver and the uterus especially become the seat of more or less localized tenderness, and possibly the tenderness in the ovarian region which is so common, and so often unattended by real inflammation, is, in part, of this order.

The secondary results of the visceralgias are not easy to study. Besides the disorders of secretion and function above alluded to, swelling of the liver with jaundice and paresis of the muscular walls of the hollow viscera may be mentioned as having been ascribed to neuralgia.

It is not known to what degree neuritis occurs as a cause or {1216} complication of these neuralgias, and this is a question which is greatly in need of further study.

Migraine, or Sick Headache.

This is often classified as an affection of a different order from the neuralgias, but there seem to be no real grounds for this distinction.

The superficial neuralgias themselves are probably not one, but a group of affections, with the common bond of severe and paroxysmal pain.

Neither is what is called migraine always one and the same disease.

Although in its most typical form it presents very striking characteristics, such as a marked preliminary stage, with peculiar visual and sensory auras, sometimes occupying one entire half of the body, a short and regular course and periodical return, deep-seated pain without tender points, and prominent unilateral vascular disorders, yet these symptoms shade off by imperceptible degrees into those of neuralgia of the fifth pair, or more often into one or another form of unilateral neuralgic headache which stands midway between the two.

The vascular phenomena of migraine are believed by various observers, as is well known, to constitute the primary and essential pathological feature of the disease, and to be the cause of the pain. But this is a pure hypothesis, and as a matter of fact the cases are abundant in which no greater vascular changes are present than in other neuralgias of equal severity.

Migraine seems to occupy an intermediate position between the grave neuroses, especially epilepsy, and the neuralgias of neurosal origin.

The symptomatology will be described at greater length below.

GENERAL ETIOLOGY.—The causes of neuralgia may be divided into predisposing and exciting causes.

The most important of the first group are—

1. Hereditary tendencies;

2. The influences associated with the different critical periods of life;

3. The influences attached to sex;

4. The action of constitutional diseases, such as phthisis, anæmia, gout, syphilis, diabetes, nephritis, malarial poisoning, metallic poisoning.

The most important of the second group of causes are—

1. Atmospheric influences and the local action of heat and cold;

2. Injuries and irritation of nerves;

3. Irritation of related nerves (so-called reflex and sympathetic neuralgias);

4. Acute febrile diseases.

In most cases more than one cause is to blame, and each should be separately sought for.

PREDISPOSING CAUSES.—1. Hereditary Tendencies.—It is generally admitted as beyond question that neuralgias are most common in families in which other signs of the neuropathic taint are prominent. Such affections as hysteria, neurasthenia, epilepsy, asthma, chorea, dipsomania, and even gout and phthisis as it would seem, are akin to the neuralgic tendency.

{1217} The neuropathic family is thought to contain, in fact, a much larger number of members than this,[5] but there is danger of exaggerating the importance of an influence of which we know as yet so little.

[Footnote 5: Féré, _Arch. de Névrologie_, 1884, Nos. 19 and 20, “La famille névropathique.”]

It should be remembered, moreover, that even where an inherited taint is present its influence may be but slight as compared with that of some special exciting cause.

Some neuralgias are more closely associated with the inherited neuropathic diathesis than others. The connection is especially close in the case of migraine;[6] then follow other forms of periodical headache and the visceral neuralgias. Even the superficial neuralgias[7] are more or less subject to this influence. This is thought to be especially true of the facial neuralgias.

[Footnote 6: There is a witty French saying (quoted by Liveing), “La migraine est le mal des beaux esprits;” which might be rendered, “The disease of nervous temperaments.”]

[Footnote 7: For tables of illustrative cases see Anstie, _Neuralgia and its Counterfeits_, and J. G. Kerr, _Pacific Med. and Surg. Journ._, May, 1885.]

Reasons will be offered later for suspecting that many cases usually classed as neuralgia, and characterized by gradual onset and protracted course, are essentially cases of neuritis; and there is need of further inquiry as to how far hereditary influences are concerned in producing them, and whether such influences act by increasing the liability of the peripheral nerves to become inflamed, or only by increasing the excitability of the sensory nervous centres.

2. Age.—Neuralgia is oftenest seen in middle life and at the epochs marked by the development and the decline of the sexual functions. The affection, when once established, may run over into advanced age, but cases beginning at this period are relatively rare and very intractable (Anstie).

Childhood is commonly said to be almost exempt from neuralgia, but, in fact, there seems no sufficient reason for withholding this term from the so-called growing pains of young children[8] so long as it is accorded to the almost equally irregular neuralgias of anæmia in the adult. The same remark applies to the attacks of abdominal pain in children, which often seem to be entirely disconnected from digestive disorders.

[Footnote 8: Probably due to anæmia or imperfect nutrition (see Jacobi, “Anæmia of Infancy and Childhood,” _Archives of Med._, 1881, vol. v.).]

Adolescents and children also suffer from periodical headaches, both of the migrainoid and of the neuralgic type. These are obstinate and important affections.[9] Migraine especially, coming on in early life, points to a neuropathic constitution, and will be likely to recur at intervals through life, or possibly to give place to graver neuroses.

[Footnote 9: Blache, _Revue mensuelle de l'enfance_, Mar., 1883, and Keller, _Arch. de Névroloqie_. 1883.]

3. Sex.—Women show a stronger predisposition than men to certain forms of neuralgia, as to the other neuroses, but it is generally conceded that whereas neuralgias of the fifth and occipital and of the intercostal nerves are met with oftenest among them, the brachial, crural, and sciatic neuralgias are commoner among men. This probably indicates that the neurosal element is of greater weight in the former group, the neuritic element in the latter.

4. Constitutional Diseases.—The blood-impoverishment of phthisis and anæmia, the poison of malaria, syphilis, and gout, and the obscurer {1218} forms of disordered metamorphosis of tissue, undoubtedly predispose to neuralgia and the other neuroses, as well as to neuritis and others of the direct causes of neuralgic attacks.

Anstie regards the influence of phthisis as so important as to place it fairly among the neuroses. Gout is likewise reckoned by some observers among the neuroses,[10] but we tread here upon uncertain ground. Anstie does not regard gout as a common cause of neuralgia, but most writers rate it as more important, and gouty persons are certainly liable to exhibit and to transmit an impaired nervous constitution, of which neuralgia may be one of the symptoms. The neuralgias of gout are shifting, irregular in their course, and sometimes bilateral.

[Footnote 10: Dyce-Duckworth, _Brain_, vol. iii., 1880.]

Syphilitic patients are liable to suffer, not only from osteocopic pains and pains due to the pressure of new growths, but also from attacks of truly neuralgic character. These may occur either in the early or the later stages of the disease. They may take the form of typical neuralgias, as sciatica or neuralgia of the supraorbital nerve (Fournier[11]), or they may be shifting, and liable to recur in frequent attacks of short duration, like the pains from which many persons suffer under changes of weather, anæmia, or fatigue.

[Footnote 11: Cited by Erb in _Ziemssen's Encyclopædia_.]

There are other obscure disorders of the nutrition, as yet vaguely defined, in connection with which neuralgia of irregular types is often found. Some of these are classed together under the name of lithæmia, and are believed to be due to imperfect oxidation of albuminoid products.[12]

[Footnote 12: See DaCosta, _Am. Journ. of Med. Sciences_, Oct., 1881, and W. H. Draper, _New York Med. Record_, Feb. 24, 1883.]

Diabetes seems also to be an occasional cause of neuralgia, especially sciatica, and Berger,[13] who has recently described them, says that they are characterized by limitation of the pain to single branches of the sacral nerves, by a tendency to occur at once on both sides of the body, by the prominence of vaso-motor symptoms, and, finally, by their long duration and obstinacy. There may not, at the moment, be any of the characteristic symptoms of diabetes present.

[Footnote 13: _Neurologisches Centralblatt_, 1882, cited in the _Centralbl. für Nervenheilk., etc._, 1882, p. 455.]

Chronic nephritis also causes neuralgia, either directly or indirectly; and severe neuralgic attacks may accompany the condition, which is as yet but imperfectly known, characterized pathologically by a general arterio-fibrosis and by increased tension of the arterial system.

True rheumatism does not appear to be a predisposing cause of neuralgia.

Anæmia, both acute and chronic, is a frequent cause of neuralgia, both through the imperfect nutrition of the nervous tissues, to which it leads, and, it is thought, because the relatively greater carbonization of the blood increases the irritability of the ganglionic centres.

Even a degree of anæmia which might otherwise be unimportant becomes of significance in the case of a patient who is otherwise predisposed to neuralgia; for such persons need to have their health kept at its fullest flood by what would ordinarily seem a surplus of nourishment and care.

Under the same general heading comes the debility from acute and {1219} chronic diseases, and the enfeeblement of the nervous system from moral causes, such as anxiety, disappointment, fright, overwork and over-excitement, and especially sexual over-excitement, whether gratified or suppressed (Anstie), or, on the other hand, too great monotony of life; also from the abuse of tea, coffee, and tobacco.

Lead, arsenic, antimony, and mercury may seriously impair the nutrition of all the nervous tissues, and in that way prepare the way for neuralgia.

IMMEDIATE CAUSES.—1. Atmospheric and Thermic Influences.—Neuralgia is very common in cold and damp seasons of the year, in cold and damp localities, and in persons whose work entails frequent and sudden changes of temperature. Exposures of this sort may at once excite twinges of pain here and there over the body, and may eventually provoke severe and prolonged attacks of neuralgia.

The action of damp cold upon the body is complicated, and it exerts a depressing influence on the nervous centres in general which is not readily to be explained. One important factor, however, is the cooling of the superficial layers of the blood, which occurs the more easily when the stimulus of the chilly air is not sufficiently sharp and sudden to cause a firm contraction of the cutaneous vessels, while the moisture rapidly absorbs the heat of the blood. From this result, indirectly, various disorders of nutrition of the deeper-lying tissues or distant organs; and, among these, congestion and neuritis of the sensitive nerves.

Neuralgia often coincides with the presence or advent of storms. A noteworthy and systematic study of this relationship was carried on through many years under the direction of S. Weir Mitchell[14] by a patient of his, an officer who suffered intensely from neuralgia of the stump after amputation of the leg. The attacks of pain were found to accompany falling of the barometer, yet were not necessarily proportionate to the rapidity or amount of the fall. Saturation of the air with moisture seemed to have a certain effect, but the attacks often occurred when the centre of the storm was so remote that there was no local rainfall. It was impossible to study the electrical disturbances of the air with accuracy, but a certain relationship was observed between the outbreak of the attacks and the appearance of aurora borealis.

[Footnote 14: _Am. Journ. of Med. Sci._, April, 1877, and _Philada. Med. News_, July 14, 1883.]

This patient's neuralgic attacks were almost certainly of neuritic origin, and it is possible that the exacerbations were due to changes of blood-tension in and around the nerve-sheaths. It is also possible that they were the result of circulatory changes and disordered nutrition of the nervous centres, already in a damaged condition from the irritation to which they had been exposed.

2. Injuries and Irritation of Nerves.—Wounds and injuries of nerves[15] and the irritation from the pressure of scars, new growths, and aneurisms are prolific causes of neuralgic pain, partly by direct irritation, partly by way of the neuritis which they set up. Neuralgias are likewise common during the period of the healing of wounds, as Verneuil long since pointed out. The pain may be near the wound itself or in some distant part of the body.

[Footnote 15: See S. Weir Mitchell, _Injuries of Nerves_.]

Neuralgia due to the pressure and irritation of tumors, new growths, {1220} or aneurisms requires a special word. The pain is apt to be intensely severe, but what is of especial importance is that the symptoms may not present anything which is really characteristic of their origin, except their long continuance; and this should always excite grave suspicion of organic disease.

These attacks of pain may be distinctly periodical; and this is true whether they are felt in the distribution of the affected nerve or of distant nerves.

Not only are direct injuries of nerves a cause of neuralgia, but sudden concussion or jar may have a like effect—whether by setting up neuritis or in some other way is not clear. Ollivier[16] reports a case where a blow beneath the breast caused a neuralgia which eventually involved a large portion of the cervico-brachial plexus; and the writer has seen a like result from a blow between the shoulders.

[Footnote 16: Cited by Axenfeld and Huchard, p. 116.]

Peripheral irritations, such as caries of the teeth (see below, under Facial Neuralgia) and affections involving other important plexuses, such as those of the uterine nerves, are a frequent cause of neuralgia, and should always be sought for. They act in part by setting up neuritis, and in part evidently in some more indirect manner, since the neuralgia which they excite may be referred to more or less distant regions, forming the so-called—

3. Reflex and Sympathetic Neuralgias.—The term reflex, as here used, is ill chosen, and the term sympathetic only covers our ignorance of the real processes involved, and which we should seek for in detail. Thus, disease of the uterus or ovaries may cause facial, mammary, intercostal, or gastric neuralgia.

Hallopeau[17] suggests that some of these results may be brought about by the pressure of enlarged lymphatic glands attached to the affected organ.

[Footnote 17: _Loc. cit._, p. 766.]

Another important centre of nervous irritation is the eye. Slight errors of refraction, or weakness of the muscles of fixation, especially the internal recti, are a source of frontal headaches and other nervous symptoms, and even of typical migraine,[18] to a degree which is not usually appreciated. It is improbable that in the latter case the irritation acts as more than an exciting cause, but it may nevertheless be a conditio sine quâ non of the attack.

[Footnote 18: _St. Barthol. Hosp. Repts._, vol. xix.]

Acute and chronic inflammations of the mucous membrane of the frontal sinuses, perhaps even of the nasal membrane, are likewise important; and although it is probable that the opinions sometimes expressed as to the significance of these causes are exaggerated, it is equally true that obstinate and, as it were, illogical persistence in their removal will sometimes be richly rewarded.

It is especially worthy of note that there need be no local sign whatever to call the attention of the patient to the presence of the peripheral irritation.

Nothnagel[19] has described neuralgias which come on in the first week of typhoid, and are to be distinguished from the general hyperæsthesia of later stages. He describes an occipital neuralgia of this sort which finally disappeared under the use of a blister. Other acute diseases may have a like effect. The writer has seen a severe facial neuralgia in the {1221} first week of an insidious attack of pneumonia in a person who was not of neuralgic habit, and before the fever or inflammation had become at all severe.

[Footnote 19: _Virch. Arch._, vol. liv., 1872, p. 123.]

PATHOLOGY AND DIAGNOSIS.—In surveying the clinical history of the neuralgias and the circumstances under which they occur, we have grouped together a large number of symptoms of very different character from each other, and we have now to inquire to what extent these symptoms are really united by a pathological bond.

Two opposite opinions have been held concerning the pathology of neuralgic affections. According to one opinion, every neuralgic attack, no matter how it is excited, is the manifestation of a neurosis—that is, of a functional affection of the nervous centres—to which the term neuralgia may properly be applied. This view is based on the resemblance between the different forms of neuralgia, or the apparent absence, in many cases, of any adequate irritation from without, and the fact that the persons in whom neuralgias occur usually show other signs of a neuropathic constitution.

According to the other opinion, the various forms of neuralgia are so many different affections, agreeing only in their principal symptom, and are due sometimes to congestion or anæmia of the nerves or the nerve-centres; sometimes to neuritis, the pressure of tumors, or the irritation of distant nerves; sometimes, finally, to a functional disorder of the nervous centres. The arguments in favor of this opinion are that the difference between the symptoms of the different neuralgias as regards their mode of onset and decline, their duration, the persistence of the pain, and the degree to which the attacks are accompanied by organic changes of nutrition in the tissues and in the nerve itself, are so great as to make it appear improbable that we are dealing in every case simply with one or another modification of a single affection.

This is a valid reasoning, and it is certainly proper to exhaust the possibilities of explaining the symptoms that we find in a particular case by referring them to morbid processes which we can see or of which we can fairly infer the presence, before we invoke an influence of the nature of which we understand so little as we do that of the functional neuroses. At the same time, it must be distinctly borne in mind that the symptoms of certain neuralgias, and the relation which the neuralgias in general bear to other neuroses, can only be accounted for on the neurosal theory, and that in a given case we can never be sure that this neurosal tendency is not present and is not acting as at least a predisposing cause. It is especially important to bear this possible influence in mind in deciding upon prognosis and treatment.

We may now review briefly the signs which should lead us to diagnosticate or suspect the presence of the various special causes of neuralgic symptoms.

Neuritis is indicated by the presence of organic disorders of nutrition affecting the skin, hair, or nails, or of well-marked muscular wasting; by pain, not only occurring in paroxysms, but felt also in the intermissions between the paroxysms, or continuous sensations of prickling and numbness, even without pain; by tenderness along the course of the nerve; by anæsthesia, showing itself within the first few days of the outbreak of a neuralgia; by persistent paralysis or paresis of muscles.

{1222} Neuritis may be suspected, even if one or all of these signs are absent, in the prolonged neuralgias which follow wounds or strains of nerves or exposure to damp cold, or which occur in nerves which are in the immediate neighborhood of diseased organs; also where the pain is relieved by compression of the nerve above the painful part, or, on the other hand, where pressure on the nerve excites a pain which runs upward along the course of the nerve.

It may also be suspected in the large class of superficial neuralgias which follow a regular and protracted course with gradual onset and decline, and where the pain is felt not only in the region of distribution of a nerve, but also along its course—that is, in the nerve-fibres (either the recurrent nerves or the nervi nervorum) which are distributed in the sheath of the main trunk or the adjoining tissues.[20]

[Footnote 20: See Cartaz, _Des Névralgics envisagés au point de vue de la sensibilité récurrente_, Paris, 1875.]

It must be remembered that the study of neuritis, and especially of chronic neuritis, is still in its infancy, and that we are by no means in possession of its complete clinical history.[21]

[Footnote 21: See Pitres and Vaillard, _Arch. de Névrologie_, 1883.]

The presence of congestion of the sensory nerves or nerve-centres may be inferred with some degree of probability where neuralgic attacks of relatively sudden onset and short duration occur in parts which have been exposed to heat or cold, or in connection with suppression of the menstruation, or, it is said, as a result of intermittent fever. The exacerbations of pain which take place in cases of chronic neuritis under changes of weather and after fatigue are very likely due to this cause; and the same may be true of some of the fleeting pains which occur in chlorotic and neuropathic persons who are subject to fluctuations of the circulation of vaso-motor origin.

The same vaso-motor influences which cause congestion may also cause the correlative state of anæmia, which becomes thus a cause of transient and shifting though often severe attacks, which may be irregular in their distribution. General anæmia is also a predisposing cause of severe typical seizures, as has been pointed out above.

The pressure of new growths or of aneurisms is to be suspected when neuralgic attacks are unusually severe and prolonged, recur always in the same place, and occur in persons who are not predisposed to neuralgias. The pains from this cause are apt to be relatively continuous, but they may, on the other hand, be distinctly paroxysmal, and may occupy a part of the body far removed from the irritating cause.

Bilateral pains should also excite suspicion of organic disease, though they may be due to other causes, such as gout, diabetes, and metallic poisoning.

Neuralgic attacks may be supposed to be of neurosal origin when they are of sudden onset and short duration, or when they occur in persons of neuropathic constitution, and, by exclusion, when no other cause is found. These conditions are best fulfilled in the case of migraine and the visceral neuralgias. It must, however, be borne in mind that the neuropathic predisposition is sometimes well marked even in the case of the superficial neuralgias, especially the epileptiform neuralgia of the face.

GENERAL TREATMENT.—To treat neuralgia with satisfaction it is {1223} necessary to look beyond the relief of the particular attack and search out the causes by which it was provoked. As has already been remarked, these are usually multiple, and among them will be found, in the great majority of cases, some vice of nutrition or faulty manner of life.

It is safe to say that any dyscrasia occurring simultaneously with neuralgia, whether gout, phthisis, malaria, or diabetes, should receive its appropriate treatment, whatever theory we may hold as to the real connection between the two conditions.

In protracted neuralgias it is always proper to assume that neuritis may be present—_i.e._ to treat the nerve itself by galvanism and local applications. Local irritations, such as diseases of the eye, ear, teeth, nose, or uterus, should be sought out and removed; and attention may here be called again to the fact that a neuralgia may be due to some local condition which does not of itself attract the patient's attention.

Patients who are subject to pain at changes of weather or on exposure should be suitably protected by clothing, and should have their cutaneous regulatory apparatus strengthened by baths and friction. The best protection, however, is incapable of entirely warding off the effect of atmospheric changes upon the nervous centres. Vaso-motor changes of neurotic origin can be, in a measure, prevented by removing the patient from the influence of irregularity of life and emotional excitement and through an improved nutrition.

If the patient has been subjected to chronic fatigue or nervous strain, not only must these be avoided, but their action should be counteracted by the requisite rest and tonic treatment.

Long hours of sleep at night may often be supplemented to advantage by rest during certain hours of the daytime. If the patient cannot take active exercise, massage is indicated, and in some cases of anæmia this may advantageously be combined with the wet pack, in the manner described by Mary Putnam Jacobi.[22]

[Footnote 22: _Massage and Wet Pack in the Treatment of Anæmia_.]

Where these measures cannot be carried out, the writer has found it of much service in these, as in a large class of debilitated conditions, to let the patient rub himself toward the end of the forenoon in a warm room with a towel wet in cold or warm water, and then lie down for an hour or so or until the next meal. If acceptable, the same operation may be repeated in the afternoon.

Neuralgic patients are apt to be underfed, and even where this is not distinctly the case, a systematic course of over-feeding,[23] with nourishing and digestible food, such as milk, gruel, and eggs, given at short intervals, is often of great service if thoroughly carried out. The full benefit of this treatment cannot always be secured unless the patient is removed from home, and, if need be, put to bed and cared for by a competent nurse.

[Footnote 23: See S. Weir Mitchell, _Fat and Blood; and Nervous Diseases, especially of Women_.]

A change of climate, and especially the substitution of a dry and warm for a moist and cold climate, will sometimes break up the neuralgic habit, for the time at least. In making choice of climate or locality, however, the physician should keep distinctly in view the end that he desires to gain. Thus, the debility or anæmia which is the essential condition of many neuralgias may often be relieved by surroundings which {1224} would not be thought favorable to the neuralgic tendency as such. Oftentimes the sedative influence of quiet country life is all that is required.

Of the tonic drugs, cod-liver oil, iron, arsenic, and quinine are by far the most important, and it is often well to give them simultaneously. Iron may be used in large doses if well borne, for a short time at least. Quinine may be given in small doses as a tonic, or in larger doses to combat the neuralgic condition of the nervous system. This remedy has long been found to be of great value in the periodical neuralgias of the supraorbital branch of the fifth pair, but its usefulness is not limited to these cases. It may be of service in periodical neuralgias of every sort, and often even in non-periodical neuralgia.

When the attacks recur at stated intervals care should be taken to anticipate them with the quinine by about four hours, even if the patient has to be waked in the early morning for the purpose. Single doses of fifteen, twenty, or even thirty grains may check the attacks where smaller doses have failed. Such doses cannot, however, be long continued, and are not to be classed as tonic.

Of other remedies which directly influence the neuralgic condition, the following are the most important: opium, aconite, gelsemium, phosphorus, belladonna, chloride of ammonium, cannabis Indica, croton-chloral, electricity, hydropathy, massage, counter-irritation, subcutaneous injections of water, chloroform, osmic acid, etc.; surgical operations.

Opium is usually employed only for the momentary relief of pain, but it has also been claimed that in small and repeated doses it may exert a really curative action. This should not, however, be too much counted on. Opium should never be used continuously for the simple relief of pain unless under exceptional circumstances, the danger of inducing the opium habit is so much to be dreaded. Moreover, both patient and physician are less likely to seek more permanent means of cure if this temporary remedy can always be appealed to. It is best given by subcutaneous injections of the various salts of morphine. The dose should always be small at first (gr. 1/12 and upward), unless the idiosyncrasy of the patient is already known; and there is probably no advantage in making the injections at the seat of pain or in the immediate neighborhood of the nerve supplying the affected part, except such as might attend the injection of any fluid (see below).

Belladonna (atropia), which is so often given with morphine to diminish its unpleasant effects, seems at times, even when given alone, to have an effect on neuralgia out of proportion to its anæsthetizing action, which is very slight. It is considered to be especially useful in the visceralgias.

Aconite, given, if necessary, in doses large enough and repeated often enough to cause numbness and tingling of the lips and the extremities for some days, will sometimes break up an attack, especially of trigeminal neuralgia,[24] better than any other means; but its use is liable to depress the heart, and it is a dangerous remedy if not carefully watched. Some patients complain that it causes a marked sense of depression or faintness, and a feeling of coldness; and indeed its full therapeutic effect is sometimes not obtained until such symptoms as these are induced to some degree. The use of the crystallized alkaloid, aconitia, has the advantage of ensuring certainty of dose.

[Footnote 24: See Seguin, _Arch. of Med._, vol. i., 1879; vol. vi., 1881.]

{1225} The susceptibility of different persons to this drug is so different that the dose should first be as small as 1/400 gr., but this may be repeated every three hours, and gradually increased to 1/100 gr., or until its physiological effects are felt. Patients must sometimes be kept under its influence for weeks together.[25] It is, however, a remarkable fact that occasionally a few full doses will secure an immunity from pain for a long period. Although most useful in facial neuralgias, the writer has known it to be effective in brachial and mammillary neuralgia. Aconitia can now be had in granules of 1/400 gr., or can be given in alcoholic solution.

[Footnote 25: See Seguin, _Arch. of Med._, vol. vi., 1881.]

Gelsemium is also occasionally very useful in facial and even in intercostal neuralgia, and is said to be of special service in the neuralgia due to carious teeth. The commencing dose of the fluid extract is five minims, which may be gradually increased to twenty, or until a slight degree of muscular prostration, ptosis, or dilatation of the pupil is induced.

The use of phosphorus has been revived of late years, chiefly through the efforts of J. Ashburton Thompson, and it is at least occasionally of service. Success is said to be best obtained by full doses (about 1/20 gr. every three or four hours, up to 1/5 or 1/4 gr. daily for some days), watch being kept for signs of gastric irritation. The best preparation is an alcoholic solution (Thompson's), such as the following:

Rx. Phosphorus, gr. j;
Abs. alcohol, fluidrachm vi.
Dissolve with heat.
Glycerin, fluidounce iss;
Alcohol, fluidrachm ij;
Spts. peppermint, minim v.
One teaspoonful represents gr. 1/20.

Electricity, if properly used, is capable of temporarily, and even radically, relieving the neuralgic state. The forms most often employed are faradic and galvanic electricity, though frictional electricity has also been coming into use of late, mainly as a substitute for faradism. The galvanic current is by far the most efficacious of all. This probably acts mainly by directly inducing better nutritive and better functional conditions in the nerves and nerve-centres, but the fact that it is often of use in cases of undoubted neuritis seems to indicate that it may also influence the grosser structural changes in the affected parts, if such are present. It is impossible to explain its action more exactly, and the teachings of physiological experiments do not lend us much aid.

It is probably not of much consequence which pole is used in the neighborhood of the affected nerve. It should be remembered that the peripheral nerve-trunks are so deeply buried that the electrodes cannot be directly applied to them, as they are to the exposed nerve of a frog in the laboratory, and, further, that instead of being isolated they are surrounded with tissues of good conducting power, into which the current must rapidly flow off. For these reasons the nerve near which either electrode is applied is virtually exposed to the action of both poles in almost equal degree; and although it is more customary to use the positive pole in the neighborhood of parts which are considered to be in a state of irritation, yet clinical experience has not justified the conversion of this custom into a rule. Neither is the direction of the current of material consequence.

{1226} It is, however, very important in acute cases to take care that the current-strength should not be rapidly changed; and for this reason the electrode should be drawn slowly to a distance from the nerve before it is removed, or left in situ while the current is gradually diminished by a suitable rheostat. As a rule, the former method is the more practicable.

In the treatment of acute cases moderate currents and short applications, frequently repeated, are the best. On the other hand, in cases of long standing, especially cases of sciatica, strong currents are sometimes more effective, and even interruptions and reversals of the current may be in place.

The choice of a battery is not a matter of indifference. Any stationary battery of high interior resistance will answer the purpose, but most of the portable (zinc-carbon) batteries in common use are objectionable,[26] for the reason that their interior resistance is so low in proportion to that of the body that it may almost be counted out as a factor in determining the strength of the current. The latter is liable to rise, therefore, quite suddenly as the resistance of the body—_i.e._ the vascularity of the skin—becomes modified. This objection is obviated if a large, constant resistance (water or graphite rheostat) is attached to the battery and kept always in the main circuit.

[Footnote 26: _Archives of Medicine_, April, 1884.]

Faradism probably owes its efficiency to the indirect effects of stimulation of the sensitive nerves of the skin. This may be produced either by the wire brush, which causes a sharp irritation and reddening, and is to be compared with the counter-irritants, or by the milder application of a moist or dry electrode or the hand of the operator. The latter procedure may be compared to the superficial manipulation which is sometimes so grateful, especially in nervous headaches.

The value of electricity as a general tonic should be remembered in this connection.

Hydropathy.—Douches and baths of various kinds have doubtless proved of much value in the treatment of neuralgia. The majority of them, however, are difficult of application for the general practitioner, and we confine ourselves to mentioning the tonic and soothing action of the wet pack and of the prolonged warm bath, which should be followed by sponging with cool water, and used under every possible precaution against exposure.

Long-continued local applications of gentle heat (bags of sand or salt, or hot water) are often temporarily grateful, and in the treatment of chronic cases the daily application of hot water or ice-bags to the spine is said to have a good effect. In acute and subacute neuritis, and in those forms of neuralgia in which neuritis plays a large part, such as sciatica, the persistent application of ice-bags along the course of the affected nerve, even for days together, is sometimes of great service. Even where we cannot be sure that neuritis is present, long-continued applications of ice may be of use, but alternations of cold and heat, on the other hand, are usually to be carefully avoided. This treatment is safer in chronic than in acute cases, though it may be useful in either.

Counter-irritation.—A spray of ether may be substituted for ice when only a temporary chilling is desired, for its counter-irritant effect. This {1227} has even been used on the face, the eye being protected by some suitable covering, and a good deal of benefit is to be hoped for both from this and from the similar use of chloride of methyl.

Debove[27] has found the chloride of methyl, used in this manner, singularly effective in the treatment of sciatica. A considerable and long-continued counter-irritation is thus made over a large surface and without great pain. The neuralgia is said to be greatly relieved and a rapid cure sometimes affected.

[Footnote 27: _Bulletin générale de Thérap._, cited in the _Boston Med. and Surg. Journ._, vol. cxii. p. 210.]

Counter-irritation is also practised by making applications of cutaneous irritants, such as blisters, mustard, turpentine, chloroform, or of the actual cautery carried in light superficial stripes over the skin, and repeated if necessary at short intervals. As a rule, the counter-irritation is more effective the larger the surface which is covered.

The use of the cautery and of blisters is in place in almost every form of neuralgia where the temporary disfigurement is of no consequence.

Of other cutaneous applications, aconite and chloroform liniments, menthol in substance or in alcoholic solution (drachm j or drachm ij to fluidounce j), aconite and veratrine ointments, are the most useful. A strong aconitine ointment, made with Duquesnet's aconitia and lard (drachm j to ounce j), has been recommended by Webber[28] to be used in portions of the size of half a split pea, but, though effective, it needs to be employed with great caution.

[Footnote 28: _Nervous Diseases_, Boston, 1885.]

These applications act in part as irritants, by keeping up a play of sensitive impressions in virtue of the lodgment which they effect in the skin, but also, no doubt, by reducing the sensitiveness of the cutaneous nerve-fibres, and thus removing one source of excitation of the diseased nervous centres. The remarkable temporary benefit sometimes obtained from the instillation of cocaine into the eye in cases of neuralgia of the ophthalmic division of the fifth nerve bears testimony in favor of this explanation.

Surgical operations for neuralgia are of three kinds—section (neurotomy), removal of a piece of nerve (neurectomy), and nerve-stretching. The two former operations are of course rarely practised, except upon the purely-sensitive fifth pair of nerves, the latter upon mixed nerves also.

Neurectomy is now almost always substituted for simple neurotomy, and sometimes still more effective means are taken to prevent the reunion of the nerve, such as doubling over the cut end, destroying the nerve throughout the length of the bony canal in which it lies, and even plugging the canal with cement.[29]

[Footnote 29: Heustis (_Med. News_, Dec. 8, 1883) found that the infraorbital nerve could be readily drilled out with a piece of piano wire.]

The inconvenience following nerve-section is as nothing compared to the pain of a severe and intractable neuralgia. It has rarely happened that the disease has been increased by the operation, and under proper antiseptic precautions the surgical risks are not great. There is some chance of permanent cure, and a much greater chance of securing an immunity from pain for a long period.

It is important to remember that when the neuralgia occupies the distribution of several branches of the fifth nerve, an operation on the one primarily or most severely affected may relieve the pain in all. On the {1228} other hand, the converse may be true,[30] inasmuch as the same district is supplied by recurrent fibres from several different sources. Before any operation is decided on it should be remembered that even in apparently desperate cases of trigeminal neuralgia the persistent and thorough use of tonic and other remedies may in the end be crowned with success, perhaps at the moment when it is least expected.

[Footnote 30: Cartaz, _Des névralgies envisagés au point de vue de la sensibilité récurrente_.]

During the past few years the operation of nerve-section has been to some degree superseded by that of nerve-stretching, as being less serious in its immediate (though not necessarily in its remote) consequences, and sometimes more efficacious. Hildebrandt, indeed, raises the question whether the traction which is apt to be exerted when a nerve is cut is not an important element in bringing about the result. On the other hand, cases are reported where neuralgia which had not been relieved by stretching was cured by resection.[31]

[Footnote 31: Nocht, _Ueber die Gefolge der Nerven-dehnung_.]

The best showing for the operation is in the treatment of sciatica, but most of the other superficial nerves, including the intercostals, have been successfully treated in the same manner.

On the other hand, this treatment is not without its dangers. Apart from the risks of the operation itself, cases have been reported in which the spinal cord has been injured, so that chronic myelitis has been set up, and a greater or less degree of paralysis—rarely permanent, it is true—may be induced by the direct injury to the nerve.

This means of treatment is therefore certainly to be thought of in serious and obstinate cases, but not lightly decided on.

A substitute operation for sciatica is the so-called bloodless stretching, in which, the patient having been etherized, the thigh is forcibly flexed on the pelvis, and then the leg extended on the thigh and the foot on the leg (dorsal flexion), and held for a short time in this position. A very material degree of stretching of the sciatic nerve is doubtless possible in this way, and a number of cures have been thus effected. But, though less dangerous than the stretching of the exposed nerve, this operation is not a trifling one.

In one case of sciatica the writer has seen a neuritis of some severity lighted up by this operation, perhaps because the disease was in too active a state, although it had lasted some months. The operation is probably most indicated in chronic cases.

The anatomical effects of nerve-stretching are manifold. Nerve-fibres are usually destroyed in greater or smaller number, and the conducting power of the nerve correspondingly impaired. Small blood-vessels are broken and the circulation and nutrition of the nerve-trunks altered, and it is probable that adhesions in and around the nerve-sheaths, where such exist, are severed. The nerve-fibres ramifying in the inflamed sheaths of the large trunks may also be ruptured, and it may be that the displacement of the fluid contents of the nerve brings about better nutritive conditions.[32] It is also probable that the operation either directly or indirectly affects the nutrition of the nerve-centres,[33] and although this is not without its dangers, the chances are in favor of a beneficial result.

[Footnote 32: See “Die Rückenmarks-dehnung,” Hegar, _Samml. klin. Vorträge_, 239.]

[Footnote 33: Hegar, _loc. cit._]

{1229} Another means of directly acting on neuralgic nerves is by subcutaneous injections of water, chloroform, ether, osmic acid, nitrate of silver, and other substances. The deep injection of water over the affected nerve is attended with but little danger, and is occasionally successful. The similar use of chloroform, in doses of 15 to 30 minims, is much more often effective, but sometimes causes great pain, and even abscess. It has been mainly used in sciatica, also in other neuralgias, even those of the fifth pair. In this case the injection is best made through the buccal mucous membrane. This treatment is not without danger of causing collapse, or even death, probably due to the wounding of a small vein. In one case of sciatica treated by the writer the chloroform probably entered the nerve itself to some extent, as the injection was followed by very severe pain lasting for several hours, and eventually by some degree of muscular wasting. The neuralgic pain, which had continued obstinately for a long period, was, however, cured, and had not returned at the end of some days, when the patient was lost sight of.

Osmic acid has been used recently in the same way, and the reports show about an equal number of successes and failures. The dose is about 8 minims of a 1 per cent. solution, and the injection may be repeated at intervals of a few days. It has been used successfully in various parts of the body, including the face and the fingers. The injection causes no great pain, but occasionally, though rarely, excites abscess.

Under the general heading of massage a number of manipulations may be grouped which are of value in the treatment of neuralgia, even of long-standing cases of sciatica and the like.[34] When, as often happens in the case of sciatica, the nerve is the seat of congestion and exudation, strong and deep kneading along its course, with vigorous stroking upward in the direction of the lymph-vessels, is the important part of the treatment. Besides this, however, the prolonged and gentle manipulation of the painful region may greatly relieve the patient for a time, apparently by acting on the sensitive nerves and exerting a sort of inhibitory action, in which it is not at all impossible that an influence upon the attention analogous to that of Braidism plays a part.

[Footnote 34: See Reibmayr, _Die Massage, etc._, Wien, 1883.]

A striking instance of the effect of this treatment is seen in the case of nervous headaches, which are often very greatly relieved by a series of gentle, monotonous movements of the finger-tips, as well as by the domestic remedy of gently and persistently combing or brushing the patient's hair. A still more efficient application of a similar kind is the regular vibration communicated by a large magnet or by the instrument devised by Mortimer Granville. A thoroughly satisfactory explanation of the action of this treatment is yet to be furnished.

There is no doubt that in the treatment of neuralgia a persistent and thorough use of the remedies suggested is usually the key to success. Nevertheless, special cases are sometimes reached by special means of treatment, and the following are appended as occasionally useful: Ammonio-sulphate of copper (grs. ij-vj, taken in divided doses in the course of the day); salicylate of soda, in full doses; caffeine; tonka (fluidrachm j of the fluid extract at repeated intervals of a few hours); oil of turpentine; muriate of ammonia.

{1230} Special Forms of Neuralgia.[35]

[Footnote 35: Consult, in connection with this subject, the sections on Symptomatology and Treatment.]

MIGRAINE AND PERIODICAL HEADACHE.—In many of the recent treatises upon nervous disease migraine and headache are removed from the category of the neuralgias and placed in that of the functional affections of the sympathetic vaso-motor system of nerves. This classification is based upon the fact that in many of these cases marked vascular changes—congestion or anæmia, as the case may be—are observed in the external tissues of the affected parts, while the sensations of the patient often lead us to infer the presence of similar conditions within the cranium. The pain and the other symptoms of the outbreak, it is thought, are due to the changes in blood-tension in the cortex cerebri or in the region of expansion of sensitive nerves, or, in part, to the spasm of the muscular walls of the vessels themselves. This theory is seductive from its appearance of pathological simplicity and exactness, but the writer believes, with Anstie, Latham, Allbutt, and other observers, that it is not borne out by clinical experience, and that its adoption tends to cloak the wider relationship that exists between the sensory neuroses.

Migraine, nervous headache, and the superficial and the visceral neuralgias hardly differ more fundamentally from each other than individual cases of either affection differ among themselves. It is not improbable, as we have seen, that all the phenomena of some neuralgic attacks are wholly or in part the expression of irritation of the sensory nervous system from without; but in many cases, on the other hand, the signs of the neurosal tendency are clearly marked, and there is hardly one of the symptoms of a typical migraine of which the analogue may not be found, though perhaps faintly pronounced, in one or another form of superficial neuralgia, while the relation of both to the whole family of the neuroses is still more clearly evident.

Migraine is a disease of youth and middle life, characterized, in its most typical form, by attacks of severe headache of a few or many hours' duration, of gradual onset and decline, ushered in by well-marked auras involving one or more of the cerebral functions, and terminating in nausea or vomiting or profuse secretion of pale urine, or in some other critical nervous outbreak. The pain is usually, but not invariably, deep-seated. It may be confined to one side of the head, most often the left, or may involve both sides, either from the outset or in the course of the attack. The forehead or temple is usually the first part to become painful, but in severe or prolonged seizures the parietal and occipital regions are prone to be affected likewise.