I suspect, however, that the most frequent successes with arsenic will, after all, be made in the cases of more or less anæmic male patients who are attacked with the neurotic form of angina in the midst of a career (as is especially the case with some professional careers) that implies not merely incessant labor, but great anxiety of mind. The drug does little good, however, if not positive harm, in that form of angina pectoris minor which is not the result purely of these causes, but of these, or some of these, plus the morbid action of the alcoholic excess, to which the patient has fled in order to relieve mental harassment and the fatigue that comes from overwork, especially overwork at tasks that are not congenial to his natural disposition; there is usually in such cases a heightened irritability of the alimentary canal, which is almost sure to cause arsenic to disagree: the really useful treatment is quinine for the first few days, and then, when the stomach will bear it, cod-liver oil in increasing doses, up to a large daily amount given for a long time together.
On the whole, arsenic, from its singularly happy combination of powers as a blood-tonic, a special stimulant of the nervous system, and withal as a special opposer of the periodic tendency, must be regarded as one of the most powerful weapons in the physician's hands, and (although it seems to act best in the neuralgias of the vagus and of the fifth) there is a possibility of its proving the most effective remedy in almost any given case which may come before us.
2. The narcotic-stimulant treatment for neuralgia includes some of the most powerful remedies for the disease which we possess. These remedies have very different properties, but they all agree in this, that in small doses they appear restorative of nerve-function – in large doses depressors of the same.
Four very different types, at least, of narcotic-stimulant drugs are useful in neuralgia: (a) There is the opium type, by which pain is very directly antagonized, and, besides this, sleep is also directly favored. (b) There is the belladonna type, by which pain is also much relieved, though with far greater certainty in some regions than in others (e. g., much the most powerful effect is seen in cases of pelvic visceralgia), but sleep is by no means so certainly or directly produced as by opium. (c) There is the chloral type, which is almost purely hypnotic; it is represented almost solely by chloral itself, which is resembled by scarcely any other drug. (d) There is bromide of potassium, which stands alone for its powerful action on the cerebral vaso-motor nerves, and which is useful in neuralgia simply by its power to check psychical excitement directly (through the circulation) and indirectly (through the production of sleep).
(a) Opium and the remedies that resemble it are, for the treatment of neuralgia, fully represented by the hypodermic use of morphia, which is the only kind of opiate treatment that ought ever to be employed, save in very exceptional instances. The great reasons for the preference of the subcutaneous administration over the gastric are, the economy of the drug which it affects and the much smaller degree of disturbance of digestion which it causes. The hypodermic injection of morphia, if conducted on correct principles, enables us, when necessary, to repeat the dose a great number of times with but little loss of the effect, and consequently with a much smaller rate of progressive increase of the quantity required; and the absence of depressive action on digestion enables us to carry out simultaneously that plan of generous nutrition which has already been shown to be so important a part of treatment. Indeed, the case is hardly expressed with sufficient strength, when we say that hypodermic morphia is usually harmless to the digestive functions; for in a great number of instances it will be found actually to give an important stimulus both to appetite and digestion; and the patient, who without its aid could hardly be persuaded to take food at all, will not unfrequently eat a hearty meal within half an hour after the injection.
The remarkable effects of hypodermic morphia have, however, caused it to be rashly and indiscriminately used, and so much harm has been done in this way that it is necessary to be exceedingly careful in the rules which we lay down for its employment. Upon these grounds I must hope to be excused if, in order to render this work complete, I repeat a good deal of what I have already said in other places. In the first place, I shall speak of the mode of administration, and then of the dose.
As regards the mode of administration, I prefer the use of a solution of five grains of acetate of morphia to the drachm of distilled water; if the acetate be a good specimen, this will dissolve easily (and keep some time without precipitation) without the use of any other solvent. With a solution of this strength we require nothing elaborate in the form of the syringe; a simple piston arrangement does well; only it is advisable that the tube shall have a solid steel triangular point, and a lateral opening. As regards the place of injection, I must repeat the opinion38 which I have already published, that Mr. Hunter's plan of injection at an indifferent spot is, in the great majority of instances, fully as effective as the local injection would be; nevertheless, there is one consideration which in some cases may properly induce us to adopt the latter plan. Very nervous and fanciful patients will sometimes be much more readily brought to allow the operation when it seems to go directly to the affected spot, when they would be sufficiently incredulous of the benefits of an injection performed at a distance to indulge their dislike of incurring pain by refusing to submit to it. And there is one class of cases in which it is likely that there are real physical advantages in the local injection; in instances of old-standing neuralgia with development of excessively tender "points," which are also the foci of the severest pain, it will sometimes be advisable to inject into the subcutaneous tissue at these points. There is undeniable reason for thinking that the sub-inflammatory thickening of tissues around a certain point of nerve delays the transit of the morphia into the general circulation, and enables it to act more directly and powerfully on the nerve, which it thus renders insensitive to external impressions; an important respite is thus gained, during which the nerve-centre has time to recover itself somewhat. At the same time it must be remarked that this immediate injection of a tender point is apt to be exceedingly painful, and it may be absolutely necessary to apply ether-spray before using the syringe. In early stages of neuralgia, before the formation of distinct tender points, there is no advantage whatever (except the indirect one above mentioned) in the local injection. And, on the other hand, it is often of great consequence not to run the chance of disfiguring such a part as the face, the neck, etc., when the injection can easily be done over the deltoid, or in the leg, or in some other part which even in women is habitually covered by the dress.
The dose to be employed is an exceedingly important matter, and one as to which practitioners are still very often injudicious. We ought never to commence with a larger dose than one-sixth of a grain; but very often as little as one-twelfth of a grain will give effective relief, and in not very severe cases it is well worth while to try this smaller quantity. When no larger quantity than one-sixth of a grain is employed we commonly observe no narcotic effects, i. e., there is no contraction of pupil, no heavy stupor, and, although the patient very often falls asleep, on waking he does not experience headache, nor is his tongue foul. I cannot too strongly express the opinion that it is advisable by all means to content ourselves with this degree of the action of hypodermic morphia, unless it fails to produce a decided impression on the pain. But in very severe cases our small doses will fail; and then, rather than allow the patient to continue having severe paroxysms unchecked, we must frankly admit the necessity of using a narcotic dose from one-quarter to one-half of a grain, according to circumstances. Whatever actual dose be employed, it is important not to repeat it with unnecessary frequency; once a day in the milder, and twice a day in the more severe cases, will be all that is advisable, save in very exceptional cases: the point being to administer it as quickly as possible after the commencement of an exacerbation. If by these means we can prevent the patient having any severe pains during a period of several days, we often give time to the affected nerve to recover itself so completely, especially with the aid of other measures to be presently mentioned, that the tendency to neuralgia is completely broken through, and we can drop the injections, either at once or by rapid diminution of the dose, and thereafter treat the case merely with tonics, and with the precautionary measures to be dwelt upon under the heading of Prophylaxis. But, if we have been driven to the use of distinctly narcotic doses, and these do not very speedily break the chain of neuralgic recurrence, it will not do to continue to rely upon hypodermic morphia; it will be best to try some of the local remedies (blistering, galvanism) with it. If this combination fails, we should then try the effect of atropine, the sulphate of which, hypodermically injected, fully represents for all useful purposes the mydriatic class of narcotics.
(b) The commencing hypodermic dose of atropine should be one-one hundred and twentieth grain; it is not often that so small a quantity will do any good, but it is necessary to use this agent with great precaution, as we occasionally meet with subjects in whom extremely small doses provoke most uncomfortable symptoms of atropism, as dry throat, dilated pupil, delirium, and scarlet rash. Commonly we shall find ourselves obliged to increase the dose to one-sixtieth, one-fiftieth, or one-thirtieth of a grain; and in a very few cases it may be necessary to go even as high as the one-sixteenth or one-twelfth. In my experience such instances are excessively uncommon; and I cannot but suppose that the practitioners who use the high doses frequently must inject in such a manner as to fail to get the whole dose taken up. [Absolutely inexplicable to me is the statement of the illustrious Trousseau – that hypodermic remedies are "less active" (!) than gastric remedies – except on his hypothesis.]
The most remarkable effects that I have seen from hypodermic atropia were obtained in cases of peri-uterine neuralgia, especially dysmenorrhœal neuralgia. Speaking generally of atropine, it must undoubtedly be counted far inferior to morphia as a speedy and reliable reliever of neuralgic pain, but for all pelvic neuralgias it appears to me on the whole to surpass morphia. And besides this, in other neuralgias, where opiates altogether disagree (as with some subjects they do), it is not uncommon to find that atropia acts with exceptionally good effect. And to some extent I am inclined to confirm Mr. Hunter's opinion, that, where atropia does stop neuralgia, it does so more permanently than morphia.
There is another special use of hypodermic atropine which I have not seen mentioned by any one but myself, but which is probably very important, namely, in ophthalmic neuralgia where acute iritis, or especially glaucoma, seems coming on. I may be mistaken, but I believe that in three cases I have succeeded, by prompt injection of sulphate of atropine (one-sixtieth to one-fortieth of a grain), in saving a neuralgic eye from damage, and possibly from destruction, from impending glaucoma.
(c) The class of cases for which merely hypnotic remedies are of much value is limited; nevertheless, in the milder kinds of migraine and clavus, especially when they have been brought on or are kept up by mental worry or hysterical excitement, these remedies will sometimes prove very useful. In former days, before we knew chloral, I used to employ camphor for this purpose; three or four grains being administered every two hours: and in hysterical hemicrania of a not very severe type this not unfrequently produced a short sleep, from which the patient awoke free from the pain. But chloral infinitely transcends in value any agent of this kind that was known before. Perfectly valueless for the really severe neuralgias, it is of the greatest possible use as a palliative in migraine and clavus, where the great object, for the moment, is to get the patient to sleep. A single dose of twenty to thirty grains will often effect our object: it may be repeated in two hours if sleep has not been induced; it should be given as soon as the pain has at all decidedly commenced.
And here I wish to make some special remarks on the subject of "palliation," and the relation it bears to "cure." Nothing is more common than to read serious admonitions, in medical works, about the folly of trusting to remedies which only palliate for the moment but leave the root of evil untouched; and, of course, there is a certain respectable modicum of the fire of truth behind all this orthodox smoke. In the case of neuralgia, however, it is most important to understand that mere palliation, that is, stopping of the pain for the moment, may be either most useful or highly injurious, according to the way in which it is done. The unnecessary induction of narcosis for such a purpose, doubtless, is most reprehensible; but if it were possible simply to produce sleep from which the patient should awake refreshed, without any narcotic effects, then, certainly, that sort of palliation must be good. That is precisely what the judicious use of chloral does; and I may mention, as resembling though not equalling it, the action of Indian hemp, which has been particularly recommended by Dr. Reynolds. From one-fourth to one-half of a grain of good extract of cannabis, repeated in two hours if it has not produced sleep, is an excellent remedy in migraine of the young. It is very important, in this disease, that the habit of long neuralgic paroxysms should not be set up; and if the first two or three attacks are promptly stopped, by the induction of sound, non-narcotic sleep, we may get time so to modify the constitution, by tonics and general regimen and diet, as to eradicate the neuralgic disposition, or at least reduce it to a minimum. But I would decidedly express the opinion that such remedies as either opium or belladonna are mostly unsuited to this purpose. If the migraine of young persons does not yield to chloral, to cannabis, or to muriate of ammonia (in twenty or thirty grain doses), it will not be advisable to ply the patient with any remedies of the narcotic-stimulant class, but to trust to tonic regimen and the use of galvanism.
The mention of muriate of ammonia, which, for migraine and clavus and the milder forms of sciatica, not unfrequently proves useful in stopping the violence of a paroxysm and enabling the patient to get some refreshing sleep, leads me to notice that not only may a variety of the milder narcotic-stimulants be employed in this way, but the external stimulus of heat to the extremities (very hot pediluvia) greatly assists the action of any such remedies; especially if mustard-flour be added, so that a mild vapor of mustard rises with the steam and is inhaled. Perhaps the ideal medication, to arrest a bad sick-headache, is to give twenty grains of chloral, and make the patient plunge his feet in very hot mustard-and-water and breathe the steam. He can hardly fail to fall asleep for a longer or shorter time, and awake free from pain.
(d) The use of bromide of potassium in neuralgia is a subject of great importance, and which requires much attention and discrimination. In common with, I dare say, many others, I made extensive trial of this agent when it first began to be much talked of, but was so much disappointed with its effects in neuralgias, that at one time I quite discarded it in the treatment of those affections. Renewed experience has taught me however, that, though its use is restricted, it is extremely effective if given in appropriate cases and in the right manner. For the great majority of neuralgias it is quite useless, and, what is more, proves often so depressing as indirectly to aggravate the susceptibility of the nervous system to pain. The conditions, sine quis non, of its effective employment seem to be the following: The general nervous power, as shown by activity of intelligence, and capacity of muscular exertion and the effective performance of co-ordinated movements, must be fairly good, find the circulation must be of at least average vigor; the patient must not have entered on the period of tissue-degeneration. Among neuralgics who answer to this description, those who will benefit by the bromide are chiefly subjects – especially women – in whom a certain restless hyperactivity of mind and perhaps of body also, seems to be the expression of Nature's unconscious resentment of the neglect of sexual functions. That unhappy class, the young men and young women of high principle and high mental culture to whom marriage is denied by Fate till long after the natural period for it, are especial sufferers in this way and for them the bromide appears to me a remedy of almost unique power. But I wish it to be clearly understood that it is not to the sufferers from the effects of masturbation that I think the remedy specially applicable: on the contrary, it is rather to those who have kept themselves free from this vice, at the expense of a perpetual and almost fierce activity of mind and muscle. The effects of solitary vice are a trite and vulgar story; there is something far more difficult to understand and at the same time far more worth understanding in the unconscious struggles of the organism of a pure minded person with the tyranny of a powerful and unsatisfied sexual system. It is in such cases, which it heeds all the physician's tact to appreciate, that it is sometimes possible to do striking service with bromide of potassium; but it will be necessary to accompany the treatment with strict orders as to generous diet, and, very likely, with the administration of cod-liver oil.
Having decided that bromide of potassium is the proper remedy, we must use it in sufficient doses. Not even epilepsy itself requires more decidedly that bromide, to be useful, shall be given in large doses. It is right to commence with moderate ones (ten to fifteen grains), because we can never tell, beforehand, that our patient is not one of those peculiar subjects in whom that very disagreeable phenomenon – bromic acne – will follow the use of large doses. But we must not expect good results till we reach something like ninety grains daily. Let me add that it is not so far as I know, by reducing any "hyperæsthesia" of the external genitals, of which the patient is aware, that the remedy acts; I have not seen such a nexus of disease and remedy in these cases.
3. Local Measures. – The external remedies which may be applied for the treatment of neuralgia may be divided into (a) skin-stimulants; (b) paralyzers of peripheral sensory nerves; (c) remedies adapted to diminish local congestion; (d) remedies adapted to diminish arterial pulsation; (e) electricity; (f) mechanical means of protection.
(a) Among the skin-stimulants blisters hold the highest place as a remedy for neuralgia; indeed the assertion of Valleix, that they are the best of all remedies, is still not very wide of the truth. They are by no means universally applicable, and the degree to which their action should be carried varies materially in different forms of the disease, but they are of the greatest possible service in a large number of instances.
It is possible to view the action of blisters in neuralgia in more than one way. When applied in such a manner as to vesicate decidedly, and especially if kept open and suppurating for some time, they cause considerable pain of a different kind from that of neuralgia itself and the mental effect of this, operating as a diversion of the patient's thoughts from his original trouble, may be thought to assist in breaking the chain of nervous actions by which he is made to feel neuralgic pain. There may be something in this, but I confess that I do not believe this kind of effect goes for much in genuine neuralgia. It is rather in the pain of hypochondriasis, and the so-called spinal irritation (to be described in the second part of this work), that such an action of blisters proves useful.
Another action of blisters, which some authors hold to be perhaps the most effective portions of their agency, is that which is produced by the drain of fluid, specially when they are kept open, by which means a kind of depletion is set up, and the morbid irritation that causes the nerve pain removed. I cannot at all assent to this view. In the first place, I believe that any one who has large experience of blistering in neuralgia will ultimately come, as Valleix did, to believe that prolonged drain from a blister is rarely or never useful, and that a far better plan is that of so-called flying blisters, renewed at intervals if necessary. The most genuine successes that I have procured from blistering have certainly been got in this way. But I should go further, and say that the prolonged drain and the peculiar kind of chronic irritation produced by a suppurating blistered surface can very decidedly aggravate a neuralgia; this is more especially the case when the blister is applied immediately over the focus pain.
The view which I am strongly convinced alone explains the beneficial action of blisters is that which supposes them to act as true stimulants of nerve-function. In order that this effect shall be produced, it will be necessary that the skin-irritation be either produced at some distance from the seat of the greatest pain, or that, if applied in that spot, it shall be comparatively mild in degree. And accordingly, I have been led, in my observations to apply the blister at some distance from the focus of pain. An indifferent point, however, will not do – there must be an intelligible channel of nervous communication between the irritated portion of skin and the painful nerve. This object is accomplished by placing the blister as close as may be to the intervertebral foramen from which the painful nerve issues; the effect of this is probably a stimulation of the superficial posterior branches, which is carried inward to the central nucleus of the nerve. I must say that the results which I have derived from this plan of treatment have been far more satisfactory than those which I used to obtain when I habitually applied the vesication as near as might be to the focus of peripheral pain; and I think that this result tallies well with the idea that the essential mischief in neuralgia consists in an enfeebled vitality of the central end of the posterior root. An exceedingly interesting confirmation of this idea as to its modus operandi has been afforded me by the fact that not merely neuralgic pain, but also trophic and inflammatory complications attending it, have been sensibly relieved, in several cases that I have seen, by this mode of reflex stimulation. This has been particularly the case in herpes zoster, where the process of inflammation and vesiculation has been very promptly checked by the application of a tolerably powerful blister by the side of the spine at the proper level; and I am gratified to mention that Dr. J. K. Spender, of Bath, pointed out this fact39 at a time when he had only seen my statement that the pain could be relieved in this way. In the case of the trigeminus, the same kind of reflex stimulation is most effectively obtained by applying the blister over the branches of the cervico-occipital, at the nape of the neck; and it is remarkable what powerful effects are sometimes thus produced, even in cases that wear the most unpromising aspect. For example, in the desperate epileptiform tic of old age, I have more than once seen a complete cessation of suffering, which lasted for a very long time – so long, in fact, as to make me hope against hope that it might never return. I do not now entertain any such expectations from this remedy; still, its value is very great.
There are curious differences between the effects of blistering in trigeminal or intercostal neuralgia and in sciatica. On the whole, it would appear that blistering in the neighborhood of the spine is less frequently effective in the latter, and we sometimes, after failing with this method, obtain immediate success by two or three repetitions of the flying blister, somewhere over the trunk of the nerve, especially just outside the sciatic notch. I have one lady patient in whom this series of phenomena has several times been observed; and I have seen it occur in a particular attack, in other patients, in whom, nevertheless, on another occasion the spinal blistering has been promptly effective.
I consider blistering of the posterior branches to be an important, and usually an essential, element in the treatment of all cases of sciatica in the middle period of life which have reached some severity and lasted long enough to become complicated with decided secondary affections.
In all cases where blistering is employed it is advisable to adopt the simultaneous use of hypodermic morphia or atropine; this combination of remedies is exceedingly powerful.
Lastly, it must be said of blistering, that, on the whole, it is a remedy not well fitted to be applied to aged subjects; and in its severer forms it should never be applied to patients who are greatly prostrated in strength. For it must be borne in mind that the remedy may miss its aim of relieving the neuralgia, in which case it is necessary to remember, more accurately than many practitioners appear to do, what a very serious element of misery and prostration will be introduced into the case by the vesication itself.
I am not convinced that any of the other forms of severe skin-irritation (e. g., tartar-emetic inunction, or the use of veratrine-ointment to such a degree as to produce not the anæsthetic but the irritant effects) are of any particular value; if blistering failed, I should not expect to see them succeed.
A milder degree of skin-stimulation is represented by rubefacient liniments of various kinds, which may be briskly rubbed into the skin along the track of the painful nerve, without any danger of producing vesication. Among this class I continue to prefer chloroform diluted, with six or seven parts of chloroform, to any other; in the milder forms of neuralgia, especially in young persons and first attacks, it is surprising how frequently the paroxysm may be greatly relieved, if not arrested. Still, this can only be regarded as the merest palliative; and in severer cases such applications are useless. Occasionally, when chloroform-liniment has failed, a mustard plaster will do good.
The mildest degree of skin-stimulation is represented by the continuous application of moist warmth, which is best effected by the simple application of moistened spongio-piline; so far as I have observed, however, it is rather in cases of myalgia than in true neuralgia that this does good; in the latter it is probably little more than a mere protector against cold.
(b) A variety of agents can be employed with the object of temporarily interrupting the conductivity of the painful nerve; by this means a period of rest is obtained during which the centres – sensory and psychical – have time to regain a juster equilibrium, and the habit of pain is, pro tanto, broken through.
There is one agent of this class which for general purposes I do not think is worth retaining on our list of sensory paralyses – namely, cold. Cold, to be of any value, ought to be of the degree which is represented by ice allowed to melt slowly in contact with the skin; and for the majority of neuralgias this is decidedly inferior to other remedies that can be applied by painting or inunction. The one case in which ice is supremely useful is in neuralgia of the testis; here I make no doubt that it is almost, if not quite, the most useful remedy we can employ, although of course other means must be taken to modify the neuralgic temperament. It should be applied the moment an attack comes on.
Far more useful, in neuralgias generally, is the external application of aconite or of veratrine. Aconite may be employed in the milder or the stronger form; in the former case, we simply paint the ordinary tincture on the skin over the painful nerves (avoiding any cracks or sores); in the latter, we rub in an ointment containing one grain of the best hydrate of aconitine to the drachm of lard, about twice a day, and to such an extent as to maintain complete numbness of the parts continuously, for two, three, or four days. I do not believe that this will ever, by itself, cure a true neuralgia of any considerable severity; but I have more than once known its intervention, at a crisis in treatment when it seemed that other remedies might fail, produce a striking change in the progress even of a very bad case.
A milder, but still very useful form of the same kind of action, is produced by veratrine-ointment. I would recommend, however, as a rule, that it be employed, at any rate at first, of weaker strength than that recommended in the Pharmacopœia, for with some persons it is easy to pass the anæsthetic, and to enter on the irritant, action of veratrine upon the skin. This leads me to give a caution that should properly have come earlier, when I was speaking of skin-stimulants. In aged subjects, especially, we rather frequently meet, in neuralgia, with a specially irritable state of the skin, even although there may be at the same time some loss of common and tactile sensation; and the practitioner must be warned against the danger of producing an amount of skin-irritation which will fearfully annoy his patient. I speak feelingly, having by such an indiscretion lost the richest patient who ever favored my consulting-room with his presence!