The inunction of mild veratrine-ointment is extremely useful, as an adjunct to other treatment, in migraine and supra-orbital neuralgias of suckling women, and of chlorotic girls. I have also seen it do much good in mammary neuralgia.
The last division of the subject of paralyzing agents in the treatment of neuralgia includes the surgical operations for division or resection of a painful nerve. Upon this question there is much difficulty in speaking decidedly. I admit at once, of course, that surgical interference is evidently indicated when, along with decided and intractable neuralgic pain, there is plain evidence either of the existence of a neuromatous tumor, or the presence of a foreign body impacted, or a tight cicatrix pressing upon a nerve. I admit, also, though with much greater qualifications, that carious teeth may need to be extracted before we can cure a neuralgia; but even here I should put in the decided caveat that we must consider whether the system is in a state to bear the shock, and that in any case we probably ought to mitigate the effects of the operation by performing it under chloroform. And I need hardly tell any one, who is familiar, either practically or from reading, with the subject, that thousands of carious teeth have been extracted from the mouths of neuralgic patients, not only without benefit, but with the effect of distinctly aggravating the disease. And I am yet more doubtful as to the advisability of such surgical procedures as the division or the resection of a piece of the painful nerve. Theoretically, as the reader will understand from the strong opinion I have given as to the mainly central origin of neuralgias, I never could anticipate that such a procedure would be more than temporarily successful; on the contrary, the mischief in the central end of the nerve remaining, I should suppose that the trying process of the reunion of the nerve (which always takes place) would be almost certainly attended with a revival of the neuralgia, too probably in an aggravated form. The only two cases of excision of a piece of the nerve, that I have ever seen, completely answered to this anticipation. In common fairness, however, I must admit that there is a large amount of evidence on the other side. Neuralgias of the trigeminus are pretty nearly the only cases in which the proposal of neurotomy or neurectomy ought to be entertained; in mixed nerves the inconvenience of the muscular paralyses that would follow would be usually too serious to allow of our incurring them. But resection of painful branches of the trigeminus has been performed in a great number of instances, more especially by German surgeons, with results that merit our attention; the cases recorded by Nussbaum, Wagner, Bruns, and Podratzki, may be especially referred to. On the other hand, with the exception of simple division of the nerve, which can be subcutaneously performed, and is a trivial proceeding (but has very short-lived effects), these operations are by no means without danger, especially when they are pushed to such a length as the opening of bony canals, and the resection of considerable portions of bone in order to get sufficiently far toward the centre, and fatal results have in more than one case followed. Above all, we can never too seriously reflect on the most interesting case of Niemeyer's reported by Wiesner,40 in which the most formidable operations of this kind have been performed, in an apparently desperate case of epileptiform facial tic, and in which, after all, the application of the constant current painlessly effected an infinitely greater amount of good than had been done by all those severe and painful surgical manipulations. I think it is impossible, after this, not to conclude that neurectomy ought never to be even thought of except as a last resort, in cases of extreme severity, after other measures had been patiently tried and had decisively failed.
(c) Of remedies that are intended to relieve local congestion, I must speak with very doubtful approbation. Leeches or scarifications are, I think, very seldom of value. The only remedy that has sometimes seemed to do good is local compression, and, after all, it is quite as likely that this acts by anæsthetizing the nerve as by reducing congestion.
(d) Remedies that interfere mechanically with arterial pulsation are of considerable value where they can be effectively applied. I have already pointed out the specially aggravating effect of the momentarily-repeated shocks of arterial pulsation upon neuralgic pain. Where, then, it is possible, effectively to control an artery pretty near to the point where it divides into the branches that lie close to the painful part of the nerve, it is always worth while to try the experiment. But such a measure as the compression of the carotid in trigeminal neuralgia is of very doubtful propriety; I suspect the consequent anæmiation of the brain more than does away with any benefit that might be mechanically produced. And any attempt to interfere with the general arterial circulation by cardiac depressants is not to be permitted for an instant.
(e) We enter now upon a most important subject, the treatment of neuralgia by electricity. It is necessary to exercise much caution in speaking upon this topic, and, as I shall have to express somewhat decided opinions, I may be excused for referring to the circumstances under which I have arrived at my present stand-point upon this question. I can hardly be accused of having, with any very rash haste, espoused the cause of medical electricity in the therapeutics of pain, as any one will see who cares to turn to my article on Neuralgia41 written only three years ago. At that time I had already been studying the subject for a considerable period, but was so convinced of the multitude of opportunities for fallacy that beset the student of electro-therapeutics, that I was unwilling to state more than the minimum of what I hoped and believed might be affected by this mode of treatment. Since that time I have become more fully acquainted with the researches of foreign observers, and, with the help of their indications, have been able to apply myself more fruitfully to my personal inquiries into the matter. The result is, that I am now able to speak with far greater assurance of the positive value of electricity as a remedy for neuralgic pain. I shall make bold to say that nothing but the general ignorance of the facts can account for the extraordinary supineness of the mass of English practitioners with regard to this question.
In the first place, I have arrived at a decided conviction that Faradic electricity is of little or no value in true neuralgias, and that the cases which are apparently much benefited by it will invariably be found, on more careful investigation, to belong to some other category.
On the effect of frictional electricity I have had such very small experience that I cannot venture to speak with any confidence, and the accounts that I have heard from others whose experience is much larger have not led me to attribute much importance to this agent. If I am to judge at all, I should say it merely acts as a skin-stimulant, and is, in that capacity, inferior to many other simpler and more facile applications.
Very different is the verdict of experience as regards the effects of the constant current; here the results which I have obtained have been so remarkable that even now I should distrust their accuracy, were it not that they are in accord with the general result which (among minor discrepancies) may be gathered, we may fairly say, from all the more important researches that have lately been carried out in Germany. The constant current, as I now estimate it, is a remedy for neuralgia unapproached in power by any other, save only blistering and hypodermic morphia, and even the latter is often surpassed by it in permanence of affect; while it is also applicable in not a few cases where blistering would be useless or worse.
The English medical profession has not as yet adequately appreciated the necessity for great care in the choice of apparatus and the mode of application of electricity. It is all-important, however, and especially in the case of applying galvanism for the relief of pain. The first quality that must be absolutely required in a battery, that is to be used for this purpose, is that it shall deliver its current with as little as possible variation of tension, in fact that it shall be constant, and not merely continuous; a vast majority of all the various galvanic apparatus that have been used have been merely the latter, and have consequently been almost valueless for the relief of pain. Such are Pulvermacher's chains, the voltaic piles made with elements of metallic gauze, Cruickshank's battery, and many others that have been used. A sufficiently constant current may be obtained from either of the following apparatuses, (1) Daniell's battery, (2) Bunsen's, (3) Smee's. For hospital use, the Daniell battery (in Muirhead's modification, or with the form of cells introduced by Siemens-Halske) is perhaps the most desirable; but for private practice it is worth while to sacrifice something of the superior constancy which we gain in the Daniell battery for the sake of comparative portability. All purposes which we aim at in the electric treatment of neuralgia may be sufficiently obtained by the use either of the Bunsen battery (zinc-carbon, excited by dilute sulphuric acid), as modified by Stohrer, or by the Smee battery (zinc and platinized silver, excited by dilute sulphuric acid), as in the highly convenient apparatus devised by Mr. Foveaux, of Weiss & Son's. It must be remarked that, for the purpose of treating neuralgia, we shall never need to employ more than fifteen, or at the utmost twenty, cells of either of these batteries. Both the Stohrer's Bunsen and the modified Smee of Weiss are made so that the elements are not immersed in the exciting fluid until the moment when the battery is going to be used; a simple mechanism at once throws the battery into or out of gear. In this way, destruction of the elements is minimized; and either of these two batteries may be used for from three to six months without any renewal, supposing the average work done to be one or two daily seances. If the battery is worked harder, it will require more frequent revivification. I strongly recommend London practitioners to deliver themselves from all care and trouble about the repair of their batteries, by making an agreement with the manufacturers to inspect and set them in order at stated intervals. The country practitioner, on the other hand, will do well to familiarize himself with the process of renewing the acid, of cleaning the plates, of amalgamating the zinc, etc.; in fact, to make himself independent of the manufacturer in every thing short of an actual renewal of the elements, when that becomes necessary. For all further details respecting the above-named, and other batteries, I must refer the reader to systematic works on medical electricity.42 I must now pass on to the various modes of application, and the cautions to be observed.
It is, in the first place, necessary to say, that all the best observers coincide in the statement that the use of a current intense enough to produce actual pain or severe discomfort is never to be thought of in the treatment of true neuralgias; such practice will infallibly do harm. Only such a current is to be employed as produces merely a slight tingling, and (on prolonged application) a slight burning sensation, with a little reddening of the skin at the negative electrode. This being the case, it is perhaps not unnatural for those who have not had practical experience, to suspect that an application which causes so little palpable perturbation is devoid of any positive influence at all. Such skepticism will certainly not survive any tolerably lengthened observation of the actual facts; but, as some persons may be deterred by this prima-facie view of the case from making any fair trial of the current, it may be worth while, here, to allude to the unmistakable physical effects which similarly painless constant currents are repeatedly observed to produce in cases of motor-paralysis attended with a wasted condition of muscles. Those who have had experience of the treatment of such cases know that it is a by no means infrequent thing to see both muscles and nerves aroused from a state of complete torpidity, and brought into a condition in which the Faradic current, quite powerless before, is again able to excite powerful contractions, while, at the same time, the bulk of the muscles has increased most sensibly. These, surely, are sufficient indications of a positive action of the painless constant current; and such facts have now been recorded, in multitudes, by most competent observers.
The next maxim of first-rate importance is that the applications of the current should be made at regular intervals, and at least once daily; in most instances, this is enough, but occasionally it will be found useful to operate twice in the day. The matter of regularity is, I find, of great consequence, and it will not do to intermit the galvanism immediately on the occurrence of a break in the neuralgic attacks: it should be continued for some days longer.
The length of sittings is a point as to which there is considerable difference of opinion between various authorities; but my own experience coincides with that of Eulenburg, that from five to ten, or, at the utmost, fifteen minutes, is almost the range of time.
Closely connected with the question of the length of sittings, is that of the continuity with which the current is to be applied. I have seen the best results, on the whole, from passing a weak current, without any breaks, for about five minutes. But, where there are several foci of intense pain, it will often be advisable to apply the current to each of these, successively, for three or four minutes.
The places to which the electrodes should be applied vary much according to the nature of the case.
Benedikt's rule, that the application of electricity, to be useful, must be made to the seat of the disease, is undoubtedly true; but it is capable of being applied in a somewhat different manner from that which he recommends in particular cases, the difference being due to the view of the pathology of neuralgia which is taken in this work. That view is, that the essential locus morbi is always in the posterior nerve-root (and usually in that portion of the root which is within the substance of the cord), and that the peripheral source of irritation, if any, is only of secondary – though sometimes of considerable – importance. Hence the main object, in electrization, would seem to be to direct the influence of the current upon the posterior nerve-root. This may, however, be done in different ways, according to the situations in which we place the electrodes, and the direction in which we send the current.
There are, as yet, very considerable differences of opinion among electro-therapeutists as to the principles which should govern us, both in the localization of the effect and the direction of the current. Benedikt, for example, recommends that the current should be directed toward the supposed seat of the mischief. Thus, if we suppose a neuralgia to depend on morbid action within the spinal cord, then we may galvanize the spine, taking care to make the current come out through any vertebra over which we detect tenderness. If we suppose the seat of the disease to be in the nerve-root in the mere ordinary sense of the word, then we apply the positive pole to the vertebra opposite the highest nerve-origin that can be concerned, and we stroke the negative pole down by the side of the spinous processes, some forty times in succession. The proportion of cases of idiopathic neuralgia in which this treatment succeeds is, according to Benedikt, very large. In other cases, he sends the current from the cord to the apparent seat of pain.
On the other hand, Althaus43 tells us that, whether the application be central or peripheral, it is the positive pole, alone, which should be applied to the part which we intend to affect: and that the application of the negative pole in this situation is rather likely to do harm than good, as proving too exciting. Eulenburg, also, says that in general the positive pole should be applied to the seat of the disease, the negative on an indifferent spot, or on the peripheral distribution of the nerve.
It is, however, very doubtful to me whether, in the majority of cases, the direction of the current makes any considerable difference in its effects, provided only that the stream is fairly directed so as to include the locus morbi in the circuit, and care is taken to apply it with sufficient persistence and with not too great intensity. Upon this point I am glad to be able to cite the authority of Dr. Reynolds, whose experience is very large. This author, while admitting that in theory the "direct" and the "inverse" currents would seem likely to have different effects, declares that in practice this does not prove to be the case, either in the instance of pain of nerve or of spasm of muscle. Dr. Buzzard, also, in relating a very striking case (which I had the advantage of personally observing) before the Clinical Society, particularly mentioned that the direct and the inverse currents had a precisely similar effect in relieving the pain. The patient suffered from severe and probably incurable cervico-brachial neuralgia; the poles were placed, respectively, on the nape of the neck and in the hand of the affected limb, and whether the positive was on the nape and the negative in the hand, or vice versa, the effect was the same. Very striking remission of the pain was always produced, and the immunity from suffering sometimes lasted for a considerable time, while no other plan of treatment seemed to have more than the most momentary effect.
My own experience tells the same story very decidedly, for I have on very many occasions obtained great benefit, both by the direct and by the inverse currents, in the same patient. I shall here relate a few instances:
Case I. – A married woman, aged forty-eight, whose menstrual periods had ceased quietly some six years previously. She was, on the whole, a healthy person, but had suffered from migraine in her youth, and came of a neurotic family. She was attacked with severe cervico-brachial neuralgia, which resisted all treatment for nearly three months, and, on her then trying a month's change of air and absence from medication, became worse than ever. The constant current was applied, from ten (and afterwards fifteen) cells of Weiss's battery, daily for twenty-four days, the pain vanished finally at the end of thirteen days, and the accompanying anæsthesia and partial paralysis disappeared before the treatment was concluded. In this case the negative pole was applied by the side of the three lower cervical vertebræ, and the positive was applied, successively, to three or four different parts of the most intense peripheral pain.
Case II. – A young lady, aged twenty-four, suffered from neuralgia in the leg. Galvanization (twenty cells Daniell), from the anterior tibial region to the spine was found invariably to cut short the pain. I now reversed the current; the effect was the same. After ten sittings I suspended the treatment, as there had been no attack for three days; but a week later the neuralgia returned in full fury. I resumed galvanization from periphery to spine; after twelve more sittings the attacks had become rare and slight. I continued treatment for eight days longer, during the whole of which time there was no pain. It had not recurred when I saw her fifteen months afterward.
Case III. – H. G., a footman, aged twenty-three, applied to me at Westminster Hospital, with neuralgia of the first and second divisions of the right trigeminus, of six weeks' standing. The right eye was bloodshot and streaming with tears, the skin of the right side of the nose and right cheek was anæsthetic, the right levator palpebræ was partially paralyzed. Hypodermic injections of morphia proved only very temporarily beneficial. After a fortnight's treatment with this and with flying blisters to the nape of the neck and the mastoid process, I commenced the use of the constant current daily (ten cells, Weiss). The first application (positive on nape, negative on infra-orbital foramen) stopped the pain, and procured fourteen hours' immunity. On the next day I reversed the current; the pain stopped after three minutes' galvanization; it did not recur for four days, during which time, however, I continued the daily use of the direct current. On the sixth day of treatment the patient came to me with a somewhat severe paroxysm, almost limited to the ophthalmic division; it was accompanied by spasmodic twitchings of the eyelid, and copious effusion of altered Meibomian secretion, looking like pus. Galvanization from supra-orbital foramen to nape stopped the pain in five minutes. The next day the patient presented himself, quite free from pain, which had not returned; the conjunctiva was clear, and there was no visible Meibomian secretion. Inverse galvanization was continued for ten days; but no recurrence of the pain took place. The cure was permanent three months later.
On the contrary, we sometimes see complete failure of the current to affect any good whatever; and in these cases the reversal of the current has not, so far, appeared to me to make any particular change in the result. Such was the case with a patient whose history I detailed (along with that of Case I.) to the Clinical Society. She was an ill-fed and overworked unmarried needle woman, aged thirty; the neuralgia was a most violent double occipital pain, with foci, on each side, where the great occipital nerves become superficial. The current was passed daily, for some days, from one focus to another (necessarily passing through the nerve-roots and the spinal cord), and the positions of the conductors were occasionally reversed; this not succeeding, the current was applied altogether to the spine, the negative pole being placed on the highest cervical vertebræ, but no good effect was produced after a treatment, altogether, of sixteen days.
Notwithstanding these, and a good many similar facts that could be adduced, I should hesitate to go so far as to say that there is never any importance in the direction of the current. In old-standing cases, where there are well-marked points douloureux that are exceedingly sensitive, I have found that the application of the positive pole, successively, on the most tender points, the negative being placed on the spine opposite the point of origin of the nerve, has had a more beneficial effect than any other mode of application.
There are very considerable differences, both as to the best manner of galvanization, and also as to the chances of doing good with it, in the case of neuralgias of different nerves; and, on the whole, I find Eulenburg's conclusions on this matter very just. He indicates sciatica as the affection which is by far the most curable by the constant current; he says that many cases are cured in from three to five sittings, while others require as many weeks, or even months of treatment; and that a total absence of benefit is only seen in rare cases dependent on central causes, or on diseases which are irremovable (like malignant pelvic tumors). On the other hand, he reports that intercostal neuralgia has never been materially benefited by galvanization in his hands. With regard to ordinary trigeminal neuralgias, he speaks strongly of the current as a palliative, but very doubtfully of its power to cure, in genuine and severe cases. In cervico-brachial neuralgia he speaks of it as dividing with hypodermic morphia the whole field of useful treatment, in the majority of cases. In cervico-occipital neuralgia he says it rarely does much good. I shall return to Eulenburg's estimate of its utility in migraine, presently. Let me here say that I am inclined to indorse everything in the above-detailed statements, excepting that I should place a considerably higher estimate on the curative powers of the current in ordinary trigeminal neuralgias. The remedy, like every other, will doubtless fail in a considerable number of those very bad cases which occur in the degenerative period of life; but if anyone desires to see the proof of the power it sometimes exerts, even in extreme cases, he should study the two most remarkable cases treated by Prof. Niemeyer, of Tubingen, and reported by Dr. Wiesner.44 The patients were respectively aged sixty-four and seventy-four, and the duration of the neuralgia had been respectively five and twenty-nine years; in both the pain was of the severest type, and in both the success was most striking. In one of them every possible variety of medication, and several distinct surgical operations for excision of portions of the affected nerve, had been quite vainly tried. The cases are altogether among the most interesting facts in therapeutics that have ever been recorded. Dr. Russell Reynolds has also told me of a case under his own care, in which a lady, who had been the victim, for twenty years, of an extremely severe neuralgia of the ophthalmic division of the fifth, which attacked her daily, and had caused great injury to her general health and nutrition, was not merely benefited, but the affection absolutely removed, at any rate for a long period, by a single application of the current. I have personally seen no such remarkable cases as these but I have had some extremely severe cases under my care in which the effect of the current was to arrest the pain in a few applications, and procure a remission for several days, or even weeks. And I have had several slighter cases which were as much cured, to all appearance, as any disease can be, by any remedy.
As a general rule, neuralgia of the limbs requires to be treated with a more powerful current than neuralgia of the face (twenty cells instead of ten). In the latter case, indeed, it is necessary to be exceedingly cautious (commencing with five cells), since a current of high power has been known to produce most serious effects upon the deeper-seated organs; the retina has been permanently paralyzed, by too strong a current applied on the face, and still graver dangers attend the incautious use of galvanization of the brain or of the sympathetic, of which we have now to speak.
Galvanization of the brain is a remedy chiefly employed in true migraine, and is certainly very effective in that disease. I have not found it useful to apply the current in the long axis of the cranium, but transmitted from one mastoid process to the other it has proved most useful; and I am glad to find that my experience on this point coincides with that of Eulenburg. But the use of this remedy is highly perilous in careless hands. In working with either Daniell's or Weiss's battery, it is necessary to use at first only three or four cells, and to increase the number only with the greatest caution. The sittings should never last more than half a minute; but the slightest giddiness should make us stop even sooner. On the other hand, the applications ought to be made daily, and usually twice a day. Ten cells (Daniell or Weiss) is the utmost that will ever be required, few patients will bear so much; and, apart from the possibility of more serious mischief, there is nothing which annoys and frightens patients more seriously than the sudden and intense vertigo which over-galvanization of the brain may induce.
Even more ticklish than the galvanization of the cerebral mass is galvanization of the sympathetic. I am not going to raise here the vexed question in physiological electricity as to the possibility of a galvanization the effects of which shall be accurately limited to the sympathetic. The fact is unquestionable, that very powerful and peculiar effects, utterly unprocurable in any other way, can be produced by placing one pole on the superior cervical ganglion (just behind and below the angle of the jaw) and the other on the manubrium sterni. This is a mode of galvanization which has been highly praised, more especially by Remak, and after him by Benedikt, but it has yielded rather disappointing results in neuralgia in my hands. Either I have not observed any distinct effect at all, or, if a current even a very little too strong were applied, I have repeatedly seen most uncomfortable, and sometimes very alarming, symptoms. I shall not easily forget a patient who applied at the Westminster Hospital, suffering from a severe form of facial neuralgia, and who was persuaded to come to my house and have his sympathetic galvanized. I used only twenty cells of Daniell, but the current had not been applied more than a few seconds when the patient fell on the floor, and remained in a state of half swoon for a considerable time. I allude to this and other less dangerous accidents that I have seen follow galvanization of the sympathetic, not with the view to prove that the method is useless in trigeminal neuralgia – I should certainly hesitate to say that, considering the large amount of respectable evidence in its favor – but I think that it is a procedure requiring the utmost caution, and meantime I have not personally found it nearly so useful as the methods already described.
There are sundry special applications of galvanism to particular forms of neuralgia which require a few words of notice. Of electrical treatment in regular angina pectoris I have had no experience; and in the one case of intercostal neuralgia, complicated with quasi-anginal attacks, in which I applied the constant current to the spine and the cardiac region, in the direction of the affected intercostal nerve, no effect was produced. I shall, however, mention the experience of Eulenburg, as he is a sober and dispassionate writer on the effects of electric treatment in general. He says he believes that in the proper use of the constant current we shall discover the chief, possibly the only direct, remedy for angina; and he describes the apparently favorable results he has already obtained in three or four cases. The current was from thirty cells; the positive pole was placed on the sternum (broad electrode), the negative on the lower cervical vertebræ. The alternative method which Eulenburg suggests, but has not, so far, put in practice, is direct galvanization of the sympathetic and vagus in the neck.