Neuralgia and the diseases that resemble it

by Francis Edmund Anstie

(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 Neuralgia[41] 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.