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.
The application of the constant current in neuralgic affections of the larynx and pharynx is of most indisputable service; the experience of Tobold[45] upon this point is fully borne out by my own, as far as it goes. In many cases it will be sufficient to place the positive pole (from fifteen cells Weiss) on the pomum Adami, and the negative on the nape of the neck, and to keep up a continuous current for five or ten minutes daily; but in some cases the direct application of the current to the pharynx or larynx may be required; in such, a modification of Dr. Morell Kackenzie's laryngeal conductor will be found useful. [I shall have occasion, in Part II., to notice the superior action of Faradization in mere hysteric throat-pain, as distinguished from true neuralgia.]
Neuralgia of the testicle can be best treated, if galvanism be thought necessary, by immersing the whole scrotum in a basin of salt and water, in which the positive pole is placed: the negative pole is to be placed on the upper lumbar vertebræ; the current should be from fifteen cells Weiss, and the application should last continuously for ten minutes. In neuralgia of the urethra, I should be inclined to adopt a plan, mentioned to me by Dr. Buzzard, of attaching one conductor to an ordinary silver catheter introduced into the urethra, and placing the other pole upon the perinæum.
Neuralgia of the neck of the bladder I have found to be materially relieved by the constant current from twenty cells passed through from pubis to perinæum; the sittings being rather long. I have also, on one occasion, tried the introduction of a proper porte-electricite, insulated, except at the tip; but the result was not superior to that obtained in the other way.
As a general rule, it may be said that electricity, like other local measures which tend to concentrate the patient's attention on the parts, is only to be applied to the genital organs as a last resort. This is, of course, especially true in the neuralgias of these organs in women.
In concluding what will doubtless seem to some English readers an over-long and over-favorable estimate of the employment of galvanism in neuralgias, I must carefully guard myself against the supposition that I consider it a remedy to be applied in all cases, or likely to meet with uniform success, even in the forms of the disease to which it is most appropriate. It is a weapon which I seldom employ in the first instance, for many reasons; the principal of which is the costliness of the proceeding to the patient. Either the physician must personally administer the remedy, daily, often for a considerable period, or he must make the patient provide himself with an expensive battery; and in the latter case there is, after all, the unsatisfactory consideration that the application (even after the most careful directions have been given) will perhaps be unskilfully and inefficiently made. On the other hand, it is not desirable to delay the employment of galvanism too long, if other remedies have been fairly tried; and the practitioner will do well to remember the distinctions above laid down as to the varieties of neuralgia in which it is specially likely to prove decidedly and quickly beneficial. More especially in sciatica it would really, with our present knowledge, be a decided neglect of duty were we to allow the disease to run any considerable length without giving the constant current a thorough trial. [I can only briefly refer, here, to the novel mode of galvanization introduced by Dr. Radcliffe, and based upon his ingenious theory, according to which the true effects of the voltaic current upon nerve are the result of the charge of free electricity which it sets up, and not of the current directly. The reader will find the whole argument elaborately worked out in Dr. Radcliffe's recent work on "The Dynamics of Nerve and Muscle," Macmillan & Co., 1871. It will be enough to say, here, that the object to be attained, according to this view, is to replace the neuralgic nerve in its healthy physiological state, by charging it with free positive electricity. The manner in which this is done is as follows: In a case, e. g., of cervico-brachial neuralgia, we place the positive pole as near as may be to the central origin of the affected nerve; the negative pole is held in the hand of the same side, which is immersed in a basin of warm salt and water. In this same basin is another electrode, the wire from which is put in communication with the earth—most conveniently by putting it in contact with a gas-pipe. The patient, and the battery, ought properly to be insulated. The result of this arrangement is, that the free negative electricity is carried off by the earth-wire, and the limb remains charged with free positive electricity. I have had no sufficient experience of this method to give any opinion of its merits, but the inventor thinks it decidedly superior to the ordinary modes of applying the constant current.]