THE TREATMENT OF NEURALGIA BY ELECTRICITY.

BY GEORGE M. BEARD, M.D., OF NEW YORK.

ALTHOUGH the subject of electro-therapeutics in general is now exciting great interest in all the great centres of science, there is yet, concerning the application of this agent to the treatment of neuralgia, considerable difference of opinion as well as of practice. The reasons for this difference of judgment in regard to the adoption of this most potent remedial agent to neuralgia are, it seems to me, as follows:

1. The diagnosis of neuralgia is oftentimes incorrectly made. It is confounded with rheumatism, with spinal sclerosis, with the vague wandering pains of hysteria, and with any number

of local diseases.

As I shall aim to show, in the course of this paper, the methods of electrical treatment of neuralgia must be essentially different from those employed for many of the conditions with which it is so often confounded. A form of application which will work well for rheumatism, or for the pains and aches of hysteria, may not only utterly fail to relieve true neuralgia, but may fearfully aggravate it.

2. The pathological seat of the disease in neuralgia is not properly recognised or acted on. Although I am not yet prepared to admit that atrophy of the roots of the sensory nerves is the usual lesion in neuralgia, since the arguments in favour of that view, as advanced by Dr. Anstie, are hardly satisfactory, yet the general idea that neuralgia is a central disease has long been my conviction. It is not inconsistent with this view to suppose that certain forms of neuralgia—as,

for example, some varieties of sciatica—may be in part if not wholly peripheral.

The generally accepted notion that the disease is where the pain is, has led physicians to apply the current solely to the seat of the pain. Logic and experience show that the seat of the disease, the central nervous system, should also be treated.

Then, again, it has not been recognised that the different forms of neuralgia are but manifestations of a constitutional tendency, and should be treated accordingly.

The whole central nervous system is invaded by a mysterious foe that darts out along the great pathways of nerve-force in any direction and where least expected. The special manifestations of the neuralgic tendency are often different at different periods of life.

I have now under my observation a gentleman of middle life, who, in youth, suffered from facial neuralgia; in later years, chronic cervico-brachial neuralgia has perpetually harassed him; during the past year he was prostrated by a terrible attack of gastralgia, and just now he is recovering from an invasion of sciatica. To treat such cases by merely local electrisation, whether it be central or peripheral, or both combined, may indeed palliate or relieve; but to expect permanent victory over the neuralgic tendency by merely local treatment where the pain last appears, is unreasonable and usually unsuccessful.

3. The differential action of the galvanic and faradic currents has not always been distinctly kept in view. For true neuralgia in any part of the body, the galvanic current is usually preferable to the faradic. It is not true, however, that genuine. neuralgia never yields to faradisation; it does so quite frequently; but everything depends on the kind of faradic current used, and the method of application. There is as much difference of therapeutical effect in the qualities of faradic currents as generated by different machines, as there is between the galvanic and faradic currents.

A rough, harsh current, such as is generated by Stöhrer's machine, will almost always do more evil than good to neuralgia, especially in the irritation stage. Such a current will pretty surely do harm if it be applied strong and recklessly, and may do no good when applied gently and cautiously. On the other

hand, a rapidly interrupted and pleasant current, such for example as is generated by Kidder's machine, when applied cautiously, may, and in my hands frequently has, relieved and cured true neuralgia.

The physical principles that account for this differential action of the faradic currents from these different machines is somewhat complex and cannot here be discussed. I may suggest that the physiological and therapeutical action of faradic currents seems to vary, not only with the length and thickness of the coils, but with the rate and manner of interruption, and with the details of the construction of the helix. All the leading forms of neuralgia-facial, central, occipital, cervicobrachial, gastralgia, and sciatica-I have treated with more or less success by faradisation with secondary and tertiary currents, from machines such as I have referred to; and yet the galvanic current will oftentimes succeed where the best faradic fails; and even in those cases where faradisation relieves and promises to cure, galvanisation may do the work in a much shorter time.

In regard to the question of the differential value of large and small cells in neuralgia, I may say that the idea that large cells send greater quantity of electricity through the body than small cells is opposed to the teachings of Ohm's law, and has no basis in experience. It is, however, not improbable that large cells, especially those various modifications of Daniell's, by virtue of their greater constancy and the great slowness and uniformity of the chemical changes that take place in them, may be less irritating, and therefore better adapted for neuralgia and other irritable conditions.

The difference in this respect cannot, however, be very great, since many of the greatest triumphs of the galvanic current over neuralgia have been gained by small and inconstant single cell batteries. The larger double cells are more steady in their action, but steadiness may not always be necessary even in testing neuralgia, and it is by no means impossible that in some conditions the very fluctuations of the single cell battery may have a therapeutical advantage. Certain it is, that many of the brilliant results in the treatment of diseases of the central nervous system by electricity have been obtained by portable

batteries, composed of a moderate number of small, single, and inconstant cells of zinc-carbon or zinc-platinum.

The electric moxa-faradisation with the metallic brush-is a method of treatment which in my hands has not been successful. I have seen the method used for sciatica in Berlin and in France, and I believe that it sometimes accomplishes good things; but it is a most atrociously painful procedure, and I rarely find a private patient in America who will endure it, and for this reason I have almost lost the habit of ever attempting to use it.

4. Too strong currents have been used, and too much stress has been laid on the differential action of the poles or of current direction. Beginners in electro-therapeutics make mistakes in many directions, but in no one more than in the habit of using too powerful currents. In many diseases and in many temperaments strong currents are harmful, but they are especially so in neuralgia. Better to use a mild current a long time than a strong current a short time: electro-therapeutics cannot be thus concentrated. To attempt to gain time in this way is cruel economy.

In regard to the differential action of the poles and of the - current direction, I admit that of course there is a differential therapeutic, as there is a differential physical and physiological action of the poles, but it is far less marked in therapeutics than in physics and physiology. The importance of direction of the current, whether ascending or descending, has been enormously overrated, not only in neuralgia but in all the diseases for which electricity is employed. Pain is relieved, neuralgia cured, and the nutrition in every respect improved, by the passage of the current through the body by either pole and in any direction, and the differential action of the poles and of the current direction is so slight and so complex that it cannot in the present state of physiological and pathological knowledge be reduced to any formula. I have elsewhere laid down the very general law that in therapeutics the positive pole is less irritating; but even this general statement seems to have many exceptions, in local application at least, for the negative will frequently relieve an irritated nerve as well as the positive, if not better. In central galvanisation and general

faradisation, I use, as a habit, the positive pole in making the application to the head or neck, believing this to be, on the whole, the safer.

5. The treatment has not been used with sufficient perseverance. Perhaps by the use of too strong currents the pain is at first increased; the patient and physician become alarmed and abandon the treatment. This is frequently a mistake; the fault is in the method, not in the medicine. Even when the pain is increased temporarily the permanent effect may be beneficial. Neuralgia is frequently a chronic disease, and like other chronic diseases demands chronic treatment. Neither patients nor physicians should be terrified or discouraged because the first applications appear to aggravate the attacks.

With these general remarks I proceed to speak of some of the special forms of neuralgia.

Migraine. The prognosis of migraine under electrical treatment is favourable for relief and palliation, but to thoroughly and permanently eradicate the habit is more than we can generally expect. Even relief of the pain during the height of the attack is by no means a uniform result. Here, as everywhere in electro-therapeutics, as much depends on the temperament of the patient, or his general susceptibility to electricity, as on the special disease from which he suffers. The attacks may be forestalled or aborted at the beginning by electrical treatment, just as they may be by bromide of potassium, or sodium, or hydrate of chloral, or gelsemium; but even here there is no uniformity.

In some cases the application of a very mild galvanic current to the head or neck at once causes the pain to depart, and it does not return. In other cases the same treatment does no good, and sometimes intensifies the pain. I have been at different times a victim to migraine, and have tried galvanisation before the attacks, while they were coming on, and at their height, and never with success. I have friends similarly afflicted, whom the same treatment for the same kind of attack always more or less relieves.

I think I have observed that migraine, accompanied with gastric disturbances, is more rebellious than when the disease is confined to the head.

Although electro-therapeutics must be based on clinical ex