Neuralgia and the diseases that resemble it

by Francis Edmund Anstie

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!

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.