Neuralgia and the diseases that resemble it

by Francis Edmund Anstie

The secondary affections which may arise as complications of neuralgia form a deeply interesting chapter in nervous pathology, and one which has only been explored in quite recent years. The excellent treatises of Valleix and Romberg, written only thirty years ago, make but most cursory and superficial mention of these complications, and do not attempt to group them in a scientific manner. The reflex convulsive movement of the facial muscles in severe tic-douloureux had of course been long observed; and Valleix added the correct observation that gastric disturbance was often secondarily provoked in facial neuralgia, thus improving greatly on the old view, which supposed that, where trigeminal neuralgia and stomach disorder coexisted, the latter must have been the antecedent and the cause of the former. Still, he did not explain the pathological connection. And as regards certain other most interesting results of neuralgia, which he could not avoid meeting with from time to time, e. g., lachrymation, flux from the nostril, salivation, altered nutrition of the hair, he only speaks of these as occasional phenomena, and in no way classifies them, or explains their relation to the neuralgia itself.

There did exist, however, one too little known work of some years earlier date, which, though not dealing specifically with neuralgia, and though based upon the necessarily very imperfect knowledge of the functions of the nervous system prevalent in its day, had nevertheless done much to lay the foundation of a comprehensive view of the complications of neuralgia; we refer to the work of the brothers Griffin, on "Functional Affections of the Spinal Cord and Ganglionic System," published in 1834. In this most interesting treatise, the record of acute and extensive observations made in a quiet and unpretending way by two Irish practitioners, numerous examples are cited in which neuralgic affections were seen to be inseparably united with secondary affections of the most various organs, with which the neuralgic nerves could have no connection except through the centres, by reflex action. The authors, while firmly grasping the fact of the common connection of the nerve-pain and the other phenomena (convulsions, paralysis, altered special sensation, changes in secretion, changes even in the nutrition of particular tissues) with the central nerve system, were doubtless in error in thinking that they could detect the precise seat of the original malady, by discovering certain points of tenderness over the spinal column. But their facts were observed with the greatest care, and can now be interpreted more intelligently than was possible at the time. Here, for example, is a case which forestalls one of the most interesting pieces of information which more recent research has made generally known:

"Case XXIV.—Kitty Hanley, aged fourteen years, catamenia never appeared; about six months ago was attacked with pain in the right eye and brow, occurring only at night, and then so violently as to make her scream out and disturb every one in the house; it afterward occurred in the infra-orbital nerve, and along the lower jaw in the teeth, and there was inflammation of the cornea, with superficial ulceration and slight muddiness. Tenderness was found at the upper cervical vertebræ, pressure on any of them exciting severe pain in the vertex and brow; but none in the eye or jaws, where it is never felt except at night."

The above is a well-marked example of neuralgia of the trigeminus causing secondary inflammation and ulceration of the eye of a precisely similar kind to that which had been experimentally produced by Magendie by section of the fifth, at or posterior to its Gasserian ganglion. We shall see, hereafter, how extremely important are this and similar facts, not only in regard to the clinical history, but also to the pathology of neuralgia in general.

The first regular attempt, I believe, to classify the complications of neuralgia, was made by M. Notta, in a series of elaborate papers in the "Archives Generales de Medecine" for 1854. We may specially mention his analysis of a hundred and twenty-eight cases of trigeminal neuralgia, which is well fitted to impress on the mind the frequency, though, as we shall presently see, it does not adequately represent the seriousness, of these secondary disorders. As regards special senses, Notta says that the retina was completely or almost completely paralyzed in ten cases, and in nine others vision was interfered with, partly, probably, from impaired function of the retina, but partly, also, from dilatation of the pupil or other functional derangement independent of the optic nerve. The sense of hearing was impaired in four cases. The sense of taste was perverted in one case, and abolished in another. As regards secretion, lachrymation was observed in sixty-one cases, or nearly half the total number. Nasal secretion was repressed in one case, in ten others it was increased on the affected side. Unilateral sweating is spoken of more doubtfully, but is said to have been probably present in a considerable number of cases. In eight instances there was decided unilateral redness of the face, and five times this was attended with noticeable tumefaction. In one case the unilateral tumefaction and redness persisted, and were, in fact, accompanied by a general hypertrophy of the tissues. Dilatation of the conjunctival vessels was observed in thirty-four cases. Nutrition was affected as follows: In four cases there was unilateral hypertrophy of the tissues; in two, the hair was hypertrophied at the ends, and in several others it was observed to fall out or to turn gray. The tongue was greatly tumefied in one case. Muscular contractions, on the affected side, were noted in fifty-two cases. Permanent tonic spasm, not due to photophobia, was observed in the eyelid in four cases, in the muscles of mastication four times, in the muscles of the external ear once. Paralysis affected the motor oculi, causing prolapse of the upper eyelid, in six cases; in half of these there was also outward squint. In two instances the facial muscles were paralyzed in a purely reflex manner. The pupil was dilated in three cases, and contracted in two others, without any impairment of sight; in three others it was dilated, with considerable diminution of the visual power. Finally, with regard to common sensibility, M. Notta reports three cases in which anæsthesia was observed. Hyperæsthesia of the surface only occurred in the latter stages of the disease.

To Notta's list of complications of trigeminal neuralgia must be added the following, all of which have been witnessed, and several of them in a large number of instances: Iritis, glaucoma, corneal clouding, and even ulceration; periostitis, unilateral furring of the tongue, herpes unilateralis, etc. In writing on this subject three or four years ago, I mentioned that all these secondary affections had been seen by myself, except glaucoma. That is now no longer an exception; indeed, my attention has been so forcibly called to the connection between glaucoma and facial neuralgia, that I shall presently examine it at some length.

The trigeminus is, of all nerves in the body, that one whose affections are likely to cause secondary disturbances of wide extent and various nature, owing to its large peripheral expanse, the complex nature of its functions, and its extensive and close connections with other nerves. Moreover, its relations to so important and noticeable an organ as the eye tends to call our attention strongly to the phenomena that attend its perturbations. But there is every reason to think that all secondary complications which may attend trigeminal neuralgia are represented by analogous secondary affections in neuralgias in all kinds of situations; and we may classify them in the principal groups which correspond to disturbance of large sets of functions:

1. First, and on the whole, probably, the most common of all secondary affections, we may rank some degree of vaso-motor paralysis. It may be doubted if neuralgia ever reaches more than a very slight degree without involving more or less of this; for so-called points douloureux are themselves pretty certainly, for the most part, a phenomenon of vaso-motor palsy; and the more widely-diffused soreness, such as remains in the scalp, for instance, after attacks of pain, even at an earlier stage of trigeminal neuralgia than that in which permanently tender points are formed, is probably entirely due to a temporary skin-congestion. The phenomenon presents itself in a much more striking way in the condition of the conjunctiva seen in intense attacks of neuralgia affecting the ocular and peri-ocular branches of the fifth; one sometimes finds the whole conjunctiva deeply crimson; and, in one remarkable instance that I observed, the same shade of intense red colored the mucous membrane of the nostril of the same side. In several instances, I have seen a more than usually violent attack of sciatic pain followed by the development of a pale, rosy blush over the thinner parts of the skin of the leg, especially of the calf, which were then extremely tender, in a diffuse manner, for some time after spontaneous pain had ceased.

2. Not merely the circulation, however, but the nutrition of tissues, becomes positively affected, in a considerable number of cases. It is difficult to judge, with any exactness, in what proportion of neuralgic cases this occurs, but its slighter degrees must be very common. It has very frequently happened to me, quite accidentally, in examining with some care the fixed painful points, which are so important in diagnosis, to be struck with the decided evidence to the finger of solid thickening, evidently dependent on hypertrophic development of tissue-elements; in severe and long-standing cases, I believe this condition will always be found. Probably the change is, more usually than not, sub-inflammatory; but it is certain, on the other hand, that there are great variations in the kind of tissue-changes complicating neuralgia, and that inflammation is no necessary element in them. This subject has greatly engaged my attention, and I find myself able to give what is probably a fuller account of the matter than any yet published connectedly.

The following tissues have been seen by myself to become altered under the influence of neuralgia in nerves distributed to them, or to the parts in their immediate neighborhood.