The special mark of true neuralgic pain in the abdominal pneumogastric, as distinguished from other deep-seated pains in the epigastrium, is the remarkably direct relation of its severity to the patient's exhaustion, particularly in regard to the weakness induced by want of food. While the great majority of dyspeptic pains are increased by filling the stomach, gastralgia, on the contrary, is invariably relieved by food, often most strikingly and completely. Pressure from without, also, while it aggravates most pains dependent on local organic mischief, nearly always more or less relieves gastralgia. Equally striking is the comfort given by stimulants, especially by hot brandy-and-water; in this respect gastralgia resembles colic. There is something special in the degree of mental depression which attends gastralgic pain. In this it resembles the pains of hypochondriasis, but there is a resilience of the spirits when the pain has been relieved which is not seen in the latter affection. A very frequent complication of gastralgia is severe palpitation of the heart, but during the paroxysm itself the pulse, whether rapid or not, is commonly small, at first tense, and afterward soft, but not acquiring any considerable volume till the pain has ceased.

So severe is the pain, and so complete the mental and physical prostration in bad attacks of gastralgia, that the first aspect of the patient might suggest--indeed often has suggested--the occurrence of gastric or duodenal perforation; but, as soon as the paroxysm is over all the alarming appearances vanish, leaving only a certain amount of tenderness on deep pressure. In the more typical cases there are no signs of dyspepsia whatever, no fulness nor excessive redness of the tongue, no nausea, regurgitation of food, nor pyrosis. Occasionally the neuralgic affection is complicated with more or less gastric catarrh; but this is a much rarer occurrence, in my experience, than some writers would lead one to believe; and, moreover, where a certain amount of organic disorder of the stomach is observed, it is usually a mere secondary result of the neuralgia. The most severe example of gastralgia which I ever saw was entirely unaccompanied by dyspepsia; this patient absolutely attempted suicide to escape from his agonizing pains, which recurred with the greatest frequency and obstinacy, but were at last entirely removed by strychnia. In another patient whose very interesting case will be again alluded to under the head of Complications of Neuralgia, violent abdominal pneumogastric pain was succeeded by a severe attack of trigeminal neuralgia, accompanied by inflammation of the eye, which inflicted irreparable damage; here, too, the gastralgia was entirely uncomplicated by any other stomach-symptoms.

_Cerebral Neuralgia._--We enter, here, on an extremely obscure and doubtful subject: Can there be pain in the central ma.s.ses of the encephalon? There are undoubtedly a not inconsiderable number of cases of pain, neuralgic in type on the whole, in which the suffering cannot be referred to any recognizable superficial nerve. It seems deeply situated within the cranium. I have also quoted cases of Dr. Hillier's in which not merely was there deep-seated headache in children, but there was something like a characteristic general change observed in the brain-tissues after death, viz., a great moisture and softness of texture. Notwithstanding all this, I am not convinced, nor indeed much disposed to believe, that pain is ever felt in the structure of the brain; I rather believe that, in the cases where this seems to occur, the pain is either in the intracranial portion of the nerve trunks, or, far more probably, in the twigs of nerves that are distributed to the cerebral membranes. In that case they are, strictly speaking, only varieties of neuralgia of the fifth nerve, and might have been properly discussed under that heading; but it is more convenient to speak of them apart, since their phenomena present considerable differences from those of the external neuralgias of the head and face.

I have now seen several of these cases of intracranial neuralgias, and very perplexing and (at first sight) alarming they certainly are. The first of these cases came under my care in 1868. The patient was a single lady who had greatly over-tasked an intellect that was not, perhaps, originally very strong, by trying to do hack literature on conscientious principles; insisting, for instance, on knowing something about every subject she wrote upon. Her age was thirty-eight when she applied to me; menstruation was scanty but regular; and, on the whole, she could not be said to have pa.s.sed an unhealthy life, although "nervous-headaches" and "sick-headaches" had occasionally beset her.

This time the trouble seemed to be more serious. Ten days before applying to me, she had awaked in the morning with a feeling that something was very wrong in her head; there was not so much pain as a dull, brooding sort of weight, felt deeply within the cranium, and rather anteriorly. This had not lasted many hours when she was seized with a sensation of intense cold, amounting almost to rigors, and then before long was suddenly attacked with acute splitting pain in the same situation as the feeling of weight already mentioned had occupied. This pain, which came and went, or rather intensified and remitted, without ever completely ceasing, lasted about two hours, and then rather suddenly disappeared, leaving the patient with a deep "bruised and sore feeling in her brains." The pain recurred about the middle of the next day, lasting for several hours, and again leaving behind it the sore feeling. Day by day the paroxysms returned, and, on the day before her visit to me, the patient had, she told me, been driven frantic by her sufferings and had become actually delirious. Her appearance, when I first saw her, was wretched; the face haggard, both eyes sunken and surrounded with deep rings of dusky pigment, both conjunctivae bloodshot, the whole face almost earthy in its pallor. At that hour (11 A. M.) the pain had not positively recommenced, but she was in momentary dread of its recurrence. She complained of giddiness, muscae volitantes, and great feebleness of vision, and dreaded attempting to read, as the mere effort of fixing her eyes on anything intently caused flashes of fire before them. It was difficult at first to believe that there was not some serious organic brain-mischief; but on the whole I concluded that there was an absence of any genuine symptoms of such disease. At the same time, the pain was decidedly not referred to any cutaneous sensory nerve; and on the whole it appeared probable that the affection was intracranial. There remained the diagnosis of meningeal neuralgia, and to this I provisionally made up my mind. The opinion that the pain did not depend on any fixed organic disease was decisively justified by the results of treatment. One-sixth of a grain of morphia was injected on the occasion of the first visit, and this was repeated every day, and sometimes twice a day, for a fortnight; by this sole means, with rest, quietude, and light nourishing food, the patient was brought to comparative convalescence. The injections were then gradually discontinued, and she got quite well.

In a second case, which presented itself in the out-patient room at Westminster Hospital, a young man of markedly-nervous temperament, who had been somewhat given to drink, complained of similarly deep-seated intermittent pain, which he referred, however, to a point nearer the back of the head. He suffered, also, from vertigo, especially after unusually long paroxysms. Blisters to the nape of the neck, and a few subcutaneous injections of morphia, removed the pain and the vertigo completely.

A third example was that of a gentleman, aged thirty-four, who was sent over from the neighborhood of Sydney, Australia, to see me. Here, also, there was deep-seated intracranial neuralgic pain of the most severe kind, which greatly alarmed his local medical attendants; and it was only after a great many remedies had been tried that one medical man gave the opinion that the disease was "neuralgia of the membranes of the brain," and employed the hypodermic injection of morphia. This treatment at once gave great relief, though the pain had been so severe as to cause delirium on several occasions. In order to get thoroughly re-established, he was sent to England, and desired to consult me. As was expected, the voyage proved of the greatest service, as he hardly suffered at all while on the water. On arriving in England he was at first well, but in a week or two began to feel somewhat below par, and one morning, feeling an attack of pain coming on, he came to me. He was a tall and strongly-built man, with nothing peculiar in his appearance except a certain languor and heaviness of the eyes. He appeared to have lived somewhat freely and to have smoked decidedly to excess. His description of the attacks left no doubt of their neuralgic character, and in other respects they seemed quite a.n.a.logous to the other cases mentioned above, except in one thing, that there seemed a good deal of evidence tending to show a bad local influence in the air of that part of Australia where he usually resided. Almost any change from that had always done him good, though nothing had done anything like so much as the voyage to England. On the occasion of his first visit to me I injected him with one-sixth grain acetate of morphia, thereby stopping the pain. I prescribed muriate of iron and minute doses of strychnia, which he took for some little time, but the pain never recurred during his stay in England and on the Continent. Unfortunately, as he was anxious to return to Australia, I permitted him to do so, after a stay in the Old World of only three or four months; but, very shortly indeed after his return to Sydney, his old complaint attacked him. This time, unhappily, the hypodermic morphia has proved merely palliative, and I have latterly heard very bad accounts from him; still, there has been nothing to throw doubt on the neuralgic character of the disease.

In reflecting upon the anatomy of the nervous branches to the dura mater, I have formed the opinion that there are two situations, one anterior and the other posterior, in which intracranial neuralgia may occur; the former at the giving off of Arnold's recurrent branch from the ophthalmic division, near the sella turcica, the other in the peripheral twigs of this same branch, distributed to the tentorium cerebelli.

_Pharyngeal Neuralgia._--A rather common and extremely troublesome form of neuralgia is that which attacks the pharynx. It is very much more common in women than in men, and especially in hysterical persons. The pain commonly commences in a not very acute manner; it may be felt for some days, or even weeks, as a dull aching, coming and going pretty much in accordance with the patient's state of fatigue, or of reinvigoration after meals, etc. Some trivial circ.u.mstance, such as a slightly extra degree of exhaustion, or the influence of some depressing emotion, will then change the type to that of decided neuralgia, which may become extremely severe. Nothing is more annoying, and even distressing, than the suffering itself, besides which there are abnormal sensations in the throat which almost irresistibly compel the patient to believe that there are severe inflammation and ulceration, and that the throat is in danger of being closed up. Although the pain is usually one-sided, it sometimes affects both sides, and is felt also at the back of the pharynx. The act of swallowing being painful, there is the greater suspicion of inflammation or ulceration, but careful observation shows that a large bolus of food is swallowed with as little, if not less, pain than a small mouthful of solids or even liquids.

Pharyngeal neuralgia must, I think, be considered mainly an affection of the glosso-pharyngeal nerve; the evidence for this is found in the distribution of the pain. A slight degree of the neuralgia will only involve some one or two points in or behind the tonsil; but, when the pain is strongly developed, it will be found to radiate into the tongue, in one direction, and into the neck (following the course of the carotid) in another, besides spreading well into the region occupied by the pharyngeal plexus. One disagreeable reflex effect of severe pharyngeal neuralgia consists in involuntary movements of the muscles of deglut.i.tion, another is seen in the copious outpouring of thick mucus similar to that which collects in the pharynx and oesophagus when a foreign substance has become impacted.

_Laryngeal neuralgia_ concentrates itself mainly in the twigs of the superior laryngeal branch of the pneumogastric which are distributed to the arytaeno-epiglottidean folds, the epiglottis, and the chordae vocales; more rarely a neuralgia is developed lower down, within the cavity of the larynx, apparently in one or more of the scanty twigs to the mucous membrane supplied by the recurrent laryngeal.

Pure neuralgias of the larynx, like those of the pharynx, are more common in women, and especially in weakly hysterical women, than in men.

They are easily excited and greatly aggravated by movements of the parts, and thus it happens that, among men, by far the most numerous subjects of laryngeal neuralgia are found among clergymen, professional singers, and others whose occupation compels them to strenuous and fatiguing employment of the laryngeal muscles. It is rather a singular and striking fact, however, that the so-called "clergyman's sore-throat," which is characterized by most unpleasant sensations, and by a more or less complete loss of voice, is not, in the majority of cases, attended with any distinct laryngeal neuralgia. It seems that a predisposition to neuralgia is a necessary element in the latter affection.

FOOTNOTES:

[3] "Gunshot Wounds and other Injuries to Nerves." Philadelphia: Lippincott & Co., 1864.

[4] _Med. Times and Gazette_, March 26, 1864.

[5] "London Hosp. Reports," 1866.

[6] "Stimulants and Narcotics," Macmillan, 1854, p. 86.

[7] Trousseau, Clinique Medicale. Vanlair, "Des dieffrentes Formes du Nevralgies," Journ de Med. de Bruxelles, tome xl.

[8] Amer. Jour. Med. Science. Jan. 1850.

[9] "Diseases of the Heart and Great Vessels." Third edition, 1862.

[10] _Gaz. des Hop._, 114, 117, 120. 1862.

[11] _Wien Med. Presse_, xxiv., 1866; Syd. Soc. Yearbook, 1865-'66, p.

120.

[12] Berlin Klin. Woch., 1865; Syd. Soc. Yearbook, 1865-'66, p. 120.

[13] See Wahn, _Journ. de Med. et Chir. Prat._ 1854. Also several original and quoted cases in Dr. Handfield Jones's "Functional Nervous Disorders," second edition, 1870.

[14] _Journ. de Med. et Chir. Prat._, July, 1862.

CHAPTER II.

COMPLICATIONS OF NEURALGIA.

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 cla.s.sifies 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 pract.i.tioners, 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 vertebrae, 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 Ga.s.serian 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 cla.s.sify 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 a.n.a.lysis 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 anaesthesia was observed. Hyperaesthesia 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; periost.i.tis, 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 a.n.a.logous secondary affections in neuralgias in all kinds of situations; and we may cla.s.sify them in the princ.i.p.al 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.

(_a_) The hair has changed in color in many cases. Of twenty-seven patients suffering from neuralgia of the ophthalmic division of the fifth, eleven had more or less decided localized grayness of hair on that side. The amount of this varied greatly, from mere patches of gray near the roots of the hair to decided grayness of the majority of the hairs over the larger part of half the head, nearly to the vertex; but in each case it was a change of color that did not exist on the other side of the head. In four of these cases there was also grayness of part of the eyebrow on the affected side. A very remarkable phenomenon, which I have sometimes identified, is fluctuation of the color, the grayness notably increasing during, and for some time after, an acute attack of pain, and the same hairs returning afterward more or less to their original color. My attention was first called to this curious occurrence in my own case. I have so often related this case [see, for instance, my article on Neuralgia in "Reynolds's System of Medicine," vol. ii.] that I shall merely recall the fact that, when pain attacks me severely, the hair of the eyebrow on the affected side displays a very distinct patch of gray (on some occasions it has been quite white) opposite the tissue of the supra-orbital nerve, and that the same hairs (which can be easily identified) return almost to the natural color when I am free from neuralgia. I must, however, add the very curious fact, which I observed accidentally in experimenting (as regards urinary elimination) on the effects of large doses of alcohol, that a dose sufficiently large to produce uncomfortably narcotic effects invariably caused the same temporary change of color in the hair of the same eyebrow, even when no decided pain was produced, but only general malaise. The subject will be again referred to under the heading of Pathology.

Change in the size and texture of the hairs, in neuralgia, has been noted by Romberg and Notta, and has been several times observed by myself. Occasionally the individual hairs near the distribution of the painful nerve become coa.r.s.ely hypertrophied; at times the number of hairs appears to multiply, but I imagine this is only a case of more rapid and exuberant development of hairs that would be otherwise weak and small. In one very remarkable instance of sciatica this came under my observation; the whole front of the painful leg, from the knee nearly to the ankle, became clothed, in the course of about six months, with a dense fell of hair, which strongly reminded me of similar abnormal hair-growths that have been occasionally seen in connection with traumatic injuries to the spinal cord. More commonly, the effect of neuralgia upon hair is to make it brittle, and to cause it to fall out in considerable quant.i.ties; one young lady, who consulted me for a severe migraine, was seriously afraid of having a good head of hair completely ruined in this way, but the hair gradually grew again after the neuralgia had disappeared.

(_b_) The periosteum of bone and the fibrous fasciae in the neighborhood of the painful points of neuralgic nerves not unfrequently take on a condition of subacute inflammation, with marked thickening and tenderness on pressure. The most striking instance of this that I have seen was in a lady suffering from severe cervico-brachial neuralgia. In the neighborhood of the emergence of the musculo-spiral nerve at the outer side of the arm, there was developed what looked for all the world like a large syphilitic node, except that the skin was brightly reddened over it; this disappeared altogether some little time after the neuralgia had been relieved by ordinary treatment. I must say that, but for the peculiar circ.u.mstances of the case, putting syphilis out of the question, I could not have avoided the suspicion, at first, that the swelling was specific. But I have several times seen similar, though less developed, swellings in neuralgia, and in one case I noticed the occurrence of such a swelling on the malar bone, in an old woman in whom the neuralgic pain was limited to the auriculo-temporal and the supra-orbital branches of the fifth.

A very important point is to be noted in connection with these sub-inflammatory swellings in connection with neuralgia. Pressure on them will, frequently, not merely excite the neuralgic pains in the branches of the affected nerve, but send a powerful reflex influence through the cord to distant organs, causing vomiting, for instance, or affecting the action of the heart in a very perceptible manner. I shall show, when I come to speak of the phenomena of so-called spinal irritation, that this circ.u.mstance has led to erroneous influences in many cases. These exquisitely tender points are often found where Trousseau places his neuralgic _point apophysaire_, namely, over, or very near, the spinous processes of the vertebrae. The tenderness is quite unlike that which is known as hysterical hyperaesthesia; it is much severer, and is limited to one, two, or three points, corresponding, in fact, to the superficial part of the posterior branches of as many spinal nerves.

(_c_) The nutrition of the skin over neuralgic nerves is sometimes notably affected even when the process does not reach the truly inflammatory stage, which will be more particularly mentioned presently.

A certain coa.r.s.eness of texture of the skin has struck me much, in several cases of long-standing facial neuralgia. And there is a most curious phenomenon (which will be especially considered hereafter in regard to the singular influence of the constant galvanic current upon it), the distribution of a greater or less amount of dark pigment to the skin near the painful part. This phenomenon is much more marked during the paroxysms, and in the slighter cases entirely disappears in the intervals, but in old-standing severe cases it becomes more or less permanent.

(_d_) The mucous membranes, in situations where we can observe them, not unfrequently show interesting changes, the nutrition of the epithelium of parts covering the painful nerve being exaggerated. It has been noted by various observers, in neuralgia affecting the second and third divisions of the trigeminus, that the half of the tongue corresponding to the painful nerve was covered with a dense fur. This is by no means universally the case, but I have seen it occur several times. In my own case, in which the neuralgia is limited for the most part to the ophthalmic division, and only rarely spreads even to the second division of the nerve, this does not usually occur, but I have noticed it on one or two occasions. And I once made the still more singular observation that a large narcotic dose of alcohol, which was sufficient to cause comparatively free elimination of unchanged alcohol in the urine, caused furring of the tongue, which was decidedly thicker on the side of the affected nerve than on the other half of the tongue.

(_e_) We come now to a group of complications of neuralgia which are exceedingly important, and by no means adequately appreciated as yet, viz., the acute inflammations which directly result from neuralgic affections in a certain percentage of cases, probably much larger than has been at all generally suspected.

The most familiar of the inflammatory complications of neuralgia is herpes zoster, the favorite seat of which is the skin which covers one or more of the intercostal s.p.a.ces: the eruption, as occurring in this situation, is so well known that it would be waste of time to describe it. In young subjects zoster is commonly painless, at least the sensations are those of heat, p.r.i.c.king, and irritation, rather than of acute pain; but from p.u.b.erty onward there is an increasing tendency, especially in those otherwise predisposed to neuralgia, for zoster to be preceded, accompanied, or followed by neuralgia of the intercostal nerves corresponding to the distribution of the eruption. Most commonly, the eruptive period is, in my experience, nearly or quite free from neuralgia, but it often recurs, or breaks out for the first time, when the vesicles are drying up, but more especially if, as is sometimes the case, especially in elderly people, the scabs fall off and leave superficial ulcers. Neuralgia may last, after herpes zoster, for any time from a few days to many weeks, and I have known it so agonizingly severe and so persistent as actually to kill an aged woman from sheer exhaustion. In spite of sundry objections that have been raised to the theory of the nervous origin of zoster, it appears to me that the evidence in favor of it is overwhelming, more especially now that it is proved that the disease, with all the same characteristics presented by it when seen on the chest or abdomen, may occur on the face (following the branches of the trigeminus), or on the forearm (following the course of nerves from the brachial plexus). Two of the severest cases of neuralgia attending herpes that I have ever seen were in private patients (whose family history, unfortunately, I had no means of ascertaining) who were affected, respectively, in the facial and in the brachial nerve-territories.

A far more formidable occasional complication of neuralgia is inflammation affecting the eye. Mr. Jonathan Hutchinson records several cases in which neuralgic herpes zoster of the face was attended with iritis, with serious or even irremediable damage to the organ. For my own part, I have witnessed several instances in which neuralgia of the first and second divisions of the fifth has been attended with skin-inflammation, but only in one of these (just alluded to) did the inflammation present the characteristic appearances of herpes: in all the rest it far more closely resembled erysipelas. The skin was excessively reddened in an almost or quite continuous patch over the whole territory through which ran the painful nerves; by no means only linearly in the course of the nerves, though accurately limited to the district of the first or first and second divisions of the fifth. In the first case I saw (a woman, aged thirty-two), nothing could be more startling than the rapidity with which an irregular patch of the skin, including half of one cheek, the side of the nose, and a large part of the forehead and scalp on the same side, became converted into the dense, fiery-red, brawny tissue, with minute vesicles scattered over its surface, which looks so characteristic of erysipelas; this commenced immediately on the subsidence of severe neuralgic pain. During the erysipelatoid inflammation, though there was no spontaneous pain, the neuralgia could be instantly lighted up for a moment by pressure on the infra-orbital foramen, on the supra-orbital notch, or upon the malar bone, about its centre. Since that time I have seen several cases of a similar character; two of these, which were reported in the _Lancet_ for 1866, I shall here reproduce: [Extensive inquiries convinced me that the tendency to erysipelatous complication of facial neuralgia is exceedingly common. Eulenburg expressly confirms my original statement to this effect, and extends it to all neuralgias.]