the malady has been discovered. M. Laborde has shown that there is a distinct change in certain portions of the spinal cord; that the anterior columns are more translucent than natural, and present a very appreciable greyish-rose tint to the naked eye; and that a similar change may be observed, although to a less degree, in the lateral columns. The consistence of these tracts of nerve-tissue is diminished; and upon microscopic examination there may be observed a marked proliferation of the elements of the connective tissue, cells and nuclei being dispersed in the midst of a finely granular substance, in which there are fibrils of extreme tenuity. In the parts which are the most affected nervous tubules are either lost altogether, or they present a varicose appearance; while the other portions of the spinal column preserve a perfect integrity.

6. Treatment.-There is nothing special to be observed in the treatment of the early febrile symptoms; but it is of the very highest importance that the nature of the affection should be recognised as soon as possible, and that the paralysis should be encountered vigorously.

The treatment which has been the most efficacious has been the judicious use of electricity-viz., its application, in proper forms and in suitable intensity, to the affected muscles. It often happens that, as in the case of G. H., which you have lately seen, the recovery is complete; and this after several years' duration of the paralysis. The most efficacious application is that of the interrupted battery current; and a curious fact is commonly elicited by its continued use. You find, for example, a group of wasted, palsied muscles, inactive to faradisation, but responding readily to galvanism. You apply galvanism on several occasions, and observe that gradually some voluntary power returns, and with this a diminution of response to the agent you are employing. The same muscles were unaffected by faradisation at the first; but now as their voluntary power returns and their contractility to the battery current diminishes-they act readily when the induced current is applied. At this period in the history of a case I have found it desirable to change the form of electricity, and to employ faradisation, carefully avoiding the use of such power as shall cause pain to the patient. Galvanism requires most patient exhibition in cases of this kind: for many months it should be continued, provided that there be the smallest improvement in voluntary power, or in the nutrition of the limb. When, after six or eight applications of both faradic and battery electricity, there has been no appearance of electric irritability, I have seen no good result from its continued It is probable that, under such circumstances, the muscles are so changed in structure, or, rather, so thoroughly destroyed in proper texture, that nothing can restore them; and the only thing that can be done is to prevent the deformity which might arise from the unopposed action of those other antagonistic groups of muscles which yet retain their integrity.

use.

Electricity may have its action assisted by frictions and passive movements; but I have not seen any definite result, quoad the paralysis or wasting, from the exhibition of drugs. Of course, if the child be out of health, you would do your best to bring it into a more favourable condition; and in one case you would give alteratives, in another iron, in a third cod liver oil, and the like. But your main object must be to treat the muscles, and to treat them without delay.

7. Your prognosis, in a case of infantile paralysis, is bad when the loss of voluntary power is absolute, when the wasting is extreme, and when, after three or four applications of electricity, you can detect no trace of contractility in the muscles. It is bad under such circumstances, whether the disease be of old standing or of comparatively recent development. On the other hand, if some slight voluntary power remain, or even if, when it be lost altogether, you still find in the wasted limb some flickering contraction as you apply the battery current, you may confidently expect a cure or a notable improvement, although the wasting and the paralysis may be highly marked, and although they may have existed for many years, provided that you will persevere steadily in directing the course of treatment that I have described.

Even at the very onset of the malady you may form some notion of its probable severity by regarding the intensity of the initial fever: and you may, when the paralysis is passing into its period of localisation, ascertain by an electric examination the direction in which the malady will throw its strongest forces. Thus taught, you may often prevent the occurrence or full development of symptoms which are very obstinate when once established, and may relieve your patient, by the treatment of a few weeks, from that which, if once firmly rooted, may require twice as many months to cure.Lancet, July 11, 1868, p. 35.

14.-ON COMPRESSION OF THE BRAIN.

By JONATHAN HUTCHINSON, Esq.

[The symptoms given by most writers as those indicative of compression of the brain may much mislead us in practice. This is especially so in cases of injury to the head, in which if we rely upon them we are liable to overlook compression in nine out of ten cases in which it is present.]

We must include under the term "symptoms of compression," all phenomena which are due to the squeezing of the contents of the cranium. Now it is clear that there must be various degrees of it, and my first objection to the above description is, that if it applies at all, it applies only to the more advanced ones. Yet it is clear that one whose cranial cavity has been encroached upon to the extent of but one ounce, from effused blood, secreted pus, or depressed bone, must have his brain and its normal fluids (blood and cerebro-spinal serum) correspondingly compressed and diminished in volume; and that one in whom the encroachment amounts to two ounces ought to have double the inconvenience and so on, until the continuance of the functions of life is no longer possible. Writers ought, therefore, to be able to assign the symptoms of slight compression of the brain as well as those of the advanced degrees, for it may be that treatment is more important in early stages than

in later ones.

Another distinction which we ought to make, is between general compression, or squeezing of the whole cerebral mass, and local compression of some one part. We must also think. in cases in which foreign materials are intruded into the cranial cavity, of the effects likely to be produced by stretching as well as by squeezing. In many positions, pressure upon one part would inevitably cause stretching of others, such as nerve-trunks, or commissural bands. Lastly, we must remember that compression induced suddenly is a very different thing from compression taking place by slow degrees. If the increase in the quantity of intruding material be very slow, we well know that, unless some special nerve-trunks chance to be involved, no symptoms will be produced, even when the amount is very considerable.

Speaking generally, the effect of the effusion of new material, e. g. blood, into the cranium, will probably be first to eject a corresponding quantity of normal fluid in order to make room. Thus, the quantity of cerebro-spinal fluid will diminish, and also the quantity of circulating blood, and the capillary circulation will be diminished. The venous circulation will be retarded, but probably the whole quantity of venous blood will not diminish nearly so early nor so much as that in the arteries. Many of the venous sinuses are protected from pressure, and the effect of pressure at the exit of a sinus from the skull would be just the opposite to that upon an artery-it would keep the blood in the vein, whilst it would keep it out of the artery. We may suitably remember the phenomena of glaucoma, as illustrating the effects of pressure on arteries and veins. It is, I think, perfectly clear that a squeezed brain must be, quoad the supply of arterial blood, an anæmic brain.

The degree of pallor will vary with the degree of compression. We have to ask next as to the conditions of local and of general compression. All forms of compression taking place suddenly, will, for a time, be chiefly felt locally, and will have th al symptom of local lesion, namely, a local

paralysis or paresis. The portion of brain close to the compressing cause will be displaced and squeezed. After a little time, however, the adjacent portions of brain will yield, so as to accommodate the displaced portion, and the compression will become diffused and comparatively slight; so slight that its symptoms may wholly disappear. Only in certain positions, as for instance, of the cerebellum beneath the strong tentorium, is it possible that local pressure can continue permanently without becoming diffused. Pressure on any part of either hemisphere of the cerebrum will certainly, after a while, influence the other also. Clinical experience amply verifies this inference. I must again remind you that we must observe the distinction between mere pressure and stretching, and also between pressure upon nerve-trunks and pressure upon the central masses. In the case to which I have referred in the foot-note, the pupil of one eye became dilated and fixed, but this was clearly due to the local pressure of the blood-clot upon the trunk of the third nerve at the sphenoidal fissure. If blood be freely effused at the base of the brain, as from rupture of the basilar artery, it will lift the medulla and pons away from the bone, and by stretching the fibrils of the pneumogastric, speedily cause death without producing any general compression.

Examples of unmixed compression of the brain are very rarely met with. In the great majority of cases the injury is complicated, both by severe concussion and by laceration of the brain, and a mixed group of symptoms is the result. In the description which I have quoted, it is said the phenomena of compression are those of apoplexy." Surely, however, the symptoms of apoplexy are most varied, and are, further, but rarely due to compression. In ordinary apoplexy some portion of the brain mass, often the thalamus or corpus striatum, is ploughed up by the extravasated blood, and the resulting hemiplegia is due to the laceration rather than to the effusion as a means of compression. Just so in the numerous cases in which injuries to the head are productive of laceration of the brain, and its concomitant extravasation into the arachnoid sac. My belief is, that in all these cases, the laceration is the far more important agent as regards the symptoms which follow. This is, I admit, difficult of proof, but I shall adduce cases showing, on the one hand, that severe lacerations, under conditions in which compression is impossible, are still attended by the symptoms referred to, and that, on the other hand, effusions of blood without laceration, if not of very great extent, cause no appreciable disturbance. Amongst the causes by which compression of the brain may be produced, we must mention 1st, extravasations of blood, (a) between the dura mater and bone, (b) into the arachnoid sac, (c) into the cerebral substance; 2nd, inflammatory effusions,-whether serum or pus, into any of the three situations just mentioned; 3rd, the growth of tumours; 4th, the depression of large portions of bone.

Respecting the last of these I would venture to assert that it is very rarely indeed the cause of symptoms. The portion of bone depressed must be very large indeed, which could cause symptoms of compression. In ordinary cases the extent to which the cranial cavity is diminished by a depressed fracture is very trivial, as any one may convince himself who has opportunities for examining such skulls from within before the fragments of bone or the dura mater have been disturbed. In all the cases of extensive depression which I have seen, the so-called symptoms of compression were wholly absent. Cases of severe fracture with depression are almost always attended by laceration as well, and the symptoms of the latter lesion have, I feel convinced, been often mistaken for those of compression.

[Here follows a series of most interesting cases, to which are appended the following concluding remarks]:

You will have gathered from the cases which we have narrated that the diagnosis of compression is full of difficulty. On the one hand, compression is frequently suspected when it is not present, and on the other, it is sometimes overlooked when really there. In surgical practice we have to be prepared for it under several different conditions, to say nothing, for the present, of certain others, perhaps more common, which chiefly concern the physician. First, we have the cases in which it comes on from effusion

of blood between the dura mater and bone, after injury to the head; second, those in which it results from extravasation into the arachnoid sac; third, those from abscess between the dura mater and bone; and fourth, those from inflammatory effusions within the arachnoid or into the brain substance.

I will take these seriatim; and first, those from Effusion of blood between bone and dura mater. These are especially important, because generally supposed to be capable of relief by treatment. Yet it is a remarkable fact that the modern annals of surgery do not, as far as I am aware, contain any cases in which life has been saved by trephining for this state of things. I suppose the fact is, that death usually occurs too quickly and too suddenly to permit either of diagnosis or treatment. The symptoms of compression are not present at first; the patient is merely confused, as if from slight concussion, and when more urgent conditions supervene, he dies very quickly. The symptoms preceding death are not, as we have seen in several very definite cases, those which have formerly been held to denote compression. The patient, it is true, becomes insensible; but he is pale, with dilated pupils, a rapid, feeble pulse, and irregular respiration. The "stertor" is only present at times, the countenance is not "bloated," and the pulse is far from "laboured." As for the relaxation of sphincters, &c., there is no time for such symptoms to show themselves, for the patient will probably be dead in an hour. Sometimes the condition comes on, as it were, by two steps, there being two separate effusions of blood. The first makes the patient heavy and stupid, and, it may be, causes a temporary and incomplete hemiplegia, the second kills him quickly. The more carefully we study this group of cases, the higher value shall we be inclined to put upon the previous history of the case as a means of diagnosis, and the less shall we rely on the symptoms. The importance of an interval of immunity between the accident and the occurrence of symptoms has been long recognised as the chief indication of a ruptured meningeal artery; and it is to this, almost exclusively, that we must still give attention, if we wish to diagnose these cases. Unfortunately, it is not always that we can get correct statements as to the early symptoms; but whenever there is clear testimony as to complete immunity at first, and the symptoms have come on suddenly, and at too early a period for the development of inflammation, then we may, with tolerable confidence, infer the existence of hemorrhage. The period at which the hemorrhage occurs may vary in these cases, just as it may after wound of an artery in one of the limbs. It is rarely profuse enough at first to cause symptoms. It may increase in the course of a few hours, or it may burst out suddenly, as a sort of secondary hemorrhage, at the end of one or two days afterwards. In rare instances it may even be delayed for a week, just as a wounded artery at the wrist may bleed after a similar interval. When it is sufficient in amount to squeeze the blood out of the vessels of the compressed brain, then symptoms will occur such as we have described in detail in several cases.

Our inferences as to the side on which the blood-clot lies will be helped by observation of the hemiplegia (if it have been present), by the dilatation of one pupil, and the examination of the scalp. The hemiplegia will be on the opposite side; a fixed dilated pupil will, I think, generally be present on the same side, and a puffy swelling in the scalp will often be found directly over the fracture.

Even if a case of this kind have been recognised in time for an operation, our embarrassment does not end here. It is very likely that difficulty might occur in finding and securing the injured part of the vessel, whilst, also, the removal of a blood-clot from the sphenoidal fossa (its usual position) might be no easy matter.

The second group of cases-those in which the blood is under the dura mater-may, in rare instances, resemble in every feature those just described. If a large superficial vessel have been injured, it is possible that an interval may occur, and then a large clot be poured out. More usually, however, these cases are complicated by laceration of the brain, and the symptoms of severe concussion are present from the first. The bleeding

usually takes place, not from one large vessel, but from many small ones, and hence it is poured out with much less of compressive force, and ceases much short of the results which a ruptured middle meningeal can produce. The patient may therefore live much longer, remaining throughout insensible, and with the stertor, laboured pulse, and flushed face formerly held to be universal in compression. The marked inequality in size of pupils, which we have noted in the subcranial cases, will rarely be present, nor will hemiplegia usually be marked.

Our third group is a very important one, because, although rare, it is one in which a correct diagnosis would probably lead to a method of treatment which would save the patient's life. We may encounter large collections of pus between the dura mater and cranium, either as the consequence of chronic caries (syphilitic), or of injury ("Potts' puffy tumour" cases). When it occurs slowly, intense pain, gradually increasing in spite of treatment, wearing the patient out by loss of rest, but unattended by paralysis of any kind, will probably be the chief symptom. The increase of effusion will be slow, and the brain will accommodate itself to the pressure. It is possible, however, that special nerve-trunks may be compressed or stretched. Towards the end of the case the patient-emaciated, exsanguined, and reduced to the last degree of weakness-will probably become comatose, the coma being possibly ushered in by convulsions. The cases of abscess between the dura mater and bone, consequent on fracture or contusion of the skull, will be exceedingly difficult to distinguish from those of arachnitis. Arachnitis is infinitely the more common result of such injuries; and you are aware that I have recently asserted and, I think, proved, that hemiplegia is its usual symptom. In these cases there is almost always a little lymph or pus between the bone and membrane, but no collection which you could let out by trephining. If you adopt the rule of trephining in all cases in which, after bruise or fracture of the skull, the patient has become hemiplegic or comatose, with inflammatory symptoms, you will operate in twenty cases of arachnitis for one in which you will find any considerable collection external to the dura mater. Nor is it, as far as I can see, possible to assign any symptoms which will materially help in the differential diagnosis. The more definite the hemiplegia may have been, and the longer the time during which it has preceded the coma, the less likely is it that there is pressure, and the more probable is the diagnosis of arachnitis. If the patient have had rigors of a definite character, the diagnosis of osteitis, thrombosis, and pyæmia may be given, and whatever the position of the inflammatory effusion, your operation will be bootless.

If the diagnosis of compression from abscess between bone and membranes, after injury to the skull, be difficult, that of compression from arachnoid effusion, or from abscess in the brain, is yet more so. Indeed, if it be true (as I believe) that the contact of inflammatory secretions with the surface of the hemisphere, without mechanical compression, may induce hemiplegia, it is clearly impossible to tell whether the latter condition is superadded or not. Nor is this diagnosis of much importance in practice. The symptoms which result from abscess in the substance of the brain vary so much in different cases, that it is impossible to be precise in regard to them. Incomplete hemiplegia of the opposite limbs, with attacks of spasms, with headache, and later on, tendency to coma, are probably the chief. Should these symptoms follow a known punctured wound of the brain, trephining and perforation of the membranes and brain may be justifiable.

You will have noticed that I have said nothing as to depressed bone as a cause of compression. I have omitted it, because really I have nothing clinical to tell you about it. I have never seen a case in which there seemed definite reason to think that depression produced symptoms. Where the depression is very great, and the fragment very large, it is possible that symptoms may be caused, but I have not myself seen a well-marked case. That our common cases of depressed fracture should be attended with symptoms of compression it is absurd to expect. The fragments rarely intrude into the cranial cavity sufficiently to displace more than a few