HYDROCEPHALUS (hudor [Gk.], water, kephale [Gk.], the head), a term in medicine applied to two different forms of disease of the brain, both of which are attended with the effusion of fluid into its cavities. They are named respectively Acute and Chronic Hydrocephalus. They have different pathological associations, and have no necessary connexion with each other.
Acute Hydrocephalus is the term still largely employed to describe the disease now known to physicians as tuber-cular cerebral meuingitis, that is, inflammation of the membranes of the brain produced by the presence of tubercle., This disease is most common in children under ten years of age, but is by no means limited to that period of life, and may affect adults. The scrofulous or tubercular constitution is an important factor in this malady, which is admitted to be one of strongly hereditary tendency; yet unquestionably there are many instances in which no such taint can be traced. In numerous cases it is manifestly connected with bad hygienic conditions, with insufficient or improper feeding, or with over exercise of the mental powers, all of which will doubtless more readily exert their influence where an inherited liability exists, and the same may be said regarding its occasional occurrence as one of the after consequences of certain of the diseases of childhood, especially measles and hooping-cough.
Acute hydrocephalus is usually described as passing through certain stages ; but it must be observed, as regards at least its earlier manifestations, that, so far from being well defined, they are often exceedingly vague, and render this disease in an especial manner liable to escape detection for a length of time, or to be confounded with others to which at its commencement it bears an acknowledged resemblance, such, for instance, as typhoid fever or gastro-intestinal derangements. Nevertheless, there are certain typical features characterizing the disease in each of its stages which it is important to describe, as in many instances these present themselves with greater or less distinctness.
The premonitory symptoms of acute hydrocephalus are mostly such as relate to the general nutrition. A falling off in flesh and failure of strength are often observed for a considerable time before the characteristic phenomena of the disease appear. The patient, if a child, becomes listless and easily fatigued, loses appetite, and is restless at night. There is headache after exertion, and the temper often undergoes a marked change, the child becoming unusually peevish and irritable. These symptoms may persist dur-ing many weeks; but on the other hand such premonitory indications may be entirely wanting, and the disease be developed to all appearance quite suddenly.
The onset is in most instances marked by the occurrence of vomiting, often severe, but sometimes only slight, and there is in general obstinate constipation. In not a few cases the first symptoms are convulsions, which, however, may in this early stage subside, and remain absent, or reappear at a later period. Headache is one of the most constant of the earlier symptoms, and is generally intense and accompanied with sharper paroxysms, which cause the patient to scream, with, a peculiar and characteristic cry. There is great intolerance of light and sound, and general nervous sensitiveness. Fever is present to a greater or less extent, the temperature ranging from 100° to 103° Fahr.; yet the pulse is not quickened in proportion, being on the contrary rather slow, but exhibiting a tendency to irregularity, and liable to become rapid on slight exertion. The breathing, too, is somewhat irregular. Symptoms of this character, constituting the stage of excitement, continue for a period varying from one to two weeks, when they are succeeded by the stage of depression. There is now a marked change in the symptoms, which is apt to lead to the belief that a favourable turn has taken place. The patient becomes quieter and inclines to sleep, but it will be found on careful watching that this quietness is but a condition of apathy or partial stupor into which the child has sunk. The vomiting has now ceased, and there is less fever; the pulse is slower, and shows a still greater tendency to irregularity than before, while the breathing is of markedly unequal character, being rapid and shallow at one time, and long drawn out and sinking away at another. There is manifestly little suffering, although the peculiar cry may still be uttered, and the patient lies prostrate, occasionally rolling the head uneasily upon the pillow, or picking at the bedclothes or at his face with his fingers. He does not ask for food, but readily swallows what is offered. The countenance is pale, but is apt to flush up suddenly for a time. The eyes present important altera-tions, the pupils being dilated or unequal, and scarcely responding to light. There may be double vision, or partial or complete blindness. Squinting is common in this stage, and there may also be drooping of an eyelid, due to paralysis of the part, and one or more limbs may be likewise paralysed.
To this succeeds the third or final stage, in which certain of the former symptoms recur, while others become intensi-fied. There is generally a return of the fever, the tem-perature rising sometimes to a very high degree. The pulse becomes feeble, rapid, and exceedingly irregular, as is also the case with the breathing. Coma is profound, but yet the patient may still be got to swallow nourish-ment, though not so readily as before. Convulsions are apt to occur, while paralysis, more or less extensive, affects portions of the body or groups of muscles. The pupils are now widely dilated, and there is generally complete blind-ness and often deafness. In this condition the patient's strength undergoes rapid decline, and the body becomes markedly emaciated. Death takes place either suddenly in a fit, or more gradually from exhaustion. Shortly before the fatal event it is not uncommon for the patient, who, it may be for many days previously, lay in a state of profound stupor, to awake up, ask for food, and talk to those around. But tho hopes which may thus be raised are quickly dispelled by the setting in of the symptoms of rapid sinking.
The duration of a case of acute hydrocephalus varies somewhat, but in general death takes place within three weeks from the onset of the symptoms, The disease may be said to be almost invariably fatal, yet it must be admitted that cases presenting all the principal symptoms of acute hydrocephalus do occasionally recover, though such instances are undoubtedly very rare. Indeed, the condition of the brain in this disease, as revealed on post mortem examination, renders its fatal character in no way surprising. The peculiar formation called tubercle is found deposited in the membranes of the brain, more particularly at its base. The irritation set up as a consequence of this is accompanied with the effusion of fluid into the arachnoid and ventricles, which by its pressure tends to produce softening and destruction of the brain substance, and hence to abolish its functions. In many instances the brain is found to be reduced to a state of complete disorganization.
Besides this condition of the brain, there exists in most cases deposition of tubercle elsewhere, as in the lungs and abdominal glands, and this may have given evidence of its presence even before the head symptoms had appeared. This is especially the case in adults, in whom acute hydro-cephalus is more apt to arise as a complication in the course of pulmonary or other disease of tubercular origin than in the manner in which it occurs in children as above described.
With respect to treatment, little can be stated of an encouraging nature. Still it must be observed that much may be done in the way of prevention of this disease, and, in its earlier stages, even in the way of cure. It is most important in families where the history indicates a tuberculous or scrofulous tendency, and particularly where acute hydrocephalus has already occurred, that every effort should be used to fortify the system and avoid the causes already alluded to as favouring the development of the disease during that period in which children are liable to suffer from it, With this view wholesome food, warm clothing, cleanliness, regularity, and the avoidance of overexertion, physical and mental, are of the utmost conse-quence.
Although there is but little that can be done when the disease has set in, yet the timely use of remedies may mitigate and even occasionally remove the symptoms. The severe headache may often be relieved by the applica-tion of one or two leeches to the temples, and by the frequent use of cold water or ice applied to the head. The treat-ment by blistering the scalp and administering mercury, formerly so much practised, is now acknowledged to be of no real efficacy ; and on the whole the maintenance of the patient's strength by light nourishment and the use of sedatives to compose the nervous system are the measures most likely to be attended with success. The bromide, with which may be combined the iodide of potassium, is the medicinal agent of most value for this purpose. Should convulsions occur, they are best treated by chloral or chloroform.
Chronic Hydrocephalus is a different form of disease from that last described, both as regards its pathology and its effects. It consists in an effusion of fluid into the serous cavities (arachnoid and ventricles) of the brain, not preceded by tuberculous deposit or acute inflammation, but apparently depending on chronic inflammatory changes affecting the membranes, and is to be regarded as a kind of dropsy. The disease is frequently congenital, and its presence in the foetus is apt to be a source of difficulty in parturition, It is, however, more commonly developed in the course of the first six months of life ; but it occasionally arises in older children, or even in adults, as in the well-known instance of Dean Swift, who died from this disease.
Chronic hydrocephalus affects mostly children who bear evidence of a scrofulous, ricketty, or otherwise delicate constitution. The chief symptoms observed are the gradual increase in size of the upper part of the head out of all proportion to tho face or the rest of the body. Occurring at an age when as yet the separate bones con-stituting the skull have not become welded, this enlarge-ment may go on to a very considerable extent in all direc-tions, but chiefly in the transverse and antero-posterior diameters, the spaces between the bone3 becoming more and more expanded, though ultimately, should the child survive, ossification takes place. In a well-marked case the deformity is very striking. The upper part of the forehead projects abnormally, and the orbital plates of the frontal bone being inclined forwards give a downward direction to the eyes, which have also peculiar rolling movements. The face is small, and this, with the enlarged head, gives a remarkably aged expression to the child. There is generally defective development in other respects, the body being ill nourished, the bones thin, the hair scanty and fine, and the teeth carious or absent.
As illustrating the extent to which this disease may proceed, it may be mentioned that the average circum-ference of the adult head is about 22 inches, while in the child it is of course considerably less. In chronic hydro-cephalus the head of an infant three months old has been known to measure 29 inches; and in the well-known case of the man Cardinal, who died in Guy's Hospital, the head measured 33 inches. In the museum of the faculty of medicine in Paris there is a hydrocephalic skull measur-ing 39 inches. In aggravated cases the head cannot be supported by the neck, and the patient has to keep in the recumbent posture. The expansibility of the skull pre-vents destructive pressure on the brain, yet this organ is materially affected by the presence of the fluid. The cerebral ventricles are widely distended, and the convolu-tions flattened, while occasionally the fluid escapes into the cavity of the cranium, which it fills, pressing down the brain to the base of the skull. As a consequence of such changes, the functions of the brain are interfered with, and in general the mental condition of the patient is impaired to a greater or less extent. The child is dull and listless, irritable, and sometimes imbecile. The special senses become affected as the disease advances, especially vision, and sight is often lost, as is also hearing. Towards the close paralysis is apt to occur. Hydrocephalic children rarely live long, generally dying from the malady in a few year3, or succumbing to some of the disorders of childhood, which they are little able to resist. Nevertheless there have been many instances of persons with this disease reaching maturity, and even living to old age. It must also be borne in mind that there are grades of this affection, and that children may present many of the symptoms of it in a comparatively slight degree, aud yet recover, the head ceasing to expand, and becoming firmly ossified.
Various methods of treatment have been employed in this disease, but the results are seldom satisfactory. Compression of the head by bandages, and the administration of mercury with the view of promoting absorption of the fluid, are now little resorted to. Tapping the fluid from time to time through one of the spaces between the bones, drawing off a little, and thereafter employing gentle pressure, has been tried, but seldom with permanent
benefit. On the whole, the plan of treatment which aims at maintaining the patient's nutrition by appropriate food and tonics, is at once the most rational and successful, provided it be resorted to in time to admit of the arrest of the progress of the symptoms. (J. o. A.)