INFLAMMATION OF THE SINUSES OF THE DURA MATER. 119 the heart from emptying itself properly, thereby retarding the current of the blood. Neither the researches of Von Dusch, nor the observations of other writers indicate any symptoms as pathognomonic of this affection, and the only conclusion at which we can arrive with reference to it is, that when head symptoms set in suddenly in previously debilitated subjects, and do not run the course of any ordinary form of cerebral disease, such symptoms will probably be found to be due to the formation of thrombus in the sinuses. LECTURE IX. CHRONIC HYDROCEPHALUS-various conditions under which fluid collects in the skull -divided into the external and the internal-symptoms of both nearly identicalchanges in form and size of the head—and their mode of production-course of the disease termination almost always fatal. INTERNAL HYDROCEPHALUS-important questions involved in its pathology-frequent connection with malformation of brain—but also follows inflammation of lining of ventricles description of post-mortem appearances—case illustrative of its connection with inflammation-process of cure usually mere arrest of disease. EXTERNAL HYDROCEPHALUS-circumstances in which it exists-its relation to hæmorrhage into the arachnoid.—Treatment of both forms of the disease.-Importance, but difficulty, of distinguishing curable and incurable cases.—Gölis's plan.—Compression.-Puncture.-Cases suited for each mode of treatment. WE have now completed our examination of the acute inflammatory affections of the brain, and with them we may consider that we have dismissed the most important class of diseases of that organ. Before we pass, however, to those in the production of which inflammation bears no part, we must study one malady which forms a kind of connecting link between the two. Chronic Hydrocephalus, or Dropsy of the Brain, is a morbid condition met with in children at various ages, and coming on in a great variety of circumstances. Sometimes it is congenital, and is then often, though by no means invariably, associated with malformation of the brain. In subsequent childhood, an excess of blood in the brain, or its deficiency, or the existence of some impediment to the circulation through the organ, are conditions all of which have been found to give rise to the effusion of fluid into the cavities of the brain, or upon its surface. Instances of chronic hydrocephalus are on record, which have succeeded to hæmorrhage into the sac of the arachnoid; others, that have been connected with wasting of the brain, in consequence of the supply of blood being inadequate to its due nutrition, or in which obliteration of the sinuses by disease, or the pressure of a morbid growth upon some of the vessels of the brain, has interfered with the due performance of the cerebral circulation. In many cases, however, I SYMPTOMS OF CHRONIC HYDROCEPHALUS. 121 believe, as do MM. Rokitansky and Vrolik, that the disease is not a mere passive dropsy, nor simply a consequence of arrested cerebral development, but that it is the result of a slow kind of inflammation of the arachnoid, especially of that lining the ventricles, which may have existed during fœtal life, or may not have attacked the child until after its birth. I may further add that each year leads me to estimate more highly the share of inflammation of the lining of the ventricles in the production of chronic hydrocephalus. According to the situation in which the fluid collects, a division has been made of chronic hydrocephalus into the external and the internal; the former term being applied to cases in which the fluid collects in the sac of the arachnoid; the latter, to those in which it accumulates in the ventricles of the brain. The two conditions sometimes coexist, but generally they are independent of each other; the internal hydrocephalus being the more frequent and the more important; and to it we will therefore first direct our attention. The early symptoms of the disease vary. When it is congenital, indications of cerebral disturbance are generally apparent from the infant's birth. These are sometimes serious-such, for instance, as convulsions, recurring almost daily; at other times they are comparatively slight, and consist in nothing more than strabismus, or a strange rolling of the eyes, unattended by any very definite sign of affection of the brain. The size of the head generally attracts attention before long, and causes importance to be attached to symptoms which otherwise might have given rise to but little anxiety. In some instances, however, the increased size of the head is not very obvious until the child is a few weeks old, although well-marked symptoms of mischief in the brain existed from its birth. Enlargement of the head, indeed, is by no means invariably the first indication of chronic hydrocephalus. In 12 out of 45 cases, fits, returning frequently, had existed for some weeks before the head was observed to increase in size; in 6, the enlargement of the head succeeded to an attack resembling acute hydrocephalus; and in four other instances it had been preceded by some well-marked indication of cerebral disturbance. In the remaining 23 cases no distinct cerebral symptom preceded the enlargement of the head; but in almost every instance the Rokitansky, Pathologische Anatomie, vol. ii. p. 754; Vrolik, Handboek der ZiekLedundige Ontleedkunde, Amsterdam, 1840, 8vo. p. 514-537. 122 CHANGES IN THE FORM OF THE SKULL. child's health had been noticed to be failing for some time, although the cause of its illness was not apparent. In whatever way the disease begins, impairment of the process of nutrition is sure to be one among its earliest symptoms. The child may suck well, and, indeed, may seen eager for food, but it loses both flesh and strength; and often, although the head has not yet attained any disproportionate size, the child is unable to support it, either losing the power it had once possessed, or never attaining that which, with its increasing age, it ought to acquire. The bowels are usually, though not invariably, constipated. Sometimes diarrhoea comes on for a day or two; but, under either condition, the evacuations are almost always of an unhealthy character. Thus far, indeed, there is but little to distinguish the case from any other in which a young infant is imperfectly nourished; but, even though no well-marked cerebral symptom be present, occasional attacks of heat of head will be observed, attended with pulsation or tension of the anterior fontanelle, while crying and restlessness often alternate with a drowsy condition, though the child almost always sleeps ill at night. In many instances, too, the open condition of the fontanelles and sutures excites attention long before any enlargement of the head becomes perceptible. By-and-bye, however, the increased size of the head grows very manifest, and the child's physiognomy soon assumes the distinguishing features of chronic hydrocephalus. As the disease advances, the unossified sutures become wider, the fontanelles increase in size, their angles extend far into the sutures in which they terminate, while the fluid, pressing equally in all directions, tends to impart a globular shape to the receptacle in which it is contained. Some of the casts upon the table afford striking illustrations of this change in the form of the cranium, which would be still more remarkable were it not for the very unequal resistance of different parts of its parietes. The bones at the vertex of the skull are much less firmly fixed than the others, and ossification is nowhere so tardy as at the anterior fontanelle, and along the inner edges of the parietal bones. Hence it results that the great increase in the size of the head is effected by enlargement of the anterior fontanelle, and by widening of the sagittal suture. The os frontis consequently becomes pushed forwards, the parietal bones are driven backwards and outwards, and the occipital bone downwards and backwards. The displacement of the bones is very obvious in this hydrocephalic skull, but it is still more striking in the two COURSE AND TERMINATION OF THE DISEASE. 123 You notice the great pro engravings which I here show you.* minence of the forehead, and the alteration in the position of the parietal bones, which are driven backwards as well as outwards, so that the natural relations of their protuberances are altogether changed; while in this remarkable case of a man named Cardinal, who, though hydrocephalic from his infancy, lived to the age of 29 years, the occipital bone lies almost completely in a horizontal position. You will observe, too, another remarkable alteration produced by the yielding of the orbitar plates of the frontal bone, which are driven by the accumulating fluid from a horizontal into an oblique direction. Sometimes, indeed, they become nearly perpendicular, when, by contracting the orbits, they give to the eyeballs that unnatural prominence, and that peculiar downward direction, which constitute one of the most remarkable features in cases of chronic hydrocephalus. Few objects are more pitiable than a little child who is the subject of far-advanced chronic hydrocephalus. While the skin. hangs in wrinkles on its attenuated limbs, the enlarged head appears full, almost to bursting, owing to the stretching of the scalp; and the scanty growth of hair does not at all conceal the distended veins that run over its whole surface. The size of the skull, too, appears greater than it really is, since the face not only does not partake of the enlargement, but retains its infantile dimensions much longer than natural. The eyes are so displaced by the altered direction. of the orbitar plates that the white sclerotica projects below the upper lid, and the iris is more than half hidden beneath the lower. Often, too, there is a considerable degree of convergent strabismus, or a constant rolling movement of the eyeball, which the child is unable to control; or the pupil is dilated, and quite insensible to light. The symptoms of cerebral disturbance that attend the advance of the disease differ much in severity. Sometimes there is little besides a state of uneasiness and restlessness, aggravated at intervals when the head grows hot and the fontanelle becomes tense. In other cases convulsions occur very frequently, being induced by extremely slight causes, or coming on without any. In several instances I have observed spasmodic attacks of difficult breathing, attended with a crowing sound in inspiration, and those symptoms which constitute spasmodic croup, seizures of which sometimes * Baillie's Morbid Anatomy, fasc. x. plate iii. fig. 1, and the drawing of Cardinal's skull, in Bright's Reports, vol. ii. part 2, plate xxxv. |