Hydrocephalus. Under this term, which literally means 'water in the head,' are included three distinct diseases—viz. acute hydrocephalus, chronic hydrocephalus, and spurious hydrocephalus, or, as Dr Marshall Hall termed it, hydrocephaloid disease.
Acute Hydrocephalus, or, as it is now generally and more satisfactorily termed, tubercular meningitis, is essentially an inflammation of the membranes of the brain due to the presence of Tubercles (q.v.). The occurrence of fluid within the skull or the brain, though frequent, is merely a secondary and subordinate phenomenon. It is an extremely fatal form of disease, common in childhood, much less so during adult life. The symptoms are very variable and perplexing, so that only the barest outline of the most frequent and important can be attempted here. There is usually a premonitory period of some days or weeks, during which the appetite and digestion are disturbed, the disposition is altered either in the direction of listlessness or irritability, the strength impaired, and the body becomes slightly thinner. The first distinct symptom of the disease is usually severe headache, with sickness and feverishness; the pulse is rapid and the temperature raised, but variable. Vomiting very often occurs at this stage, and sometimes a peculiar cry at intervals, which if present is very characteristic.
In this first stage of hydrocephalus, which most commonly lasts two or three days, the symptoms generally are those of excitement. In the second stage the pulse becomes irregular, variable, and often slow. General heaviness and stupor come on. The light, which annoyed the child in the first stage, is no longer a source of annoyance; the pupils become dilated, the power of sight is imperfect or lost, and squinting is almost always to be observed. The little patient now lies on his back in a drowsy condition; and at this period spasmodic twitchings, convulsions, or paralysis may appear. The excretions are passed unconsciously. The second stage may last a week or two, and is often attended by deceptive appearances of amendment, the child not unfrequently regaining the use of its senses for a day or two, but then relapsing into a deeper stupor than before. The symptoms in the third or last stage, which may last only a few hours or may extend to a fortnight, are very similar to those in the second, except that the pulse again becomes very rapid, beating sometimes so quickly that it can scarcely be counted, and gradually gets more and more weak till the patient expires. The characteristic appearances after death are the presence of tubercles in the membranes of the brain, usually near the base, and generally more or less softening of the central part of the brain, with the effusion of serous fluid into the ventricles.
It must not be supposed that the stages described above can be observed in every case. There is, in fact, hardly any disease whose course is so variable and so apt to mislead those observing it. In its earlier stages its recognition is sometimes almost impossible; yet it is only then that any treatment can be expected to be successful. Cold applied to the head, leeching, and purgation sometimes appear to do good; but in the vast majority of cases the disease proves rapidly fatal. Recovery has been proved to take place only in some few exceptional instances.
Chronic Hydrocephalus is a perfectly distinct disease from that just described; while the latter is an inflammation, the former is a dropsy. In chronic hydrocephalus a watery fluid collects within the skull, before the bones have united to form the solid brain-case, and by pressure outwards causes them to separate, and increases the size of the head sometimes to an enormous extent. Thus Dr David Monro relates the case of a girl six years old whose head measured 2 feet 4 inches in circumference. While the skull is rapidly enlarging, the bones of the face grow no faster than usual, and the great disproportion of size between the head and the face is at once diagnostic of the disease. This disorder sometimes commences before birth, and almost always in early childhood, before the fontanelles and sutures of the skull have closed. In some rare cases it has occurred later, as, for example, at seven or nine years old, and the closed sutures have opened under the augmenting pressure. When the sutures will not yield, death from pressure on the brain speedily ensues. Most children with chronic hydrocephalus either recover or die in infancy; but a few survive, bearing their complaint to adult life, or even to old age. Blindness, deafness, palsy, and idiocy—one or more—are commonly associated with this disease, but occasionally the intellect and senses are sufficiently perfect for the ordinary requirements of social life.
The results of treatment are generally not encouraging, though sometimes benefit appears to result. It may be attempted by internal remedies or by surgical appliances. The medical treatment most in favour consists in the administration of diuretics, purgatives, and especially mercury, which may be given in the form of calomel in minute doses, and applied as ointment externally. The surgical expedients are bandaging and puncturing the head. The latter has in many cases certainly prolonged life, although the disease has finally conquered. Neither of these means is applicable after the bones of the skull have united.
This disease occasionally occurs in adult or in advanced life, after enlargement of the head has become impossible. Stupor, paralysis, and an inability or unwillingness to speak are in these cases the most prominent symptoms. Dean Swift's death was due to this disease, and it is recorded that during the last three years of his life he remained in a state of silence, with few and slight exceptions.
Spurious Hydrocephalus resembles acute hydrocephalus in many of its symptoms, and has often been mistaken for it. Instead, however, of being an inflammatory disease it is a disease of debility, and is due to a deficient supply of blood to the brain. The following are, according to Watson, the distinctive characters of this spurious hydrocephalus: the pale, cool cheek; the half-shut, regardless eye; the insensible pupil; the interrupted, sighing respiration; and the state of the unclosed fontanelle. If the symptoms are those of acute hydrocephalus the surface of the fontanelle will be convex and prominent; while if they are due to spurious hydrocephalus, and originate in emptiness and want of support, the fontanelle will be concave and depressed. The remedies in this disease, which readily yields to treatment, are nourishing diet, small doses of wine or even of brandy in arrowroot, decoction of bark, ammonia, &c.