When pronounced. the characters of the disease are auite un mistakable. There is pain of the head and restlessness, followed by quick, hard pulse, hot and dry skin, white tongue, heat of head, and flushing of face ; the eyes are red and ferrety, and the pupils contracted ; there is intolerance of light, and perhaps of noise ; there are rigors, nausea, vomiting, and constipation, fol lowed by convulsions, delirium, coma. Delirium, strange to say, is often absent, or only slight and transient, until a semi-comatose state follows on convulsion; at other times it is and maniacal.
Pain is a very constant symptom, and is generally referred to the forehead, but it may prove a very fallacious guide; intense headaches find their solution very often in simple gastric disorder : the pain of inflammation is sharp and darting, rather than aching, and when associated with intolerance of light and of head, flushing of face, pulsation in the branches of the external carotid, noise, we may be sure that it is something more than mere headache. Heat showing increased action there, lead to the belief that there is corresponding increased action of the internal carotid, caused by inflammation within the cranium.
The nausea and vomiting are sometimes very striking ; the smallest portion of food or drink being rejected, and sickness continuing even when nothing is taken into the stomach. That this is not caused by gastric inflammation is proved by the absence of pain and tenderness at the epigastrium: when accompanied, as it often is, by constipation, we have to bear in mind that this condition may of itself cause sickness and great cerebral disturbance in cases in which there is no inflammation present. The diagnostic value of such symptoms must, therefore, in the first instance, depend on their being asso ciated with others more distinctly referable to the brain itself; their persist ence after the action of a brisk purgative, or obstinate slowness of the bowels, in persons not habitually costive. are not to be lightly passed over.
Rigor rarely accompanies the onset of the disease ; it afterwards occurs frequently in its progress, and may assume such a character of periodicity as to resemble intermittent fever, and lull -the medical attendant into fatal se curity.
Convulsions appear at very various periods : in yoang persons they sometimes usher in the attack, while in adults they are more generally delayed till the closing scene ; whensoever they exist they are an important, and, at the same time, an alarming sign. The distinction between these and the true epileptic seizure will be afterwards pointed out (see 5). The symptoms of disease do not remit, after the convulsive seizure has passed, in true inflammation of the brain, as they do in epilepsy.
Various alterations in sensibility and motility succeed to the exaltation which first accbmpanied inflammatory action ; and the progress of the case may be marked by spasm or loss of power ; these indicate changes in cerebral structure, or pressure from effusion of lymph, serum, or pus, but have no direct bearing on the question of inflammation. Strabismus and double vision, it may be remarked, are generally the first in this sequence.
The presence or absence of delirium seems in great measure to depend on the portion of the encephalon attacked by inflammation. It can scarcely fail to be present if the gray matter of the hemispheres be involved, but does not necessarily imply this particular lesion. In character it very much resembles an attack of acute mania, and the distinction is sometimes not easily made out. Regard must be especially had to the relation the delirium bears to the
signs of increased action, and the order of their occurrence; maniacal excite ment necessarily produces flushing of the face and acceleration of the pulse, but to a much less degree than inflammation. Evidence may also perhaps be obtained of previoaa perversion of intellect when the disorder is linked with insanity. Constipation is common to both states, and there will be little chance of confounding the nausea and vomiting of inflammation with the refusal of food, so often manifested by the maniac. The alleged cause of the attack, whether physical or mental, may sometimes help our diagnosis, although it be quite true that a purely mental one may excite increased action and actual inflammation, as well as mania. The occurrence of convulsions along with the delirium renders the diagnosis more certain.
The extent to which these symptoms are present, and their number, must vary much in different cases. Without attempting to go too minutely into the diagnosis of the particular portion of the encephalon which is the seat of disease, it may be observed that pain, and the recurrence of rigor, seem rather referable to inflammation of the membranes of the brain generally, while convolutions point to that more immediately investing the cerebral mass—the pia mater and the lining membrane of the ventricles; delirium chiefly accompanies inflammation of the gray matter, and alterations in sensibility and power of movement have espe cial reference to lesion of the central conducting fibres uniting the brain to the spinal system. Whether it be that the exciting cause acts simultaneously on more than one structure from the first, or that inflammation in one part is readily transmissible to the adjoining textures, certain it is that we seldom find local and circumscribed inflammatory action limited to any one tissue, and the symptoms are therefore necessarily more or less ambiggous; nay more, it is even true that those belonging more especially to one form of structure may be excited by the simple proximity of inflammation in another. Nausea and vomiting are common to all the forms of inflammation; they are to be more carefully noted in consequence of their occasional occurrence as premonitory symptoms, which must be viewed with great anxiety. in persons who have been known to suffer from discharge from the ear, or to have had any other of the antecedents of cerebral disease; they are sufficient to cause us to be on the alert for the appearance of any other symptom of inflammation. Idiopathic inflammation of the membranes and particularly of the arachnoid and pia mater is much more frequent in children and young persons than in adults; in them its first symptom is commonly an attack of con vulsion; inflammation of the substance of the brain again, is the more usual form in mature age, generally combined, however, with meningitis. From this combination, no doubt, it happens that the course of the symptoms is seldom the same in any two individuals; thus, sudden alteration in manner may be observed passing at once into violent delirium, and followed by vomiting, while convulsion occurs only at a later period; or vomiting and pain of the head may be the first in the order of sequence, and delirium only follow towards the close of the scene, without any appearance of convulsion at all; or again, convulsions may be the earliest symptom, but I believe this to be the rarest mode of attack, when the substance of the brain is the seat of the inflam mation.