It is observed as one of the consequences of typhus fever, and frequently succeeds blows upon the head, after the acute cerebral symptoms so induced have subsided. This condition of vision may also be the effect of lead poison, syphilis, the effect of tabes dorsalis, arthritis, or be consequent upon great and long-continued anxiety and distress of mind, interfering with the nutrition, and causing atrophy of those portions of the brain more immediately connected with the optic nerve.

Dr. F. Hawkins, when speaking of the inflammatory affections of the brain, says: "It is well known that sympathy with the nerves of the digestive organs will give rise to various affections of vision, from the slightest dimness up to temporary amaurosis, from the occasional appearance of a luminous spot, up to that of forms and spectra which are shaped by the imagination into distinct apparitions. It is difficult, therefore, to arrive at any certain conclusion with respect to the existence of cerebral disease from the indications afforded by the organ of vision; and numerous cases of affection of the optic nerves have been considered as only sympathetic, which, in fact, were symptoms of disease acting at once on the origin of those nerves of the brain. A gentleman came to town about two years ago on discovering suddenly, with surprise and alarm, that the sight of one eye had utterly failed him. He consulted all the oculists and surgeons chiefly celebrated for the treatment of such cases, and most of them were of opinion that this partial defect of vision was purely sympathetic, and would be removed by the use of senna and blue pill, and in fact it was, to a certain extent, so removed: but as he died soon afterwards in Ireland, with the symptoms, as I have been informed, of disease of the brain, and as he inherited, and himself evinced, a tendency to cerebral disorder, which appeared to be

hereditary (his mother being at this moment afflicted with hemiplegia), I think there can be little doubt that his temporary loss of sight was a symptom, not merely, as it was supposed, of dyspepsia, but of a morbid state then existing in the brain. In a recent case of paralysis the occurrence and fatal termination of which the friends of science everywhere deplore, it appeared from the result that a singular affection of the optic nerves which had previously been attributed to derangement of the stomach, indicated with too much truth the existence of irritation or pressure, affecting the organ of one of those nerves.'

In the early stages of cerebral amaurosis, termed amblyopia, or incomplete amaurosis, the patient complains of his vision becoming gradually indistinct, objects appearing either lighted up by a bright flame, or surrounded by a fog or mist. These symptoms are somewhat analogous to those described by Romberg as symptomatic of gutta serena.

"The outlines of objects," says Romberg, "appear not only indistinct, but also broken, and thus disfigured. The light of the candle appears rent; while reading, the patient misses single syllables, words, and lines, and he is forced to follow them by moving his eye, head, or entire body. At times, the upper or lower, the right or left half, the circumference or centre of the object only is seen; at others the loss of vision is still more partial, and is confined to different spots of small extent, and with differently shaped outlines. Instances also occur in which the object is only seen when it bears a definite relation to the eye, and it vanishes on the slightest movement of the eye or head."

Let me consider briefly some of the more characteristic symptoms of centric cerebral amaurosis connected with

* "Croomian Lectures on the Inflammatory Affections of the Brain," by F. Hawkins, M.D.

organic diseases of the brain, and disturbances of the cerebral circulation. The ordinary premonitory or associated symptoms, by means of which we may be facilitated in our diagnosis of cerebral from sympathetic conditions of morbid vision are as follow:-*

In all cases of centric cerebral amaurosis, the patient complains of vertigo and headache. The cephalalgia is sometimes acute in character, but occasionally of so mild a type as altogether to escape observation. The headache is associated occasionally with sympathetic affections of the other organs of sense, such as the hearing, smelling, &c. The mind in many cases also exhibits symptoms of disorder. The patient complains at times of great depression of spirits, is occasionally suicidal, and frequently troubled with hallucinations.

The cephalalgia of centric cerebral amaurosis is, according to the experience of all authorities, not generally of a permanent and stationary kind; it occasionally entirely disappears, but is extremely liable to recur in violent paroxysms. "The remissions," says Dr. Copland," from this severe suffering are often so remarkable as to lead a superficial observer to the belief, that it is merely periodical headache connected with dyspepsia." The character of the headache differs remarkably in various cases. Sometimes it is acute and lancinating; in other instances it is oppressive and obtuse. The pain is frequently referred to a particular spot. During the severe paroxysms, the headache is aggravated to perfect torture by the slightest motion, is greatly increased by mental

Mr. Jabez Hogg has called professional attention to an extremely ingenious instrument, termed the "Ophthalmoscope," by means of which the more obscure diseases of the eye are easily detected, and diagnosed. This discovery will effectually aid the physician in distinguishing cerebral from those amaurotic affections, the effect of organic changes in the delicate structure of the eye itself.-(Vide Mr. Hogg "On the Use of the Ophthalmoscope in the Exploration of Internal Diseases of the Eye." London, 1859.)

† Med. Dict.

application, aggravated when the patient stoops, and becomes acute under the influence of stimulants.

Dyspeptic symptoms, often accompanying a pain and sickness of the stomach, occur occasionally during the severer paroxysms of cephalalgia. When alluding to these symptoms, Dr. Abercrombie observes, "after some continuance of fixed headache, the organs of sense become affected, as the sight, the hearing, the taste, and smell, and occasionally the intellect." The loss of sight generally takes place gradually, being first obscured, and, after some time, entirely lost.

Double vision soon supervenes. This condition may either be permanent or occur at intervals. A remarkable case is on record in which blindness took place rather suddenly, and, after it had continued some time, sight was restored by an emetic. The vision was distinct for an hour, and then, alas! was permanently lost. The intellect is frequently impaired in these cases, and sometimes the speech is lost. The morbid appearances after death present no uniformity.

"In two cases there were tumours so situated as directly to compress the optic nerve; in another, a large tumour pressed upon the corpora quadrigemina; in a third, the disease was situated at the lower part of the anterior lobe; and in another, in which the right eye was affected, it was in the substance of the left hemisphere, near the posterior part. In a case by Drelincurtius, the disease was an enlargement of the pineal gland; and in another case, in which there were both blindness and deafness, a large tumour was found, situated between the brain and the cerebellum."*

Amaurosis is occasionally the effect of local pressure on the optic nerve, or on some portion of the brain in its immediate neighbourhood. This affection arises from

*"Abercrombie on Diseases of the Brain," p. 318.

organic disease of the cerebellum, as well as the cerebrum, and from lesions in parts of the brain remote from the origin of the nerves of sight. The impairment of vision is often the consequence of white softening, abscess, and atrophy of the brain and other conditions of the tissue connected with disordered states of nutrition. This disorder, however, is not necessarily the effect of congestion, or organic alterations in the optic nerve or thalamus. Andral relates the particulars of several instances of disease of the cerebellum, accompanied by a complete loss of vision. This distinguished pathologist, when referring to these cases, says, "I am unable to account for the phenomenon. In two out of twelve cases of softening of the cerebellar lobes, blindness existed on the side of the body opposite the lesion."*

The organic diseases within the cranium, which occasionally produce amaurosis, are such as result from inflammation, softening (acute and chronic) serous effusion, induration, abscesses of various kinds, tumours, tuberculous formations, adipose tumours, flesh-like tumours, tumours of a fibro-cartilaginous nature, bony and calcareous concretions, hygromatous tumours, cysts containing a serous or albuminous fluid, hydatids, fungus hæmatodes, melanosis, hæmatomatous tumours, disease of the blood-vessels, aneurismal tumours, thickening of the membranes, depositions of matter between their laminæ; dense tumours of a uniform whitish or ash colour, and exhibiting the appearance and properties of coagulated albumen, which are most frequently attached to the dura mater; diseases of the cranial bones, osteosa coma, exostosis, &c.

In an amaurotic boy, who was attacked by mania a short time before his death, Beer found a considerable

"Clinique Médicale." Andral.