Hemianopsia is another ocular symptom sometimes present in cases of brain tumor, as it may also be in other forms of encephalic lesion. It was present in 5 of 100 cases. Norris25 gives a full description, brought well up to the present time, of this symptom, and a discussion of the lesions upon which it depends. Seguin26 also discusses this subject. Starr27 has collected a large number of cases of lesion causing this symptom, some of which have been reproduced in our table. We will not go into any details as to the character of this symptom, referring the reader to the sources indicated. In the first case given in our table (Case 10) the hemianopsia was produced by a tumor in front of, and impinging upon, the optic chiasm; in the other four cases (Cases 40, 41, 42, and 43) the tumor was situated in the occipital lobe, and was surrounded by an area of destroyed tissue. Hemianopsia is not, strictly speaking, a symptom of brain tumor, but is likely to be present in cases occurring in certain regions of the brain. Starr's conclusions with reference to lateral homonymous hemianopsia when it is not produced by a lesion of one optic tract are that it may result from a lesion situated either (1) in the pulvinar of one optic thalamus; (2) in the posterior part of one interior capsule or its radiation backward toward the occipital lobe; (3) in the medullary portion of the occipital lobe; or (4) in the cortex of one occipital lobe. The conclusions of Seguin are only different in so far as they more closely limit the position of the lesion.
25 Vol. IV.
26 Pp. 84, 85 of present Volume.
27 Amer. Journ. Med. Sci., N. S., vol. lxxxvii., January, 1884, p. 65.
Phosphenes, or subjective sensations of light, occur in various forms—simply flashes or sheets of light, scintillations, balls of fire, etc. They are not very common as isolated phenomena, and probably are dependent in most cases upon irritation of the nerve and retina in some of the stages of neuro-retinitis. Even visual hallucinations are occasionally present, as in one of Bennett's cases of tumor of the Rolandic region.
Conjugate deviation of the eyes, with rotation of the head, a symptom of the early stages of apoplectic attacks, is also sometimes observed in brain tumor. The patient is found with both eyes turned to one side and slightly upward, as if looking over one or the other shoulder, the head and neck being usually rotated in the same direction. Sometimes the deviation is slight, sometimes it is marked. Frequently the muscles of the neck on one side are rigid. The eyes are commonly motionless, but occasionally exhibit oscillations. This sign, well known to neurologists, usually disappears in cases of apoplexy in a few hours or days, although it occasionally persists for a long time. It will be more fully considered under Local Diagnosis.
Diminution or loss of hearing, tinnitus, and hyperæsthesia of hearing are all occasionally observed. The most decided disturbances of this sense are those which are found in connection with tumors of the base or of the cerebellum in such a position as to involve the auditory nerve or auditory tracts. Tinnitus, acoustic hyperæsthesia, with complete or partial deafness, accompanying facial paralysis, with or without paresis of the limbs of the opposite side, indicate clearly a tumor of the base so situated as to involve the superficial origin or intracranial course of the auditory and facial nerves.
The sense of smell is affected, of course, when the olfactory bulbs are involved in the growth, either directly or by pressure, as in certain tumors of the antero-frontal region (Cases 4 and 8). Disturbances in the power of consciously perceiving odors, or abnormal perceptions of odors or hallucinations of smell, are sometimes present in cerebral tumors involving certain convolutions. The lower postero-parietal region or the temporo-sphenoidal region of the base would seem, from the few reported cases, to be implicated when this sense is centrally affected. Smell was lost or impaired in two cases of tumors of the postero-parietal region, in one limited to the supramarginal convolutions. In a case reported by Allan McLane Hamilton (Case 47), an induration of the lower part of the right temporo-sphenoidal lobe involving the uncinate gyrus, the patient, preceding light epileptic attacks, always had an olfactory aura of a peculiar character—a disagreeable odor, sometimes of smoke and sometimes of a fetid character. In this case the olfactory nerves were examined and found to be healthy.
Taste may be involved in several ways. In the first place, subjective sensations of taste, particularly the so-called metallic taste, may be present when the growths involve the cranial nerves in such a way as to cause irritation to be conveyed to the nucleus of the hypoglossal. When it is remembered that a mild galvanic current applied to the nape of the neck or face will often cause this metallic taste, it can be seen that the irritation of a tumor situated at almost any point of the base might lead to abnormal taste-phenomena. Neoplasms involving the trunk of the portio dura may of course cause diminution or loss of taste on the anterior extremity of the tongue by the involvement of the chorda tympani nerve. In the very few cases in which the hypoglossal trunk may be involved disturbances of taste posteriorly may occur. In two cases (Cases 33 and 36) some possible indications as to the cortical areas of taste are given. One was a tumor so situated as to cause pressure on the orbital, and possibly anterior, portion of the temporo-sphenoidal lobe; the other was a lesion closely localized to the supramarginal lobule.
Trophic disturbances of decided character are sometimes present in cases of brain tumor. Their presence, character, and extent depend upon the position of the tumor and the cranial nerves involved. Trophic disorders of the eye have been noted in cases of tumor of the antero-frontal region, and also of various positions at the base, especially those so situated as to involve the trigeminal nerve. In a fibroma of the superior antero-frontal region (Case 1) conjunctivitis and corneitis of the left eye, with anæsthesia of the conjunctiva, were present, and were very marked symptoms. This patient, who was under the care of one of us at the Philadelphia Hospital, was examined by O. E. Shakespeare, ophthalmologist to the hospital. At his first examination the bulbar conjunctivæ were slightly injected and the cornea clear. The sensibility of the cornea was possibly a little lowered. Ten days later, at a second examination, the central corneal epithelium of the left eye was found to be hazy and the whole bulbar conjuntivæ much congested. “This condition soon developed into a severe superficial corneitis, which was mainly limited to a central area of an extent about equal to three-fourths of the diameter of the cornea, which threatened to slough, a narrow peripheral ring of the cornea being comparative unaffected. At the same time the engorgement of the bulbar conjunctiva increased. The sclera, the iris, and the deeper parts were apparently not involved in the inflammatory process.”