In a few cases percussion of the head elicited or intensified pain in the region corresponding to the location of the tumors. We believe that percussion of the skull may afford valuable aid in localizing encephalic tumors, particularly when they are meningeal or cortical. Ferrier10 holds that percussion often elicits pain over the cranial region beneath which a lesion is localized, and Alex. Robertson of Glasgow11 has also directed attention to the value of percussion of the skull in the localization of disease on the surface of the brain.
10 Brain, January, 1879.
11 Abstr. Internat. Med. Congress, 1881, p. 85, and Journal of Nervous and Mental Disease, April, 1882.
Vomiting is of frequent occurrence, although it does not usually come on as early or remain as persistently as headache. It is more likely to be paroxysmal, with longer or shorter intervals of relief. It frequently occurs at the time of the exacerbations of the headache, and between the paroxysms of vomiting, nausea, slight or great, is often present. It probably occurs in about 50 per cent. of all cases of brain tumor. It is recorded as having been present in 34 out of 100 cases. It was comparatively infrequent in antero-frontal growths, occurring only twice out of 10 cases.
A case reported by one of us (Case 70) was a remarkable example of persistent cerebral vomiting. For four weeks before her death the patient vomited almost incessantly. The tumor in this case involved the middle cerebellar peduncle and the adjacent region of the right cerebellar hemisphere, and had grazed and superficially softened the floor of the fourth ventricle.
We incline to agree with Ferrier12 that the majority of cases of cerebral vomiting can be ascribed to irradiation of irritation by the nerves of the cerebral membranes or to the physical effects of acute pain. The nuclei of the trigeminus and of the vagus are in close anatomical relationship in the medulla oblongata. Irritative impressions conveyed from the cerebral membranes, and particularly from the dura mater, to the trigeminal nuclei in the medulla are transferred to the vagus and give rise to vomiting. In tumors of the cerebellum the vomiting may be brought about through the affection of the centres of equilibration and the concurrent vertiginous sensations (Ferrier), or it may be due to direct irritation by contiguity of the floor of the fourth ventricle. In general, the tumors situated farthest forward in the brain appeared to be the least likely to give rise to vomiting.
12 Brain, July, 1879.
Vertigo was noted in 31 out of 100 cases. Under this general designation dizziness, giddiness, reeling, insecurity in the erect posture, etc. have been included. The vertigo can be explained in several ways besides by the view which refers it to an affection of centres of equilibration in the cerebellum. Like headache and vomiting, it seems sometimes to be the outcome of pure irritation of the cerebral membranes. Alterations in the intracranial circulation produced by the growth of the tumor is another probable cause. Experiments have demonstrated the existence of a communication between the arachnoid cavity and the labyrinth, and consequently the increased intracranial tension present may result in pressure on the labyrinthine fibres of the auditory nerve, and thus occasion vertigo.
The importance of ophthalmoscopic examinations in suspected cases of brain tumor can scarcely be overestimated. They will often serve to clinch the diagnosis in favor of tumor. Of the 100 tabulated cases, choked discs were recorded in 8; optic neuritis or neuro-retinitis in 18. These results serve to show the importance of the examination of the eyes. It will be seen that with Allbutt, Norris, and others we make a distinction between choked disc, papillitis, congestion papilla, or ischæmia of the discs, and descending or interstitial neuritis. The differences between these two varieties of inflammation of the interocular ends of the optic nerve are well presented by Norris in a previous volume of this work,13 which will make it unnecessary for us to describe the conditions present in these cases. An examination of the tabulated cases will show that true choked discs were present in tumors situated in all portions of the encephalon. They were not infrequently present in tumors of the convexity. Descending neuritis would seem most likely to occur when the tumors are so situated that inflammation set up by them can readily extend by anatomical continuity along the membranes to the optic nerves. The lymph-space theory best accounts for the occurrence of choked discs in cases of tumor situated remotely from the base. In choked disc the appearance is one of intense swelling and engorgement of the optic papilla. In descending neuritis, as described by Graefe and Norris, there is rather a dull-red suffusion of the disc. Some of the cases reported as neuritis may have been choked discs, and the reverse, as physicians often do not make any distinction.
13 Vol. IV. p. 771 et seq.