Tumours of the Brain.
A. GROWTHS.
Associated Conditions.—Growths may occur in the eye, of the same nature as the growth in the brain. Such cases are not common, but are occasionally met with. The disc shown in Pl. III. 4, is the left disc of a boy, whose right eye was the seat of a tubercular growth, in whose brain there was another similar growth, of which vomiting and optic neuritis were the only signs. In such a case the ocular growth becomes an important symptom. Choroidal miliary tubercles may be expected to be found occasionally in cases in which a tubercular mass exists in the brain, but they occur rather in acute general tuberculosis, in which meningitis is more frequent.
Consecutive Changes.—Optic neuritis is the ocular lesion in intra-cranial growths, which are, on the other hand, its most frequent causes. It is present, in various degrees, in a large proportion of the cases of intra-cranial tumour. In what proportion cannot be determined by statistics from published cases, on account of the selection for publication on special grounds. From my own experience I should say that neuritis occurs in about four-fifths of the cases. This is a much smaller proportion than has been deduced from published cases. Annuske and Reich, for instance, collected eighty-eight cases with ophthalmoscopic examination and autopsy, and found that there was no ophthalmoscopic change in only five per cent. But these cases have all been recorded during the period when ophthalmoscopic observation possessed the interest of novelty, and a far larger proportion of cases with neuritis have probably been published than of cases without neuritis.
It does not seem possible at present to say on what the occurrence of optic neuritis depends; why it is present in the majority, absent in the minority. Position of growth has apparently no influence on its occurrence. It has been met
