TUMORS OF THE CEREBELLUM cause well-marked general symptoms, such as headache, double choked disks, vomiting, and often dizziness. Focal symptoms, however, will be entirely wanting if the tumor is not very large and situated in one hemisphere, especially in its poste rior portion, so as not to affect the func tions of the middle lobe or those of the pans. The most reliable and constant symptoms of a growth affecting the middle lobe are the disturbed muscular movements, the cranial-nerve symptoms, and the subjective sensations of inse curity, both while standing and lying. The inco-ordination of muscular move ments is most pronounced in the legs, next in the trunk, and least in the arms. The patient's gait is similar to that of a drunken person, the feet well separated laterally in standing and walking, and the body is often thrown to one side, for ward, or backward by forced muscular movements. There is no paralysis of legs
or arms, unless the fibres in the pyram idal tracts are affected, and no anes thesia. The patient has a sense of in security of his position, especially while standing, and this is sometimes com plained of when he is lying in bed. If the tumor is situated well forward and in the median portion of the middle lobe, the cranial-nerve symptoms will be bi lateral; if to one side they will either be unilateral or, at least, most marked on the side corresponding to the tumor. The facial, auditory, and sixth nerves are most commonly affected. The °ph thalmoplegic symptoms observed in tu mors of the cerebellum affecting the supe rior peduncles appear secondary to the inco-ordination; when they are due to a tumor in the corpora quadrigemina they precede the ataxia.