The causes of increased density of the cerebellar vermis are as follows: first, because there is inflammation, commonly encephalitis, cerebritis, meningitis or cerebellar vermis, and may also be viral meningitis. When there are inflammatory diseases, the inflammation has metamorphosis, exudation, hyperplasia or necrosis, and there is also a certain amount of inflammatory cell exudation, which can lead to increased density of the cerebellar vermis. Secondly, it may be due to cysts or tumors, such as cerebellar vermis cysts, benign tumors of the cerebellar vermis, cerebellar vermis hernia, when there are tumors or cysts can lead to abnormal proliferation of tissues or cells of the cerebellar vermis, or accumulation, which will lead to increased density. Thirdly, it may be due to the abnormal development of tissue cells, in the clinical development of the cerebellar vermis, such as the increase of connective tissue or abnormal cell proliferation and division, which will also lead to the increased density of the cerebellar vermis.