Marienko N. Structure and individual anatomical variability of human cerebellar hemispheres

TThe dissertation is devoted to the study of individual anatomical variability of human cerebellar hemispheres. The study was performed on 100 cerebellums of corpses of people of both sexes who died from causes not related to CNS diseases. The range of individual anatomical variability of the structure of the lobules of the human cerebellar hemispheres was determined. The variants of the structure of the white matter of the cerebellar hemispheric lobules were established, their systematic classification was developed and their prevalence was calculated. The connection of the structure of the cerebellar hemispheric lobules with the structure of the corresponding cerebellar vermal lobules was determined and the main provisions of the principle of medio-lateral continuity were specified. The structure of the lobules I-VI of the hemispheres depends on the structure of the corresponding vermal lobules. Thus, the lobules I-III of the hemisphere are a direct extension of the corresponding vermal lobules, the lobules IV-V of the hemispheres continue in the lateral direction the corresponding vermal lobules, but the type of branching of the white matter is changing. Lobule VI is an anatomical continuation of the lobule VI of the vermis, but the structure of these lobules is significantly different. The structure of the lobules VII-X of the hemispheres does not depend on the structure of the corresponding vermal lobules. The lobules VII-VIII of the hemispheres retain anatomical connection with the corresponding vermal lobules, but do not repeat their shape. Lobules IX and X do not have direct connection with the corresponding vermal lobules and do not have a common structure. Therefore, the principle of medio-lateral continuity is preserved only in the lobules I-VI, and the structure of the lobules VII-X of the hemispheres has no common features of the structure with the lobules of the vermis. The dependence of the structure of the cerebellar hemispheric lobules on the linear size of the cerebellum was established. The medio-lateral size of the lobules is associated with the width of the cerebellum: the greater the average width of the cerebellum, the farther from the median sagittal plane the particle ends (P < 0,05). The structure of the lobule IX is related to the height of the cerebellum: the greater average height is the cerebellum, the greater the number of branches the lobule includes (P < 0.05). A fractal analysis of the white matter of the human cerebellum hemispheres at a distance of 5-40 mm from the medial sagittal plane and complete parasagittal sections of the cerebellum was performed and the dependence of the fractal dimension of the white matter of the cerebellum on the structure of the lobules was established. The fractal index of the lobules I-VI, the lower semilunar lobule and gracile lobule, the lobules VIII and IX decreases in the lateral parts of the cerebellar hemispheres; the fractal index of the upper semilunar lobule is the smallest in the paravermal region and increases in the medio-lateral direction. The fractal index of white matter of complete parasagittal sections of the cerebellar hemispheres does not differ significantly from the fractal index of the vermis.