Cerebellar Nuclei and Connections in Man

The dentate nucleus: It is largest of all cerebellar nuclei. It is only obvious in mammals being greatly enlarged in man and apes. It is constructed of irregularly folded laminae of grey matter that are deficient antero medially to form the hilus of the nucleus. This hilus allows the emergence of the white matter fibres from inside the nucleus. These fibres represent the myelinated axons of the nerve cells of the nucleus and are continued upward to form the main bulk of the superior cerebellar peduncle. The shape of the dentate nucleus, in cross section, simulates that of the inferior olivary nucleus of the medulla oblongata. Its neurons are mainly large multipolar cells with branching dendrites. Among these large cells small stellate cells are also found in the nucleus. The mean values of length and breadth of the dentate nucleus were estimated, in Bangladeshi cadavers of both sexes, to be 8.619±2.995mm and 14.770±3.604mm respectively and these values increased with the advance of age then became slightly decreased in late ages. Significant differences of each of the mean length and breadth of the dentate nucleus on both sides were observed between different age groups while statistically insignificant differences between male and female existed [1]. Rhombencephalosynapsis is a hindbrain malformation featured by complete or partial absence of the cerebellar vermis with variable degrees of midline continuity of the cerebellar hemispheres, dentate nuclei, and sometimes the superior cerebellar peduncles. Prenatal diagnosis of this condition is reported to be feasible by ultrasound and magnetic resonance imaging [2].