The prenatal development of the human cerebellar field in Down syndrome.

OBJECTIVES: To describe the development of the osseous field enclosing the cerebellum and part of the brain stem (the neuro-osteological cerebellar field) in Down syndrome, and compare the development with normal developmental standard of the field. DESIGN: Radiographic, cephalometric and histologic examination of 58 legally or spontaneously aborted Down syndrome prenatal human fetuses; crown-rump length of 80-255 mm and approximate gestational age from 13 to 26 weeks. RESULTS: The growth of the Down syndrome cerebellar field is smaller in the sagittal and vertical directions than in normal fetuses. CONCLUSION: In the present study the pathological development of the cerebellar field was described in a genotypic sample. In combining normal and pathological development of neural and osseous tissues a better understanding of the genotype/phenotype interactions is attainable and fields of common gene expression maybe defined.

The pre-natal development and osseous growth of the human cerebellar field.

OBJECTIVES: To describe the pre-natal development of the bones that enclose the cerebellum and part of the brain stem (the neuro-osteological cerebellar field) in the mid-sagittal plane. DESIGN: Radiographic, cephalometric and histologic examination of normal pre-natal human fetuses; 50 normal fetuses, with crown-rump length of 18-227 mm and approximate gestational age from 6 to 26 weeks. RESULTS: The cerebellar field expressed extensive growth during development both sagittally and vertically. Because of changes in shape, the field was displaced in an anterio-caudal direction. CONCLUSION: In the present study we recorded normal measurements of size, shape and position of the cerebellar field. These standards can be used as references in skeletal analysis of cases with cranial abnormalities and cerebellar malformations.