Neurons of the Inferior Medullary Velum in the Cerebellopontine Angle

Abstract

The edge of the inferior medullary velum (tenia) is attached in part to the surface of several structures localized in the cerebellopontine angle, including the cochlear nuclear complex and the pontobulbar body. Since superficial layers of these structures contain numerous neurons, we examined the possibility that neurons are also present within the velum. On light microscopy, we found groups of neurons accumulated immediately under the pia mater covering the tenia. The number of groups in different specimens varied from one to three, and the groups were rounded or oval in shape. A bundle of fibers running from the main mass of the brain stem toward these groups was revealed with a myelin-staining technique. The majority of neurons in the groups were angular in shape. These findings may contribute to our understanding of the general and surgical anatomy of the cerebellopontine angle.