Image-Guided Management of Brain Stem Lesions

Abstract

The brain stem, which comprises the mesencephalon, pons, and medulla, is a highly complex and functional structure. It is packed with cranial nerves nuclei, many neuronal fascicules and pathways, as well as reticular formations. Its surface has intimate relationships with afferent and efferent cranial nerves, and is surrounded by delicate vasculature. The brain stem is embedded deep in the cranium, located almost entirely in the posterior fossa, protected by the clivus and the petrous bone anteriorly and laterally, and covered by the cerebellum posteriorly. Because of the complex neurosurgical access and the functional importance of the structure, the management of mass lesions of the brain stem remains difficult and controversial.