Gliomas are confined to a fiber tract – Concept and clinical implications

Abstract

A novel classification of white fibers of the brain has been proposed based on the direction and depth of the various fiber bundles. The implications of this classification for glioma surgery are presented. Using fiber dissection techniques described by Klingler, the various association, commissural and projection fiber bundles of the brain were studied. The fibers were studied by the naked eye and with the use of magnification. The white fibers of the cerebrum were divided architecturally into five groups- four horizontal groups and one vertical group, based on three dimensional understanding of the white fibers. The four horizontal groups are the superficial, middle, deep and central groups and the vertical group included the projection fibres. The association fibers constitute the superficial, middle and deep groups. The commissural fibers form the central group. In this article, the course of the major fiber bundles of the brain is discussed. The cortical structures and subcortical networks that are involved in major human functions are presented. The implications of the proposed classification of white fibers in the surgical management of gliomas are discussed. Deciphering the cortical and subcortical anatomy of the brain is crucial to avoid neurological morbidity while performing intra-axial brain tumor surgery.