Defining the Temporal and Occipital Lobes: Cadaveric Study with Application to Neurosurgery of the Inferior Brain

Abstract

BACKGROUNDFor surgical interventions, a precise understanding of the anatomical variations of the brain and defined anatomical landmarks to demarcate the regions of the temporal lobe is essential. Many anatomical studies have facilitated important surgical approaches to the temporobasal region. Because there is considerable sulcal variability, morphological analysis of the brain is imperative. The aim of this study was to define the boundaries of the temporal and occipital lobes and to define the variations in sulci and gyri in the inferior aspect. METHODSIn 110 cerebral hemispheres variations were identified and the major landmarks of the gyral-sulcal pattern at the inferior aspect of the brain were defined. RESULTSThe anatomy of the inferior aspect of the brain is defined in detail by morphological analysis of formalin-fixed hemispheres with a view to informing important surgical approaches. CONCLUSIONSSince the literature defines no clear separation between the temporal and occipital lobes, certain landmarks such as the preoccipital notch (PON) and a basal temporo-occipital line were suggested as ways of making the distinction. The parahippocampal ramus (PhR) is a constant structure that can be used as a reliable landmark for the posterior end of the hippocampus.