Collateral Eminence, Medial View

Description

Collateral eminence forms a longitudinal ridge along the floor of the temporal horn of the lateral ventricle, created by the impression of the collateral sulcus on the inferior temporal lobe. From a medial perspective, the eminence sits lateral to the hippocampus and its ventricular bulge (hippocampal formation), with the choroid fissure and choroid plexus positioned more superiorly along the medial wall. Anteriorly, the eminence approaches the level of the amygdaloid region at the temporal pole, while posteriorly it continues toward the atrium, maintaining a parallel course to the hippocampus. Orientation is everything. Recognizing the collateral eminence matters when teaching or planning intraventricular and mesial temporal approaches, because it is an internal ventricular landmark that helps separate the hippocampal sulcus region medially from the lateral floor of the temporal horn and can prevent misidentification of hippocampal tissue during procedures such as selective amygdalohippocampectomy for drug-resistant temporal lobe epilepsy. This fixed medial viewpoint also supports correlation with cross-sectional neuroimaging, where the collateral sulcus and its ventricular impression can vary in depth and may alter the apparent contour of the temporal horn on MRI. Neuroanatomy and neuroradiology courses can pair this illustration with coronal and axial MR slices to teach temporal horn landmarks, and neurosurgical atlases can use it to annotate safe orientation points when entering the temporal horn through a transcortical or transsylvian corridor. It also works well for exam figures covering ventricular topography and the relationship between ventricular surfaces and adjacent cortical sulci. Anatomical accuracy verified by SciePro's Medical Advisory Board.