Microsurgical Anatomy of the Temporal Lobe and Its Implications on Temporal Lobe Epilepsy Surgery

Figure 5

(a) A coronal cut is performed to the specimen positioned as in a pterional craniotomy at the level of limen insula to have a similar view of the anterior temporal lobectomy after the removal of lateral temporal neocortex. The yellow arrow shows the origin of a early cortical branch of MCA. (b) The choroidal plexus is attached to the choroidal fissure with taeniaes to forniceal and thalamic sides. The choroidal fissure should be opened always at forniceal side to prevent both to thalamus and choroidal arteries and veins passing close to thalamic side of the choroid plexus. In this view, arachnoid membrane of the ambient cistern is removed to show the PCA and the basal vein. (c–e) Stepwise dissection of the sylvian fissure, the temporal horn, and the choroidal fissure. (c) The presentation of the amygdala at the temporo-opercular surface is shown in green oval line. An incision in the inferior limiting sulcus has been completed to expose the head of the hippocampus, the choroidal fissure, and the anterior choroidal artery. (d) Closer view of the (c). The roof of the temporal horn has been elevated to have a better view of the temporal horn, the hippocampus, the choroid plexus, and the collateral eminence. (e) Amygdalohippocampectomy has been competed, exposing the vascular elements in the ambient cistern. Inferior surfaces of the anterior and posterior segments of the uncus are related to internal carotid artery and the posterior cerebral artery, respectively. The anterior choroidal artery is related to the superior surfaces of both uncal segments in most cases. (f) Superior view of the left MTR showing the relation of the ventricular and the cisternal components of the MTR to the tentorial edge and cerebral peduncle. The posterior part of the uncus faces the cerebral peduncle across the crural cistern, the apex of the uncus is positioned lateral to the oculomotor nerve. The tentorial edge crosses below the medial part of the uncus. (g) Lateral view of the ventricular surface of the medial temporal lobe. The lateral geniculate body is located just above the choroidal fissure and the middle segment of the medial temporal lobe. The choroidal fissure, along which the choroid plexus (removed) attaches, is located between the fimbria and the thalamus. A.: artery; A.C.A.: anterior cerebral artery; A.Ch.A.: anterior choroidal artery; Amb.: ambient; Ant.: anterior; Brs.: branches; Car.: carotid; Chor.: choroidal; Cist.: cisternal; CNII.: optic nerve; CNIII.: oculomotor nerve; CNIV.: trochlear nerve; Coll.: collateral; Emin.: eminence; Fiss.: fissure; Giac.: Giacomini; Hippo.: hippocampal; Inf.: inferior; Intralim.: intralimbic; Lat.: lateral; M1.: M1 segment of middle cerebral artery; M2.: M2 segment of middle cerebral artery; Men.: meningeal; Mes.: mesencephalic; Mid.: middle; Parahippo.: parahippocampal; P.C.A.: posterior cerebral artery; Plex.: plexus; Post.: posterior; Semilun.: semilunar; Sulc.: sulcus; Sup.: superior; Temp.: temporal; Tent.: tentorial; Uncin.: uncinate; V.: vein.