Externally, it is covered by the insula and surrounded by the fornix and lateral ventricles (Fig.
![hippocampus anatomy landmarks hippocampus anatomy landmarks](https://prod-images-static.radiopaedia.org/images/44335507/52e8fc67b96ee3a2d8fc8d609ee086_gallery.jpeg)
The central core of each hemisphere consists of the basal ganglia thalamus internal, external, and extreme capsules claustrum and insula.
![hippocampus anatomy landmarks hippocampus anatomy landmarks](https://www.researchgate.net/profile/Song-Lin-Ding/publication/283092085/figure/fig1/AS:614310296444951@1523474396290/Medial-view-of-the-uncus-and-the-general-location-of-hippocampal-subfields-in-the-uncal.png)
The anatomical aspects considered important for hemispherotomy include the concept of the central core of the hemisphere, the anatomy of the tentorium cerebelli and the falx as well as their relationship to the corpus callosum and the central core of the hemisphere, and the relationship between the ACAs and the corpus callosum from an intraventricular perspective.Ĭentral Core. Other minor differences include the removal or preservation of the insula and the preservation or ligation of branches of the MCA.īecause both hemispherotomy and hemispherectomy are essentially anatomy-oriented procedures, we endeavored to demonstrate through dissections the anatomical landmarks that are relevant in performing hemispherotomy as well as the practical applications of those landmarks during the procedure. The main differences among these hemispherotomy variants lie in how the lateral ventricle is accessed-whether access starts from the temporal horn or from the body of the lateral ventricle-and the extent of brain resection necessary to gain access.
![hippocampus anatomy landmarks hippocampus anatomy landmarks](http://www.ajnr.org/content/ajnr/36/5/846/F4.large.jpg)
2–4,10–12,14 As stated by Morino, et al., 5 however, all of these variations have four principles in common: disruption of the descending and ascending fibers through the corona radiata and internal capsule removal of the mesial temporal structures intraventricular callosotomy and disruption of the frontal horizontal fibers, including the occipitofrontalis fasciculus and uncinate fascicle. Recently, several technical variations of hemispherotomy have been described. Because of its technical peculiarities-intraventricular callosotomy-the hemispherotomy is especially indicated in those cases with an enlarged lateral ventricle. Indications for a hemispherotomy are the same as those for a hemispherectomy, namely hemiconvulsion-hemiplegia-epilepsy syndrome Sturge–Weber disease Rasmussen syndrome atrophic cerebral hemisphere caused by vascular disorder, trauma, or infection and cortical dysplasia involving a broad area of the cerebral hemisphere. The term “hemispherotomy” was introduced by Delalande and colleagues1 in 1992 to describe a modified functional hemispherectomy,7,8 in which cortical resection is minimized and the rest of the hemisphere is functionally isolated by disconnecting the neuronal fibers. Furthermore, they can be used to perform any resection around the central core of the hemisphere and the tentorial incisura. After a temporal lobectomy, the landmarks include the choroid plexus and posterior/ascending portion of the tentorium to disconnect the parietal and occipital lobes, the callosal sulcus or distal anterior cerebral artery (ACA) to sever the intraventricular fibers of the corpus callosum, and the head of the caudate nucleus and ACA to detach the frontal lobe.ĬONCLUSIONS: These landmarks can be used in any hemispherotomy during which a cerebral hemisphere is disconnected from its lateral surface. During most hemispherotomies, the surgeon reaches the lateral ventricle through the frontoparietal opercula or temporal lobe removes the mesial temporal structures and disconnects the frontal lobe ahead, the parietal and occipital lobes behind, and the intraventricular fibers of the corpus callosum above the central core. Externally, this core is covered by the insula and surrounded by the fornix, choroid plexus, and lateral ventricle. The central core of a hemisphere consists of extreme, external, and internal capsules claustrum lentiform and caudate nuclei and thalamus.
![hippocampus anatomy landmarks hippocampus anatomy landmarks](https://www.researchgate.net/profile/Claire-Cury/publication/280529854/figure/fig3/AS:613888827596809@1523373910243/Anatomy-of-the-hippocampus-Schema-of-the-internal-organisation-of-the-hippocampus.png)
Anatomical landmarks were used in five hemispheric deafferentations. METHODS: This anatomical study was performed in five adult cadaveric heads following perfusion of the cerebral arteries and veins with colored latex. They also propose key anatomical landmarks for hemispherotomies that can be used to disconnect the hemisphere from its lateral surface around the insula, through the lateral ventricle toward the midline. OBJECT: The authors introduce the surgical concept of the central core of a hemisphere, from which anatomical structures are disconnected during most current hemispherotomy techniques.