Search Results

You are looking at 1 - 10 of 164 items for :

  • Refine by Access: user x
Clear All
Free access

Letter to the Editor. Fornix infarction

Alex Mamourian

of their study is that formal neuropsychological testing was not performed, however. Regarding their only case with symptomatic cerebral ischemia, it is worth noting the infarct seen in Fig. 4 of the paper involves not only the corpus callosum but also the bilateral columns of the fornix. Acute infarcts of the fornix would account for the patient’s disorientation at the conclusion of the procedure, and it was gratifying to read that symptoms resolved after 1 month. The same infarct pattern involving both the corpus callosum and the anterior fornix was illustrated

Free access

Comparative anatomical analysis of the transcallosal-transchoroidal and transcallosal-transforniceal-transchoroidal approaches to the third ventricle

João Luiz Vitorino Araujo, José C. E. Veiga, Hung Tzu Wen, Almir F. de Andrade, Manoel J. Teixeira, José P. Otoch, Albert L. Rhoton Jr., Mark C. Preul, Robert F. Spetzler, and Eberval G. Figueiredo

the third ventricle. 17 , 20 , 35 , 38 , 39 The transcallosal-transchoroidal approach to the third ventricle allows for adequate exposure of the middle and posterior regions of the ventricle. However, the fornix column limits exposure of the anterior region of the third ventricle. 30 , 38 There is evidence that a unilateral lesion of the fornix column has little or no impact on memory. 2 , 4 , 8 , 15 , 22 , 25 , 28 , 30 , 43 Various regions and structures participate in the memory circuit, and the fornix is just one of these structures. Changes to other parts of

Open access

Posterior transcallosal intervenous-interforniceal approach to a periaqueductal tumor

David S. Hersh, Katherine N. Sanford, and Frederick A. Boop

highlighted by the patient’s preoperative imaging. The coronal T2-weighted MRI demonstrates the separation of the forniceal crura posterior to the body of the fornix, and the lateral location of the crura relative to the internal cerebral veins. This view illustrates that a midline, posterior interhemispheric, transcallosal intervenous-interforniceal approach would provide a direct path to the underlying tumor. 3:51 Positioning and opening With this in mind, a posterior transcallosal intervenous-interforniceal approach was performed. The patient was placed in the MRI

Full access

Neural and vascular architecture of the septum pellucidum: an anatomical study and considerations for safe endoscopic septum pellucidotomy

Laszlo Barany, Cintia Meszaros, Oliver Ganslandt, Michael Buchfelder, and Peter Kurucz

T he medial wall of the lateral ventricle’s frontal horn is formed by the septum pellucidum, which stretches between the corpus callosum and the fornix . 30 , 36 The endoscopic fenestration of this structure (endoscopic septum pellucidotomy [ESP] or septostomy) is a well-accepted treatment for patients with specific forms of hydrocephalus 1 , 10 , 13–15 , 27 , 28 , 32 , 35 or with a symptomatic septum pellucidum cyst. 34 It is generally accepted that the perforation should be made on an avascular area of the septum pellucidum due to the limitation of the

Full access

Magnetic resonance–guided focused ultrasound for ablation of mesial temporal epilepsy circuits: modeling and theoretical feasibility of a novel noninvasive approach

Whitney E. Parker, Elizabeth K. Weidman, J. Levi Chazen, Sumit N. Niogi, Rafael Uribe-Cardenas, Michael G. Kaplitt, and Caitlin E. Hoffman

visualization of the tissue area being heated to various temperatures in order to determine, in real time, whether the desired tissue volume has been ablated. Instead of targeting the mesial temporal structures, this modality would target the posterior outflow tract of the hippocampus and potentially disrupt posterior escape and spread of electrical activity from a mesial temporal onset zone. The fornix-fimbria posterior outflow target represents a white matter pathway found to have diffusion abnormalities and corresponding axonal pathology in MTS. 8 , 9 The anterior nucleus

Open access

Endoscopic transventricular resection of a colloid cyst

Sebastian Lehmann and Henry W. S. Schroeder

placed and the navigation-guided sheath for the endoscope is carefully inserted, following the preplanned trajectory, reaching the lateral ventricle with direct view to the interventricular septum and the head of the caudate nucleus. Once the caudate nucleus head is covered by the endoscope sheath, the sheath is used as a retractor to dislocate the head of the caudate nucleus a little bit laterally to get the ideal approach to the colloid cyst’s attachment at the roof of the third ventricle. The anatomical landmarks for orientation are the fornix, the choroid plexus

Free access

Neuromodulation for restoring memory

Sarah K. B. Bick and Emad N. Eskandar

integral to memory function ( Fig. 1 ). 80 It involves circular projections from hippocampus to fornix, to mammillary bodies, to anterior nucleus of the thalamus, to cingulum, to the entorhinal cortex, and back to the hippocampus. Much of the work on neuromodulation for memory has focused on altering activity in the Papez circuit. FIG. 1. Structures involved in memory circuitry and their interconnections. Dark gray structures indicate components of the circuit of Papez, and light gray structures indicate other components of memory circuitry discussed in the

Free access

Comparative analysis of endoscopic third ventriculostomy trajectories in pediatric cases

Zsolt Zador, David J. Coope, and Ian D. Kamaly-Asl

(the floor of the third ventricle just anterior to the mammillary bodies) ( Fig. 2B and C ). The depth of the intersection with the anatomical structures was used to simulate the extent of tissue displacement caused by the rigid neuroendoscope. Displacement was categorized as 1) “anterior displacement,” which included displacement to the fornix, or 2) “lateral displacement,” which included displacement to the caudate nucleus, genu of the internal capsule, or thalamus. The diameter of the rigid neuroendoscope was incorporated into our simulations by assigning the

Free access

Deep brain stimulation for dementias

David S. Xu and Francisco A. Ponce

severity of illness at the time of diagnosis, influence life expectancy. 20 Interestingly, an older age of AD onset has been associated with a slower rate of cognitive decline rather than a younger age, suggesting that AD onset in the young may represent a different disease phenotype. 4 , 37 Fornix Stimulation Rationale and Targeting Table 1 presents a summary of DBS targeting data reported on the rationale for, and targeting of, fornix stimulation. The cognitive effects of fornix stimulation were first encountered incidentally during bilateral DBS treatment of the

Free access

Microsurgical and endoscopic approaches to the pulvinar

Osamu Akiyama, Ken Matsushima, Abuzer Gungor, Satoshi Matsuo, Dylan J. Goodrich, R. Shane Tubbs, Paul Klimo Jr., Aaron A. Cohen-Gadol, Hajime Arai, and Albert L. Rhoton Jr.

in 6 formalin-fixed adult human cadaveric heads injected with colored silicone. Approaches above the tentorium include the superior parietal lobule , posterior interhemispheric transprecuneus, posterior interhemispheric transcallosal, and posterior interhemispheric transtentorial approaches. The visible neural and vascular structures related to the reachable parts of the pulvinar were examined in all approaches with the surgical microscope and rigid endoscope. In the study, the pulvinar is divided into 2 parts: ventricular and cisternal, separated by the fornix