Browsing by Subject "Epilepsy surgery"

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    External cortical landmarks for localization of the hippocampus: Application for temporal lobectomy and amygdalohippocampectomy
    (Scientific Scholar, 2018-08-22) Tubbs, R. Shane; Loukas, Marios; Barbaro, Nicholas M.; Shah, Kushal J.; Cohen-Gadol, Aaron A.; Neurological Surgery, School of Medicine
    Background: Accessing the hippocampus for amygdalohippocampectomy and minimally invasive procedures, such as depth electrode placement, require an accurate knowledge regarding the location of the hippocampus. Methods: The authors removed 10 human cadaveric brains from the cranium and observed the relationships between the lateral temporal neocortex and the underlying hippocampus. They then measured the distance between the hippocampus and superficial landmarks. The authors also validated their study using magnetic resonance imaging (MRI) scans of 10 patients suffering from medial temporal lobe sclerosis where the distance from the hippocampal head to the anterior temporal tip was measured. Results: In general, the length of the hippocampus was along the inferior temporal sulcus and inferior aspect of the middle temporal gyrus. Although the hippocampus tended to be more superiorly located in female specimens and on the left side, this did not reach statistical significance. The length of the hippocampus tended to be shorter in females, but this too failed to reach statistical significance. The mean distance from the anterior temporal tip to the hippocampal head was identical in the cadavers and MRIs of patients with medial temporal lobe sclerosis. Conclusions: Additional landmarks for localizing the underlying hippocampus may be helpful in temporal lobe surgery. Based on this study, there are relatively constant anatomical landmarks between the hippocampus and overlying temporal cortex. Such landmarks may be used in localizing the hippocampus during amygdalohippocampectomy and depth electrode implantation in verifying the accuracy of image-guided methods and as adjuvant methodologies when these latter technologies are not used or are unavailable.
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    Superficial cortical landmarks for localization of the hippocampus: Application for temporal lobectomy and amygdalohippocampectomy
    (Wolters Kluwer, 2015-02-03) Tubbs, R. Shane; Loukas, Marios; Barbaro, Nicholas M.; Cohen-Gadol, Aaron A.; Department of Neurological Surgery, IU School of Medicine
    BACKGROUND: Accessing the hippocampus for amygdalohippocampectomy and procedures such as depth electrode placement requires accurate knowledge regarding the location of the hippocampus. METHODS: The authors removed 10 human cadaveric brains (20 sides) from their crania, noted relationships between the lateral temporal neocortex and underlying hippocampus, and measured the distance between the hippocampus and superficial landmarks. RESULTS: Mean distances were as follows: 3.8 cm from the tip of the temporal lobe to the head of the hippocampus; 6.5 cm from the tip of the temporal lobe to the junction of the fornix and hippocampus; and 3.5 cm between the tail and head of the hippocampus. The head of the hippocampus ranged from 0 to 5 mm inferior to the inferior temporal sulcus. The tail of the hippocampus ranged from 2.2 to 7 mm superior to the inferior temporal sulcus. In two specimens, the tail was deep to the superior temporal sulcus. Generally the length of the hippocampus was along the inferior temporal sulcus and inferior aspect of the middle temporal gyrus. The hippocampus tended to be more superiorly located and shorter in females and left sides, but this was not statistically significant. CONCLUSIONS: Additional landmarks for localizing the underlying hippocampus may be helpful in temporal lobe surgery. Our study showed relatively constant anatomic landmarks between the hippocampus and overlying temporal cortex that may help localize the hippocampus during amygdalohippocampectomy and depth electrode implantation, verify the accuracy of image-guided methods, and used as adjuvant methodologies when these latter technologies are unavailable.
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    Transsylvian selective amygdalohippocampectomy for treatment of medial temporal lobe epilepsy: Surgical technique and operative nuances to avoid complications
    (Medknow Publications And Media Pvt. Ltd., part of Wolters Kluwer Health, 2014) Kovanda, Timothy J.; Tubbs, R. Shane; Cohen-Gadol, Aaron A.; Department of Neurological Surgery, School of Medicine
    Background: A number of different surgical techniques are effective for treatment of drug-resistant medial temporal lobe epilepsy. Of these, transsylvian selective amygdalohippocampectomy (SA), which was originally developed to maximize temporal lobe preservation, is arguably the most technically demanding to perform. Recent studies have suggested that SA may result in better neuropsychological outcomes with similar postoperative seizure control as standard anterior temporal lobectomy, which involves removal of the lateral temporal neocortex. Methods: In this article, the authors describe technical nuances to improve the safety of SA. Results: Wide sylvian fissure opening and use of neuronavigation allows an adequate exposure of the amygdala and hippocampus through a corticotomy within the inferior insular sulcus. Avoidance of rigid retractors and careful manipulation and mobilization of middle cerebral vessels will minimize ischemic complications. Identification of important landmarks during amygdalohippocampectomy, such as the medial edge of the tentorium and the third nerve within the intact arachnoid membranes covering the brainstem, further avoids operator disorientation. Conclusion: SA is a safe technique for resection of medial temporal lobe epileptogenic foci leading to drug-resistant medial temporal lobe epilepsy.