Microsurgical anatomy of the anterior approach to the mesial temporal region

AbstractAnterior approaches to the mesial temporal lobe are favored by its anatomy limited medially by the cerebral peduncle and laterally by the lateral temporal lobe. We have routinely used an anterior subfrontal approach to operate on mesial temporal lesions. In this paper, we describe its microsurgical anatomy and detail its clinical application. Surgical positioning, removal of the orbital rim, and drilling the sphenoid ridge are the main principles of this technique. Adequate positioning is crucial to displace the temporal lobe from the middle fossa to improve exposure. Removing the orbital rim ensures an ample range of movement for the surgical microscope, augments visualization, and improves surgical versatility. Finally, drilling the sphenoid ridge amplifies exposure near the area of interest, permitting increased visualization and manipulation.

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Microsurgical Anatomy of the Supracerebellar Transtentorial Approach to the Posterior Mediobasal Temporal Region: Technical Considerations With a Case Illustration

Operative Neurosurgery ◽

10.1227/01.neu.0000317367.61899.65 ◽

2008 ◽

Vol 62 (suppl_1) ◽

pp. ONS1-ONS8 ◽

Cited By ~ 7

Author(s):

Roham Moftakhar ◽

Yusuf Izci ◽

Mustafa K. Basşkaya

Keyword(s):

Temporal Lobe ◽

Vascular Anatomy ◽

Surgical Anatomy ◽

Parahippocampal Gyrus ◽

Temporal Region ◽

Microsurgical Anatomy ◽

Posterior Portion ◽

Surgical Access ◽

Formidable Challenge ◽

Left Posterior

Abstract Objective: Surgical access to the posterior portion of the mediobasal temporal lobe presents a formidable challenge to neurosurgeons, and much controversy still exists regarding the selection of the surgical approach to this region. The supracerebellar transtentorial (SCTT) approach to the posterior mediobasal temporal region can be used as an alternative to the subtemporal or transtemporal approaches. The aim of this study was to demonstrate the surgical anatomy of the SCTT approach and review the gyral, sulcal, and vascular anatomy of the posterior mediobasal temporal lobe. The use of this approach in the resection of a ganglioglioma located in the left posterior parahippocam-pal gyrus is illustrated. Methods: The SCTT approach to the posterior parahippocampal gyrus was performed on three silicone-injected cadaveric heads. The gyral, sulcal, and arterial anatomy of the posterior mediobasal temporal lobe was studied in six formalin-fixed injected hemispheres. Results: The SCTT approach provided a direct path to the posterior mediobasal temporal lobe and exposed the posterior parahippocampal gyrus as well as the adjacent gyri in all of the cadaveric specimens. Through this approach, gross total resection of the ganglioglioma was possible in our patient. Conclusion: The SCTT approach provided a viable surgical route to the posterior mediobasal temporal lobe in the cadaveric studies. This approach provides an advantage over the subtemporal and transtemporal routes in that there is less temporal lobe retraction.

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Microsurgical Anatomy of the Temporal Lobe: Part 1: Mesial Temporal Lobe Anatomy and Its Vascular Relationships as Applied to Amygdalohippocampectomy

Neurosurgery ◽

10.1097/00006123-199909000-00028 ◽

1999 ◽

Vol 45 (3) ◽

pp. 549-592 ◽

Cited By ~ 124

Author(s):

Hung Tzu Wen ◽

Albert L. Rhoton ◽

Evandro de Oliveira ◽

Alberto C. C. Cardoso ◽

Helder Tedeschi ◽

...

Keyword(s):

Temporal Lobe ◽

Microsurgical Anatomy ◽

Mesial Temporal Lobe

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Electroencephalography in Mesial Temporal Lobe Epilepsy: A Review

Epilepsy Research and Treatment ◽

10.1155/2012/637430 ◽

2012 ◽

Vol 2012 ◽

pp. 1-17 ◽

Cited By ~ 16

Author(s):

Manouchehr Javidan

Keyword(s):

Temporal Lobe Epilepsy ◽

Temporal Lobe ◽

Mesial Temporal Lobe Epilepsy ◽

General Information ◽

Seizure Freedom ◽

Temporal Region ◽

Epileptiform Discharges ◽

Mesial Temporal Lobe ◽

Magnetic Resonance Imaging Mri ◽

Sensitivity Specificity

Electroencephalography (EEG) has an important role in the diagnosis and classification of epilepsy. It can provide information for predicting the response to antiseizure drugs and to identify the surgically remediable epilepsies. In temporal lobe epilepsy (TLE) seizures could originate in the medial or lateral neocortical temporal region, and many of these patients are refractory to medical treatment. However, majority of patients have had excellent results after surgery and this often relies on the EEG and magnetic resonance imaging (MRI) data in presurgical evaluation. If the scalp EEG data is insufficient or discordant, invasive EEG recording with placement of intracranial electrodes could identify the seizure focus prior to surgery. This paper highlights the general information regarding the use of EEG in epilepsy, EEG patterns resembling epileptiform discharges, and the interictal, ictal and postictal findings in mesial temporal lobe epilepsy using scalp and intracranial recordings prior to surgery. The utility of the automated seizure detection and computerized mathematical models for increasing yield of non-invasive localization is discussed. This paper also describes the sensitivity, specificity, and predictive value of EEG for seizure recurrence after withdrawal of medications following seizure freedom with medical and surgical therapy.

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Hippocampal transection for stereo-electroencephalography–proven dominant mesial temporal lobe epilepsy in a child: a detailed case report and critical review

Journal of Neurosurgery Pediatrics ◽

10.3171/2018.5.peds1896 ◽

2018 ◽

Vol 22 (5) ◽

pp. 497-503

Author(s):

Jun T. Park ◽

Guadalupe Fernandez Baca Vaca ◽

Rachel Tangen ◽

Jonathan Miller

Keyword(s):

Temporal Lobe Epilepsy ◽

Temporal Lobe ◽

Verbal Memory ◽

Mesial Temporal Lobe Epilepsy ◽

Hemispheric Dominance ◽

Seizure Outcome ◽

Temporal Region ◽

Detailed Case ◽

Epileptiform Discharges ◽

Mesial Temporal Lobe

Resection of the hippocampus ipsilateral to the verbal memory–dominant hemisphere frequently results in severe memory deficits. In adults with epilepsy, multiple hippocampal transections (MHTs) have resulted in excellent seizure outcome with preservation of verbal memory. The authors report the first detailed case of a child undergoing MHTs for mesial temporal lobe epilepsy. A 13-year-old right-handed boy had intractable seizures characterized by epigastric discomfort evolving to unresponsiveness and chewing automatisms, lasting 1 minute and occurring 2–3 times weekly, sometimes ending in a generalized tonic-clonic seizure. He had no seizure risk factors and nonfocal examination results. Interictal electroencephalography (EEG) showed frequent left temporal epileptiform discharges (maximum FT9) and intermittent slowing. Video EEG, FDG-PET, and 1.5-T MRI were nonlocalizing. Neuropsychological evaluation suggested left temporal lobe dysfunction. A stereo-EEG investigation using 8 electrodes localized the seizure onset zone to the anterior mesial temporal region, immediately involving the hippocampus. The temporal pole and amygdala were resected en bloc with 3 MHTs. Comparison of neuropsychological tests 4 months before and 6 months after the surgery showed a significant decline only in confrontational naming and no significant change in verbal memory. Six and a half years later, the patient remains seizure free with no antiepileptic drugs. In children with established hemispheric dominance suffering from mesial temporal lobe epilepsy, MHTs may be an option.

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Through the Choroidal Fissure

Operative Neurosurgery ◽

10.1227/01.neu.0000369920.68166.6c ◽

2010 ◽

Vol 66 (suppl_2) ◽

pp. ons221-ons229 ◽

Cited By ~ 2

Author(s):

Anhua Wu ◽

Steve W. Chang ◽

Pushpa Deshmukh ◽

Robert F. Spetzler ◽

Mark C. Preul

Keyword(s):

Temporal Lobe ◽

Cerebral Artery ◽

Posterior Cerebral Artery ◽

Temporal Region ◽

Mesial Temporal Lobe ◽

Optimal Approach

Abstract BACKGROUND We compared the transsylvian transchoroidal (TSTC) approach with the lateral transtemporal (LTT) approach. Both approaches proceed through the choroidal fissure but through different incisions and along different trajectories. METHODS Four fixed, silicon-injected heads (8 sides) were used. Nine strategic anatomic points within the dissections were compared between the TSTC and LTT approaches in 7 other silicon-injected heads (14 sides). Neuronavigation was used to gather coordinates from selected points of both approaches to calculate surgical angles and distances to common targets. RESULTS The surgical angle of the TSTC approach for the inferior choroidal point was wider compared with the LTT approach (P < .05). The surgical angles for the P2a-P2p point were similar for both approaches. In the TSTC approach, the P2-P3 point angle was smaller than in the LTT approach (P < .05). The TSTC approach provided (except for the P2-P3 point) significantly shorter distances to all defined anatomic targets compared with the LTT approach. When the posterior cerebral artery was the target in the TSTC approach, the hippocampus was retracted 3 to 8 mm compared with 8 to 13 mm in the LTT approach. CONCLUSION We quantitatively described anatomic features of the TSTC approach and compared them with the LTT approach. For approaching the mesial temporal region, the TSTC approach offers an adequate surgical angle and shorter or similar distances proximal to P2-P3 and requires less temporal lobe and hippocampal retraction than the LTT approach. Such information can help surgeons select the optimal approach to the mesial temporal lobe and its surrounding structures. The TSTC approach should be considered for lesions located in the medial temporal region.

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