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(a) Lateral view of the left hemisphere. The lateral surface of the temporal lobe consists of three parallel gyri: superior, middle, and inferior temporal gyri. These gyri are separated by the superior and inferior temporal sulci. The lateral parietotemporal line (red dashed line), an imaginary line connecting the preoccipital notch and parietooccipital sulcus, separates the temporal and occipital lobes, and the occipitotemporal line (blue dashed line), an imaginary line connecting the posterior margin of the sylvian fissure with lateral parietotemporal line, separates the temporal and parietal lobes. (b) Inferior view of the left temporal lobe. The basal surface of the temporal lobe consists of, from lateral to medial, the inferior margin of the inferior temporal gyrus, the fusiform gyrus, and the parahippocampal gyrus. The fusiform gyrus is separated laterally from the inferior temporal gyrus by the occipitotemporal sulcus, and medially from the parahippocampal gyrus by the collateral posteriorly and rhinal sulci anteriorly, which are not continuous in every case. The basal parietotemporal line connecting the preoccipital notch and inferior end of parietooccipital sulcus separates the temporal and occipital lobes at the basal surface. (c) The relationship of the temporal lobe with bony structures in a right hemisphere. The cranial sutures and the superior temporal line have been preserved, and the dura has been opened. The pterion is located at the lateral margin of the sphenoid ridge near the junction of the coronal, squamosal, and frontosphenoid sutures and the lateral end of the greater sphenoid wing and stem of the sylvian fissure. The squamosal suture follows the anterior part of the posterior limb of the sylvian fissure before turning downward, at the level of the postcentral and supramarginal gyri, to cross the junction of the middle and posterior third of the temporal lobe. The pole of the temporal pole fits into the cupped inner surface of the greater wing of the sphenoid bone. Most of the lateral surface of the temporal lobe is positioned deep to the squamous part of the temporal bone, except, the posterior part of the lateral surface extending deep to the parietal bone. The basal surface of the temporal lobe sits on the floor of the middle fossa and is positioned at the level of the upper edge of the zygomatic arch. (d) The medial view of the temporal lobe in a right hemisphere. This region is divided into three segments: anterior, middle, and posterior. The anterior segment begins at where the rhinal sulcus turns upward at the posterior edge of the temporal pole (yellow interrupted line) to a vertical line crossing the posterior edge of the uncus (green interrupted line), the middle segment extends from this point to the level of the quadrigeminal plate (red interrupted line), and the posterior segment extends from the quadrigeminal plate to the calcarine point (blue interrupted line) located at the junction of the parietooccipital and calcarine sulci. (e) The superior view of the left temporal lobe. This surface facing the the sylvian fissure is divided, from anterior to posterior, in three portion: the planum polare, the anterior transverse temporal gyrus, referred to as the Heschl's gyrus, and the planum temporale containing the middle and posterior transvers temporal gyri. Ant.: anterior; Cent., central; Calc.: calcarine; Fiss.: fissure; Hippo.: hippocampus; Inf.: inferior; Mid.: middle; Occ.: occipital; Parahippo.: parahippocampal; Par.-Occip.: parieto-occipital; Par.-Temp.: parietotemporal; Post.: posterior; Squam.: squamous; Sulc.: sulcus; Sup.: superior; Temp.: temporal; Trans.: transvers Tr.: tract; Zygo.: zygomatic.
Source publication
Objective. We review the neuroanatomical aspects of the temporal lobe related to the temporal lobe epilepsy. The neuronal, the ventricular, and the vascular structures are demonstrated. Methods. The previous articles published from the laboratory of the senior author are reviewed. Results. The temporal lobe has four surfaces. The medial surface has...
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Citations
... This network is often disrupted in TLE, 19 contributes to preoperative memory impairment, 20 and is transected during ATL. 21 However, both tracts are typically preserved following SLAH. The present study was conducted to examine memory outcomes following SLAH and ATL and to determine how the interplay between structural adequacy and reserve of frontotemporal WM relates to risk for memory decline following each surgical technique. ...
Background
With expanding neurosurgical options in epilepsy, it is important to characterise each options’ risk for postoperative cognitive decline. Here, we characterise how patients’ preoperative white matter (WM) networks relates to postoperative memory changes following different epilepsy surgeries.
Methods
Eighty-nine patients with temporal lobe epilepsy with T1-weighted and diffusion-weighted imaging as well as preoperative and postoperative verbal memory scores (prose recall) underwent either anterior temporal lobectomy (ATL: n=38) or stereotactic laser amygdalohippocampotomy (SLAH; n=51). We computed laterality indices (ie, asymmetry) for volume of the hippocampus and fractional anisotropy (FA) of two deep WM tracts (uncinate fasciculus (UF) and inferior longitudinal fasciculus (ILF)).
Results
Preoperatively, left-lateralised FA of the ILF was associated with higher prose recall (p<0.01). This pattern was not observed for the UF or hippocampus (ps>0.05). Postoperatively, right-lateralised FA of the UF was associated with less decline following left ATL (p<0.05) but not left SLAH (p>0.05), while right-lateralised hippocampal asymmetry was associated with less decline following both left ATL and SLAH (ps<0.05). After accounting for preoperative memory score, age of onset and hippocampal asymmetry, the association between UF and memory decline in left ATL remained significant (p<0.01).
Conclusions
Asymmetry of the hippocampus is an important predictor of risk for memory decline following both surgeries. However, asymmetry of UF integrity, which is only severed during ATL, is an important predictor of memory decline after ATL only. As surgical procedures and pre-surgical mapping evolve, understanding the role of frontal-temporal WM in memory networks could help to guide more targeted surgical approaches to mitigate cognitive decline.
... Laterally, the temporal lobe is limited superiorly by the Sylvian fissure and separated by the superior temporal sulcus (STS) and inferior temporal sulcus (ITS) temporal sulci, which are parallel to each other. 5,[8][9][10][11][12] The ITG is often separated into small parts by 1 or more sulcal bridges and can merge into the MTG with no apparent boundary. 5,8,10,11 The temporal lobe is separated by these sulci laterally into the superior temporal gyrus, middle temporal gyrus (MTG), and ITG, and these gyri are respectively known as T1, T2, and T3. ...
... separates the temporal lobe from the occipital lobe on the lateral surface. 5,6,[8][9][10][11][12] On the inferior surface, the temporal lobe blends caudally into the occipital lobe with no clear boundary. 5,6 A theoretical basal parieto-temporal line extends from the junction of the calcarine and parieto-occipital fissure (tip of the cuneus) to the PON and separates the temporal and occipital lobes. ...
... In his commentary on an anatomical study, de Oliveira emphasized that this technique was taught to them by Türe [37]. Later, many groups interested in this subject were established around the world and many studies were conducted [38][39][40][41][42]. Now in the 2020s, Türe and his fellows are publishing many articles about white matter tracts [43][44][45][46], and fellows of Yaşargil and Türe continue to work on augmented reality, virtual reality simulations, and three-dimensional (3D) models of white matter [47]. ...
White matter fiber dissection is a technical procedure used in neuroanatomy studies to gain a comprehensive three-dimensional understanding of both gray and white matter anatomy as well as deep nuclei [1]. While difficult and time consuming, this technique is critical for constructing a proper conceptual notion about accurate intrinsic brain anatomy and architecture. This method is the legacy of many early anatomists [2–8].
... The inferior surface consists of the inferior margin of the inferior temporal gyrus, the fusiform gyrus, and the parahippocampal gyrus from lateral to medial. These gyri are separated by the occipitotemporal sulcus and the collateral sulcus (Kucukyuruk et al. 2012). ...
... The uncinate fasciculus (UNC) and inferior longitudinal fasciculus (ILF) were selected due to evidence that they are often affected in TLE, 24 contribute to preoperative memory in TLE, [14][15][16]25 and are injured or transected during ATL 26,27 ( Figure 1A). The UNC is a long-range WM tract that connects lateral orbitofrontal cortex and Brodmann area 10 with the anterior temporal lobe. ...
Background and Objectives
Risk for memory decline is a substantial concern in patients with temporal lobe epilepsy (TLE) undergoing anterior temporal lobectomy (ATL). Although prior studies have identified associations between memory and integrity of white matter (WM) networks within the medial temporal lobe (MTL) pre -operatively, we contribute a novel study examining whether microstructural asymmetry of deep and superficial WM networks within the MTL predicts post-operative memory decline.
Methods
Patients with drug-resistant TLE were recruited from two epilepsy centers in a prospective longitudinal study. All patients completed pre-operative T1 and diffusion-weighted MRI (dMRI), as well as pre- and post-operative neuropsychological testing. Pre-operative fractional anisotropy (FA) of the WM directly beneath the neocortex (i.e., superficial WM; SWM) and of deep WM tracts associated with memory were calculated. Asymmetry was calculated for hippocampal volume (HCV) and FA of each WM tract or region and examined in linear and logistic regressions with pre- to post-operative memory change as the primary outcome.
Results
Data were analyzed from 42 patients with TLE (19 left TLE; LTLE, 23 right TLE; RTLE) who underwent ATL. Leftward FA asymmetry of the entorhinal SWM was associated with decline on prose and associative recall in LTLE, whereas leftward FA asymmetry of the uncinate fasciculus (UNC) was associated with decline on prose recall only. After controlling for pre-operative memory score and HCV, leftward FA asymmetry of the entorhinal SWM uniquely contributed to decline in both prose and associative recall ( β = -.46; SE = .14 and β = -.68; SE = .22, respectively), and leftward FA asymmetry of the UNC uniquely contributed to decline in prose recall ( β = -.31 ; SE = .14). A model combining asymmetry of HCV and entorhinal FA correctly classified memory outcomes in 79% of patients with LTLE for prose (AUC=.89; sensitivity=82%; specificity=75%) and 81% of patients for associative (AUC=.79; sensitivity=83%; specificity=80%) recall. Entorhinal SWM asymmetry was the strongest predictor in both models.
Discussion
Pre-operative asymmetry of deep and SWM integrity within the MTL is a strong predictor of post-operative memory decline in TLE, suggesting that surgical decision-making may benefit from considering each patient’s WM network adequacy and reserve in addition to hippocampal integrity.
Classification of Evidence
This study provides Class II evidence that preoperative asymmetry of deep and SWM integrity within the MTL is a predictor of post-operative memory decline.
... Each of these surgical modifications were undertaken with the aim of minimizing the neurological morbidity and neuropsychological sequelae secondary to collateral damage of nearby structures (8). Results of selective approaches have been variable with some studies showing improved neuropsychological outcomes and others showing worse seizure freedom rates than ATLR (9). ...
Objectives: One-third of individuals with focal epilepsy do not achieve seizure freedom despite best medical therapy. Mesial temporal lobe epilepsy (MTLE) is the most common form of drug resistant focal epilepsy. Surgery may lead to long-term seizure remission if the epileptogenic zone can be defined and safely removed or disconnected. We compare published outcomes following open surgical techniques, radiosurgery (SRS), laser interstitial thermal therapy (LITT) and radiofrequency ablation (RF-TC).
Methods: PRISMA systematic review was performed through structured searches of PubMed, Embase and Cochrane databases. Inclusion criteria encompassed studies of MTLE reporting seizure-free outcomes in ≥10 patients with ≥12 months follow-up. Due to variability in open surgical approaches, only comparative studies were included to minimize the risk of bias. Random effects meta-analysis was performed to calculate effects sizes and a pooled estimate of the probability of seizure freedom per person-year. A mixed effects linear regression model was performed to compare effect sizes between interventions.
Results: From 1,801 screened articles, 41 articles were included in the quantitative analysis. Open surgery included anterior temporal lobe resection as well as transcortical and trans-sylvian selective amygdalohippocampectomy. The pooled seizure-free rate per person-year was 0.72 (95% CI 0.66–0.79) with trans-sylvian selective amygdalohippocampectomy, 0.59 (95% CI 0.53–0.65) with LITT, 0.70 (95% CI 0.64–0.77) with anterior temporal lobe resection, 0.60 (95% CI 0.49–0.73) with transcortical selective amygdalohippocampectomy, 0.38 (95% CI 0.14–1.00) with RF-TC and 0.50 (95% CI 0.34–0.73) with SRS. Follow up duration and study sizes were limited with LITT and RF-TC. A mixed-effects linear regression model suggests significant differences between interventions, with LITT, ATLR and SAH demonstrating the largest effects estimates and RF-TC the lowest.
Conclusions: Overall, novel “minimally invasive” approaches are still comparatively less efficacious than open surgery. LITT shows promising seizure effectiveness, however follow-up durations are shorter for minimally invasive approaches so the durability of the outcomes cannot yet be assessed. Secondary outcome measures such as Neurological complications, neuropsychological outcome and interventional morbidity are poorly reported but are important considerations when deciding on first-line treatments.
... To the best of our knowledge, such anastomoses have described in the literature only once. [8] Practical relevance and applications ...
... e magnitude of those deficits varies widely in the literature, but reports go as high as 60% of patients with permanent visual deficits. [8,13,16,18] erefore, a detailed understanding of this region's vasculature cannot be overstated. ...
Background: The objective of this paper was to describe the arterial supply of the uncus and quantify the branches directed to the anteromedial aspect of the human temporal cortex.
Methods: We studied 150 human cerebral hemispheres identifying main afferent arteries supplying the anteromedial temporal cortex with particular attention to the uncus, determining the territory supplied by each artery through either cortical or perforating branches.
Results: The uncus was supplied by 419 branches of the anterior choroidal artery (AChA), 210 branches of the internal carotid artery (ICA), 353 branches of the middle cerebral artery (MCA), and 122 branches of the posterior cerebral artery (PCA). The total of supplying vessels was 1104 among the 150 hemispheres studied,
which corresponds to 7.36 arteries per uncus. The average of branches per hemisphere was as follows: 2.79 from AChA, 1.40 from ICA, 2.35 from MCA, and 0.81 from PCA. The relative contribution of each artery for the total of specimens studied was as follows: 38% from AChA, 19% from ICA, 32% from the MCA, and 11% from the PCA. We identified cortical anastomoses mostly between the MCA and PCA (27 cases).
Conclusion: We described and quantified the uncus’ vascularization, including anatomical variations. This updated, detailed description of the mesial temporal vascularization is paramount to improve the treatment of neurosurgical conditions.
... The landmark for the superior extent of the resection of the amygdala is often described as an imaginary line from the inferior choroidal point to either the internal cerebral artery terminus 14 or the middle cerebral artery bifurcation. 18,19 Full exposure of the insular pia, however, allows one to use the junction of the anterior pia of the insula and the limen insula as this boundary ( Figure 5). After identifying the inferior choroidal point, this line can be demarcated on the surface of the amygdala and incised to open the ependyma overlying the amygdala, followed by deepening this incision linearly with suction, until the pia of the crural cistern is encountered, including the pia previously exposed during separation of the amygdala from the hippocampus. ...
BACKGROUND
Anterior temporal lobectomy (ATL) is the most effective treatment for drug-resistant mesial temporal lobe epilepsy. Extrapial en bloc hippocampal resection facilitates complete removal of the hippocampus. With increasing use of minimally invasive treatments, considering open resection techniques that optimize the integrity of tissue specimens is important both for obtaining the correct histopathological diagnosis and for further study.
OBJECTIVE
To describe the operative strategy and clinical outcomes associated with an extrapial approach to hippocampal resection during ATL.
METHODS
A database of epilepsy surgeries performed by a single surgeon between October 2011 and February 2019 was reviewed to identify all patients who underwent ATL using an extrapial approach to hippocampal resection. To reduce confounding variables for outcome analysis, subjects with prior resections, tumors, and cavernous malformations were excluded. Seizure outcomes were classified using the Engel scale.
RESULTS
The surgical technique is described and illustrated with intraoperative images. A total of 62 patients met inclusion criteria (31 females) for outcome analysis. Patients with most recent follow-up <3 yr (n = 33) and >3 yr (n = 29) exhibited 79% and 52% class I outcomes, respectively. An infarct was observed on postoperative magnetic resonance imaging in 3 patients (1 asymptomatic and 2 temporarily symptomatic). An en bloc specimen in which the subiculum and all hippocampal subfields were preserved was obtained in each case. Examples of innovative research opportunities resulting from this approach are presented.
CONCLUSION
Extrapial resection of the hippocampus can be performed safely with seizure freedom and complication rates at least as good as those reported with the use of subpial techniques.
... The earliest sites of amyloid plaques accrual is usually the basal part of the isocortex, with tau tangles first appearing in the transentorhinal and perirhinal cortices, all of which are supplied by the PCA and MCA. 63,64 Here we observed higher CBF in the MCA at baseline, especially in the proximal area (covering partly the hippocampus, entorhinal and perirhinal cortices and parahippocampal gyrus). Higher CBF was also observed in the proximal and middle ACA as well; areas covering amongst others the precuneus and posterior cingulate. ...
Accumulating evidence suggests vascular dysregulation in preclinical Alzheimer’s disease. In this study, cerebral hemodynamics and their coupling with cognition in middle-aged apolipoprotein ε4 carriers (APOEε4+) were investigated. Longitudinal 3 T T1-weighted and arterial spin labelling MRI data from 158 participants (40–59 years old) in the PREVENT-Dementia study were analysed (125 two-year follow-up). Cognition was evaluated using the COGNITO battery. Cerebral blood flow (CBF) and cerebrovascular resistance index (CVRi) were quantified for the flow territories of the anterior, middle and posterior cerebral arteries. CBF was corrected for underlying atrophy and individual hematocrit. Hemodynamic measures were the dependent variables in linear regression models, with age, sex, years of education and APOEε4 carriership as predictors. Further analyses were conducted with cognitive outcomes as dependent variables, using the same model as before with additional APOEε4 × hemodynamics interactions. At baseline, APOEε4+ showed increased CBF and decreased CVRi compared to non-carriers in the anterior and middle cerebral arteries, suggestive of potential vasodilation. Hemodynamic changes were similar between groups. Interaction analysis revealed positive associations between CBF changes and performance changes in delayed recall (for APOEε4 non-carriers) and verbal fluency (for APOEε4 carriers) cognitive tests. These observations are consistent with neurovascular dysregulation in middle-aged APOEε4+.
... In the last few decades, in light of the expanding body of evidence concerning the role of the AB in seizure genesis and propagation (Feindel et al. 2009), the investigation of its anatomy and connections has given extensive clinical applications in epilepsy surgery (Penfield and Baldwin 1952;Wieser and Yasargil 1982;Peuskens et al. 2004;Ellis 2008;Halpern et al. 2008;Miatton et al. 2011;Wang et al 2011;Kucukyuruk et al. 2012;Tyrand et al. 2012;Bozkurt et al 2016;Mathon and Clemeceau 2016;Muzumdar et al. 2016). In addition, it is thought that the AB plays a role in the genesis of the affective symptomatology of many neuropsychiatric disorders (Gurvits et al. 1996;Schumann and Amaral 2006;Bouchard et al 2008;Baur et al. 2013;Josephs et al. 2014) and it has been shown to be an effective deep brain stimulation (DBS) target for the treatment of the refractory forms of some of these conditions (Kennedy et al. 2011;Langevin 2012;Schlaepfer et al 2013;Sturm et al. 2013;Koek et al. 2014;Langevin et al. 2015;Luyten et al. 2016;Blomstedt et al. 2017;Lavano et al. 2018). ...
The amygdaloid body is a limbic nuclear complex characterized by connections with the thalamus, the brainstem and the neocortex. The recent advances in functional neurosurgery regarding the treatment of refractory epilepsy and several neuropsychiatric disorders renewed the interest in the study of its functional Neuroanatomy. In this scenario, we felt that a morphological study focused on the amygdaloid body and its connections could improve the understanding of the possible implications in functional neurosurgery. With this purpose we performed a morfological study using nine formalin-fixed human hemispheres dissected under microscopic magnification by using the fiber dissection technique originally described by Klingler. In our results the amygdaloid body presents two divergent projection systems named dorsal and ventral amygdalofugal pathways connecting the nuclear complex with the septum and the hypothalamus. Furthermore, the amygdaloid body is connected with the hippocampus through the amygdalo-hippocampal bundle, with the anterolateral temporal cortex through the amygdalo-temporalis fascicle, the anterior commissure and the temporo-pulvinar bundle of Arnold, with the insular cortex through the lateral olfactory stria, with the ambiens gyrus, the para-hippocampal gyrus and the basal forebrain through the cingulum, and with the frontal cortex through the uncinate fascicle. Finally, the amygdaloid body is connected with the brainstem through the medial forebrain bundle. Our description of the topographic anatomy of the amygdaloid body and its connections, hopefully represents a useful tool for clinicians and scientists, both in the scope of application and speculation.
