Microsurgical and Tractographic Anatomical Study of Transtemporal-Transchoroidal Fissure Approaches to the Ambient Cistern

2020 ◽  
Author(s):  
Emrah Egemen ◽  
Pinar Celtikci ◽  
Yücel Dogruel ◽  
Fatih Yakar ◽  
Defne Sahinoglu ◽  
...  
Keyword(s):  
White Matter ◽  
Anterior Commissure ◽  
Temporal Cortex ◽  
Anatomical Study ◽  
Middle Temporal Gyrus ◽  
Detailed Knowledge ◽  
Fiber Tractography ◽  
Human Connectome Project ◽  
Fiber Dissection ◽  
Ambient Cistern

Abstract BACKGROUND Approaching ambient cistern lesions is still a challenge because of deep location and related white matter tracts (WMTs) and neural structures. OBJECTIVE To investigate the white matter anatomy in the course of 3 types of transtemporal-transchoroidal fissure approaches (TTcFA) to ambient cistern by using fiber dissection technique with translumination and magnetic resonance imaging fiber tractography. METHODS Eight formalin-fixed cerebral hemispheres were dissected on surgical corridor from the temporal cortex to the ambient cistern by using Klingler's method. The trans-middle temporal gyrus, trans-inferior temporal sulcus (TITS), and trans-inferior temporal gyrus (TITG) approaches were evaluated. WMTs that were identified during dissection were then reconstructed on the Human Connectome Project 1021 individual template for validation. RESULTS The trans-middle gyrus approach interrupted the U fibers, arcuate fasciculus (AF), the ventral segment of inferior frontoocipital fasciculus (IFOF), the temporal extensions of the anterior commissure (AC) posterior crura, the tapetum (Tp) fibers, and the anterior loop of the optic radiation (OR). The TITS approach interrupted U fibers, inferior longitudinal fasciculus (ILF), IFOF, and OR. The TITG approach interrupted the U fibers, ILF, and OR. The middle longitudinal fasciculus, ILF, and uncinate fasciculus (UF) were not interrupted in the trans-middle gyrus approach and the AF, UF, AC, and Tp fibers were not interrupted in the TITS/gyrus approaches. CONCLUSION Surgical planning of the ambient cistern lesions requires detailed knowledge about WMTs. Fiber dissection and tractography techniques improve the orientation during surgery and may help decrease surgical complications.

scholarly journals The Connectivity–Based Parcellation of The Angular Gyrus: Fiber Dissection And MR Tractography Study

2022 ◽  
Author(s):  
Fatih Yakar ◽  
Pınar Çeltikçi ◽  
Yücel Doğruel ◽  
Emrah Egemen ◽  
Abuzer Güngör
Keyword(s):  
Anterior Commissure ◽  
Angular Gyrus ◽  
Middle Temporal Gyrus ◽  
Supramarginal Gyrus ◽  
Middle Temporal ◽  
Fiber Tracts ◽  
Human Connectome Project ◽  
Cortical Parcellation ◽  
Fiber Dissection ◽  
First Time

Abstract The angular gyrus (AG) wraps the posterior end of the superior temporal sulcus (STS), so it is considered as a continuation of the superior/middle temporal gyrus and forms the inferior parietal lobule (IPL) with the supramarginal gyrus (SMG). The AG was functionally divided in the literature, but there is no fiber dissection study in this context. This study divided AG into superior (sAG) and inferior (iAG) parts by focusing on STS. Red blue silicone injected eight human cadaveric cerebrums were dissected via the Klingler method focusing on the AG. White matter (WM) tracts identified during dissection were then reconstructed on the Human Connectome Project 1065 individual template for validation. According to this study, superior longitudinal fasciculus (SLF) II and middle longitudinal fasciculus (MdLF) are associated with sAG; the anterior commissure (AC), optic radiation (OR) with iAG; the arcuate fasciculus (AF), inferior frontooccipital fasciculus (IFOF), and tapetum (Tp) with both parts. In cortical parcellation of AG based on STS, sAG and iAG were found to be associated with different fiber tracts. Although it has been shown in previous studies that there are functionally different subunits with AG parcellation, here, for the first time, different functions of the subunits have been revealed with cadaveric dissection and tractography images.

scholarly journals Identification of a distinct association fiber tract “IPS-FG” to connect the intraparietal sulcus areas and fusiform gyrus by white matter dissection and tractography

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Tatsuya Jitsuishi ◽  
Atsushi Yamaguchi
Keyword(s):  
White Matter ◽  
Posterior Parietal Cortex ◽  
Structural Connectivity ◽  
Temporal Cortex ◽  
Fusiform Gyrus ◽  
Intraparietal Sulcus ◽  
Visuomotor Integration ◽  
Fiber Tract ◽  
Fiber Tracts ◽  
Human Connectome Project

Abstract The intraparietal sulcus (IPS) in the posterior parietal cortex (PPC) is well-known as an interface for sensorimotor integration in visually guided actions. However, our understanding of the human neural network between the IPS and the cortical visual areas has been devoid of anatomical specificity. We here identified a distinctive association fiber tract “IPS-FG” to connect the IPS areas and the fusiform gyrus (FG), a high-level visual region, by white matter dissection and tractography. The major fiber bundles of this tract appeared to arise from the medial bank of IPS, in the superior parietal lobule (SPL), and project to the FG on the ventral temporal cortex (VTC) in post-mortem brains. This tract courses vertically at the temporo-parieto-occipital (TPO) junction where several fiber tracts intersect to connect the dorsal-to-ventral cortical regions, including the vertical occipital fasciculus (VOF). We then analyzed the structural connectivity of this tract with diffusion-MRI (magnetic resonance imaging) tractography. The quantitative tractography analysis revealed the major streamlines of IPS-FG interconnect the posterior IPS areas (e.g., IP1, IPS1) with FG (e.g., TF, FFC, VVC, PHA2, PIT) on the Human Connectome Project multimodal parcellation atlas (HCP MMP 1.0). Since the fronto-parietal network, including the posterior IPS areas, is recruited by multiple cognitive demands, the IPS-FG could play a role in the visuomotor integration as well as the top-down modulation of various cognitive functions reciprocally.

Anatomy of the Anterior Temporal Lobe and the Frontotemporal Region Demonstrated by Fiber Dissection

Neurosurgery ◽  
2004 ◽  
Vol 55 (5) ◽  
pp. 1174-1184 ◽  
Author(s):  
Diedrik Peuskens ◽  
Johannes van Loon ◽  
Frank Van Calenbergh ◽  
Raymond van den Bergh ◽  
Jan Goffin ◽  
...  
Keyword(s):  
White Matter ◽  
Temporal Lobe ◽  
Anterior Commissure ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Surgical Approaches ◽  
Anterior Temporal Lobe ◽  
White Matter Tracts ◽  
Fiber Dissection ◽  
Dissection Technique

Abstract OBJECTIVE: The white matter structure of the anterior temporal lobe and the frontotemporal region is complex and not well appreciated from the available neurosurgical literature. The fiber dissection method is an excellent means of attaining a thorough knowledge of the three-dimensional structure of the white matter tracts. This study was performed to demonstrate the usefulness of the dissection technique in understanding the white matter anatomy and the effects of current surgical approaches on the subcortical structure of the region. METHODS: Seventeen brain specimens obtained at routine autopsy were dissected by use of Klingler's fiber dissection technique after preparation by fixation and freezing. The dissections were performed with an operating microscope and followed a stepwise pattern of progressive white matter dissection. RESULTS: The dissection is described in an orderly fashion showing the white matter tracts of the anterior temporal lobe and the frontotemporal region. An insight is gained into the three-dimensional course of the anterior loop of the optic radiation, the temporal stem, the anterior commissure, and the ansa peduncularis. CONCLUSION: The anterior temporal lobe and the frontotemporal region contain several important white matter tracts that can be uniquely understood by performing a white matter dissection of the region. Surgical procedures on the anterior temporal lobe differ substantially as to their repercussions on the subcortical white matter tract anatomy, as shown by the findings in this study.

scholarly journals Sleep quality relates to emotional reactivity via intracortical myelination

SLEEP ◽  
2020 ◽  
Author(s):  
Nicola Toschi ◽  
Luca Passamonti ◽  
Michele Bellesi
Keyword(s):  
White Matter ◽  
Sleep Quality ◽  
Emotional Reactivity ◽  
Temporal Cortex ◽  
Posterior Cingulate Cortex ◽  
Mediating Effect ◽  
White Matter Integrity ◽  
Poor Sleep ◽  
Negative Consequences ◽  
Human Connectome Project

Abstract A good quality and amount of sleep are fundamental to preserve cognition and affect. New evidence also indicates that poor sleep is detrimental to brain myelination. In this study, we test the hypothesis that sleep quality and/or quantity relate to variability in cognitive and emotional function via the mediating effect of interindividual differences in proxy neuroimaging measures of white matter integrity and intracortical myelination. By employing a demographically and neuropsychologically well-characterized sample of healthy people drawn from the Human Connectome Project (n = 974), we found that quality and amount of sleep were only marginally linked to cognitive performance. In contrast, poor quality and short sleep increased negative affect (i.e. anger, fear, and perceived stress) and reduced life satisfaction and positive emotionality. At the brain level, poorer sleep quality and shorter sleep duration related to lower intracortical myelin in the mid-posterior cingulate cortex (p = 0.038), middle temporal cortex (p = 0.024), and anterior orbitofrontal cortex (OFC, p = 0.034) but did not significantly affect different measures of white matter integrity. Finally, lower intracortical myelin in the OFC mediated the association between poor sleep quality and negative emotionality (p < 0.05). We conclude that intracortical myelination is an important mediator of the negative consequences of poor sleep on affective behavior.

The temporoinsular projection system: an anatomical study

2020 ◽  
Vol 132 (2) ◽  
pp. 615-623 ◽  
Author(s):  
Pieter Nachtergaele ◽  
Ahmed Radwan ◽  
Stijn Swinnen ◽  
Thomas Decramer ◽  
Mats Uytterhoeven ◽  
...  
Keyword(s):  
White Matter ◽  
Temporal Lobe ◽  
Insular Cortex ◽  
Anatomical Study ◽  
Amygdaloid Complex ◽  
Projection System ◽  
Temporal Pole ◽  
Fiber Dissection ◽  
Mesial Temporal Lobe ◽  
Association Fibers

OBJECTIVEConnections between the insular cortex and the amygdaloid complex have been demonstrated using various techniques. Although functionally well connected, the precise anatomical substrate through which the amygdaloid complex and the insula are wired remains unknown. In 1960, Klingler briefly described the “fasciculus amygdaloinsularis,” a white matter tract connecting the posterior insula with the amygdala. The existence of such a fasciculus seems likely but has not been firmly established, and the reported literature does not include a thorough description and documentation of its anatomy. In this fiber dissection study the authors sought to elucidate the pathway connecting the insular cortex and the mesial temporal lobe.METHODSFourteen brain specimens obtained at routine autopsy were dissected according to Klingler’s fiber dissection technique. After fixation and freezing, anatomical dissections were performed in a stepwise progressive fashion.RESULTSThe insula is connected with the opercula of the frontal, parietal, and temporal lobes through the extreme capsule, which represents a network of short association fibers. At the limen insulae, white matter fibers from the extreme capsule converge and loop around the uncinate fasciculus toward the temporal pole and the mesial temporal lobe, including the amygdaloid complex.CONCLUSIONSThe insula and the mesial temporal lobe are directly connected through white matter fibers in the extreme capsule, resulting in the appearance of a single amygdaloinsular fasciculus. This apparent fasciculus is part of the broader network of short association fibers of the extreme capsule, which connects the entire insular cortex with the temporal pole and the amygdaloid complex. The authors propose the term “temporoinsular projection system” (TIPS) for this complex.

scholarly journals Anterior peri-insular quadrantotomy: a cadaveric white matter dissection study

2020 ◽  
Vol 25 (4) ◽  
pp. 331-339
Author(s):  
Pablo Gonzalez-Lopez ◽  
Giulia Cossu ◽  
Etienne Pralong ◽  
Matias Baldoncini ◽  
Mahmoud Messerer ◽  
...  
Keyword(s):  
White Matter ◽  
Motor Cortex ◽  
Frontal Lobe ◽  
Anterior Commissure ◽  
Internal Capsule ◽  
The Body ◽  
White Matter Tracts ◽  
Precise Understanding ◽  
Fiber Dissection ◽  
Dissection Techniques

OBJECTIVEAnterior quadrant disconnection represents a safe surgical option in well-selected pediatric patients with a large frontal lobe lesion anterior to the motor cortex. The understanding of the anatomy of the white matter tracts connecting the frontal lobe with the rest of the cerebrum forms the basis of a safe and successful disconnective surgery. The authors explored and illustrated the relevant white matter tracts sectioned during each surgical step using fiber dissection techniques.METHODSFive human cadaveric hemispheres were dissected to illustrate the frontal connections in the 3 planes. The dissections were performed from lateral to medial, medial to lateral, and ventral to dorsal to describe the various tracts sectioned during the 4 steps of this surgery, namely the anterior suprainsular window, intrafrontal disconnection, anterior callosotomy, and frontobasal disconnection.RESULTSAt the beginning of each surgical step, the U fibers were cut. During the anterior suprainsular window, the superior longitudinal fasciculus (SLF), the uncinate fasciculus, and the inferior fronto-occipital fasciculus (IFOF) were visualized and sectioned, followed by sectioning of the anterior limb of the internal capsule. During the intrafrontal disconnection, the SLF was cut, along with the corona radiata. At the medial surface the cingulum was sectioned. The anterior callosotomy disconnected the anterior third of the body of the callosum, the genu, and the rostrum. The frontobasal disconnection addressed the last remaining fibers connecting the frontal lobe with the rest of the hemisphere, namely the anterior limb of the anterior commissure.CONCLUSIONSThe anterior peri-insular quadrantotomy aims at effectively treating children with large lesions of the frontal lobe anterior to the motor cortex. A precise understanding of the gyral anatomy of this lobe along with the several white matter connections is crucial to avoid motor complications and to ensure complete disconnection.

scholarly journals Development of human white matter pathways in utero over the second and third trimester

2021 ◽  
Vol 118 (20) ◽  
pp. e2023598118
Author(s):  
Siân Wilson ◽  
Maximilian Pietsch ◽  
Lucilio Cordero-Grande ◽  
Anthony N. Price ◽  
Jana Hutter ◽  
...  
Keyword(s):  
White Matter ◽  
Corpus Callosum ◽  
Fractional Anisotropy ◽  
Diffusion Tensor ◽  
Fetal Brain ◽  
In Utero ◽  
Developmental Trajectory ◽  
Detailed Knowledge ◽  
Human Connectome Project ◽  
Nonlinear Trends

During the second and third trimesters of human gestation, rapid neurodevelopment is underpinned by fundamental processes including neuronal migration, cellular organization, cortical layering, and myelination. In this time, white matter growth and maturation lay the foundation for an efficient network of structural connections. Detailed knowledge about this developmental trajectory in the healthy human fetal brain is limited, in part, due to the inherent challenges of acquiring high-quality MRI data from this population. Here, we use state-of-the-art high-resolution multishell motion-corrected diffusion-weighted MRI (dMRI), collected as part of the developing Human Connectome Project (dHCP), to characterize the in utero maturation of white matter microstructure in 113 fetuses aged 22 to 37 wk gestation. We define five major white matter bundles and characterize their microstructural features using both traditional diffusion tensor and multishell multitissue models. We found unique maturational trends in thalamocortical fibers compared with association tracts and identified different maturational trends within specific sections of the corpus callosum. While linear maturational increases in fractional anisotropy were seen in the splenium of the corpus callosum, complex nonlinear trends were seen in the majority of other white matter tracts, with an initial decrease in fractional anisotropy in early gestation followed by a later increase. The latter is of particular interest as it differs markedly from the trends previously described in ex utero preterm infants, suggesting that this normative fetal data can provide significant insights into the abnormalities in connectivity which underlie the neurodevelopmental impairments associated with preterm birth.

scholarly journals The white matter tracts of the cerebrum in ventricular surgery and hydrocephalus

2017 ◽  
Vol 126 (3) ◽  
pp. 945-971 ◽  
Author(s):  
Abuzer Güngör ◽  
Serhat Baydin ◽  
Erik H. Middlebrooks ◽  
Necmettin Tanriover ◽  
Cihan Isler ◽  
...  
Keyword(s):  
White Matter ◽  
Anterior Commissure ◽  
Internal Capsule ◽  
Surgical Approaches ◽  
White Matter Tracts ◽  
Lateral Ventricles ◽  
Fiber Dissection ◽  
Dissection Technique ◽  
Relationship Of ◽  
The Relationship

OBJECTIVE The relationship of the white matter tracts to the lateral ventricles is important when planning surgical approaches to the ventricles and in understanding the symptoms of hydrocephalus. The authors' aim was to explore the relationship of the white matter tracts of the cerebrum to the lateral ventricles using fiber dissection technique and MR tractography and to discuss these findings in relation to approaches to ventricular lesions. METHODS Forty adult human formalin-fixed cadaveric hemispheres (20 brains) and 3 whole heads were examined using fiber dissection technique. The dissections were performed from lateral to medial, medial to lateral, superior to inferior, and inferior to superior. MR tractography showing the lateral ventricles aided in the understanding of the 3D relationships of the white matter tracts with the lateral ventricles. RESULTS The relationship between the lateral ventricles and the superior longitudinal I, II, and III, arcuate, vertical occipital, middle longitudinal, inferior longitudinal, inferior frontooccipital, uncinate, sledge runner, and lingular amygdaloidal fasciculi; and the anterior commissure fibers, optic radiations, internal capsule, corona radiata, thalamic radiations, cingulum, corpus callosum, fornix, caudate nucleus, thalamus, stria terminalis, and stria medullaris thalami were defined anatomically and radiologically. These fibers and structures have a consistent relationship to the lateral ventricles. CONCLUSIONS Knowledge of the relationship of the white matter tracts of the cerebrum to the lateral ventricles should aid in planning more accurate surgery for lesions within the lateral ventricles.

Surgical Approaches to the Temporal Horn: An Anatomic Analysis of White Matter Tract Interruption

2016 ◽  
Vol 13 (2) ◽  
pp. 258-270 ◽  
Author(s):  
Paulo A. S. Kadri ◽  
Jean G. de Oliveira ◽  
Niklaus Krayenbühl ◽  
Uğur Türe ◽  
Evandro P. L. de Oliveira ◽  
...  
Keyword(s):  
White Matter ◽  
Anterior Commissure ◽  
Anterior Segment ◽  
Clinical Manifestations ◽  
Fiber Bundles ◽  
Surgical Approaches ◽  
Middle Temporal Gyrus ◽  
Uncinate Fasciculus ◽  
Middle Temporal ◽  
Temporal Horn

Abstract BACKGROUND: Surgical access to the temporal horn is necessary to treat tumors and vascular lesions, but is used mainly in patients with mediobasal temporal epilepsy. The surgical approaches to this cavity fall into 3 primary categories: lateral, inferior, and transsylvian. The current neurosurgical literature has underestimated the interruption of involved fiber bundles and the correlated clinical manifestations. OBJECTIVE: To delineate the interruption of fiber bundles during the different approaches to the temporal horn. METHODS: We simulated the lateral (trans-middle temporal gyrus), inferior (transparahippocampal gyrus), and transsylvian approaches in 20 previously frozen, formalin-fixed human brains (40 hemispheres). Fiber dissection was then done along the lateral and inferior aspects under the operating microscope. Each stage of dissection and its respective fiber tract interruption were defined. RESULTS: The lateral (trans-middle temporal gyrus) approach interrupted “U” fibers, the superior longitudinal fasciculus (inferior arm), occipitofrontal fasciculus (ventral segment), uncinate fasciculus (dorsolateral segment), anterior commissure (posterior segment), temporopontine, inferior thalamic peduncle (posterior fibers), posterior thalamic peduncle (anterior portion), and tapetum fibers. The inferior (transparahippocampal gyrus) approach interrupted “U” fibers, the cingulum (inferior arm), and fimbria, and transected the hippocampal formation. The transsylvian approach interrupted “U” fibers (anterobasal region of the extreme capsule), the uncinate fasciculus (ventromedial segment), and anterior commissure (anterior segment), and transected the anterosuperior aspect of the amygdala. CONCLUSION: White matter dissection improves our knowledge of the complex anatomy surrounding the temporal horn. Identifying the fiber bundles at risk during each surgical approach adds important information for choosing the appropriate surgical strategy.

The Unique Fiber Anatomy of Middle Temporal Gyrus Default Mode Connectivity

2021 ◽  
Author(s):  
Robert G Briggs ◽  
Onur Tanglay ◽  
Nicholas B Dadario ◽  
Isabella M Young ◽  
R Dineth Fonseka ◽  
...  
Keyword(s):  
White Matter ◽  
Language Processing ◽  
Ex Vivo ◽  
Diffusion Imaging ◽  
Middle Temporal Gyrus ◽  
Middle Temporal ◽  
Default Mode ◽  
Linear Sequence ◽  
Human Connectome Project ◽  
Association Fibers

Abstract BACKGROUND The middle temporal gyrus (MTG) is understood to play a role in language-related tasks such as lexical comprehension and semantic cognition. However, a more specific understanding of its key white matter connections could promote the preservation of these functions during neurosurgery. OBJECTIVE To provide a detailed description of the underlying white matter tracts associated with the MTG to improve semantic preservation during neurosurgery. METHODS Tractography was performed using diffusion imaging obtained from 10 healthy adults from the Human Connectome Project. All tracts were mapped between cerebral hemispheres with a subsequent laterality index calculated based on resultant tract volumes. Ten postmortem dissections were performed for ex vivo validation of the tractography based on qualitative visual agreement. RESULTS We identified 2 major white matter bundles leaving the MTG: the inferior longitudinal fasciculus and superior longitudinal fasciculus. In addition to long association fibers, a unique linear sequence of U-shaped fibers was identified, possibly representing a form of visual semantic transfer down the temporal lobe. CONCLUSION We elucidate the underlying fiber-bundle anatomy of the MTG, an area highly involved in the brain's language network. Improved understanding of the unique, underlying white matter connections in and around this area may augment our overall understanding of language processing as well as the involvement of higher order cerebral networks like the default mode network in these functions.

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