Microsurgical Anatomy of the White Matter Tracts in Hemispherotomy

2014 ◽  
Vol 10 (2) ◽  
pp. 305-324 ◽  
Author(s):  
Baris Kucukyuruk ◽  
Kaan Yagmurlu ◽  
Necmettin Tanriover ◽  
Mustafa Uzan ◽  
Albert L. Rhoton
Keyword(s):  
White Matter ◽  
Anterior Commissure ◽  
Posterior Part ◽  
Internal Capsule ◽  
Epileptic Seizures ◽  
Microsurgical Anatomy ◽  
Subcortical Structures ◽  
Posterior Edge ◽  
White Matter Tracts ◽  
Posterior Limb

Abstract BACKGROUND: Hemispherotomy is a surgical procedure performed for refractory epileptic seizures due to wide hemispheric damage. OBJECTIVE: To describe the microanatomy of the white matter tracts transected in a hemispherotomy and the relationship of the surgical landmarks used during the intraventricular callosotomy. METHODS: The cortical and subcortical structures were examined in 32 hemispheres. RESULTS: Incision of the temporal stem along the inferior limiting sulcus crosses the insulo-opercular fibers, uncinate, inferior occipitofrontal and middle longitudinal fasciculi, anterior commissure, and optic and auditory radiations. The incision along the superior limiting sulcus transects insulo-opercular fibers and the genu and posterior limb of internal capsule. The incision along the anterior limiting sulcus crosses the insulo-opercular fibers, anterior limb of the internal capsule, anterior commissure, and the anterior thalamic bundle. The disconnection of the posterior part of the corpus callosum may be incomplete if the point at which the last cortical branch of the anterior cerebral artery (ACA) turns upward and disappears from the view through the intraventricular exposure is used as the landmark for estimating the posterior extent of the callosotomy. This ACA branch turns upward before reaching the posterior edge of the splenium in 85% of hemispheres. The falx, followed to the posterior edge of the splenium, is a more reliable landmark for completing the posterior part of an intraventricular callosotomy. CONCLUSION: The fiber tracts disconnected in hemispherotomy were reviewed. The falx is a more reliable guide than the ACA in completing the posterior part of the intraventricular callosotomy.

Diffusion tensor imaging in neonatal encephalopathy: a systematic review

2019 ◽  
Vol 105 (5) ◽  
pp. 480-488 ◽  
Author(s):  
Megan Dibble ◽  
Mary Isabel O'Dea ◽  
Tim Hurley ◽  
Angela Byrne ◽  
Gabrielle Colleran ◽  
...  
Keyword(s):  
Diffusion Tensor Imaging ◽  
White Matter ◽  
Diffusion Tensor ◽  
Neurodevelopmental Outcome ◽  
Internal Capsule ◽  
Adverse Outcomes ◽  
Restricted Diffusion ◽  
Neonatal Encephalopathy ◽  
White Matter Tracts ◽  
Posterior Limb

Background and objectiveDiffusion tensor imaging (DTI) during the first few days of life can be used to assess brain injury in neonates with neonatal encephalopathy (NE) for outcome prediction. The goal of this review was to identify specific white matter tracts of interest that can be quantified by DTI as being altered in neonates with this condition, and to investigate its potential prognostic ability.MethodsSearches of Medline and the Cochrane Database of Systematic Reviews were conducted to identify studies with diffusion data collected in term-born neonates with NE.Results19 studies were included which described restricted diffusion in encephalopathic neonates as compared with healthy controls, with the posterior limb of the internal capsule and the genu and splenium of the corpus callosum identified as particular regions of interest. Restricted diffusion was related to adverse outcomes in the studies that conducted a follow-up of these infants.ConclusionsObtaining diffusion measures in these key white matter tracts early in life before pseudonormalisation can occur can not only identify the extent of the damage but also can be used to examine the effectiveness of treatment and to predict neurodevelopmental outcome.

scholarly journals Ideomotor Apraxia in Left Thalamic Hemorrhage: Discrepancy between Clinical Course and SPECT

1991 ◽  
Vol 4 (1) ◽  
pp. 15-24 ◽  
Author(s):  
Armin Schnider ◽  
Theodor Landis ◽  
Helmuth R. Rösler
Keyword(s):  
Left Hemisphere ◽  
Right Hemisphere ◽  
Posterior Part ◽  
Internal Capsule ◽  
Subcortical Structures ◽  
Functional Interpretation ◽  
Posterior Limb ◽  
Ideomotor Apraxia ◽  
Left Thalamus ◽  
The Right

We present a patient who developed severe ideomotor apraxia (IA) and subcortical aphasia after a hemorrhage involving the posterior part of the left thalamus and the posterior limb of the internal capsule. The cerebral blood flow (CBF) of the left hemisphere as measured by 99Tc-HM-PAO SPECT was initially diminished as compared to the right hemisphere. The apraxia and aphasia eventually resolved. Despite this clinical improvement CBF of the left hemisphere worsened. Our findings do not support the view that apraxia and aphasia following lesion of deep subcortical structures is due to cortical derangement induced by disruption of unspecific activating thalamo-cortical pathways. The results call for caution in the functional interpretation of perfusion deficits detected by SPECT.

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 Microsurgical anatomy of the inferior limiting insular sulcus and the temporal stem

2015 ◽  
Vol 122 (6) ◽  
pp. 1263-1273 ◽  
Author(s):  
Eduardo Carvalhal Ribas ◽  
Kaan Yagmurlu ◽  
Hung Tzu Wen ◽  
Albert L. Rhoton
Keyword(s):  
White Matter ◽  
Medial Temporal Lobe ◽  
Anterior Commissure ◽  
Internal Capsule ◽  
Microsurgical Anatomy ◽  
Uncinate Fasciculus ◽  
Fiber Tracts ◽  
Transsylvian Approach ◽  
Temporal Stem ◽  
Optic Radiations

OBJECT The purpose of this study was to describe the location of each white matter pathway in the area between the inferior limiting insular sulcus (ILS) and temporal horn that may be crossed in approaches through the temporal stem to the medial temporal lobe. METHODS The fiber tracts in 14 adult cadaveric cerebral hemispheres were examined using the Klingler technique. The fiber dissections were completed in a stepwise manner, identifying each white matter pathway in different planes and describing its position in relation to the anterior end of the ILS. RESULTS The short-association fibers from the extreme capsule, which continue toward the operculae, are the most superficial subcortical layer deep to the ILS. The external capsule fibers are found deeper at an intermediate layer and are formed by the uncinate fasciculus, inferior frontooccipital fasciculus, and claustrocortical fibers in a sequential anteroposterior disposition. The anterior commissure forms the next deeper layer, and the optic radiations in the sublenticular part of the internal capsule represent the deepest layer. The uncinate fasciculus is found deep to the anterior third of the ILS, whereas the inferior frontooccipital fasciculus and optic radiations are found superficial and deep, respectively, at the posterior two-thirds of this length. CONCLUSIONS The authors' findings suggest that in the transsylvian approach, a 6-mm incision beginning just posterior to the limen insula through the ILS will cross the uncinate fasciculus but not the inferior frontooccipital fasciculus or optic radiations, but that longer incisions carry a risk to language and visual functions.

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.

Diffusion tensor tractography of the temporal stem on the inferior limiting sulcus

2008 ◽  
Vol 108 (4) ◽  
pp. 775-781 ◽  
Author(s):  
Feng Wang ◽  
Tao Sun ◽  
Xing-Gang Li ◽  
Na-Jia Liu
Keyword(s):  
White Matter ◽  
Diffusion Tensor ◽  
Anterior Commissure ◽  
Region Of Interest ◽  
Diffusion Tensor Tractography ◽  
Optic Radiation ◽  
Uncinate Fasciculus ◽  
White Matter Tracts ◽  
Temporal Horn ◽  
Temporal Stem

Object The aim of this study was to use diffusion tensor tractography (DTT) to define the 3D relationships of the uncinate fasciculus, anterior commissure, inferior occipitofrontal fasciculus, inferior thalamic peduncle, and optic radiation and to determine the positioning landmarks of these white matter tracts. Methods The anatomy was studied in 10 adult human brain specimens. Brain DTT was performed in 10 healthy volunteers. Diffusion tensor tractography images of the white matter tracts in the temporal stem were obtained using the simple single region of interest (ROI) and multi-ROIs based on the anatomical knowledge. Results The posteroinferior insular point is the anterior extremity of intersection of the Heschl gyrus and the inferior limiting sulcus. On the inferior limiting sulcus, this point is the posterior limit of the optic radiation, and the temporal stem begins at the limen insulae and ends at the posteroinferior insular point. The distance from the limen insulae to the tip of the temporal horn is just one third the length of the temporal stem. The uncinate fasciculus comprises the core of the anterior temporal stem, behind which the anterior commissure and the inferior thalamic peduncle are located, and they occupy the anterior third of the temporal stem. The inferior occipitofrontal fasciculus passes through the entire temporal stem. The most anterior extent of the Meyer loop is located between the anterior tip of the temporal horn and the limen insulae. Most of the optic radiation crosses the postmedian two thirds of the temporal stem. Conclusions On the inferior limiting sulcus, the posteroinferior insular point is a reliable landmark of the posterior limit of the optic radiations. The limen insulae, anterior tip of the temporal horn, and posteroinferior insular point may be used to localize the white matter fibers of the temporal stem in analyzing magnetic resonance imaging or during surgery.

Microsurgical Anatomy of the White Matter Tracts of Brainstem and Cerebellum

2020 ◽  
pp. 199-223
Author(s):  
Nataly Mireya Alvear-Quito ◽  
Srikant S. Chakravarthi ◽  
Austin Epping ◽  
María Fernanda Tejada-Pineda ◽  
Amin B. Kassam ◽  
...  
Keyword(s):  
White Matter ◽  
Microsurgical Anatomy ◽  
White Matter Tracts

Abstract TP75: Normal Appearing White Matter Integrity and Motor Impairment Severity in Acute Ischemic Stroke

Stroke ◽  
2020 ◽  
Vol 51 (Suppl_1) ◽  
Author(s):  
Carson Ingo ◽  
Chen Lin ◽  
James Higgins ◽  
Yurany Arevalo ◽  
Shyam Prabhakaran
Keyword(s):  
Ischemic Stroke ◽  
White Matter ◽  
Acute Ischemic Stroke ◽  
Motor Function ◽  
Motor Impairment ◽  
Internal Capsule ◽  
Posterior Limb ◽  
Normal Appearing White Matter ◽  
Stroke Group ◽  
Microstructural Integrity

Introduction: The effect of white matter hyperintensities (WMH) as measured by fluid-attenuated inversion recovery (FLAIR) magnetic resonance imaging on functional impairment and recovery after ischemic stroke has been investigated thoroughly. However, there has been growing interest to investigate normal-appearing white matter (NAWM) microstructural integrity following ischemic stroke onset with techniques such as diffusion tensor imaging (DTI). Methods: 52 patients with acute ischemic stroke and 36 without stroke were evaluated with a DTI and FLAIR imaging protocol and clinically assessed for severity of motor impairment using the Motricity Index within 72 hours of suspected symptom onset. Results: There were widespread decreases in fractional anisotropy (FA) and increases in mean diffusivity (MD) and radial diffusivity (RD) for the acute stroke group compared to the non-stroke group. As shown in the abstract figure with the blue voxels, there was a significant positive association between FA and motor function and a significant negative association between MD/RD and motor function. The NAWM regions of interest that were most sensitive to the Motricity Index were the anterior/posterior limb of the internal capsule in the infarcted hemisphere and the splenium of the corpus callosum, external capsule, posterior limb/retrolenticular part of the internal capsule, superior longitudinal fasciculus, and cingulum (hippocampus) of the intra-/contralateral hemisphere. Conclusion: The microstructural integrity of NAWM is a significant parameter to identify neural differences not only between those individuals with and without acute ischemic stroke, but also correlated with severity of acute motor impairment.

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 Microsurgical anatomy of the central core of the brain

2018 ◽  
Vol 129 (3) ◽  
pp. 752-769 ◽  
Author(s):  
Eduardo Carvalhal Ribas ◽  
Kaan Yağmurlu ◽  
Evandro de Oliveira ◽  
Guilherme Carvalhal Ribas ◽  
Albert Rhoton
Keyword(s):  
White Matter ◽  
Caudate Nucleus ◽  
Internal Capsule ◽  
Central Core ◽  
Surgical Approaches ◽  
Microsurgical Anatomy ◽  
Functional Importance ◽  
Posterior Portion ◽  
External Capsule ◽  
The Brain

OBJECTIVEThe purpose of this study was to describe in detail the cortical and subcortical anatomy of the central core of the brain, defining its limits, with particular attention to the topography and relationships of the thalamus, basal ganglia, and related white matter pathways and vessels.METHODSThe authors studied 19 cerebral hemispheres. The vascular systems of all of the specimens were injected with colored silicone, and the specimens were then frozen for at least 1 month to facilitate identification of individual fiber tracts. The dissections were performed in a stepwise manner, locating each gray matter nucleus and white matter pathway at different depths inside the central core. The course of fiber pathways was also noted in relation to the insular limiting sulci.RESULTSThe insular surface is the most superficial aspect of the central core and is divided by a central sulcus into an anterior portion, usually containing 3 short gyri, and a posterior portion, with 2 long gyri. It is bounded by the anterior limiting sulcus, the superior limiting sulcus, and the inferior limiting sulcus. The extreme capsule is directly underneath the insular surface and is composed of short association fibers that extend toward all the opercula. The claustrum lies deep to the extreme capsule, and the external capsule is found medial to it. Three fiber pathways contribute to form both the extreme and external capsules, and they lie in a sequential anteroposterior disposition: the uncinate fascicle, the inferior fronto-occipital fascicle, and claustrocortical fibers. The putamen and the globus pallidus are between the external capsule, laterally, and the internal capsule, medially. The internal capsule is present medial to almost all insular limiting sulci and most of the insular surface, but not to their most anteroinferior portions. This anteroinferior portion of the central core has a more complex anatomy and is distinguished in this paper as the “anterior perforated substance region.” The caudate nucleus and thalamus lie medial to the internal capsule, as the most medial structures of the central core. While the anterior half of the central core is related to the head of the caudate nucleus, the posterior half is related to the thalamus, and hence to each associated portion of the internal capsule between these structures and the insular surface. The central core stands on top of the brainstem. The brainstem and central core are connected by several white matter pathways and are not separated from each other by any natural division. The authors propose a subdivision of the central core into quadrants and describe each in detail. The functional importance of each structure is highlighted, and surgical approaches are suggested for each quadrant of the central core.CONCLUSIONSAs a general rule, the internal capsule and its vascularization should be seen as a parasagittal barrier with great functional importance. This is of particular importance in choosing surgical approaches within this region.

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