White Matter Governed Superior Frontal Sulcus Surgical Paradigm: A Radioanatomic Microsurgical Study—Part II

2020 ◽  
Vol 19 (4) ◽  
pp. E357-E369
Author(s):  
Amin B Kassam ◽  
Alejandro Monroy-Sosa ◽  
Melanie B Fukui ◽  
Bhavani Kura ◽  
Jonathan E Jennings ◽  
...  
Keyword(s):  
White Matter ◽  
Literature Review ◽  
Diffusion Tensor ◽  
Ventricular Catheter ◽  
Clinical Safety ◽  
Frontal Horn ◽  
Pubmed Database ◽  
Entry Points ◽  
Frontal Aslant Tract ◽  
Superior Frontal Sulcus

Abstract BACKGROUND Kocher's point (KP) and its variations have provided standard access to the frontal horn (FH) for over a century. Anatomic understanding of white matter tracts (WMTs) has evolved, now positioning us to better inform the optimal FH trajectory. OBJECTIVE To (1) undertake a literature review analyzing entry points (EPs) to the FH; (2) introduce a purpose-built WMT-founded superior frontal sulcus parafascicular (SFSP)-EP also referred to as the Kassam-Monroy entry point (KM-EP); and (3) compare KM-EP with KP and variants with respect to WMTs. METHODS (1) Literature review (PubMed database, 1892-2018): (a) stratification based on the corridor: i. ventricular catheter; ii. through-channel endoscopic; or iii. portal; (b) substratification based on intent: i. preoperatively planned or ii. intraoperative (postdural opening) for urgent ventricular drainage. (2) Anatomic comparisons of KM-EP, KP, and variants via (a) cadaveric dissections and (b) magnetic resonance-diffusion tensor imaging computational 3D modeling. RESULTS A total of 31 studies met inclusion criteria: (a) 9 utilized KP coordinate (1 cm anterior to the coronal suture (y-axis) and 3 cm lateral of the midline (x-axis) approximated by the midpupillary line) and 22 EPs represented variations. All 31 traversed critical subcortical WMTs, specifically the frontal aslant tract, superior longitudinal fasciculus II, and inferior fronto-occipital fasciculus, whereas KM-EP (x = 2.3, y = 3.5) spares these WMTs. CONCLUSION KP (x = 3, y = 1) conceived over a century ago, prior to awareness of WMTs, as well as its variants, anatomically place critical WMTs at risk. The KM-EP (x = 2.3, y = 3.5) is purpose built and founded on WMTs, representing anatomically safe access to the FH. Correlative clinical safety, which will be directly proportional to the size of the corridor, is yet to be established in prospective studies.

White Matter-Governed Superior Frontal Sulcus Surgical Paradigm: A Radioanatomic Microsurgical Study—Part I

2020 ◽  
Vol 19 (4) ◽  
pp. E343-E356 ◽  
Author(s):  
Alejandro Monroy-Sosa ◽  
Srikant S Chakravarthi ◽  
Melanie B Fukui ◽  
Bhavani Kura ◽  
Jonathan E Jennings ◽  
...  
Keyword(s):  
White Matter ◽  
Diffusion Tensor ◽  
Internal Capsule ◽  
Entry Point ◽  
Coronal Suture ◽  
Corona Radiata ◽  
Cingulum Bundle ◽  
Sagittal Sinus ◽  
Precentral Sulcus ◽  
Superior Frontal Sulcus

Abstract BACKGROUND Frontal subcortical and intraventricular pathologies are traditionally accessed via transcortical or interhemispheric-transcallosal corridors. OBJECTIVE To describe the microsurgical subcortical anatomy of the superior frontal sulcus (SFS) corridor. METHODS Cadaveric dissections were undertaken and correlated with magnetic resonance imaging/diffusion-tensor imaging-Tractography. Surgical cases demonstrated clinical applicability. RESULTS SFS was divided into the following divisions: proximal, precentral sulcus to coronal suture; middle, 3-cm anterior to coronal suture; and distal, middle division to the orbital crest. Anatomy was organized as layered circumferential rings projecting radially towards the ventricles: (1) outer ring: at the level of the SFS, the following lengths were measured: (A) precentral sulcus to coronal suture = 2.29 cm, (B) frontal bone projection of superior sagittal sinus (SSS) to SFS = 2.37 cm, (C) superior temporal line to SFS = 3.0 cm, and (D) orbital crest to distal part of SFS = 2.32 cm; and (2) inner ring: (a) medial to SFS, U-fibers, frontal aslant tract (FAT), superior longitudinal fasciculus I (SLF-I), and cingulum bundle, (b) lateral to SFS, U-fibers, (SLF-II), claustrocortical fibers (CCF), and inferior fronto-occipital fasciculus, and (c) intervening fibers, FAT, corona radiata, and CCF. The preferred SFS parafascicular entry point (SFSP-EP) also referred to as the Kassam-Monroy entry point (KM-EP) bisects the distance between the midpupillary line and the SSS and has the following coordinates: x = 2.3 cm (lateral to SSS), y ≥ 3.5 cm (anterior to CS), and z = parallel corona radiata and anterior limb of the internal capsule. CONCLUSION SFS corridor can be divided into lateral, medial, and intervening white matter tract segments. Based on morphometric assessment, the optimal SFSP-EP is y ≥ 3.5 cm, x = 2.3 cm, and z = parallel to corona radiata and anterior limb of the internal capsule.

scholarly journals Diffusion tensor imaging revealed different pathological processes of white matter hyperintensities

2019 ◽  
Author(s):  
Zhigang Min ◽  
Hairong Shan ◽  
Long Xu ◽  
Daihai Yuan ◽  
Xuexia Sheng ◽  
...  
Keyword(s):  
Diffusion Tensor Imaging ◽  
White Matter ◽  
White Matter Hyperintensities ◽  
Diffusion Tensor ◽  
Mean Diffusivity ◽  
Brain Regions ◽  
Periventricular White Matter ◽  
Frontal Horn ◽  
Fazekas Scale ◽  
Normal White Matter

Abstract Background The purpose of this study was to verify the pathological heterogeneity of white matter hyperintensities (WMHs). We compared diffusion tensor imaging (DTI) metrics within different brain regions using identical grading protocols, and subsequently investigated the microstructural changes in these areas as the WMH progressed. Methods Seventy-three patients with WMH and 18 healthy controls who received DTI were included in this study. We measured fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (DA), and radial diffusivity (DR) of periventricular and deep WMH in six brain regions and grouped these measures according to the Fazekas scale. We then compared the DTI metrics of different regions with the same Fazekas scale grade. Results Significantly lower FA values (all p<0.001), and higher MD (all p<0.001) and DR values (all p<0.001) were associated with WMH observed within the periventricular white matter around the frontal horn (pFH) and the frontal lateral ventricle (pFLV) compared to other regions with the same Fazekas grades. However, in the normal white matter of the pFH and pFLV, FA was not significantly lower than all other regions. Furthermore, in these areas, MD, DA, and DR were not significantly higher than in all other regions. Conclusion Distinct pathological processes occurred within frontal periventricular WMH and other regions; these processes may represent the effects of severe demyelination within the frontal periventricular white matter.

scholarly journals STMO-09 Recovery from speech deficit after injury to frontal aslant tract in glioma surgery

2020 ◽  
Vol 2 (Supplement_3) ◽  
pp. ii10-ii10
Author(s):  
Kuniaki Saito ◽  
Keiichi Kobayashi ◽  
Daisuke Shimada ◽  
Shohei Iijima ◽  
Nobuyoshi Sasaki ◽  
...  
Keyword(s):  
White Matter ◽  
Diffusion Tensor ◽  
Inferior Frontal Gyrus ◽  
Lower Grade ◽  
Dominant Hemisphere ◽  
Language Deficits ◽  
Glioma Surgery ◽  
Language Deficit ◽  
Language Recovery ◽  
Frontal Aslant Tract

Abstract BACKGROUND: The frontal aslant tract (FAT) is a white matter fiber connecting the superior frontal gyrus to the lateral inferior frontal gyrus. Damage to FAT in dominant hemisphere can lead to speech deficits which, in most cases, resolve within weeks to months. However, little is known about mechanisms of recovery and factors for predicting permanent language deficits. METHODS: Eighteen patients with glioma (age ranged 24 to 78, 10 glioblastomas and 8 lower grade gliomas) located in the medial frontal lobe in the dominant hemisphere involving the supplementary motor area (SMA) and FAT were included. FAT was visualized using diffusion tensor imaging tractography in pre- and postoperative MRI. Postoperative language deficit, resected area of FAT and surrounding brain regions including the cingulate gyrus and corpus callosum (CC) were retrospectively reviewed. RESULTS: In 17 of 18 cases, postoperative language deficits were observed. Speech deficits resolved within a month in 12 cases, while recovery was incomplete in five cases. In two patients without complete recovery, CC located beneath SMA was removed because of tumor infiltration. Other two patients had substantial injury of middle third portion of FAT. The last case had preceding infarction in the contralateral frontal white matter including FAT. In cases with complete language recovery, transcallosal fibers connecting the contralateral SMA to the ipsilateral inferior frontal gyrus were detected by postoperative DTI-tractography. These fibers were damaged anywhere along its length in patients without complete language recovery, indicating that they may play an important role in recovery after FAT injury. CONCLUSION: Injury to CC or middle third portion of FAT can cause permanent language disorder. Transcallosal fibers from contralateral SMA seems to be involved in the recovery from language deficit after injury to FAT. In glioma surgery involving dominant SMA or FAT, these fibers should be preserved to avoid permanent speech deficit.

Ventriculostomy-associated hemorrhage: a risk assessment by radiographic simulation

2017 ◽  
Vol 127 (3) ◽  
pp. 532-536 ◽  
Author(s):  
Faith C. Robertson ◽  
Muhammad M. Abd-El-Barr ◽  
Srinivasan Mukundan ◽  
William B. Gormley
Keyword(s):  
Intracranial Hemorrhage ◽  
Tertiary Care ◽  
Patient Specific ◽  
Ventricular Catheter ◽  
Empirical Measures ◽  
Cortical Vein ◽  
Vessel Injury ◽  
Frontal Horn ◽  
Entry Points ◽  
Vein Injury

OBJECTIVEVentriculostomy entry sites are commonly selected by freehand estimation of Kocher's point or approximations from skull landmarks and a trajectory toward the ipsilateral frontal horn of the lateral ventricles. A recognized ventriculostomy complication is intracranial hemorrhage from cortical vessel damage; reported rates range from 1% to 41%. In this report, the authors assess hemorrhagic risk by simulating traditional ventriculostomy trajectories and using CT angiography (CTA) with venography (CTV) data to identify potential complications, specifically from cortical draining veins.METHODSRadiographic analysis was completed on 50 consecutive dynamic CTA/CTV studies obtained at a tertiary-care academic neurosurgery department. Image sections were 0.5 mm thick, and analysis was performed on a venous phase that demonstrated high-quality opacification of the cortical veins and sagittal sinus. Virtual ventriculostomy trajectories were determined for right and left sides using medical diagnostic imaging software. Entry points were measured along the skull surface, 10 cm posteriorly from the nasion, and 3 cm laterally for both left and right sides. Cannulation was simulated perpendicular to the skull surface. Distances between the software-traced cortical vessels and the virtual catheter were measured. To approximate vessel injury by twist drill and ventricular catheter placement, veins within a 3-mm radius were considered a hemorrhage risk.RESULTSIn 100 virtual lines through Kocher's point toward the ipsilateral ventricle, 19% were predicted to cause cortical vein injury and suspected hemorrhage (radius ≤ 3 mm). Little difference existed between cerebral hemispheres (right 18%, left 20%). The average (± SD) distance from the trajectory line and a cortical vein was 7.23 ± 4.52 mm. In all 19 images that predicted vessel injury, a site of entry for an avascular zone near Kocher's point could be achieved by moving the trajectory less than 1.0 cm laterally and less than 1.0 cm along the anterior/posterior axis, suggesting that empirical measures are suboptimal, and that patient-specific coordinates based on preprocedural CTA/CVA imaging may optimize ventriculostomy in the future.CONCLUSIONSIn this institutional radiographic imaging analysis, traditional methods of ventriculostomy site selection predicted significant rates of cortical vein injury, matching described rates in the literature. CTA/CTV imaging potentiates identification of patient-specific cannulation sites and custom trajectories that avoid cortical vessels, which may lessen the risk of intracranial hemorrhage during ventriculostomy placement. Further development of this software is underway to facilitate stereotactic ventriculostomy and improve outcomes.

Individual differences in white and grey matter structure associated with verbal habits of thought

2019 ◽  
Author(s):  
Justin C. Hayes ◽  
Katherine L Alfred ◽  
Rachel Pizzie ◽  
Joshua S. Cetron ◽  
David J. M. Kraemer
Keyword(s):  
Individual Differences ◽  
White Matter ◽  
Cognitive Processing ◽  
Grey Matter ◽  
Structural Changes ◽  
Structural Integrity ◽  
Diffusion Tensor ◽  
Self Report ◽  
White Matter Tracts

Modality specific encoding habits account for a significant portion of individual differences reflected in functional activation during cognitive processing. Yet, little is known about how these habits of thought influence long-term structural changes in the brain. Traditionally, habits of thought have been assessed using self-report questionnaires such as the visualizer-verbalizer questionnaire. Here, rather than relying on subjective reports, we measured habits of thought using a novel behavioral task assessing attentional biases toward picture and word stimuli. Hypothesizing that verbal habits of thought are reflected in the structural integrity of white matter tracts and cortical regions of interest, we used diffusion tensor imaging and volumetric analyses to assess this prediction. Using a whole-brain approach, we show that word bias is associated with increased volume in several bilateral language regions, in both white and grey matter parcels. Additionally, connectivity within white matter tracts within an a priori speech production network increased as a function of word bias. These results demonstrate long-term structural and morphological differences associated with verbal habits of thought.

Accuracy of diffusion tensor magnetic resonance imaging tractography assessed using intraoperative subcortical stimulation mapping and magnetic source imaging

2007 ◽  
Vol 107 (3) ◽  
pp. 488-494 ◽  
Author(s):  
Jeffrey I. Berman ◽  
Mitchel S. Berger ◽  
Sungwon Chung ◽  
Srikantan S. Nagarajan ◽  
Roland G. Henry
Keyword(s):  
White Matter ◽  
Magnetic Resonance ◽  
Diffusion Tensor ◽  
Fiber Tracking ◽  
Bipolar Electrode ◽  
Source Imaging ◽  
Magnetic Source Imaging ◽  
Motor Pathway ◽  
Magnetic Source ◽  
Subcortical Stimulation

Object Resecting brain tumors involves the risk of damaging the descending motor pathway. Diffusion tensor (DT)–imaged fiber tracking is a noninvasive magnetic resonance (MR) technique that can delineate the subcortical course of the motor pathway. The goal of this study was to use intraoperative subcortical stimulation mapping of the motor tract and magnetic source imaging to validate the utility of DT-imaged fiber tracking as a tool for presurgical planning. Methods Diffusion tensor-imaged fiber tracks of the motor tract were generated preoperatively in nine patients with gliomas. A mask of the resultant fiber tracks was overlaid on high-resolution T1- and T2-weighted anatomical MR images and used for stereotactic surgical navigation. Magnetic source imaging was performed in seven of the patients to identify functional somatosensory cortices. During resection, subcortical stimulation mapping of the motor pathway was performed within the white matter using a bipolar electrode. Results A total of 16 subcortical motor stimulations were stereotactically identified in nine patients. The mean distance between the stimulation sites and the DT-imaged fiber tracks was 8.7 ±3.1 mm (±standard deviation). The measured distance between subcortical stimulation sites and DT-imaged fiber tracks combines tracking technique errors and all errors encountered with stereotactic navigation. Conclusions Fiber tracks delineated using DT imaging can be used to identify the motor tract in deep white matter and define a safety margin around the tract.

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