scholarly journals Successful hemispherotomy for a patient with intractable epilepsy secondary to bilateral congenital brain malformation with lateralized pyramidal tract of diffusion tensor image tractography

2016 ◽  
Vol 6 ◽  
pp. 30-32 ◽  
Author(s):  
Yuri Nagai ◽  
Ayataka Fujimoto ◽  
Tohru Okanishi ◽  
Hironao Motoi ◽  
Sotaro Kanai ◽  
...  
Keyword(s):  
Diffusion Tensor ◽  
Pyramidal Tract ◽  
Intractable Epilepsy ◽  
Diffusion Tensor Image ◽  
Brain Malformation ◽  
Congenital Brain Malformation

scholarly journals Resection of cerebral gangliogliomas causing drug-resistant epilepsy: short- and long-term outcomes using intraoperative MRI and neuronavigation

2015 ◽  
Vol 38 (1) ◽  
pp. E5 ◽  
Author(s):  
Björn Sommer ◽  
Cornelia Wimmer ◽  
Roland Coras ◽  
Ingmar Blumcke ◽  
Bogdan Lorber ◽  
...  
Keyword(s):  
Diffusion Tensor ◽  
Intraoperative Imaging ◽  
Intractable Epilepsy ◽  
Complete Resection ◽  
Blood Oxygenation ◽  
Seizure Outcome ◽  
Incomplete Resection ◽  
Brain Areas ◽  
Total Resection

OBJECT Cerebral gangliogliomas (GGs) are highly associated with intractable epilepsy. Incomplete resection due to proximity to eloquent brain regions or misinterpretation of the resection amount is a strong negative predictor for local tumor recurrence and persisting seizures. A potential method for dealing with this obstacle could be the application of intraoperative high-field MRI (iopMRI) combined with neuronavigation. METHODS Sixty-nine patients (31 female, 38 male; median age 28.5 ± 15.4 years) suffering from cerebral GGs were included in this retrospective study. Five patients received surgery twice in the observation period. In 48 of the 69 patients, 1.5-T iopMRI combined with neuronavigational guidance was used. Lesions close to eloquent brain areas were resected with the implementation of preoperative diffusion tensor imaging tractography and blood oxygenation level–dependent functional MRI (15 patients). RESULTS Overall, complete resection was accomplished in 60 of 69 surgical procedures (87%). Two patients underwent biopsy only, and in 7 patients, subtotal resection was accomplished because of proximity to critical brain areas. Excluding the 2 biopsies, complete resection using neuronavigation/iopMRI was documented in 33 of 46 cases (72%) by intraoperative imaging. Remnant tumor mass was identified intraoperatively in 13 of 46 patients (28%). After intraoperative second-look surgery, the authors improved the total resection rate by 9 patients (up to 91% [42 of 46]). Of 21 patients undergoing conventional surgery, 14 (67%) had complete resection without the use of iopMRI. Regarding epilepsy outcome, 42 of 60 patients with seizures (70%) became completely seizure free (Engel Class IA) after a median follow-up time of 55.5 ± 36.2 months. Neurological deficits were found temporarily in 1 (1.4%) patient and permanently in 4 (5.8%) patients. CONCLUSIONS Using iopMRI combined with neuronavigation in cerebral GG surgery, the authors raised the rate of complete resection in this series by 19%. Given the fact that total resection is a strong predictor of long-term seizure control, this technique may contribute to improved seizure outcome and reduced neurological morbidity.

scholarly journals Utility of diffusion tensor imaging studies linked to neuronavigation and other modalities in repeat hemispherotomy for intractable epilepsy

2016 ◽  
Vol 17 (4) ◽  
pp. 483-490 ◽  
Author(s):  
Erin N. Kiehna ◽  
Elysa Widjaja ◽  
Stephanie Holowka ◽  
O. Carter Snead ◽  
James Drake ◽  
...  
Keyword(s):  
Diffusion Tensor Imaging ◽  
Diffusion Tensor ◽  
Intractable Epilepsy ◽  
Seizure Freedom ◽  
Rasmussen’S Encephalitis ◽  
Initial Procedure ◽  
Surgical Options ◽  
Failed Surgery ◽  
Association Fibers

OBJECT Hemispherectomy for unilateral, medically refractory epilepsy is associated with excellent long-term seizure control. However, for patients with recurrent seizures following disconnection, workup and investigation can be challenging, and surgical options may be limited. Few studies have examined the role of repeat hemispherotomy in these patients. The authors hypothesized that residual fiber connections between the hemispheres could be the underlying cause of recurrent epilepsy in these patients. Diffusion tensor imaging (DTI) was used to test this hypothesis, and to target residual connections at reoperation using neuronavigation. METHODS The authors identified 8 patients with recurrent seizures following hemispherectomy who underwent surgery between 1995 and 2012. Prolonged video electroencephalography recordings documented persistent seizures arising from the affected hemisphere. In all patients, DTI demonstrated residual white matter association fibers connecting the hemispheres. A repeat craniotomy and neuronavigation-guided targeted disconnection of these residual fibers was performed. Engel class was used to determine outcome after surgery at a minimum of 2 years of follow-up. RESULTS Two patients underwent initial hemidecortication and 6 had periinsular hemispherotomy as their first procedures at a median age of 9.7 months. Initial pathologies included hemimegalencephaly (n = 4), multilobar cortical dysplasia (n = 3), and Rasmussen's encephalitis (n = 1). The mean duration of seizure freedom for the group after the initial procedure was 32.5 months (range 6–77 months). In all patients, DTI showed limited but definite residual connections between the 2 hemispheres, primarily across the rostrum/genu of the corpus callosum. The median age at reoperation was 6.8 years (range 1.3–14 years). The average time taken for reoperation was 3 hours (range 1.8–4.3 hours), with a mean blood loss of 150 ml (range 50–250 ml). One patient required a blood transfusion. Five patients are seizure free, and the remaining 3 patients are Engel Class II, with a minimum follow-up of 24 months for the group. CONCLUSIONS Repeat hemispherotomy is an option for consideration in patients with recurrent intractable epilepsy following failed surgery for catastrophic epilepsy. In conjunction with other modalities to establish seizure onset zones, advanced MRI and DTI sequences may be of value in identifying patients with residual connectivity between the affected and unaffected hemispheres. Targeted disconnection of these residual areas of connectivity using neuronavigation may result in improved seizure outcomes, with minimal and acceptable morbidity.

scholarly journals Brain tumor classification using the diffusion tensor image segmentation (D-SEG) technique

2014 ◽  
Author(s):  
T. L. Jones ◽  
T. J. Byrnes ◽  
G. Yang ◽  
F. A. Howe ◽  
B. A. Bell ◽  
...  
Keyword(s):  
Image Segmentation ◽  
Brain Tumor ◽  
Diffusion Tensor ◽  
Tumor Classification ◽  
Diffusion Tensor Image

scholarly journals The Translational Role of Diffusion Tensor Image Analysis in Animal Models of Developmental Pathologies

2012 ◽  
Vol 34 (1) ◽  
pp. 5-19 ◽  
Author(s):  
Ipek Oguz ◽  
Matthew S. McMurray ◽  
Martin Styner ◽  
Josephine M. Johns
Keyword(s):  
Image Analysis ◽  
Animal Models ◽  
Diffusion Tensor ◽  
Diffusion Tensor Image

Accuracy of Diffusion Tensor Magnetic Resonance Imaging-Based Tractography for Surgery of Gliomas Near the Pyramidal Tract

Neurosurgery ◽  
2011 ◽  
Vol 70 (2) ◽  
pp. 283-294 ◽  
Author(s):  
Shiro Ohue ◽  
Shohei Kohno ◽  
Akihiro Inoue ◽  
Daisuke Yamashita ◽  
Hironobu Harada ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Motor Function ◽  
Navigation System ◽  
Diffusion Tensor ◽  
Pyramidal Tract ◽  
Motor Evoked Potentials ◽  
Fiber Tracking ◽  
Integrated Navigation ◽  
Threshold Intensity ◽  
Integrated Navigation System

Abstract BACKGROUND: Diffusion tensor (DT) imaging-based fiber tracking is a noninvasive magnetic resonance technique that can delineate the course of white matter fibers. OBJECTIVE: To evaluate the accuracy and usefulness of this DT imaging-based fiber tracking for surgery in patients with gliomas near the pyramidal tract (PT). METHODS: Subjects comprised 32 patients with gliomas near the PT. DT imaging-based fiber tracks of the PT were generated before and within 3 days after surgery in all patients. A tractography-integrated navigation system was used during the operation. Cortical and subcortical motor-evoked potentials (MEPs) were also monitored during resection to maximize the preservation of motor function. The threshold intensity for subcortical MEPs was examined by searching the stimulus points and changing the stimulus intensity. Minimum distance between the resection border and the illustrated PT was measured on postoperative tractography. RESULTS: In all subjects, DT imaging-based tractography of the PT was successfully performed, preoperatively demonstrating the relationship between tumors and the PT. With the use of the tractography-integrated navigation system and intraoperative MEPs, motor function was preserved postoperatively in all patients. A significant correlation was seen between threshold intensity for subcortical MEPs and the distance between the resection border and PT on postoperative DT imaging. CONCLUSION: DT imaging-based fiber tracking is a reliable and accurate method for mapping the course of subcortical PTs. Fiber tracking and intraoperative MEPs were useful for preserving motor function in patients with gliomas near the PT.

scholarly journals Local and Distant responses to single pulse electrical stimulation reflect different forms of connectivity

2020 ◽  
Author(s):  
Britni Crocker ◽  
Lauren Ostrowski ◽  
Ziv M. Williams ◽  
Darin D. Dougherty ◽  
Emad N. Eskandar ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Resting State ◽  
Diffusion Tensor ◽  
Effective Connectivity ◽  
Clinical Care ◽  
Structural Connectivity ◽  
Intractable Epilepsy ◽  
Single Pulse ◽  
Intracranial Electrode ◽  
The Brain

AbstractBackgroundMeasuring connectivity in the human brain can involve innumerable approaches using both noninvasive (fMRI, EEG) and invasive (intracranial EEG or iEEG) recording modalities, including the use of external probing stimuli, such as direct electrical stimulation.Objective/HypothesisTo examine how different measures of connectivity correlate with one another, we compared ‘passive’ measures of connectivity during resting state conditions map to the more ‘active’ probing measures of connectivity with single pulse electrical stimulation (SPES).MethodsWe measured the network engagement and spread of the cortico-cortico evoked potential (CCEP) induced by SPES at 53 total sites across the brain, including cortical and subcortical regions, in patients with intractable epilepsy (N=11) who were undergoing intracranial recordings as a part of their clinical care for identifying seizure onset zones. We compared the CCEP network to functional, effective, and structural measures of connectivity during a resting state in each patient. Functional and effective connectivity measures included correlation or Granger causality measures applied to stereoEEG (sEEGs) recordings. Structural connectivity was derived from diffusion tensor imaging (DTI) acquired before intracranial electrode implant and monitoring (N=8).ResultsThe CCEP network was most similar to the resting state voltage correlation network in channels near to the stimulation location. In contrast, the distant CCEP network was most similar to the DTI network. Other connectivity measures were not as similar to the CCEP network.ConclusionsThese results demonstrate that different connectivity measures, including those derived from active stimulation-based probing, measure different, complementary aspects of regional interrelationships in the brain.

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