Intractable Epilepsy and Structural Lesions of the Brain: Mapping, Resection Strategies, and Seizure Outcome

Epilepsia ◽  
1991 ◽  
Vol 32 (2) ◽  
pp. 179-186 ◽  
Author(s):  
Issam A. Awad ◽  
Jeffrey Rosenfeld ◽  
Jennifer Ahl ◽  
Joseph F. Hahn ◽  
Hans Lüders
Keyword(s):  
Brain Mapping ◽  
Intractable Epilepsy ◽  
Seizure Outcome ◽  
The Brain

scholarly journals Surgical treatment of refractory epilepsy associated with space occupying lesions experience and review

1996 ◽  
Vol 54 (3) ◽  
pp. 384-392 ◽  
Author(s):  
Paulo Thadeu Brainer-Lima ◽  
Sujai Rao ◽  
Arthur Cukiert ◽  
Elza Marcia Targas Yacubian ◽  
Gary Gronich ◽  
...  
Keyword(s):  
Surgical Treatment ◽  
Seizure Frequency ◽  
Refractory Epilepsy ◽  
Operative Procedure ◽  
Intractable Epilepsy ◽  
Special Problem ◽  
Seizure Outcome ◽  
Epileptogenic Focus ◽  
The Brain ◽  
Space Occupying Lesion

Surgery for space occupying lesions of the brain associated with intractable epilepsy represents a special problem because relief of the epilepsy is as much an operative goal as excision of the space occupying lesion itself. This study concerns 32 patients with space occupying lesions and intractable epilepsy who underwent excision of the lesion with acute intraoperative electrocorticography guided resection of the epileptogenic focus. Of the 32 patients, 16 formed a subgroup of gangliogliomas alone. The remaining were mixed lesions, predominantly benign. The duration of seizures in these patients ranged from 2 to 30 years, and the seizure frequency varied from 1 to 300 convulsions per month. The operative procedures included temporal corticectomy, amygdalo-hippocampectomy, and extratemporal corticectomies. Twenty nine patients were in Engel class I postoperatively, and three patients were in Engel class II. The findings with gangliogliomas are also considered in a separate group. This study strongly suggests that the operative procedure under electrocorticography guidance improves seizure outcome in space occuping lesions related intractable epilepsy.

Brain Mapping in Functional Neurosurgery

2011 ◽  
pp. 127-134
Author(s):  
George Zouridakis ◽  
Javier Diaz ◽  
Farhan Baluch
Keyword(s):  
Brain Mapping ◽  
Developmental Disorders ◽  
Sensor Arrays ◽  
Intractable Epilepsy ◽  
Functional Brain ◽  
Functional Brain Mapping ◽  
Brain Functions ◽  
Technological Advances ◽  
Powerful Research Tool ◽  
The Brain

Functional brain mapping is a procedure that can be used to identify cortical areas that mediate sensorimotor and higher cognitive brain functions, such as language, attention, memory, and cognition. Clinically, it is currently used for preoperative surgical planning in patients suffering from intractable epilepsy and brain tumors, and may soon have significant applications in brain injury, stroke, dementia, and developmental disorders. Functional brain mapping is also a very powerful research tool in the area of cognitive neuroscience and, lately, in psychiatry. Recent technological advances in neuroimaging techniques, the development of large sensor arrays, the use of sophisticated computer systems and superior graphics, gradually make more apparent the relevance of this technique in providing answers to complex questions about the structural and functional connectivity of the brain, and the way it represents and processes information.

Neuro-Clinical Signatures of Language Impairments: A Theoretical Framework for Function-to-structure Mapping in Clinics

2020 ◽  
Vol 20 (9) ◽  
pp. 800-811 ◽  
Author(s):  
Ferath Kherif ◽  
Sandrine Muller
Keyword(s):  
Brain Mapping ◽  
Theoretical Framework ◽  
Brain Regions ◽  
Language Impairments ◽  
Structure Mapping ◽  
Language Functions ◽  
The Past ◽  
Language Recovery ◽  
The Brain ◽  
Bow Tie

In the past decades, neuroscientists and clinicians have collected a considerable amount of data and drastically increased our knowledge about the mapping of language in the brain. The emerging picture from the accumulated knowledge is that there are complex and combinatorial relationships between language functions and anatomical brain regions. Understanding the underlying principles of this complex mapping is of paramount importance for the identification of the brain signature of language and Neuro-Clinical signatures that explain language impairments and predict language recovery after stroke. We review recent attempts to addresses this question of language-brain mapping. We introduce the different concepts of mapping (from diffeomorphic one-to-one mapping to many-to-many mapping). We build those different forms of mapping to derive a theoretical framework where the current principles of brain architectures including redundancy, degeneracy, pluri-potentiality and bow-tie network are described.

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 Mapping Sensorimotor Cortex With Slow Cortical Potential Resting-State Networks While Awake and Under Anesthesia

Neurosurgery ◽  
2012 ◽  
Vol 71 (2) ◽  
pp. 305-316 ◽  
Author(s):  
Jonathan D. Breshears ◽  
Charles M. Gaona ◽  
Jarod L. Roland ◽  
Mohit Sharma ◽  
David T. Bundy ◽  
...  
Keyword(s):  
Brain Mapping ◽  
Sensorimotor Cortex ◽  
Resting State ◽  
Intractable Epilepsy ◽  
Cortical Potential ◽  
Data Driven ◽  
Resting State Networks ◽  
Seed Selection ◽  
Brain Organization ◽  
Slow Cortical Potential

Abstract BACKGROUND: The emerging insight into resting-state cortical networks has been important in our understanding of the fundamental architecture of brain organization. These networks, which were originally identified with functional magnetic resonance imaging, are also seen in the correlation topography of the infraslow rhythms of local field potentials. Because of the fundamental nature of these networks and their independence from task-related activations, we posit that, in addition to their neuroscientific relevance, these slow cortical potential networks could play an important role in clinical brain mapping. OBJECTIVE: To assess whether these networks would be useful in identifying eloquent cortex such as sensorimotor cortex in patients both awake and under anesthesia. METHODS: This study included 9 subjects undergoing surgical treatment for intractable epilepsy. Slow cortical potentials were recorded from the cortical surface in patients while awake and under propofol anesthesia. To test brain-mapping utility, slow cortical potential networks were identified with data-driven (seed-independent) and anatomy-driven (seed-based) approaches. With electrocortical stimulation used as the gold standard for comparison, the sensitivity and specificity of these networks for identifying sensorimotor cortex were calculated. RESULTS: Networks identified with a data-driven approach in patients under anesthesia and awake were 90% and 93% sensitive and 58% and 55% specific for sensorimotor cortex, respectively. Networks identified with systematic seed selection in patients under anesthesia and awake were 78% and 83% sensitive and 67% and 60% specific, respectively. CONCLUSION: Resting-state networks may be useful for tailoring stimulation mapping and could provide a means of identifying eloquent regions in patients while under anesthesia.

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.

scholarly journals Characterization of postsurgical functional connectivity changes in temporal lobe epilepsy

2020 ◽  
Vol 133 (2) ◽  
pp. 392-402 ◽  
Author(s):  
Victoria L. Morgan ◽  
Baxter P. Rogers ◽  
Hernán F. J. González ◽  
Sarah E. Goodale ◽  
Dario J. Englot
Keyword(s):  
Functional Connectivity ◽  
Temporal Lobe ◽  
Network Connectivity ◽  
Temporal Lobectomy ◽  
Seizure Outcome ◽  
Seizure Recurrence ◽  
Female Age ◽  
Selective Amygdalohippocampectomy ◽  
The Brain

OBJECTIVESeizure outcome after mesial temporal lobe epilepsy (mTLE) surgery is complex and diverse, even across patients with homogeneous presurgical clinical profiles. The authors hypothesized that this is due in part to variations in network connectivity across the brain before and after surgery. Although presurgical network connectivity has been previously characterized in these patients, the objective of this study was to characterize presurgical to postsurgical functional network connectivity changes across the brain after mTLE surgery.METHODSTwenty patients with drug-refractory unilateral mTLE (5 left side, 10 female, age 39.3 ± 13.5 years) who underwent either selective amygdalohippocampectomy (n = 13) or temporal lobectomy (n = 7) were included in the study. Presurgical and postsurgical (36.6 ± 14.3 months after surgery) functional connectivity (FC) was measured with 3-T MRI and compared with findings in age-matched healthy controls (n = 44, 21 female, age 39.3 ± 14.3 years). Postsurgical connectivity changes were then related to seizure outcome, type of surgery, and presurgical disease parameters.RESULTSThe results demonstrated significant decreases of FC from control group values across the brain after surgery that were not present before surgery, including many contralateral hippocampal connections distal to the surgical site. Postsurgical impairment of contralateral precuneus to ipsilateral occipital connectivity was associated with seizure recurrence. Presurgical impairment of the contralateral precuneus to contralateral temporal lobe connectivity was associated with those who underwent selective amygdalohippocampectomy compared to those who had temporal lobectomy. Finally, changes in thalamic connectivity after surgery were linearly related to duration of epilepsy and frequency of consciousness-impairing seizures prior to surgery.CONCLUSIONSThe widespread contralateral hippocampal FC changes after surgery may be a reflection of an ongoing epileptogenic progression that has been altered by the surgery, rather than a direct result of the surgery itself. This network evolution may contribute to long-term seizure outcome. Therefore, the combination of presurgical network mapping with the understanding of the dynamic effects of surgery on the networks may ultimately be used to create predictors of the likelihood of long-term seizure recurrence in individual patients after mTLE surgery.

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