Pre-surgical mapping of eloquent cortex for paediatric epilepsy surgery candidates: Evidence from a review of advanced functional neuroimaging (original) (raw)
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Real-Time Functional Mapping With Electrocorticography in Pediatric Epilepsy
Clinical EEG and Neuroscience, 2013
SIGFRIED (SIGnal modeling For Real-time Identification and Event Detection) software provides real-time functional mapping (RTFM) of eloquent cortex for epilepsy patients preparing to undergo resective surgery. This study presents the first application of paradigms used in functional magnetic resonance (fMRI) and electrical cortical stimulation mapping (ESM) studies for shared functional cortical mapping in the context of RTFM. Results from the 3 modalities are compared. A left-handed 13-year-old male with intractable epilepsy participated in functional mapping for localization of eloquent language cortex with fMRI, ESM, and RTFM. For RTFM, data were acquired over the frontal and temporal cortex. Several paradigms were sequentially presented: passive (listening to stories) and active (picture naming and verb generation). For verb generation and story processing, fMRI showed atypical right lateralizing language activation within temporal lobe regions of interest and bilateral frontal...
Epilepsia, 2018
We aimed to investigate the current practices guiding surgical resection strategies involving epileptogenic zones (EZs) near or in eloquent cortex (EC) at pediatric epilepsy surgery centers worldwide. A survey was conducted among 40 respondents from 33 pediatric epilepsy surgery centers worldwide on the weight assigned to diagnostic tests used to define the EZ and EC, how EC is viewed, and how surgeries are planned for foci near or in eloquent cortex. A descriptive analysis was performed that revealed considerable variation in the use of diagnostic tests and resective strategies toward EZ and EC. The wide variation in strategies may contribute to undesirable outcomes characterized by poor seizure control with added deficits and underscores the need to establish best practices in pediatric epilepsy surgery. The survey data were used to formulate a set of recommendations to help minimize deficits and to report them consistently.
Real-time functional MR imaging (fMRI) for presurgical evaluation of paediatric epilepsy
Pediatric Radiology, 2007
Background The role of fMRI in the presurgical evaluation of children with intractable epilepsy is being increasingly recognized. Real-time fMRI allows the clinician to visualize functional brain activation in real time. Since there is no off-line data analysis as in conventional fMRI, the overall time for the procedure is reduced, making it clinically feasible in a busy clinical sitting. Objective (1) To study the accuracy of real-time fMRI in comparison to conventional fMRI with off-line processing; (2) to determine its effectiveness in mapping the eloquent cortex and language lateralization in comparison to invasive procedures such as intraoperative cortical stimulation and Wada testing; and (3) to evaluate the role of fMRI in presurgical decision making in children with epilepsy. Materials and methods A total of 23 patients (age range 6–18 years) underwent fMRI with sensorimotor, visual and language paradigms. Data processing was done in real time using in-line BOLD. Results The results of real-time fMRI matched those of off-line processing done using the well-accepted standard technique of statistical parametric mapping (SPM) in all the initial ten patients in whom the two techniques were compared. Coregistration of the fMRI data on a 3-D FLAIR sequence rather than a T1-weighted image gave better information regarding the relationship of the lesion to the area of activation. The results of intraoperative cortical stimulation and fMRI matched in six out of six patients, while the Wada test and fMRI had similar results in four out of five patients in whom these techniques were performed. In the majority of patients in this series the technique influenced patient management. Conclusion Real-time fMRI is an easily performed and reliable technique in the presurgical workup of children with epilepsy.
Neurosurgical Focus, 2020
OBJECTIVEThe goal of this study was to evaluate the predictive value and relative contribution of noninvasive presurgical functional imaging modalities based on the authors’ institutional experience in pursuing seizure-free surgical outcomes in children with medically refractory epilepsy.METHODSThis was a retrospective, single-institution, observational cohort study of pediatric patients who underwent evaluation and surgical treatment for medically refractory partial epilepsy between December 2003 and June 2016. During this interval, 108 children with medically refractory partial epilepsy underwent evaluation for localization and resective epilepsy surgery. Different noninvasive functional imaging modalities, including ictal SPECT, FDG-PET, and magnetoencephalography–magnetic source imaging, were utilized to augment a standardized paradigm (electroencephalography/semiology, MRI, and neuropsychology findings) for localization. Outcomes were evaluated at a minimum of 2 years (mean 7.5...
UTILITY FUNCTIONAL MAGNETIC RESONANCE IMAGING IN CHILDREN WITH EPILEPSY
Evaluation of brain imaging has evolved over the past 15 years, moving from analysing the structure to function through functional magnetic resonance imagery (fMRI). This investigation in children with epilepsy is made in order to understand brain functional areas and the function of epileptic brain and for surgery planning. In this article we present the usefulness and limitations of functional MRI to children diagnosed with epilepsy.
Functional MRI Applications in Epilepsy Surgery
Canadian Journal of Neurological Sciences / Journal Canadien des Sciences Neurologiques, 2012
Functional magnetic resonance imaging (fMRI) is a non-invasive neuroimaging technique that has grown rapidly in popularity over the past decade. It is already prevalent in psychology, cognitive and basic neuroscience research and is being used increasingly as a tool for clinical decision-making in epilepsy. It has been used to determine language location and laterality in patients, sometimes eliminating the need for invasive tests. fMRI can been used pre-surgically to guide resection margins, preserving eloquent cortex. Other fMRI paradigms assessing memory, visual and somatosensory systems have limited clinical applications currently, but show great promise. Simultaneous recording of electroencephalogram (EEG) and fMRI has also provided insights into the networks underlying seizure generation and is increasingly being used in epilepsy centres. In this review, we present some of the current clinical applications for fMRI in the pre-surgical assessment of epilepsy patients, and exami...
Neuroimaging as a Clinical Tool in Surgical Planning and Guidance for Pediatric Epilepsy
2011
Epilepsy is the fourth most common neurological disorder in all ages. According to the Epilepsy Foundation, 1% of the population is expected to develop epilepsy before 20 years of age. Extratemporal cortical resection is the most common curative epilepsy surgery in infants* and children, whereas temporal lobectomy is the most common in adults. Children with intractable epilepsy may benefit from early surgical intervention to avoid the potential negative effects of continued seizures and prolonged use of Neuroimaging as a Clinical Tool in Surgical Planning and Guidance for Pediatric Epilepsy
The utility of functional magnetic resonance imaging in epilepsy and language
Current neurology and neuroscience reports, 2002
Functional magnetic resonance imaging (fMRI) is a viable presurgical tool for use with the pediatric epilepsy population as replacement for the intra-carotid sodium amobarbital test (IAT) used to identify hemispheric language dominance. This paper reviews the current imaging research on the identification of language cortex in pediatric epilepsy patients and in normal children. A review of the literature comparing fMRI to the IAT and electrocortical stimulation suggests that fMRI reliably identifies the dominant hemisphere, with pediatric and adult studies producing comparable results. Within-hemisphere localization of eloquent cortex with fMRI is more problematic. Paradigm selection, data analysis techniques, and considerations specific to imaging children are discussed. Utility of fMRI for studying neural plasticity as a result of brain insult (e.g., epilepsy) is also considered.
Neurosurgery, 2009
To determine the clinical value of motor functional magnetic resonance imaging (fMRI) in the presurgical evaluation of a large group of children and adolescents with epilepsy caused by lesions close to the central sulcus. METHODS: Forty-three patients (19 males; mean age, 13 years) with lesional focal epilepsy underwent motor fMRI as part of a multidisciplinary standardized presurgical evaluation between 2000 and 2006. fMRI data were analyzed using statistical parametric mapping (SPM2) and screened for the presence of movement-related artifacts. The ways in which the results of motor fMRI influenced the decision-making process were reviewed. RESULTS: The success rate of motor fMRI was 93% and data were of high quality in 67.5% of the patients. Together with other clinical considerations, motor fMRI results contributed to the surgical management of 32 patients (74%). They helped 1) to determine the type of surgery in 23 patients (72%; 12 cases with and 11 cases without invasive functional mapping), 2) to indicate a reduced benefit-risk ratio with the consequence that surgery was not further considered in 5 patients (16%), and 3) to indicate that surgery was not an appropriate option because of the high risk of motor function deficit in 4 patients (12%). CONCLUSION: Motor fMRI can be performed with a high degree of success and good data quality in this population of patients. It has an important additive role in the discussion of the feasibility of resective surgery contributing to the decision-making process for children with epilepsy caused by brain lesions close to the central sulcus.