T he incidence of pediatric epilepsy ranges from 23–102 per 100,000 individuals in the US, with up to one-third of these cases remaining medically refractory. 14 , 22 In these cases, various surgical techniques may be utilized to achieve seizure freedom, including resection, functional disconnection, stereotactic laser ablation, vagal nerve stimulation, and reciprocal neurostimulation. 10 , 18 , 29 Especially given the increased frequency of atypical language organization in this patient population, determining language laterality and localization in pediatric
Virendra R. Desai, Aditya Vedantam, Sandi K. Lam, Lucia Mirea, Stephen T. Foldes, Daniel J. Curry, P. David Adelson, Angus A. Wilfong, and Varina L. Boerwinkle
Darrin J. Lee, Nader Pouratian, Susan Y. Bookheimer, and Neil A. Martin
provide the topographic specificity offered by fMR imaging. 3 Given these constraints, fMR imaging, with corroborating evidence from Wada testing, intraoperative ESM, and clinical outcomes, likely offers the best opportunity to study language distribution and organization in patients with vascular malformations. Although language lateralization and dominance in patients with vascular malformations has been previously studied, prior reports have focused on global laterality indices as a measure of language dominance. 18 , 27 However, the reports indicated that Broca
Tomer Gazit, Fani Andelman, Yifat Glikmann-Johnston, Tal Gonen, Aliya Solski, Irit Shapira-Lichter, Moran Ovadia, Svetlana Kipervasser, Miriam Y. Neufeld, Itzhak Fried, Talma Hendler, and Daniella Perry
A crucial aspect of neurosurgery within or close to eloquent cortex is the preoperative identification of brain regions involved in a number of cognitive, sensory, or motor tasks. In the presurgical assessment of language, both the localization 38 and lateralization 28 , 32 of functional areas are essential for the prevention of postoperative deficits such as aphasia and dysarthria. More specifically, assessing language lateralization in patients with epilepsy is challenging and complex because of their atypical language network. Language structure
Daiana R. Pur, Roy Eagleson, Marcus Lo, Michael T. Jurkiewicz, Andrea Andrade, and Sandrine de Ribaupierre
lateralization; in case 12, verb generation resulted in bilateral language localization and picture naming on the right, while rs-fMRI showed left language lateralization. In case 2, both tasks indicated right language lateralization, while rs-fMRI indicated left language lateralization. Overlap between the rs-fMRI language networks and task-based fMRI language networks is illustrated for 2 cases in Fig. 4 . FIG. 4. Resting-state fMRI and task-based fMRI language network maps for case 4 ( upper ) and case 3 ( lower ). RSN maps are represented on an MNI template (3 × 3 × 3 mm
Brittany M. Stopa, Joeky T. Senders, Marike L. D. Broekman, Mark Vangel, and Alexandra J. Golby
score as less than chance (< 0), slight (0.01–0.20), fair (0.21–0.40), moderate (0.41–0.60), substantial (0.61–0.80), and near perfect (0.81–0.99), as given by Viera and Garrett. 15 Intended Purpose for Ordering fMRI The most common goals for ordering fMRI were to: identify language laterality (n = 46, 92%), plan extent of resection (n = 44, 88%), and discuss neurological risks with the patient (n = 43, 86%). In response to how useful they thought fMRI was for these purposes (scale 0–100), responders rated “identify language laterality” as a median of 79 (IQR 66
Bornali Kundu, Amy Penwarden, Joel M. Wood, Thomas A. Gallagher, Matthew J. Andreoli, Jed Voss, Timothy Meier, Veena A. Nair, John S. Kuo, Aaron S. Field, Chad Moritz, M. Elizabeth Meyerand, and Vivek Prabhakaran
of a slow-growing lesion that encroaches on a functional area and hypothetically causes recruitment of surrounding brain areas, or even the homologous contralateral areas, to compensate for functional loss. 22 , 25 Language lateralization can be quantified by calculating the LI, which is the difference in the ratio of significantly activated voxels between the left and right hemispheres, determined while the individual is performing a task. 29 While LI seems to depend on numerous factors, such as the task used, 37 statistical thresholding, 24 and lesion type
Olivia Foesleitner, Benjamin Sigl, Victor Schmidbauer, Karl-Heinz Nenning, Ekaterina Pataraia, Lisa Bartha-Doering, Christoph Baumgartner, Susanne Pirker, Doris Moser, Michelle Schwarz, Johannes A. Hainfellner, Thomas Czech, Christian Dorfer, Georg Langs, Daniela Prayer, Silvia Bonelli, and Gregor Kasprian
uncorrected p value (p uncorr) threshold < 0.001 were considered for further analysis. For group analysis, preoperative scans (verb-generation and semantic task) were contrasted to postoperative scans at p < 0.001 for left or right TLEs separately. Additionally, a metric language laterality index (LI) was calculated from each activation map using a bootstrap algorithm. 18 Broca’s and Wernicke’s areas and their contralateral homologs were defined according to the network atlas integrated in the CONN toolbox, congruent to FC analysis. 19 This parcellation is based on an
Andrew S. Little, Kris A. Smith, Kristin Kirlin, Leslie C. Baxter, Steve Chung, Rama Maganti, and David M. Treiman
The authors introduce a minimal-access subtemporal approach for selective resection of the amygdala and hippocampus in patients with temporal lobe epilepsy and describe seizure and neuropsychological outcomes.
Between October 2003 and April 2007, 41 consecutive patients with intractable unilateral nonlesional temporal lobe epilepsy underwent image-guided subtemporal amygdalohippocampectomy. Baseline characteristics, preoperative evaluations, and seizure outcomes were assessed. Eighteen patients underwent pre- and postoperative neuropsychological testing for cognitive functioning, executive functioning, verbal and visual memory, and mood.
Important aspects of the subtemporal approach include a low temporal keyhole craniotomy, use of image guidance, preservation of the tentorium, incision in the fusiform gyrus, and subpial, en bloc resection of the hippocampus. There were no deaths and no cases of significant postoperative morbidity. At 1 year, 29 of 36 patients (81%) were without seizures or auras. At 2 years, 17 of 23 (74%) patients were seizure- and aura-free. Detailed neuropsychological testing of language, memory, cognitive functioning, and executive functioning suggested that most patients exhibited either stability or improvement in their scores, regardless of language lateralization.
A minimal-access subtemporal approach for amygdalohippocampectomy is an effective treatment for temporal lobe epilepsy yielding encouraging preliminary seizure and neuropsychological outcomes.
Yi-Ching Lynn Ho, Keith Yu-Ching Goh, Xavier Golay, Wee-Tin Hong, Shih-Hui Lim, Andrew Beng-Siong Pan, Violet Gek-Eng Chua, Francis Hui, and Yih-Yian Sitoh
if surgery is performed, thereby minimizing morbidity. Although assessments of other cases of craniopagus soon after birth have typically focused on structural/morphological aspects, the maturity of the patients in the present case made possible and necessitated the assessment of language functionality. Our findings should provide interesting data on language laterality in twins, which has been postulated as genetically influenced and correlated with handedness. 18, 23, 43, 45 Such information might be obtained noninvasively by using fMR imaging studies with the
Xiaofeng Deng, Yan Zhang, Long Xu, Bo Wang, Shuo Wang, Jun Wu, Dong Zhang, Rong Wang, Jia Wang, and Jizong Zhao
dominance. However, it has been reported that the Broca and Wernicke areas can be lateralized asymmetrically in the setting of intracranial lesions. 12 , 19 , 24 In such a case, studying the global LI alone, which could lead to wrong conclusions regarding language lateralization, might be inappropriate, because the activated voxels in different hemispheres will offset each other according to the formula of the LI. Therefore, we assessed the Broca and Wernicke areas separately in this study. Little is known about the difference in patterns of language cortex