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Kokkinos V, Seimenis I. Concordance of verbal memory and language fMRI lateralization in people with epilepsy. J Neuroimaging 2024; 34:95-107. [PMID: 37968766 DOI: 10.1111/jon.13171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2023] [Revised: 10/29/2023] [Accepted: 11/01/2023] [Indexed: 11/17/2023] Open
Abstract
BACKGROUND AND PURPOSE This work investigates verbal memory functional MRI (fMRI) versus language fMRI in terms of lateralization, and assesses the validity of performing word recognition during the functional scan. METHODS Thirty patients with a diagnosis of epilepsy underwent verbal memory, visuospatial memory, and language fMRI. We used word encoding, word recognition, image encoding, and image recognition memory tasks, and semantic description, reading comprehension, and listening comprehension language tasks. We used three common lateralization metrics: network spatial distribution, maximum statistical value, and laterality index (LI). RESULTS Lateralization of signal spatial distribution resulted in poor similarity between verbal memory and language fMRI tasks. Signal maximum lateralization showed significant (>.8) but not perfect (1) similarity. Word encoding LI showed significant correlation only with listening comprehension LI (p = .016). Word recognition LI was significantly correlated with expressive language semantic description LI (p = .024) and receptive language reading and listening comprehension LIs (p = .015 and p = .019, respectively). There was no correlation between LIs of the visuospatial tasks and LIs of the language tasks. CONCLUSIONS Our results support the association between language and verbal memory lateralization, optimally determined by LI quantification, and the introduction of quantitative means for language fMRI interpretation in clinical settings where verbal memory lateralization is imperative.
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Affiliation(s)
- Vasileios Kokkinos
- Comprehensive Epilepsy Center, Northwestern Memorial Hospital, Chicago, Illinois, USA
- Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
- Department of Medicine, School of Health Sciences, Democritus University of Thrace, Alexandroupoli, Greece
| | - Ioannis Seimenis
- Department of Medicine, School of Health Sciences, Democritus University of Thrace, Alexandroupoli, Greece
- Medical School, National and Kapodistrian University of Athens, Athens, Greece
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Kaur N, Nowacki AS, Lachhwani DK, Berl MM, Hamberger MJ, Klaas P, Bingaman W, Busch RM. Characterization and Prediction of Short-term Outcomes in Memory After Temporal Lobe Resection in Children With Epilepsy. Neurology 2023; 100:e1878-e1886. [PMID: 36927884 PMCID: PMC10159761 DOI: 10.1212/wnl.0000000000207143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Accepted: 01/19/2023] [Indexed: 03/18/2023] Open
Abstract
BACKGROUND AND OBJECTIVES The aim of this study was to characterize short-term outcomes in episodic memory, as assessed by the Children's Memory Scale (CMS), after temporal lobe resection in children with epilepsy using empirical methods for assessing cognitive change (i.e., reliable change indices [RCI] and standardized regression-based change scores [SRB]) and develop and internally validate clinically applicable models to predict postoperative memory decline. METHODS This retrospective cohort study included children aged 6-16 years who underwent resective epilepsy surgery that included the temporal lobe (temporal only: "temporal" and multilobar: "temporal plus") and who completed preoperative and postoperative neuropsychological assessments including the CMS. Change scores on the CMS delayed memory subtests (Faces, Stories, and Word Pairs) were classified as decline, no change, or improvement using epilepsy-specific RCI and SRB. Logistic regression models for predicting postoperative memory decline were developed and internally validated with bootstrapping. RESULTS Of the 126 children included, most of them demonstrated either no significant change (54%-69%) or improvement (8%-14%) in memory performance using RCI on individual measures at a median of 7 months after surgery. A subset of children (23%-33%) showed postoperative declines. Change distributions obtained using RCI and SRB were not statistically significantly different from each other. Preoperative memory test score, surgery side, surgery extent, and preoperative full-scale IQ were predictors of memory decline. Prediction models for memory decline included subsets of these variables with bias-corrected concordance statistics ranging from 0.70 to 0.75. The models were well calibrated although slightly overestimated the probability of verbal memory decline in high-risk patients. DISCUSSION This study used empiric methodology to characterize memory outcome in children after temporal lobe resection. Provided online calculator and nomograms may be used by clinicians to estimate the risk of postoperative memory decline for individual patients before surgery.
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Affiliation(s)
- Navkiranjot Kaur
- From the Cleveland Clinic Lerner College of Medicine (N.K., A.S.N., R.M.B.), Case Western Reserve University; Quantitative Health Sciences (A.S.N.), Lerner Research Institute, Cleveland Clinic; Epilepsy Center (D.K.L., W.B., R.M.B.), Neurological Institute, Cleveland Clinic, OH; Division of Pediatric Neuropsychology (M.M.B.), Childrens National Medical Center, Washington, DC; Department of Neurology (M.J.H.), Columbia University Medical Center, New York, NY; and Department of Psychiatry & Psychology (P.K., R.M.B.), and Department of Neurology (P.K., R.M.B.), Neurological Institute, Cleveland Clinic, OH
| | - Amy S Nowacki
- From the Cleveland Clinic Lerner College of Medicine (N.K., A.S.N., R.M.B.), Case Western Reserve University; Quantitative Health Sciences (A.S.N.), Lerner Research Institute, Cleveland Clinic; Epilepsy Center (D.K.L., W.B., R.M.B.), Neurological Institute, Cleveland Clinic, OH; Division of Pediatric Neuropsychology (M.M.B.), Childrens National Medical Center, Washington, DC; Department of Neurology (M.J.H.), Columbia University Medical Center, New York, NY; and Department of Psychiatry & Psychology (P.K., R.M.B.), and Department of Neurology (P.K., R.M.B.), Neurological Institute, Cleveland Clinic, OH
| | - Deepak K Lachhwani
- From the Cleveland Clinic Lerner College of Medicine (N.K., A.S.N., R.M.B.), Case Western Reserve University; Quantitative Health Sciences (A.S.N.), Lerner Research Institute, Cleveland Clinic; Epilepsy Center (D.K.L., W.B., R.M.B.), Neurological Institute, Cleveland Clinic, OH; Division of Pediatric Neuropsychology (M.M.B.), Childrens National Medical Center, Washington, DC; Department of Neurology (M.J.H.), Columbia University Medical Center, New York, NY; and Department of Psychiatry & Psychology (P.K., R.M.B.), and Department of Neurology (P.K., R.M.B.), Neurological Institute, Cleveland Clinic, OH
| | - Madison M Berl
- From the Cleveland Clinic Lerner College of Medicine (N.K., A.S.N., R.M.B.), Case Western Reserve University; Quantitative Health Sciences (A.S.N.), Lerner Research Institute, Cleveland Clinic; Epilepsy Center (D.K.L., W.B., R.M.B.), Neurological Institute, Cleveland Clinic, OH; Division of Pediatric Neuropsychology (M.M.B.), Childrens National Medical Center, Washington, DC; Department of Neurology (M.J.H.), Columbia University Medical Center, New York, NY; and Department of Psychiatry & Psychology (P.K., R.M.B.), and Department of Neurology (P.K., R.M.B.), Neurological Institute, Cleveland Clinic, OH
| | - Marla J Hamberger
- From the Cleveland Clinic Lerner College of Medicine (N.K., A.S.N., R.M.B.), Case Western Reserve University; Quantitative Health Sciences (A.S.N.), Lerner Research Institute, Cleveland Clinic; Epilepsy Center (D.K.L., W.B., R.M.B.), Neurological Institute, Cleveland Clinic, OH; Division of Pediatric Neuropsychology (M.M.B.), Childrens National Medical Center, Washington, DC; Department of Neurology (M.J.H.), Columbia University Medical Center, New York, NY; and Department of Psychiatry & Psychology (P.K., R.M.B.), and Department of Neurology (P.K., R.M.B.), Neurological Institute, Cleveland Clinic, OH
| | - Patricia Klaas
- From the Cleveland Clinic Lerner College of Medicine (N.K., A.S.N., R.M.B.), Case Western Reserve University; Quantitative Health Sciences (A.S.N.), Lerner Research Institute, Cleveland Clinic; Epilepsy Center (D.K.L., W.B., R.M.B.), Neurological Institute, Cleveland Clinic, OH; Division of Pediatric Neuropsychology (M.M.B.), Childrens National Medical Center, Washington, DC; Department of Neurology (M.J.H.), Columbia University Medical Center, New York, NY; and Department of Psychiatry & Psychology (P.K., R.M.B.), and Department of Neurology (P.K., R.M.B.), Neurological Institute, Cleveland Clinic, OH
| | - William Bingaman
- From the Cleveland Clinic Lerner College of Medicine (N.K., A.S.N., R.M.B.), Case Western Reserve University; Quantitative Health Sciences (A.S.N.), Lerner Research Institute, Cleveland Clinic; Epilepsy Center (D.K.L., W.B., R.M.B.), Neurological Institute, Cleveland Clinic, OH; Division of Pediatric Neuropsychology (M.M.B.), Childrens National Medical Center, Washington, DC; Department of Neurology (M.J.H.), Columbia University Medical Center, New York, NY; and Department of Psychiatry & Psychology (P.K., R.M.B.), and Department of Neurology (P.K., R.M.B.), Neurological Institute, Cleveland Clinic, OH
| | - Robyn M Busch
- From the Cleveland Clinic Lerner College of Medicine (N.K., A.S.N., R.M.B.), Case Western Reserve University; Quantitative Health Sciences (A.S.N.), Lerner Research Institute, Cleveland Clinic; Epilepsy Center (D.K.L., W.B., R.M.B.), Neurological Institute, Cleveland Clinic, OH; Division of Pediatric Neuropsychology (M.M.B.), Childrens National Medical Center, Washington, DC; Department of Neurology (M.J.H.), Columbia University Medical Center, New York, NY; and Department of Psychiatry & Psychology (P.K., R.M.B.), and Department of Neurology (P.K., R.M.B.), Neurological Institute, Cleveland Clinic, OH.
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Deifelt Streese C, Manzel K, Wu Z, Tranel D. Lateralized differences for verbal learning across trials in temporal lobe epilepsy are not affected by surgical intervention. Epilepsy Behav 2022; 128:108561. [PMID: 35065396 PMCID: PMC8898285 DOI: 10.1016/j.yebeh.2022.108561] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Revised: 01/03/2022] [Accepted: 01/04/2022] [Indexed: 11/24/2022]
Abstract
This research aimed to broaden understanding of learning verbal material in participants with left- and right-sided mesial temporal lobe epilepsy (MTLE). We modeled word list-learning to determine how anterior temporal lobe resection affects verbal learning. Verbal learning (across trials) was assessed using the first five trials of the Rey Auditory Verbal Learning Test (RAVLT) in 128 participants with MTLE. Mixedeffects modeling was used to determine whether learning curves differed between participants with left- and right-sided MTLE pre- and post- anterior temporal lobe resection. Laterality of MTLE had a significant effect on both the model intercept and the linear slope, whereby participants with left-sided MTLE retained fewer words on both the first trial and on each subsequent trial than participants with right-sided MTLE; and this held regardless of anterior temporal lobe resection status (t(117) = -3.516, p < .001; t(120.50) = -2.049, p = .042, for intercept and linear slope, respectively). There were no significant differences in the learning curves after anterior temporal lobe resection surgery in either left- or right-sided MTLE. Our findings suggest that acquisition of verbal information may be especially impaired in patients with left-sided MTLE. Further, we show that verbal learning across trials was not affected by surgical intervention. This finding contributes to the broader understanding of the impacts of anterior temporal lobe resection on verbal memory function, and has important implications for the clinical management and surgical planning for patients with temporal lobe epilepsy.
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Affiliation(s)
- Carolina Deifelt Streese
- Department of Neurosurgery, Carver College of Medicine, 200 Hawkins Drive, Iowa City, IA 52242, United States; Department of Neurology, Carver College of Medicine, 200 Hawkins Drive, Iowa City, IA 52242, United States.
| | - Kenneth Manzel
- Department of Neurology, Carver College of Medicine, 200 Hawkins Drive, Iowa City, IA 52242, United States
| | - Zhengyuan Wu
- Department of Neurology, Carver College of Medicine, 200 Hawkins Drive, Iowa City, IA 52242, United States
| | - Daniel Tranel
- Department of Neurology, Carver College of Medicine, 200 Hawkins Drive, Iowa City, IA 52242, United States; Department of Psychological and Brain Sciences, University of Iowa, 340 Iowa Avenue, Iowa City, IA 52242, United States
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Feasibility, Contrast Sensitivity and Network Specificity of Language fMRI in Presurgical Evaluation for Epilepsy and Brain Tumor Surgery. Brain Topogr 2021; 34:511-524. [PMID: 33837867 DOI: 10.1007/s10548-021-00839-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Accepted: 03/30/2021] [Indexed: 02/05/2023]
Abstract
Language fMRI has become an integral part of the planning process in brain surgery. However, fMRI may suffer from confounding factors both on the patient side, as well as on the provider side. In this study, we investigate how patient-related confounds affect the ability of the patient to perform language fMRI tasks (feasibility), the task sensitivity from an image contrast point of view, and the anatomical specificity of expressive and receptive language fMRI protocols. 104 patients were referred for language fMRI in the context of presurgical procedures for epilepsy and brain tumor surgery. Four tasks were used: (1) a verbal fluency (VF) task to map vocabulary use, (2) a semantic description (SD) task to map sentence formation/semantic integration skills, (3) a reading comprehension (RC) task and (4) a listening comprehension (LC) task. Feasibility was excellent in the LC task (100%), but in the acceptable to mediocre range for the rest of the tasks (SD: 87.50%, RC: 85.57%, VF: 67.30%). Feasibility was significantly confounded by age (p = 0.020) and education level (p = 0.003) in VF, by education level (p = 0.004) and lesion laterality (p = 0.019) in SD and by age (p = 0.001), lesion laterality (p = 0.007) and lesion severity (p = 0.048) in RC. All tasks were comparable regarding sensitivity in generating statistically significant image contrast (VF: 90.00%, SD: 92.30%, RC: 93.25%, LC: 88.46%). The lobe of the lesion (p = 0.005) and the age (p = 0.009) confounded contrast sensitivity in the VF and SD tasks respectively. Both VF and LC tasks demonstrated unilateral lateralization of posterior language areas; only the LC task showed unilateral lateralization of anterior language areas. Our study highlights the effects of patient-related confounding factors on language fMRI and proposes LC as the most feasible, less confounded, and efficiently lateralizing task in the clinical presurgical context.
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Comparison of Language and Memory Lateralization by Functional MRI and Wada Test in Epilepsy. FRONTIERS IN NEUROLOGY AND NEUROSCIENCE RESEARCH 2021; 2:100009. [PMID: 34189523 PMCID: PMC8238456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The intracarotid sodium amobarbital procedure (ISAP or Wada test) lateralizes cerebral functions to the cerebral hemispheres preoperatively. Functional magnetic resonance imaging (fMRI) is increasingly used to characterize preoperative language and memory lateralization. In this study, concordance of fMRI with Wada was examined in patients with medically intractable seizures. The relationship of the distance between the epileptogenic focus to functional activation area with patients' post-operative deficits in language was also analyzed. 27 epilepsy patients with preoperative fMRI and Wada data were analyzed using established fMRI paradigms for language and memory. Activation of Broca's and Wernicke's areas were measured in three dimensions. Language and memory lateralization were determined, and standard neuropsychiatry Wada test procedures were used for comparison. The shortest distance between a language area to the border of surgical focus (LAD) was also measured and compared with postoperative language deficits. Our study found that concordance between fMRI and Wada testing was 0.41 (Kappa's 'fair to good' concordance) for language dominance and 0.1 (Kappa's 'poor' concordance) for memory. No significant correlation was found between LAD and post-op language deficit (p=0.439). A correlation was found between LAD and post-op memory deficit (p=0.049; the further distance from surgical lesion to language area is associated with less post-operative memory loss). Females demonstrated significantly increased postoperative seizure improvement (Fisher's p-value=0.0296; female=8; male=6). A significant association between handedness (right-handed subjects) and postoperative seizure improvement was found (p=0.02) as well as a significant trend for interaction of gender and handedness on postoperative seizure improvement (p=0.09). Overall, our results demonstrate fMRI as a useful preoperative adjunct to Wada testing for language lateralization in patients with medically intractable seizures.
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Foit NA, Bernasconi A, Bernasconi N. Functional Networks in Epilepsy Presurgical Evaluation. Neurosurg Clin N Am 2020; 31:395-405. [PMID: 32475488 DOI: 10.1016/j.nec.2020.03.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Continuing advancements in neuroimaging methodology allow for increasingly detailed in vivo characterization of structural and functional brain networks, leading to the recognition of epilepsy as a disorder of large-scale networks. In surgical candidates, analysis of functional networks has proved invaluable for the identification of eloquent brain areas, such as hemispherical language dominance. More recently, connectome-based biomarkers have demonstrated potential to further inform clinical decision making in drug-refractory epilepsy. This article summarizes current evidence on epilepsy as a network disorder, emphasizing potential benefits of network analysis techniques for preoperative assessments and resection planning.
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Affiliation(s)
- Niels Alexander Foit
- Neuroimaging of Epilepsy Laboratory, McConnell Brain Imaging Centre, Montreal Neurological Institute and Hospital, McGill University, 3801 Rue Université, Montreal, Quebec H3A 2B4, Canada
| | - Andrea Bernasconi
- Neuroimaging of Epilepsy Laboratory, McConnell Brain Imaging Centre, Montreal Neurological Institute and Hospital, McGill University, 3801 Rue Université, Montreal, Quebec H3A 2B4, Canada
| | - Neda Bernasconi
- Neuroimaging of Epilepsy Laboratory, McConnell Brain Imaging Centre, Montreal Neurological Institute and Hospital, McGill University, 3801 Rue Université, Montreal, Quebec H3A 2B4, Canada.
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Guerin JB, Greiner HM, Mangano FT, Leach JL. Functional MRI in Children: Current Clinical Applications. Semin Pediatr Neurol 2020; 33:100800. [PMID: 32331615 DOI: 10.1016/j.spen.2020.100800] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Functional magnetic resonance imaging has become a critical research tool for evaluating brain function during active tasks and resting states. This has improved our understanding of developmental trajectories in children as well as the plasticity of neural networks in disease states. In the clinical setting, functional maps of eloquent cortex in patients with brain lesions and/or epilepsy provides crucial information for presurgical planning. Although children are inherently challenging to scan in this setting, preparing them appropriately and providing adequate resources can help achieve useful clinical data. This article will review the basic underlying physiologic aspects of functional magnetic resonance imaging, review clinically relevant research applications, describe known validation data compared to gold standard techniques and detail future directions of this technology.
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Affiliation(s)
- Julie B Guerin
- Department of Pediatric Radiology and Medical Imaging, Cincinnati Children's Hospital Medical Center, Cincinnati, OH; Department of Radiology, Mayo Clinic, Rochester, MN
| | - Hansel M Greiner
- Division of Neurology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH; Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH
| | - Francesco T Mangano
- Division of Pediatric Neurosurgery, University of Cincinnati College of Medicine Department of Neurosurgery, Cincinnati, OH
| | - James L Leach
- Department of Pediatric Radiology and Medical Imaging, Cincinnati Children's Hospital Medical Center, Cincinnati, OH; Department of Radiology, Mayo Clinic, Rochester, MN.
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Batouli SAH, Alemi R, Khoshkhouy Delshad H, Oghabian MA. The influence of mental fatigue on the face and word encoding activations. Clin Neurol Neurosurg 2020; 189:105626. [DOI: 10.1016/j.clineuro.2019.105626] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Revised: 11/23/2019] [Accepted: 11/27/2019] [Indexed: 11/25/2022]
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9
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Parra-Díaz P, García-Casares N. Evaluación de la memoria en la epilepsia del lóbulo temporal para predecir sus cambios tras la cirugía. Una revisión sistemática. Neurologia 2019; 34:596-606. [DOI: 10.1016/j.nrl.2017.02.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Revised: 02/12/2017] [Accepted: 02/17/2017] [Indexed: 10/19/2022] Open
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10
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Parra-Díaz P, García-Casares N. Memory assessment in patients with temporal lobe epilepsy to predict memory impairment after surgery: a systematic review. NEUROLOGÍA (ENGLISH EDITION) 2019. [DOI: 10.1016/j.nrleng.2017.02.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
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Sveikata L, Kavan N, Pegna AJ, Seeck M, Assal F, Momjian S, Schaller K, Vulliemoz S. Postoperative memory prognosis in temporal lobe epilepsy surgery: The contribution of postictal memory. Epilepsia 2019; 60:1639-1649. [PMID: 31329286 DOI: 10.1111/epi.16281] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Revised: 06/13/2019] [Accepted: 06/18/2019] [Indexed: 11/27/2022]
Abstract
OBJECTIVE The prediction of verbal memory decline after temporal lobe epilepsy (TLE) surgery remains difficult at an individual level. We evaluated the prognostic value of postictal memory testing in predicting the postoperative verbal memory function. METHODS Sixty-three consecutive patients were included in the analysis who underwent TLE surgery at our center with preoperative interictal/postictal and postoperative memory testing. Verbal memory was evaluated using the Rey Auditory Verbal Learning Test (RAVLT). We used reliable change indices with 90% confidence interval (90% RCIs) to evaluate a significant postoperative memory decline. The sensitivity (Sn), specificity (Sp), positive predictive value (PPV), negative predictive value (NPV), area under the curve (AUC), and accuracy (ACC) were calculated. The analysis was performed for all TLE patients and for the subgroup with hippocampal sclerosis (HS). RESULTS Left-TLE patients (n = 31) had lower verbal memory scores on RAVLT than right-TLE at 3 months (57% vs 78%) and 12 months (53% vs 78%) after surgery. The 90% RCI was estimated to be a loss of 4 out of 15 items. The predictive value was Sn = 42%, Sp = 84%, PPV = 39%, NPV = 86%, AUC = 0.630, and ACC = 76% to predict a verbal memory decline in the whole group (n = 63). In HS patients (n = 41), the postictal verbal memory test had Sn = 50%, Sp = 88%, PPV = 50%, NPV = 88%, AUC = 0.689, and ACC = 81% to predict a significant postoperative decline. SIGNIFICANCE Postictal memory is a noninvasive bedside memory test that can help predict the postoperative verbal memory decline in patients with HS with an overall accuracy of 81%.
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Affiliation(s)
- Lukas Sveikata
- Division of Neurology, Department of Clinical Neurosciences, Geneva University Hospitals and Faculty of Medicine, Geneva, Switzerland
| | - Nicole Kavan
- Neuropsychology Unit, Department of Clinical Neurosciences, Geneva University Hospitals and Faculty of Medicine, Geneva, Switzerland
| | - Alan J Pegna
- Neuropsychology Unit, Department of Clinical Neurosciences, Geneva University Hospitals and Faculty of Medicine, Geneva, Switzerland.,School of Psychology, University of Queensland, Brisbane, Queensland, Australia
| | - Margitta Seeck
- Division of Neurology, Department of Clinical Neurosciences, Geneva University Hospitals and Faculty of Medicine, Geneva, Switzerland
| | - Frederic Assal
- Division of Neurology, Department of Clinical Neurosciences, Geneva University Hospitals and Faculty of Medicine, Geneva, Switzerland
| | - Shahan Momjian
- Division of Neurosurgery, Department of Clinical Neurosciences, Geneva University Hospitals and Faculty of Medicine, Geneva, Switzerland
| | - Karl Schaller
- Division of Neurosurgery, Department of Clinical Neurosciences, Geneva University Hospitals and Faculty of Medicine, Geneva, Switzerland
| | - Serge Vulliemoz
- Division of Neurology, Department of Clinical Neurosciences, Geneva University Hospitals and Faculty of Medicine, Geneva, Switzerland
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Balter S, Lin G, Leyden KM, Paul BM, McDonald CR. Neuroimaging correlates of language network impairment and reorganization in temporal lobe epilepsy. BRAIN AND LANGUAGE 2019; 193:31-44. [PMID: 27393391 PMCID: PMC5215985 DOI: 10.1016/j.bandl.2016.06.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Revised: 02/27/2016] [Accepted: 06/15/2016] [Indexed: 06/02/2023]
Abstract
Advanced, noninvasive imaging has revolutionized our understanding of language networks in the brain and is reshaping our approach to the presurgical evaluation of patients with epilepsy. Functional magnetic resonance imaging (fMRI) has had the greatest impact, unveiling the complexity of language organization and reorganization in patients with epilepsy both pre- and postoperatively, while volumetric MRI and diffusion tensor imaging have led to a greater appreciation of structural and microstructural correlates of language dysfunction in different epilepsy syndromes. In this article, we review recent literature describing how unimodal and multimodal imaging has advanced our knowledge of language networks and their plasticity in epilepsy, with a focus on the most frequently studied epilepsy syndrome in adults, temporal lobe epilepsy (TLE). We also describe how new analytic techniques (i.e., graph theory) are leading to a refined characterization of abnormal brain connectivity, and how subject-specific imaging profiles combined with clinical data may enhance the prediction of both seizure and language outcomes following surgical interventions.
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Affiliation(s)
- S Balter
- Department of Neurology, University of California, San Francisco, CA, United States; UCSF Comprehensive Epilepsy Center, United States
| | - G Lin
- Palo Alto University, Palo Alto, CA, United States
| | - K M Leyden
- Multimodal Imaging Laboratory, University of California, San Diego, CA, United States
| | - B M Paul
- Department of Neurology, University of California, San Francisco, CA, United States; UCSF Comprehensive Epilepsy Center, United States
| | - C R McDonald
- Multimodal Imaging Laboratory, University of California, San Diego, CA, United States; Department of Psychiatry, University of California, San Diego, CA, United States.
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Rajesh P, Thomas B, Pammi VC, Kesavadas C, Alexander A, Radhakrishnan A, Thomas S, Menon R. Hippocampal activations in mesial temporal lobe epilepsy due to hippocampal sclerosis- an observational study on intramural encoding-delayed recall paradigms using task-based memory fMRI. Epilepsy Res 2018; 145:31-39. [DOI: 10.1016/j.eplepsyres.2018.05.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Revised: 05/13/2018] [Accepted: 05/25/2018] [Indexed: 10/16/2022]
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14
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Scharfman HE, Kanner AM, Friedman A, Blümcke I, Crocker CE, Cendes F, Diaz-Arrastia R, Förstl H, Fenton AA, Grace AA, Palop J, Morrison J, Nehlig A, Prasad A, Wilcox KS, Jette N, Pohlmann-Eden B. Epilepsy as a Network Disorder (2): What can we learn from other network disorders such as dementia and schizophrenia, and what are the implications for translational research? Epilepsy Behav 2018; 78:302-312. [PMID: 29097123 PMCID: PMC5756681 DOI: 10.1016/j.yebeh.2017.09.016] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Revised: 09/18/2017] [Accepted: 09/18/2017] [Indexed: 12/18/2022]
Abstract
There is common agreement that many disorders of the central nervous system are 'complex', that is, there are many potential factors that influence the development of the disease, underlying mechanisms, and successful treatment. Most of these disorders, unfortunately, have no cure at the present time, and therapeutic strategies often have debilitating side effects. Interestingly, some of the 'complexities' of one disorder are found in another, and the similarities are often network defects. It seems likely that more discussions of these commonalities could advance our understanding and, therefore, have clinical implications or translational impact. With this in mind, the Fourth International Halifax Epilepsy Conference and Retreat was held as described in the prior paper, and this companion paper focuses on the second half of the meeting. Leaders in various subspecialties of epilepsy research were asked to address aging and dementia or psychosis in people with epilepsy (PWE). Commonalities between autism, depression, aging and dementia, psychosis, and epilepsy were the focus of the presentations and discussion. In the last session, additional experts commented on new conceptualization of translational epilepsy research efforts. Here, the presentations are reviewed, and salient points are highlighted.
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Affiliation(s)
- Helen E Scharfman
- Departments of Psychiatry, Neurosciences and Physiology, and the Neuroscience Institute, New York University Langone Medical Center, New York, NY 10016, USA.
| | - Andres M Kanner
- University of Miami, Miller School of Medicine, 1120 NW 14th Street, Room #1324, Miami, FL 33136, USA
| | - Alon Friedman
- Department of Medical Neuroscience, Faculty of Medicine, Dalhousie University, Halifax, NS, Canada; Department of Pediatrics, Faculty of Medicine, Dalhousie University, Halifax, NS, Canada; Department of Physiology and Cell Biology, Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Ingmar Blümcke
- Neuropathological Institute, University Hospitals Erlangen, Germany
| | - Candice E Crocker
- Nova Scotia Early Psychosis Program, Department of Psychiatry, Dalhousie University, Halifax, NS, Canada
| | - Fernando Cendes
- Department of Neurology, University of Campinas, 13083-888 Campinas, Sao Paulo, Brazil
| | - Ramon Diaz-Arrastia
- Centre for Neuroscience & Regenerative Medicine, Uniformed Services University of the Health Sciences, 12725 Twinbrook Parkway, Rockville, MD 20852, USA
| | - Hans Förstl
- Department of Psychiatry, University of Munich, Klinikum rechts der Isar, Ismaninger Strabe 22, D-81675 Munich, Germany
| | - André A Fenton
- Centre for Neural Science, New York University, 4 Washington Place, Room 809, New York, NY 10003, USA
| | - Anthony A Grace
- University of Pittsburgh, 456 Langley Hall, 4200 Fifth Avenue, Pittsburgh, PA 15269, USA
| | - Jorge Palop
- Department of Neurology, Gladstone Institute, 1650 Owens Street, San Francisco, CA 94158-2261, USA
| | - Jason Morrison
- Department of Psychiatry, Dalhousie University, Halifax, NS, Canada
| | - Astrid Nehlig
- INSERM U 1129, Hôpital Necker, Paris, Faculty of Medicine, Strasbourg, France
| | - Asuri Prasad
- Department of Pediatrics, Children's Hospital of Western Ontario, London, ON, Canada
| | - Karen S Wilcox
- Department of Pharmacology & Toxicology, Anticonvulsant Drug Development Program, University of Utah, Salt Lake City, UT, USA
| | - Nathalie Jette
- Icahn School of Medicine at Mount Sinai, Department of Neurology, New York, NY, USA; Department of Clinical Neurosciences, University of Calgary, Calgary, Alberta, Canada
| | - Bernd Pohlmann-Eden
- Brain Repair Center, Life Science Research Institute, Dalhousie University, Room 229, PO Box 15000, Halifax, NS B3H4R2, Canada.
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Wieser HG. Presurgical diagnosis of epilepsies – concepts and diagnostic tools. JOURNAL OF EPILEPTOLOGY 2016. [DOI: 10.1515/joepi-2016-0014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
SummaryIntroduction.Numerous reviews of the currently established concepts, strategies and diagnostic tools used in epilepsy surgery have been published. The focus concept which was initially developed by Forster, Penfield and Jasper and popularised and enriched by Lüders, is still fundamental for epilepsy surgery.Aim.To present different conceptual views of the focus concept and to discuss more recent network hypothesis, emphasizing so-called “critical modes of an epileptogenic circuit”.Method.A literature search was conducted using keywords: presurgical evaluation, epileptic focus concepts, cortical zones, diagnostic tools.Review and remarks.The theoretical concepts of the epileptic focus are opposed to the network hypothesis. The definitions of the various cortical zones have been conceptualized in the presurgical evaluation of candidates for epilepsy surgery: the seizure onset zone versus the epileptogenic zone, the symptomatogenic zone, the irritative and functional deficit zones are characterized. The epileptogenic lesion, the “eloquent cortex” and secondary epileptogenesis (mirror focus) are dealt with. The current diagnostic techniques used in the definition of these cortical zones, such as video-EEG monitoring, non-invasive and invasive EEG recording techniques, magnetic resonance imaging, ictal single photon emission computed tomography, and positron emission tomography, are discussed and illustrated. Potential modern surrogate markers of epileptogenicity, such asHigh frequency oscillations, Ictal slow waves/DC shifts, Magnetic resonance spectroscopy, Functional MRI,the use ofMagnetized nanoparticlesin MRI,Transcranial magnetic stimulation,Optical intrinsic signalimaging, andSeizure predictionare discussed. Particular emphasis is put on the EEG: Scalp EEG, semi-invasive and invasive EEG (Stereoelectroencephalography) and intraoperative electrocorticography are illustrated. Ictal SPECT and18F-FDG PET are very helpful and several other procedures, such as dipole source localization and spike-triggered functional MRI are already widely used. The most important lateralizing and localizing ictal signs and symptoms are summarized. It is anticipated that the other clinically valid surrogate markers of epileptogenesis and epileptogenicity will be further developed in the near future. Until then the concordance of the results of seizure semiology, localization of epileptogenicity by EEG and MRI remains the most important prerequisite for successful epilepsy surgery.Conclusions and future perspectives.Resective epilepsy surgery is a widely accepted and successful therapeutic approach, rendering up to 80% of selected patients seizure free. Although other therapies, such as radiosurgery, and responsive neurostimulation will increasingly play a role in patients with an unresectable lesion, it is unlikely that they will replace selective resective surgery. The hope is that new diagnostic techniques will be developed that permit more direct definition and measurement of the epileptogenic zone.
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Sidhu MK, Stretton J, Winston GP, McEvoy AW, Symms M, Thompson PJ, Koepp MJ, Duncan JS. Memory network plasticity after temporal lobe resection: a longitudinal functional imaging study. Brain 2016; 139:415-30. [PMID: 26754787 PMCID: PMC4805088 DOI: 10.1093/brain/awv365] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Accepted: 10/30/2015] [Indexed: 11/13/2022] Open
Abstract
Anterior temporal lobe resection can control seizures in up to 80% of patients with temporal lobe epilepsy. Memory decrements are the main neurocognitive complication. Preoperative functional reorganization has been described in memory networks, but less is known of postoperative reorganization. We investigated reorganization of memory-encoding networks preoperatively and 3 and 12 months after surgery. We studied 36 patients with unilateral medial temporal lobe epilepsy (19 right) before and 3 and 12 months after anterior temporal lobe resection. Fifteen healthy control subjects were studied at three equivalent time points. All subjects had neuropsychological testing at each of the three time points. A functional magnetic resonance imaging memory-encoding paradigm of words and faces was performed with subsequent out-of-scanner recognition assessments. Changes in activations across the time points in each patient group were compared to changes in the control group in a single flexible factorial analysis. Postoperative change in memory across the time points was correlated with postoperative activations to investigate the efficiency of reorganized networks. Left temporal lobe epilepsy patients showed increased right anterior hippocampal and frontal activation at both 3 and 12 months after surgery relative to preoperatively, for word and face encoding, with a concomitant reduction in left frontal activation 12 months postoperatively. Right anterior hippocampal activation 12 months postoperatively correlated significantly with improved verbal learning in patients with left temporal lobe epilepsy from preoperatively to 12 months postoperatively. Preoperatively, there was significant left posterior hippocampal activation that was sustained 3 months postoperatively at word encoding, and increased at face encoding. For both word and face encoding this was significantly reduced from 3 to 12 months postoperatively. Patients with right temporal lobe epilepsy showed increased left anterior hippocampal activation on word encoding from 3 to 12 months postoperatively compared to preoperatively. On face encoding, left anterior hippocampal activations were present preoperatively and 12 months postoperatively. Left anterior hippocampal and orbitofrontal cortex activations correlated with improvements in both design and verbal learning 12 months postoperatively. On face encoding, there were significantly increased left posterior hippocampal activations that reduced significantly from 3 to 12 months postoperatively. Postoperative changes occur in the memory-encoding network in both left and right temporal lobe epilepsy patients across both verbal and visual domains. Three months after surgery, compensatory posterior hippocampal reorganization that occurs is transient and inefficient. Engagement of the contralateral hippocampus 12 months after surgery represented efficient reorganization in both patient groups, suggesting that the contralateral hippocampus contributes to memory outcome 12 months after surgery.
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Affiliation(s)
- Meneka K Sidhu
- 1 Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, Queen Square, London WC1N 3BG, UK 2 Epilepsy Society MRI Unit, Chesham Lane, Chalfont St. Peter SL9 0RJ, Buckinghamshire, UK
| | - Jason Stretton
- 1 Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, Queen Square, London WC1N 3BG, UK 2 Epilepsy Society MRI Unit, Chesham Lane, Chalfont St. Peter SL9 0RJ, Buckinghamshire, UK 3 MRC Cognition and Brain Science Unit, Chaucer Road, Cambridge, CB2 7EF, UK
| | - Gavin P Winston
- 1 Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, Queen Square, London WC1N 3BG, UK 2 Epilepsy Society MRI Unit, Chesham Lane, Chalfont St. Peter SL9 0RJ, Buckinghamshire, UK
| | - Andrew W McEvoy
- 1 Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, Queen Square, London WC1N 3BG, UK 2 Epilepsy Society MRI Unit, Chesham Lane, Chalfont St. Peter SL9 0RJ, Buckinghamshire, UK
| | - Mark Symms
- 1 Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, Queen Square, London WC1N 3BG, UK 2 Epilepsy Society MRI Unit, Chesham Lane, Chalfont St. Peter SL9 0RJ, Buckinghamshire, UK
| | - Pamela J Thompson
- 1 Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, Queen Square, London WC1N 3BG, UK 2 Epilepsy Society MRI Unit, Chesham Lane, Chalfont St. Peter SL9 0RJ, Buckinghamshire, UK
| | - Matthias J Koepp
- 1 Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, Queen Square, London WC1N 3BG, UK 2 Epilepsy Society MRI Unit, Chesham Lane, Chalfont St. Peter SL9 0RJ, Buckinghamshire, UK
| | - John S Duncan
- 1 Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, Queen Square, London WC1N 3BG, UK 2 Epilepsy Society MRI Unit, Chesham Lane, Chalfont St. Peter SL9 0RJ, Buckinghamshire, UK
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Douw L, Leveroni CL, Tanaka N, Emerton BC, Cole AC, Reinsberger C, Stufflebeam SM. Loss of resting-state posterior cingulate flexibility is associated with memory disturbance in left temporal lobe epilepsy. PLoS One 2015; 10:e0131209. [PMID: 26110431 PMCID: PMC4481466 DOI: 10.1371/journal.pone.0131209] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2015] [Accepted: 05/30/2015] [Indexed: 01/08/2023] Open
Abstract
The association between cognition and resting-state fMRI (rs-fMRI) has been the focus of many recent studies, most of which use stationary connectivity. The dynamics or flexibility of connectivity, however, may be seminal for understanding cognitive functioning. In temporal lobe epilepsy (TLE), stationary connectomic correlates of impaired memory have been reported mainly for the hippocampus and posterior cingulate cortex (PCC). We therefore investigate resting-state and task-based hippocampal and PCC flexibility in addition to stationary connectivity in left TLE (LTLE) patients. Sixteen LTLE patients were analyzed with respect to rs-fMRI and task-based fMRI (t-fMRI), and underwent clinical neuropsychological testing. Flexibility of connectivity was calculated using a sliding-window approach by determining the standard deviation of Fisher-transformed Pearson correlation coefficients over all windows. Stationary connectivity was also calculated. Disturbed memory was operationalized as having at least one memory subtest score equal to or below the 5th percentile compared to normative data. Lower PCC flexibility, particularly in the contralateral (i.e. right) hemisphere, was found in memory-disturbed LTLE patients, who had up to 22% less flexible connectivity. No significant group differences were found with respect to hippocampal flexibility, stationary connectivity during both rs-fMRI and t-fMRI, or flexibility during t-fMRI. Contralateral resting-state PCC flexibility was able to classify all but one patient with respect to their memory status (94% accuracy). Flexibility of the PCC during rest relates to memory functioning in LTLE patients. Loss of flexible connectivity to the rest of the brain originating from the PCC, particularly contralateral to the seizure focus, is able to discern memory disturbed patients from their preserved counterparts. This study indicates that the dynamics of resting-state connectivity are associated with cognitive status of LTLE patients, rather than stationary connectivity.
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Affiliation(s)
- Linda Douw
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, United States of America
- Department of Radiology, Harvard Medical School, Boston, MA, United States of America
- Department of Anatomy and Neurosciences, VU University Medical Center, Amsterdam, The Netherlands
- * E-mail:
| | - Catherine L. Leveroni
- Department of Psychiatry, Massachusetts General Hospital, Boston, MA, United States of America
| | - Naoaki Tanaka
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, United States of America
- Department of Radiology, Harvard Medical School, Boston, MA, United States of America
| | - Britt C. Emerton
- Department of Psychiatry, Massachusetts General Hospital, Boston, MA, United States of America
| | - Andrew C. Cole
- Department of Neurology, Massachusetts General Hospital, Boston, MA, United States of America
| | - Claus Reinsberger
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, United States of America
- Department of Neurology, Brigham and Women’s Hospital, Boston, MA, United States of America
- Institute of Sports Medicine, Faculty of Science, University of Paderborn, Paderborn, Germany
| | - Steven M. Stufflebeam
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, United States of America
- Department of Radiology, Harvard Medical School, Boston, MA, United States of America
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Sidhu MK, Stretton J, Winston GP, Symms M, Thompson PJ, Koepp MJ, Duncan JS. Memory fMRI predicts verbal memory decline after anterior temporal lobe resection. Neurology 2015; 84:1512-9. [PMID: 25770199 PMCID: PMC4408284 DOI: 10.1212/wnl.0000000000001461] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Accepted: 12/08/2014] [Indexed: 11/15/2022] Open
Abstract
Objective: To develop a clinically applicable memory functional MRI (fMRI) method of predicting postsurgical memory outcome in individual patients. Methods: In this prospective cohort study, 50 patients with temporal lobe epilepsy (23 left) and 26 controls underwent an fMRI memory encoding paradigm of words with a subsequent out-of-scanner recognition assessment. Neuropsychological assessment was performed preoperatively and 4 months after anterior temporal lobe resection, and at equal time intervals in controls. An event-related analysis was used to explore brain activations for words remembered and change in verbal memory scores 4 months after surgery was correlated with preoperative activations. Individual lateralization indices were calculated within a medial temporal and frontal region and compared with other clinical parameters (hippocampal volume, preoperative verbal memory, age at onset of epilepsy, and language lateralization) as a predictor of verbal memory outcome. Results: In left temporal lobe epilepsy patients, left frontal and anterior medial temporal activations correlated significantly with greater verbal memory decline, while bilateral posterior hippocampal activation correlated with less verbal memory decline postoperatively. In a multivariate regression model, left lateralized memory lateralization index (≥0.5) within a medial temporal and frontal mask was the best predictor of verbal memory outcome after surgery in the dominant hemisphere in individual patients. Neither clinical nor functional MRI parameters predicted verbal memory decline after nondominant temporal lobe resection. Conclusion: We propose a clinically applicable memory fMRI paradigm to predict postoperative verbal memory decline after surgery in the language-dominant hemisphere in individual patients.
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Affiliation(s)
- Meneka K Sidhu
- From the Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, London; and the Epilepsy Society MRI Unit, Chalfont St. Peter, UK
| | - Jason Stretton
- From the Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, London; and the Epilepsy Society MRI Unit, Chalfont St. Peter, UK
| | - Gavin P Winston
- From the Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, London; and the Epilepsy Society MRI Unit, Chalfont St. Peter, UK
| | - Mark Symms
- From the Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, London; and the Epilepsy Society MRI Unit, Chalfont St. Peter, UK
| | - Pamela J Thompson
- From the Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, London; and the Epilepsy Society MRI Unit, Chalfont St. Peter, UK
| | - Matthias J Koepp
- From the Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, London; and the Epilepsy Society MRI Unit, Chalfont St. Peter, UK
| | - John S Duncan
- From the Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, London; and the Epilepsy Society MRI Unit, Chalfont St. Peter, UK.
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Doucet GE, Rider R, Taylor N, Skidmore C, Sharan A, Sperling M, Tracy JI. Presurgery resting-state local graph-theory measures predict neurocognitive outcomes after brain surgery in temporal lobe epilepsy. Epilepsia 2015; 56:517-26. [PMID: 25708625 DOI: 10.1111/epi.12936] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/08/2015] [Indexed: 11/30/2022]
Abstract
OBJECTIVE This study determined the ability of resting-state functional connectivity (rsFC) graph-theory measures to predict neurocognitive status postsurgery in patients with temporal lobe epilepsy (TLE) who underwent anterior temporal lobectomy (ATL). METHODS A presurgical resting-state functional magnetic resonance imaging (fMRI) condition was collected in 16 left and 16 right TLE patients who underwent ATL. In addition, patients received neuropsychological testing pre- and postsurgery in verbal and nonverbal episodic memory, language, working memory, and attention domains. Regarding the functional data, we investigated three graph-theory properties (local efficiency, distance, and participation), measuring segregation, integration and centrality, respectively. These measures were only computed in regions of functional relevance to the ictal pathology, or the cognitive domain. Linear regression analyses were computed to predict the change in each neurocognitive domain. RESULTS Our analyses revealed that cognitive outcome was successfully predicted with at least 68% of the variance explained in each model, for both TLE groups. The only model not significantly predictive involved nonverbal episodic memory outcome in right TLE. Measures involving the healthy hippocampus were the most common among the predictors, suggesting that enhanced integration of this structure with the rest of the brain may improve cognitive outcomes. Regardless of TLE group, left inferior frontal regions were the best predictors of language outcome. Working memory outcome was predicted mostly by right-sided regions, in both groups. Overall, the results indicated our integration measure was the most predictive of neurocognitive outcome. In contrast, our segregation measure was the least predictive. SIGNIFICANCE This study provides evidence that presurgery rsFC measures may help determine neurocognitive outcomes following ATL. The results have implications for refining our understanding of compensatory reorganization and predicting cognitive outcome after ATL. The results are encouraging with regard to the clinical relevance of using graph-theory measures in presurgical algorithms in the setting of TLE.
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Affiliation(s)
- Gaelle E Doucet
- Department of Neurology, Thomas Jefferson University, Philadelphia, Pennsylvania, U.S.A
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Memory Assessment in the Clinical Context Using Functional Magnetic Resonance Imaging. Neuroimaging Clin N Am 2014; 24:585-97. [DOI: 10.1016/j.nic.2014.07.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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Kunii N, Kawai K, Kamada K, Ota T, Saito N. The significance of parahippocampal high gamma activity for memory preservation in surgical treatment of atypical temporal lobe epilepsy. Epilepsia 2014; 55:1594-601. [PMID: 25182809 DOI: 10.1111/epi.12764] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/22/2014] [Indexed: 11/29/2022]
Abstract
OBJECTIVE Resective surgery for mesial temporal lobe epilepsy (MTLE) with a correspondent lesion has been established as an effective and safe procedure. Surgery for temporal lobe epilepsies with bilateral hippocampal sclerosis or without correspondent lesions, however, carries a higher risk of devastating memory decline, underscoring the importance of establishing the memory-dominant side preoperatively and adopting the most appropriate procedure. In this study, we focused on high gamma activities (HGAs) in the parahippocampal gyri and investigated the relationship between memory-related HGAs and memory outcomes after hippocampal transection (HT), a hippocampal counterpart to neocortical multiple subpial transection. The transient nature of memory worsening after HT provided us with a rare opportunity to compare HGAs and clinical outcomes without risking permanent memory disorders. METHODS We recorded electrocorticography from parahippocampal gyri of 18 patients with temporal lobe epilepsy while they executed picture naming and recognition tasks. Memory-related HGA was quantified by calculating differences in power amplification of electrocorticography signals in a high gamma range (60-120 Hz) between the two tasks. We compared memory-related HGAs from correctly recognized and rejected trials (hit-HGA and reject-HGA). Using hit-HGA, we determined HGA-dominant sides and compared them with memory outcomes after HT performed on seven patients. RESULTS We observed memory-related HGA mainly between 500 and 600 msec poststimulus. Hit-HGA was significantly higher than reject-HGA. Three patients who had surgery on the HGA-dominant side experienced transient memory worsening postoperatively. The postoperative memory functions of the other four patients remained unchanged. SIGNIFICANCE Parahippocampal HGA was indicated to reflect different memory processes and be compatible with the outcomes of HT, suggesting that HGA could provide predictive information on whether the mesial temporal lobe can be resected without causing memory worsening. This preliminary study suggests a refined surgical strategy for atypical MTLE based on reliable memory lateralization.
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Affiliation(s)
- Naoto Kunii
- Department of Neurosurgery, The University of Tokyo, Tokyo, Japan
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Haneef Z, Chen DK. Functional neuro-imaging as a pre-surgical tool in epilepsy. Ann Indian Acad Neurol 2014; 17:S56-64. [PMID: 24791091 PMCID: PMC4001213 DOI: 10.4103/0972-2327.128659] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2013] [Revised: 09/20/2013] [Accepted: 10/02/2013] [Indexed: 12/03/2022] Open
Abstract
Functional neuro-imaging techniques are helpful in the pre-surgical evaluation of epilepsy for localization of the epileptogenic zone as ancillary tools to electroencephalography (EEG) and magnetic resonance imaging (MRI) or when other localization techniques are normal, non-concordant or discordant. Positron emission tomography (PET) and ictal single photon emission computed tomography (ictal SPECT) imaging are traditional tests that have been reported to have good sensitivity and specificity although the results are better with more expertise as is true for any technique. More recently magnetoencephalogram/magnetic source imaging (MEG/MSI), diffusion tensor imaging and functional magnetic resonance imaging (fMRI) have been used in localization and functional mapping during the pre-surgical work-up of epilepsy. Newer techniques such as fMRI-EEG, functional connectivity magnetic resonance imaging and near infra-red spectroscopy, magnetic resonance spectroscopy and magneto nanoparticles hold promise for further development that could then be applied in the work-up of epilepsy surgery. In this manuscript, we review these techniques and their current position in the pre-surgical evaluation of epilepsy.
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Affiliation(s)
- Zulfi Haneef
- Kellaway Section of Neurophysiology, Department of Neurology, Baylor College of Medicine, Houston, Texas, USA
- Kellaway Section of Neurophysiology, Neurology Care Line, Michael E. DeBakey VA Medical Center, Houston, Texas, USA
| | - David K. Chen
- Kellaway Section of Neurophysiology, Department of Neurology, Baylor College of Medicine, Houston, Texas, USA
- Kellaway Section of Neurophysiology, Neurology Care Line, Michael E. DeBakey VA Medical Center, Houston, Texas, USA
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Baxendale S, Thompson PJ, Sander JW. Neuropsychological outcomes in epilepsy surgery patients with unilateral hippocampal sclerosis and good preoperative memory function. Epilepsia 2013; 54:e131-4. [PMID: 23875960 DOI: 10.1111/epi.12319] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/13/2013] [Indexed: 11/26/2022]
Abstract
We examined postoperative changes in the memory function of 68 people with unilateral hippocampal sclerosis (HS) who underwent epilepsy surgery and had no previous clinical memory impairments. One in four with right HS (RHS) and one in five with left HS (LHS) in our sample of 323 people with unilateral HS performed within normal limits on memory tests that are sensitive to hippocampal pathology in group studies. People with intact memory function prior to surgery were significantly younger and had higher IQs than those with memory impairments. The majority of those with intact memory functions prior to surgery had significant postoperative declines on the memory measures at the 1-year follow-up and no longer functioned within the average range. People with RHS and left LHS were equally at risk of a postoperative decline. Postoperative deterioration was not related to seizure outcome. A higher IQ appears to protect against postoperative memory decline in this group. This finding does not support the notion that intact memory function in people with unilateral HS represents a migration of memory function to the contralateral structures, and thus protection from surgical insult. People with good preoperative memory function in the context of unilateral HS should therefore be counseled regarding the likelihood of a significant postoperative decline in memory function following a temporal lobe resection.
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Affiliation(s)
- Sallie Baxendale
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, NIHR University College London Hospitals Biomedical Research Centre, London, United Kingdom.
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Siero JC, Bhogal A, Jansma JM. Blood Oxygenation Level–dependent/Functional Magnetic Resonance Imaging. PET Clin 2013; 8:329-44. [DOI: 10.1016/j.cpet.2013.04.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Abstract
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 examine a number of new techniques that may soon become clinically relevant.
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Dulay MF, Busch RM. Prediction of neuropsychological outcome after resection of temporal and extratemporal seizure foci. Neurosurg Focus 2012; 32:E4. [DOI: 10.3171/2012.1.focus11340] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Resection of seizure foci is an effective treatment for the control of medically intractable epilepsy. However, cognitive morbidity can occur as a result of surgical intervention. This morbidity is dependent on several factors, including location and extent of resection, disease characteristics, patient demographic characteristics, and functional status of the tissue to be resected. In this review article, the authors provide a summary of the neurocognitive outcomes of epilepsy surgery with an emphasis on presurgical predictors of postsurgical cognitive decline.
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Affiliation(s)
- Mario F. Dulay
- 1Comprehensive Epilepsy Program and Department of Neurosurgery, The Methodist Hospital Neurological Institute, Houston, Texas; and
| | - Robyn M. Busch
- 2Epilepsy Center, Neurological Institute, Cleveland Clinic, Cleveland, Ohio
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Neuropsychology in temporal lobe epilepsy: influences from cognitive neuroscience and functional neuroimaging. EPILEPSY RESEARCH AND TREATMENT 2012; 2012:925238. [PMID: 22957249 PMCID: PMC3420484 DOI: 10.1155/2012/925238] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/04/2011] [Accepted: 10/09/2011] [Indexed: 12/28/2022]
Abstract
Neuropsychologists assist in diagnosis (i.e., localization of dysfunction) and in prediction (i.e., how cognition may change following surgery) in individuals being considered for temporal lobe surgery. The current practice includes behavioural testing as well as mapping function via stimulation, inactivation, and (more recently) functional imaging. These methods have been providing valuable information in surgical planning for 60 years. Here, we discuss current assessment strategies and highlight how they are evolving, particularly with respect to integrating recent advances in cognitive neuroscience.
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