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Bruzsa AK, Walther K, Kasper BS, Gollwitzer S, Hamer H, Schwarz M. WADA test for postoperative memory prediction in left TLE. Is it still useful in the 21st century? Clin Neurol Neurosurg 2023; 225:107580. [PMID: 36638639 DOI: 10.1016/j.clineuro.2022.107580] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Revised: 12/19/2022] [Accepted: 12/28/2022] [Indexed: 12/31/2022]
Abstract
BACKGROUND Epilepsy surgery offers an effective treatment to achieve seizure freedom in refractory temporal lobe epilepsy. Since left temporal lobe surgery can be associated with verbal memory deterioration, control of cognitive decline is a main goal of therapy. This study analyzes the prognostic value of intracarotid amobarbital procedure (Wada test) in addition to specific neuropsychological and clinical variables for postoperative memory changes. METHOD Between 2013 and 2021 thirty-six patients (18 females, 18 males, mean age 41.0 years) from the Epilepsy Center Erlangen (ECE) with left hemispheric temporal lobe epilepsy underwent neuropsychological assessment preoperatively - including the Wada test - and six months postoperatively. In addition, a group of 92 patients (40 females, 52 males, mean age 36.1 years) with left or right hemispheric focus who underwent Wada test and surgery before 2013 was included as a standardization group. In all patients Wada test was carried out preoperatively to determine language dominance and memory capacity. RESULTS Postoperative verbal memory scores showed no significant difference from preoperative performance. Preoperative verbal memory performance as well as the hippocampal resection extent is particularly important in predicting postoperative verbal memory change. After left temporal lobe surgery, a significantly higher postoperative functional level was shown for figural memory. Specifically, a good contralateral hemispheric performance level assessed by the Wada test proved to be a compensatory factor for postoperative losses. CONCLUSION The Wada test is no longer necessary as a diagnostic tool for a broad group of patients with temporal lobe epilepsy. However, it can be useful for a subgroup of patients with clinical indicators such as nonspecific or incongruent preoperative verbal and figural memory impairments. In this study, Wada test data about the functional level of the contralateral hemisphere specifically allowed estimation of postoperative figural memory changes.
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Affiliation(s)
- Ann-Kathrin Bruzsa
- Department of Neurology, Epilepsy Center Erlangen, University Hospital Erlangen, Germany; Full member of ERN EpiCARE, Germany
| | - Katrin Walther
- Department of Neurology, Epilepsy Center Erlangen, University Hospital Erlangen, Germany; Full member of ERN EpiCARE, Germany
| | - Burkhard S Kasper
- Department of Neurology, Epilepsy Center Erlangen, University Hospital Erlangen, Germany; Full member of ERN EpiCARE, Germany
| | - Stefanie Gollwitzer
- Department of Neurology, Epilepsy Center Erlangen, University Hospital Erlangen, Germany; Full member of ERN EpiCARE, Germany
| | - Hajo Hamer
- Department of Neurology, Epilepsy Center Erlangen, University Hospital Erlangen, Germany; Full member of ERN EpiCARE, Germany
| | - Michael Schwarz
- Department of Neurology, Epilepsy Center Erlangen, University Hospital Erlangen, Germany; Full member of ERN EpiCARE, Germany.
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Zhu C, Liao Y, Ding Y, Huang J, Tan Q, Ruan J. Functional magnetic resonance imaging is used to evaluate memory, language, and cognitive function in patients with medication-resistant temporal lobe epidemic. Minerva Surg 2022; 77:506-508. [PMID: 34889559 DOI: 10.23736/s2724-5691.21.09267-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Affiliation(s)
- Changhua Zhu
- Department of Radiology, The People's Hospital of Xinyu City, Xinyu, China
| | - Ying Liao
- Department of Gynaecology, The People's Hospital of Xinyu City, Xinyu, China
| | - Yao Ding
- Department of Radiology, The People's Hospital of Xinyu City, Xinyu, China
| | - Jun Huang
- Department of Radiology, The People's Hospital of Xinyu City, Xinyu, China
| | - Qiuping Tan
- Department of Radiology, The People's Hospital of Xinyu City, Xinyu, China
| | - Jiugen Ruan
- Department of Radiology, The People's Hospital of Xinyu City, Xinyu, China -
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Conde-Blanco E, Pariente JC, Carreño M, Boget T, Pascual-Díaz S, Centeno M, Manzanares I, Donaire A, Pintor L, Rumià J, Roldán P, Setoain X, Bargalló N. Testing an Adapted Auditory Verbal Learning Test Paradigm for fMRI to Lateralize Verbal Memory in Patients with Epilepsy. AJNR Am J Neuroradiol 2022; 43:1445-1452. [PMID: 36137657 PMCID: PMC9575519 DOI: 10.3174/ajnr.a7622] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2022] [Accepted: 07/01/2022] [Indexed: 01/26/2023]
Abstract
BACKGROUND AND PURPOSE fMRI is a noninvasive tool for predicting postsurgical deficits in candidates with pharmacoresistant temporal lobe epilepsy. We aimed to test an adapted paradigm of the Rey Auditory Verbal Learning Test to evaluate differences in memory laterality indexes between patients and healthy controls and its association with neuropsychological scores. MATERIALS AND METHODS We performed a prospective study of 50 patients with temporal lobe epilepsy and 22 healthy controls. Participants underwent a block design language and memory fMRI. Laterality indexes and the hippocampal anterior-posterior index were calculated. Language and memory lateralization was organized into typical and atypical on the basis of laterality indexes. A neuropsychological assessment was performed with a median time from fMRI of 8 months and was compared with fMRI performance. RESULTS We studied 40 patients with left temporal lobe epilepsy and 10 with right temporal lobe epilepsy. Typical language occurred in 65.3% of patients and 90.9% of healthy controls (P = .04). The memory fMRI laterality index was obtained in all healthy controls and 92% of patients. The verbal memory laterality index was bilateral (24.3%) more frequently than the language laterality index (7.69%) in patients with left temporal lobe epilepsy. Atypical verbal memory was greater in patients with left temporal lobe epilepsy (56.8%) than in healthy controls (36.4%), and the proportion of bilateral laterality indexes (53.3%) was larger than right laterality indexes (46.7%). Atypical verbal memory might be associated with higher cognitive scores in patients. No relevant differences were seen in the hippocampal anterior-posterior index according to memory impairment. CONCLUSIONS The adapted Rey Auditory Verbal Learning Test paradigm fMRI might support verbal memory lateralization. Temporal lobe epilepsy laterality influences hippocampal memory laterality indexes. Left temporal lobe epilepsy has shown a higher proportion of atypical verbal memory compared with language, potentially to memory functional reorganization.
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Affiliation(s)
- E Conde-Blanco
- From the Departments of Neurology (E.C.-B., M. Carreño, M. Centeno, I.M., A.D.)
- Institut d'Investigacions Biomèdiques August Pi i Sunyer (E.C.-B., M. Carreño, M. Centeno, A.D., T.B., L.P., J.R., P.R., X.S., N.B.), Barcelona, Spain
- EpiCARE: European Reference Network for Epilepsy (E.C.-B., M. Carreño, M. Centeno, A.D.), Dublin, Ireland
| | - J C Pariente
- Magnetic Resonance Imaging Core Facility (J.C.P., S.P.-D.), Institut d'Investigacions Biomèdiques August Pi i Sunyer, Barcelona, Spain
| | - M Carreño
- From the Departments of Neurology (E.C.-B., M. Carreño, M. Centeno, I.M., A.D.)
- Institut d'Investigacions Biomèdiques August Pi i Sunyer (E.C.-B., M. Carreño, M. Centeno, A.D., T.B., L.P., J.R., P.R., X.S., N.B.), Barcelona, Spain
- EpiCARE: European Reference Network for Epilepsy (E.C.-B., M. Carreño, M. Centeno, A.D.), Dublin, Ireland
| | - T Boget
- Neuropsychology (T.B.)
- Institut d'Investigacions Biomèdiques August Pi i Sunyer (E.C.-B., M. Carreño, M. Centeno, A.D., T.B., L.P., J.R., P.R., X.S., N.B.), Barcelona, Spain
| | - S Pascual-Díaz
- Magnetic Resonance Imaging Core Facility (J.C.P., S.P.-D.), Institut d'Investigacions Biomèdiques August Pi i Sunyer, Barcelona, Spain
| | - M Centeno
- From the Departments of Neurology (E.C.-B., M. Carreño, M. Centeno, I.M., A.D.)
- Institut d'Investigacions Biomèdiques August Pi i Sunyer (E.C.-B., M. Carreño, M. Centeno, A.D., T.B., L.P., J.R., P.R., X.S., N.B.), Barcelona, Spain
- EpiCARE: European Reference Network for Epilepsy (E.C.-B., M. Carreño, M. Centeno, A.D.), Dublin, Ireland
| | - I Manzanares
- From the Departments of Neurology (E.C.-B., M. Carreño, M. Centeno, I.M., A.D.)
| | - A Donaire
- From the Departments of Neurology (E.C.-B., M. Carreño, M. Centeno, I.M., A.D.)
- Institut d'Investigacions Biomèdiques August Pi i Sunyer (E.C.-B., M. Carreño, M. Centeno, A.D., T.B., L.P., J.R., P.R., X.S., N.B.), Barcelona, Spain
- Biomedical Research Networking Center in Bioengineering, Biomaterials and Nanomedicine (A.D., X.S.), Barcelona, Spain
- EpiCARE: European Reference Network for Epilepsy (E.C.-B., M. Carreño, M. Centeno, A.D.), Dublin, Ireland
| | - L Pintor
- Psychiatry (L.P.)
- Institut d'Investigacions Biomèdiques August Pi i Sunyer (E.C.-B., M. Carreño, M. Centeno, A.D., T.B., L.P., J.R., P.R., X.S., N.B.), Barcelona, Spain
| | - J Rumià
- Neurosurgery (J.R., P.R.)
- Institut d'Investigacions Biomèdiques August Pi i Sunyer (E.C.-B., M. Carreño, M. Centeno, A.D., T.B., L.P., J.R., P.R., X.S., N.B.), Barcelona, Spain
| | - P Roldán
- Neurosurgery (J.R., P.R.)
- Institut d'Investigacions Biomèdiques August Pi i Sunyer (E.C.-B., M. Carreño, M. Centeno, A.D., T.B., L.P., J.R., P.R., X.S., N.B.), Barcelona, Spain
| | - X Setoain
- Nuclear Medicine (X.S.), Epilepsy Program, Hospital Clínic de Barcelona, Barcelona, Spain
- Institut d'Investigacions Biomèdiques August Pi i Sunyer (E.C.-B., M. Carreño, M. Centeno, A.D., T.B., L.P., J.R., P.R., X.S., N.B.), Barcelona, Spain
- Biomedical Research Networking Center in Bioengineering, Biomaterials and Nanomedicine (A.D., X.S.), Barcelona, Spain
| | - N Bargalló
- Radiology (N.B.)
- Institut d'Investigacions Biomèdiques August Pi i Sunyer (E.C.-B., M. Carreño, M. Centeno, A.D., T.B., L.P., J.R., P.R., X.S., N.B.), Barcelona, Spain
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Algahtany M, Abdrabou A, Elhaddad A, Alghamdi A. Advances in Brain Imaging Techniques for Patients With Intractable Epilepsy. Front Neurosci 2021; 15:699123. [PMID: 34421522 PMCID: PMC8377195 DOI: 10.3389/fnins.2021.699123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Accepted: 07/20/2021] [Indexed: 11/21/2022] Open
Abstract
Intractable epilepsy, also known as drug resistance or refractory epilepsy, is a major problem affecting nearly one-third of epilepsy patients. Surgical intervention could be an option to treat these patients. Correct identification and localization of epileptogenic foci is a crucial preoperative step. Some of these patients, however, have no abnormality on routine magnetic resonance imaging (MRI) of the brain. Advanced imaging techniques, therefore, can be helpful to identify the area of concern. Moreover, a clear delineation of certain anatomical brain structures and their relation to the surgical lesion or the surgical approach is essential to avoid postoperative complications, and advanced imaging techniques can be very helpful. In this review, we discuss and highlight the use of advanced imaging techniques, particularly positron emission tomography (PET)–MRI, single-photon emission computed tomography, functional MRI, and diffusion tensor imaging–tractography for the preoperative assessment of epileptic patients.
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Affiliation(s)
- Mubarak Algahtany
- Division of Neurosurgery, Department of Surgery, College of Medicine, King Khalid University, Abha, Saudi Arabia
| | - Ahmed Abdrabou
- Department of Radiology, Ain Shams University, Cairo, Egypt
| | - Ahmed Elhaddad
- Department of Radiology, Mansoura University, Mansoura, Egypt
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Wang P, Du F, Li J, Yu H, Tang C, Jiang R. Functional magnetic resonance imaging based on Chinese tasks to protect language function in epileptics. Brain Behav 2021; 11:e01979. [PMID: 33377600 PMCID: PMC7882180 DOI: 10.1002/brb3.1979] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Revised: 08/14/2020] [Accepted: 08/14/2020] [Indexed: 12/02/2022] Open
Abstract
OBJECTIVE To evaluate the efficacy of functional magnetic resonance imaging (fMRI) based on Chinese tasks to protect the language function in epileptics. MATERIALS AND METHODS A total of 34 native Chinese patients with epilepsy were enrolled and examined with BOLD-fMRI scan based on six Chinese tasks. The epileptics were randomly divided into the control group (n = 15) and the experimental group (n = 19). The control group underwent the hollowing and multiple subpial transection operation only based on intraoperative EEG, while the experimental group was under notification of task-state fMRI results in addition. Whereafter, the language ability of patients was evaluated by ABC assessment. RESULTS The brain regions related to Chinese function activated by different tasks were remarkably distinct and mainly concentrated in the temporal lobe and frontal lobe. In ontoanalysis, the activation signals of the fusiform gyrus, parahippocampal gyrus, hippocampus, and precentral gyrus were generally low or even could not be detected. Unlike ontoanalysis, group analysis showed that the main effect regions of AN and PN task were in right superior temporal gyrus. The main effect regions of FF and VFC task were in right middle temporal gyrus. The main effect region of SF task was in left superior temporal gyrus. The main effect region of VFL task was in right middle frontal gyrus. The ABC assessment score of the control group 6 months after surgery was significantly lower than that 1 week before surgery (p < .05), while there was no significant difference in the experimental group, and the score of the experimental group was higher than that of the control group. CONCLUSION In the surgical treatment of epilepsy, a personalized surgical plan, based on task-state fMRI and intraoperative EEG, can be developed according to the difference of activation areas to protect the language function and improve the quality of life in postoperative patients.
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Affiliation(s)
- Peng Wang
- Department of Radiology, The General Hospital of Western Theater Command, Chengdu, China
| | - Feizhou Du
- Department of Radiology, The General Hospital of Western Theater Command, Chengdu, China
| | - Jianhao Li
- Department of Radiology, The General Hospital of Western Theater Command, Chengdu, China
| | - Hongmei Yu
- Department of Radiology, The General Hospital of Western Theater Command, Chengdu, China
| | - Chencheng Tang
- Department of Radiology, The General Hospital of Western Theater Command, Chengdu, China
| | - Rui Jiang
- Department of Radiology, The General Hospital of Western Theater Command, Chengdu, China
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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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Buck S, Sidhu MK. A Guide to Designing a Memory fMRI Paradigm for Pre-surgical Evaluation in Temporal Lobe Epilepsy. Front Neurol 2020; 10:1354. [PMID: 31998216 PMCID: PMC6962296 DOI: 10.3389/fneur.2019.01354] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Accepted: 12/09/2019] [Indexed: 12/05/2022] Open
Abstract
There has been increasing interest in the clinical and experimental use of memory functional Magnetic Resonance Imaging (fMRI). The 2017 American Academy of Neurology practice guidelines on the use of pre-surgical cognitive fMRI suggests that verbal memory fMRI could be used to lateralize memory functions in people with Temporal Lobe Epilepsy (TLE) and should be used to predict post-operative verbal memory outcome. There are however technical and methodological considerations, to optimize both the sensitivity and specificity of this imaging modality. Below we discuss these constraints and suggest recommendations to consider when designing a memory fMRI paradigm.
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Affiliation(s)
- Sarah Buck
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology of Neurology, London, United Kingdom
- Epilepsy Society MRI Unit, Chalfont Saint Peter, United Kingdom
| | - Meneka K. Sidhu
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology of Neurology, London, United Kingdom
- Epilepsy Society MRI Unit, Chalfont Saint Peter, United Kingdom
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Kreidenhuber R, De Tiège X, Rampp S. Presurgical Functional Cortical Mapping Using Electromagnetic Source Imaging. Front Neurol 2019; 10:628. [PMID: 31249552 PMCID: PMC6584755 DOI: 10.3389/fneur.2019.00628] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Accepted: 05/28/2019] [Indexed: 02/03/2023] Open
Abstract
Preoperative localization of functionally eloquent cortex (functional cortical mapping) is common clinical practice in order to avoid or reduce postoperative morbidity. This review aims at providing a general overview of magnetoencephalography (MEG) and high-density electroencephalography (hdEEG) based methods and their clinical role as compared to common alternatives for functional cortical mapping of (1) verbal language function, (2) sensorimotor cortex, (3) memory, (4) visual, and (5) auditory cortex. We highlight strengths, weaknesses and limitations of these functional cortical mapping modalities based on findings in the recent literature. We also compare their performance relative to other non-invasive functional cortical mapping methods, such as functional Magnetic Resonance Imaging (fMRI), Transcranial Magnetic Stimulation (TMS), and to invasive methods like the intracarotid Amobarbital Test (WADA-Test) or intracranial investigations.
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Affiliation(s)
- Rudolf Kreidenhuber
- Department of Neurology, Christian-Doppler Medical Center, Paracelsus Medical University, Salzburg, Austria.,Centre for Cognitive Neuroscience, University of Salzburg, Salzburg, Austria
| | - Xavier De Tiège
- Laboratoire de Cartographie Fonctionelle du Cerveau, ULB Neuroscience Institute, Université Libre de Bruxelles, Brussels, Belgium.,Department of Functional Neuroimaging, Service of Nuclear Medicine, CUB Hôpital Erasme, Université Libre de Bruxelles, Brussels, Belgium
| | - Stefan Rampp
- Department of Neurosurgery, University Hospital Erlangen, Erlangen, Germany.,Department of Neurosurgery, University Hospital Halle, Halle, Germany
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Comparing the Wada Test and Functional MRI for the Presurgical Evaluation of Memory in Temporal Lobe Epilepsy. Curr Neurol Neurosci Rep 2019; 19:31. [PMID: 31044310 DOI: 10.1007/s11910-019-0945-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
PURPOSE OF REVIEW The usefulness of the Wada test (WT) predicting memory impairment from temporal lobe epilepsy (TLE) surgery has been debated, and it has progressively been replaced by functional MRI (fMRI). We review the current role of WT and fMRI in the presurgical assessment of TLE, and how novel surgical techniques might improve cognitive outcomes. RECENT FINDINGS fMRI's ability to predict global amnesia has not been assessed. Although WT can produce false-positive results, it is still indicated in patients at risk for developing global amnesia: those with significant bilateral or contralateral memory deficits. In the current review, WT exhibited no added value, beyond preclinical data, for predicting material-specific memory impairment, whereas fMRI was reliable for either verbal or non-verbal memory decline. Abnormal functional connectivity on resting state fMRI (rs-fMRI) between the posterior cingulate and the hippocampus may be a predictor of postsurgical memory outcomes. Restricted resections to the pathogenic tissue, stereotactic laser, radiosurgery, and SEEG-guided thermos-coagulation were associated with better cognitive outcome. fMRI should be used routinely in the presurgical workup of TLE to predict verbal and/or non-verbal memory decline, whereas WT may be indicated when there is a high risk of postsurgical global amnesia. Rs-fMRI is a promising tool for the presurgical workup of TLE, and more restricted resections are recommended to enhance cognitive outcomes.
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Tsougos I, Kousi E, Georgoulias P, Kapsalaki E, Fountas KN. Neuroimaging methods in Epilepsy of Temporal Origin. Curr Med Imaging 2018; 15:39-51. [DOI: 10.2174/1573405613666170622114920] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2017] [Revised: 05/04/2017] [Accepted: 05/11/2017] [Indexed: 11/22/2022]
Abstract
Background:
Temporal Lobe Epilepsy (TLE) comprises the most common form of
symptomatic refractory focal epilepsy in adults. Accurate lateralization and localization of the
epileptogenic focus are a significant prerequisite for determining surgical candidacy once the
patient has been deemed medically intractable. Structural MR imaging, clinical,
electrophysiological, and neurophysiological data have an established role in the localization of the
epileptogenic foci. Nevertheless, hippocampal sclerosis cannot be detected on MR images in more
than 30% of patients with TLE, and the presurgical assessment remains controversial.
</P><P>
Discussion: In the last years, advanced MR imaging techniques, such as 1H-MRS, DWI, DTI,
DSCI, and fMRI, may provide valuable additional information regarding the physiological and
metabolic characterization of brain tissue. MR imaging has shifted towards functional and
molecular imaging, thus, promising to improve the accuracy regarding the lateralization and the
localization of the epileptogenic focus. Additionally, nuclear medicine studies, such as SPECT and
PET imaging modalities, have become an asset for the decoding of brain function and activity, and
can be diagnostically helpful as well, since they provide valuable data regarding the altered
metabolic activity of the seizure foci.
Conclusion:
Overall, advanced MRI, SPECT, and PET imaging techniques are increasingly
becoming an essential part of TLE diagnostics, when the epileptogenic area is not identified on
structural MRI or when structural MRI, clinical, and electrophysiological findings are not in
concordance.
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Affiliation(s)
- Ioannis Tsougos
- Department of Medical Physics, School of Medicine, University of Thessaly, Larisa, Greece
| | - Evanthia Kousi
- The Royal Marsden NHS Foundation Trust, London, United Kingdom
| | - Panagiotis Georgoulias
- Department of Medical Physics, School of Medicine, University of Thessaly, Larisa, Greece
| | - Eftychia Kapsalaki
- Department of Medical Physics, School of Medicine, University of Thessaly, Larisa, Greece
| | - Kostas N. Fountas
- Department of Medical Physics, School of Medicine, University of Thessaly, Larisa, Greece
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Kiss M, Hermann P, Vidnyánszky Z, Gál V. Reducing task-based fMRI scanning time using simultaneous multislice echo planar imaging. Neuroradiology 2018; 60:293-302. [PMID: 29302710 DOI: 10.1007/s00234-017-1962-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Accepted: 12/08/2017] [Indexed: 11/29/2022]
Abstract
PURPOSE To maintain alertness and to remain motionless during scanning represent a substantial challenge for patients/subjects involved in both clinical and research functional magnetic resonance imaging (fMRI) examinations. Therefore, availability and application of new data acquisition protocols allowing the shortening of scan time without compromising the data quality and statistical power are of major importance. METHODS Higher order category-selective visual cortical areas were identified individually, and rapid event-related fMRI design was used to compare three different sampling rates (TR = 2000, 1000, and 410 ms, using state-of-the-art simultaneous multislice imaging) and four different scanning lengths to match the statistical power of the traditional scanning methods to high sampling-rate design. RESULTS The results revealed that ~ 4 min of the scan time with 1 Hz (TR = 1000 ms) sampling rate and ~ 2 min scanning at ~ 2.5 Hz (TR = 410 ms) sampling rate provide similar localization sensitivity and selectivity to that obtained with 11-min session at conventional, 0.5 Hz (TR = 2000 ms) sampling rate. CONCLUSION Our findings suggest that task-based fMRI examination of clinical population prone to distress such as presurgical mapping experiments might substantially benefit from the reduced (20-40%) scanning time that can be achieved by the application of simultaneous multislice sequences.
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Affiliation(s)
- Máté Kiss
- Brain Imaging Centre, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Magyar tudósok körútja 2, Budapest, 1117, Hungary. .,János Szentágothai PhD School, MR Research Centre, Balassa Street 6, Budapest, 1083, Hungary. .,Department of Neuroradiology, National Institute of Clinical Neuroscience, Amerikai Street 57, Budapest, 1145, Hungary.
| | - Petra Hermann
- Brain Imaging Centre, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Magyar tudósok körútja 2, Budapest, 1117, Hungary
| | - Zoltán Vidnyánszky
- Brain Imaging Centre, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Magyar tudósok körútja 2, Budapest, 1117, Hungary
| | - Viktor Gál
- Brain Imaging Centre, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Magyar tudósok körútja 2, Budapest, 1117, Hungary
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Kemp S, Prendergast G, Karapanagiotidis T, Baker G, Kelly TP, Patankar T, Keller SS. Concordance between the Wada test and neuroimaging lateralization: Influence of imaging modality (fMRI and MEG) and patient experience. Epilepsy Behav 2018; 78:155-160. [PMID: 29245083 DOI: 10.1016/j.yebeh.2017.09.027] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Revised: 09/26/2017] [Accepted: 09/28/2017] [Indexed: 11/24/2022]
Abstract
The Wada test remains the traditional test for lateralizing language and memory function prior to epilepsy surgery. Functional imaging, particularly functional MRI (fMRI), has made progress in the language domain, but less so in the memory domain. Magnetoencephalography (MEG) has received less research attention, but shows promise, particularly for language lateralization. We recruited a consecutive sample of 19 patients with epilepsy who had completed presurgical work-up, including the Wada test, and compared fMRI (memory) and MEG (language and memory) with Wada test results. The main research question was the concordance between Wada and these two imaging techniques as preepilepsy surgery investigations. We were also interested in the acceptability of the three techniques to patients. Concordance rates (N=16) were nonsignificant (Cohen's Kappa) between fMRI and Wada test (memory) and between MEG and Wada test (memory and language). The Wada test was a well-established protocol used at several epilepsy surgery centers in the UK. Patients generally found the Wada test an odd, but not aversive procedure. Sixteen (84%) patients who were scanned reported some level of obtundation in MEG. We present these discordant findings in support of the position that functional imaging and the Wada test are distinctive procedures, with little in the way of overlapping mechanisms, and that patient's experience should be taken into account when procedures are selected and offered to them.
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Affiliation(s)
- Steven Kemp
- Department of Clinical and Health Psychology, St James's University Hospital, Leeds, UK.
| | | | | | - Gus Baker
- University of Liverpool, UK/The Walton Centre NHS Foundation Trust, Liverpool, UK
| | | | | | - Simon S Keller
- University of Liverpool, UK/The Walton Centre NHS Foundation Trust, Liverpool, UK; Department of Neuroradiology, The Walton Centre NHS Foundation Trust, Liverpool, UK
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Połczyńska MM, Japardi K, Bookheimer SY. Lateralizing language function with pre-operative functional magnetic resonance imaging in early proficient bilingual patients. BRAIN AND LANGUAGE 2017; 170:1-11. [PMID: 28343082 DOI: 10.1016/j.bandl.2017.03.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2016] [Revised: 10/17/2016] [Accepted: 03/15/2017] [Indexed: 06/06/2023]
Abstract
Research on bilinguals with brain lesions is complicated by high patient variability, making it difficult to find well-matched controls. We benefitted from a database of over 700 patients and conducted an analysis of pre-operative functional magnetic resonance imaging data to assess language dominance in 25 early, highly proficient Spanish-English bilinguals, and 25 carefully matched monolingual controls. Our results showed that early bilingualism is associated with greater bilateral hemispheric involvement, and monolingualism is associated with stronger left hemisphere lateralization (p=0.009). The bilinguals showed more pronounced right hemisphere activation (p=0.008). Although language dominance values were concordant in the bilingual group, there were a few (12%) atypical cases with different lateralization patterns in L1 and L2. Finally, we found distinct areas of activity in first and second language within the language network, in addition to regions of convergence. These data underscore the need to map all languages proficiently spoken by surgical candidates.
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Affiliation(s)
- Monika M Połczyńska
- Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine at UCLA, University of California, Los Angeles, CA, USA; Faculty of English, Adam Mickiewicz University, Poznań, Poland.
| | - Kevin Japardi
- Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine at UCLA, University of California, Los Angeles, CA, USA.
| | - Susan Y Bookheimer
- Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine at UCLA, University of California, Los Angeles, CA, USA.
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Obenaus A. Neuroimaging biomarkers for epilepsy: advances and relevance to glial cells. Neurochem Int 2013; 63:712-8. [PMID: 23665337 DOI: 10.1016/j.neuint.2013.05.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2012] [Revised: 04/24/2013] [Accepted: 05/01/2013] [Indexed: 12/11/2022]
Abstract
Glial cells play an important role in normal brain function and emerging evidence would suggest that their dysfunction may be responsible for some epileptic disease states. Neuroimaging of glial cells is desirable, but there are no clear methods to assess neither their function nor localization. Magnetic resonance imaging (MRI) is now part of a standardized epilepsy imaging protocol to assess patients. Structural volumetric and T2-weighted imaging changes can assist in making a positive diagnosis in a majority of patients. The alterations reported in structural and T2 imaging is predominantly thought to reflect early neuronal loss followed by glial hypertrophy. MR spectroscopy for myo-inositol is a being pursued to identify glial alterations along with neuronal markers. Diffusion weighted imaging (DWI) is ideal for acute epileptiform events, but is not sensitive to either glial cells or neuronal long-term changes found in epilepsy. However, DWI variants such as diffusion tensor imaging or q-space imaging may shed additional light on aberrant glial function in the future. The sensitivity and specificity of PET radioligands, including those targeting glial cells (translocator protein) hold promise in being able to image glial cells. As the role of glial function/dysfunction in epilepsy becomes more apparent neuroimaging methods will evolve to assist the clinician and researcher in visualizing their location and function.
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Affiliation(s)
- Andre Obenaus
- Department of Pediatrics, School of Medicine, Loma Linda University, Loma Linda, CA, USA; Division of Interdisciplinary Studies, School of Behavioral Health, Loma Linda University, Loma Linda, CA, USA; Cell and Molecular Development and Biology Program, University of California, Riverside, CA, USA; Neuroscience Graduate Program, University of California, Riverside, CA, USA.
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