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Wu S, Wang Q, Zhai H, Zhang Y, Xu D, Yan G, Wu R. γ-Aminobutyric acid as a biomarker of the lateralizing and monitoring drug effect in patients with magnetic resonance imaging-negative temporal lobe epilepsy. Front Neurosci 2023; 17:1184440. [PMID: 37255748 PMCID: PMC10225511 DOI: 10.3389/fnins.2023.1184440] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2023] [Accepted: 04/21/2023] [Indexed: 06/01/2023] Open
Abstract
Introduction Despite verifying proton magnetic resonance spectroscopy (1H-MRS) for focal localization in magnetic resonance imaging (MRI)-negative temporal lobe epilepsy (TLE), it is necessary to illustrate metabolic changes and screen for effective biomarkers for monitoring therapeutic effect. We used 1H-MRS to investigate the role of metabolic levels in MRI-negative TLE. Materials and methods Thirty-seven patients (n = 37, 14 women) and 20 healthy controls (n = 20, 11 women) were investigated by 1H-MRS. We compared the metabolite level changes in the epileptic and contralateral sides on the mesial temporal and dorsolateral prefrontal cortices and analyzed their association with clinical symptoms. Results γ-Aminobutyric acid (GABA) levels were significantly lower on the epileptic side (2.292 ± 0.890) than in the contralateral side (2.662 ± 0.742, p = 0.029*) in patients on the mesial temporal lobe. N-acetylaspartate (NAA) levels were significantly lower on the epileptic side (7.284 ± 1.314) than on the contralateral side (7.655 ± 1.549, p = 0.034*). NAA + N-acetylaspartylglutamate levels were significantly lower on the epileptic side (7.668 ± 1.406) than on the contralateral side (8.086 ± 1.675, p = 0.032*). Glutamate levels were significantly lower on the epileptic side (7.773 ± 1.428) than on the contralateral side (8.245 ± 1.616, p = 0.040*). Moreover, a significant negative correlation was found between GABA levels in the epileptic mesial temporal lobe and tonic-clonic seizure frequency (r = -0.338, p = 0.046*). Conclusion γ-Aminobutyric acid (GABA) is a potential biomarker for lateralization and monitoring seizure frequency in MRI-negative TLE.
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Affiliation(s)
- Shuohua Wu
- Department of Radiology, The Second Affiliated Hospital of Xiamen Medical College, Xiamen, China
- Department of Medical Imaging, The Second Affiliated Hospital, Medical College of Shantou University, Shantou, China
| | - Qianqi Wang
- Department of Basic Medical Sciences, School of Medicine, Xiamen University, Xiamen, China
| | - Huige Zhai
- Center of Morphological Experiment, Medical College of Yanbian University, Jilin, China
| | - Yiwen Zhang
- Department of Neurology, The Second Affiliated Hospital of Xiamen Medical College, Xiamen, China
| | - Dongyuan Xu
- Center of Morphological Experiment, Medical College of Yanbian University, Jilin, China
| | - Gen Yan
- Department of Radiology, The Second Affiliated Hospital of Xiamen Medical College, Xiamen, China
| | - Renhua Wu
- Department of Medical Imaging, The Second Affiliated Hospital, Medical College of Shantou University, Shantou, China
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Arterial spin-labelling and magnetic resonance spectroscopy as imaging biomarkers for detection of epileptogenic zone in non-lesional focal impaired awareness epilepsy. THE EGYPTIAN JOURNAL OF RADIOLOGY AND NUCLEAR MEDICINE 2020. [DOI: 10.1186/s43055-020-00326-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Abstract
Background
The proper identification of an epileptic focus is a pivotal diagnostic issue; particularly in non-lesional focal impaired awareness epilepsy (FIAE). Seizures are usually accompanied by alterations of regional cerebral blood flow (rCBF) and metabolism. Arterial spin labeling-MRI (ASL-MRI) and proton magnetic resonance spectroscopy (1H-MRS) are MRI techniques that can, non-invasively, define the regions of cerebral perfusion and metabolic changes, respectively. The aim of the current study was to recognize the epileptogenic zone in patients with non-lesional FIAE by evaluating the interictal changes in rCBF and cerebral metabolic alterations, using PASL-MRI and 1H-MRS.
Results
For identification of the epileptogenic zone, increased ASLAI% assessed by PASL-MRI (at a cut-off value ≥ 5.96%) showed 95.78% accuracy, and increased %AF (at a cut-off value ≥ 9.98%) showed 98.14% accuracy, while decreased NAA/(Cho + Cr) ratio estimated by multi-voxels (MV) 1H-MRS (at a cut-off value ≥ 0.59) showed 97.74% accuracy. Moreover, the combined use of PASL-MRI and MV 1H-MRS yielded 100% sensitivity, 98.45% specificity and 98.86% accuracy.
Conclusion
The combined use of PASL-MRI and MV 1H-MRS can be considered as in-vivo proficient bio-marker for proper identification of epileptogenic zone in patients with non-lesional FIAE.
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Kuhn T, Gullett JM, Boutzoukas AE, Bohsali A, Mareci TH, FitzGerald DB, Carney PR, Bauer RM. Temporal lobe epilepsy affects spatial organization of entorhinal cortex connectivity. Epilepsy Behav 2018; 88:87-95. [PMID: 30243111 PMCID: PMC6294293 DOI: 10.1016/j.yebeh.2018.06.038] [Citation(s) in RCA: 3] [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: 03/16/2018] [Revised: 06/18/2018] [Accepted: 06/20/2018] [Indexed: 12/15/2022]
Abstract
Evidence for structural connectivity patterns within the medial temporal lobe derives primarily from postmortem histological studies. In humans and nonhuman primates, the parahippocampal gyrus (PHg) is subdivided into parahippocampal (PHc) and perirhinal (PRc) cortices, which receive input from distinct cortical networks. Likewise, their efferent projections to the entorhinal cortex (ERc) are distinct. The PHc projects primarily to the medial ERc (M-ERc). The PRc projects primarily to the lateral portion of the ERc (L-ERc). Both M-ERc and L-ERc, via the perforant pathway, project to the dentate gyrus and hippocampal (HC) subfields. Until recently, these neural circuits could not be visualized in vivo. Diffusion tensor imaging algorithms have been developed to segment gray matter structures based on probabilistic connectivity patterns. However, these algorithms have not yet been applied to investigate connectivity in the temporal lobe or changes in connectivity architecture related to disease processes. In this study, this segmentation procedure was used to classify ERc gray matter based on PRc, ERc, and HC connectivity patterns in 7 patients with temporal lobe epilepsy (TLE) without hippocampal sclerosis (mean age, 14.86 ± 3.34 years) and 7 healthy controls (mean age, 23.86 ± 2.97 years). Within samples paired t-tests allowed for comparison of ERc connectivity between epileptogenic and contralateral hemispheres. In healthy controls, there were no significant within-group differences in surface area, volume, or cluster number of ERc connectivity-defined regions (CDR). Likewise, in line with histology results, ERc CDR in the control group were well-organized, uniform, and segregated via PRc/PHc afferent and HC efferent connections. Conversely, in TLE, there were significantly more PRc and HC CDR clusters in the epileptogenic than the contralateral hemisphere. The surface area of the PRc CDR was greater, and that of the HC CDRs was smaller, in the epileptogenic hemisphere as well. Further, there was no clear delineation between M-ERc and L-ERc connectivity with PRc, PHc or HC in TLE. These results suggest a breakdown of the spatial organization of PHg-ERc-HC connectivity in TLE. Whether this breakdown is the cause or result of epileptic activity remains an exciting research question.
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Affiliation(s)
- Taylor Kuhn
- Department of Clinical and Health Psychology, University of Florida, Gainesville, FL, United States of America; Department of Physical Therapy, University of Florida, Gainesville, FL, United States of America.
| | - Joseph M Gullett
- Department of Clinical and Health Psychology, University of Florida, Gainesville, FL, United States of America; Department of VA Brain Rehabilitation Research Center, Malcolm Randall VA Center Gainesville, FL, United States of America
| | - Angelique E Boutzoukas
- Department of Clinical and Health Psychology, University of Florida, Gainesville, FL, United States of America
| | - Anastasia Bohsali
- Department of Neurology, University of Florida, Gainesville, FL, United States of America
| | - Thomas H Mareci
- Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, FL, United States of America
| | - David B FitzGerald
- Department of VA Brain Rehabilitation Research Center, Malcolm Randall VA Center Gainesville, FL, United States of America
| | - Paul R Carney
- Department of Pediatrics, University of Florida, Gainesville, FL, United States of America; Department of Neurology, University of Florida, Gainesville, FL, United States of America; Department of Neuroscience, University of Florida, Gainesville, FL, United States of America; J. Crayton Pruitt Department of Biomedical Engineering, University of Florida, Gainesville, FL, United States of America; B.J. and Eve Wilder Epilepsy Center Excellence, University of Florida, Gainesville, FL, United States of America
| | - Russell M Bauer
- Department of Clinical and Health Psychology, University of Florida, Gainesville, FL, United States of America; Department of VA Brain Rehabilitation Research Center, Malcolm Randall VA Center Gainesville, FL, United States of America
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Rusbridge C, Long S, Jovanovik J, Milne M, Berendt M, Bhatti SFM, De Risio L, Farqhuar RG, Fischer A, Matiasek K, Muñana K, Patterson EE, Pakozdy A, Penderis J, Platt S, Podell M, Potschka H, Stein VM, Tipold A, Volk HA. International Veterinary Epilepsy Task Force recommendations for a veterinary epilepsy-specific MRI protocol. BMC Vet Res 2015; 11:194. [PMID: 26319136 PMCID: PMC4594743 DOI: 10.1186/s12917-015-0466-x] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Accepted: 06/29/2015] [Indexed: 12/17/2022] Open
Abstract
Epilepsy is one of the most common chronic neurological diseases in veterinary practice. Magnetic resonance imaging (MRI) is regarded as an important diagnostic test to reach the diagnosis of idiopathic epilepsy. However, given that the diagnosis requires the exclusion of other differentials for seizures, the parameters for MRI examination should allow the detection of subtle lesions which may not be obvious with existing techniques. In addition, there are several differentials for idiopathic epilepsy in humans, for example some focal cortical dysplasias, which may only apparent with special sequences, imaging planes and/or particular techniques used in performing the MRI scan. As a result, there is a need to standardize MRI examination in veterinary patients with techniques that reliably diagnose subtle lesions, identify post-seizure changes, and which will allow for future identification of underlying causes of seizures not yet apparent in the veterinary literature. There is a need for a standardized veterinary epilepsy-specific MRI protocol which will facilitate more detailed examination of areas susceptible to generating and perpetuating seizures, is cost efficient, simple to perform and can be adapted for both low and high field scanners. Standardisation of imaging will improve clinical communication and uniformity of case definition between research studies. A 6–7 sequence epilepsy-specific MRI protocol for veterinary patients is proposed and further advanced MR and functional imaging is reviewed.
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Affiliation(s)
- Clare Rusbridge
- Fitzpatrick Referrals, Halfway Lane, Eashing, Godalming, GU7 2QQ, Surrey, UK. .,School of Veterinary Medicine, Faculty of Health & Medical Sciences, University of Surrey, Guildford, GU2 7TE, Surrey, UK.
| | - Sam Long
- University of Melbourne, 250 Princes Highway, Weibee, 3015, VIC, Australia.
| | - Jelena Jovanovik
- Fitzpatrick Referrals, Halfway Lane, Eashing, Godalming, GU7 2QQ, Surrey, UK.
| | - Marjorie Milne
- University of Melbourne, 250 Princes Highway, Weibee, 3015, VIC, Australia.
| | - Mette Berendt
- Department of Veterinary and Clinical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg C, Denmark.
| | - Sofie F M Bhatti
- Department of Small Animal Medicine and Clinical Biology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, Merelbeke, 9820, Belgium.
| | - Luisa De Risio
- Animal Health Trust, Lanwades Park, Kentford, Newmarket, CB8 7UU, Suffolk, UK.
| | - Robyn G Farqhuar
- Fernside Veterinary Centre, 205 Shenley Road, Borehamwood, SG9 0TH, Hertfordshire, UK.
| | - Andrea Fischer
- Centre for Clinical Veterinary Medicine, Ludwig-Maximilians-University, Veterinärstr. 13, 80539, Munich, Germany.
| | - Kaspar Matiasek
- Section of Clinical & Comparative Neuropathology, Centre for Clinical Veterinary Medicine, Ludwig-Maximilians-University, Veterinärstr. 13, 80539, Munich, Germany.
| | - Karen Muñana
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, 1052 William Moore Drive, Raleigh, NC, 27607, USA.
| | - Edward E Patterson
- University of Minnesota College of Veterinary Medicine, D426 Veterinary Medical Center, 1352 Boyd Avenue, St. Paul, MN, 55108, USA.
| | - Akos Pakozdy
- Clinical Unit of Internal Medicine Small Animals, University of Veterinary Medicine, Veterinärplatz 1, 1210, Vienna, Austria.
| | - Jacques Penderis
- Vet Extra Neurology, Broadleys Veterinary Hospital, Craig Leith Road, Stirling, FK7 7LE, Stirlingshire, UK.
| | - Simon Platt
- College of Veterinary Medicine, University of Georgia, 501 DW Brooks Drive, Athens, GA, 30602, USA.
| | - Michael Podell
- Chicago Veterinary Neurology and Neurosurgery, 3123 N. Clybourn Avenue, Chicago, IL, 60618, USA.
| | - Heidrun Potschka
- Department of Pharmacology, Toxicology and Pharmacy, Ludwig-Maximillians-University, Königinstr. 16, 80539, Munich, Germany.
| | - Veronika M Stein
- Department of Small Animal Medicine and Surgery, University of Veterinary Medicine Hannover, Bünteweg 9, 30559, Hannover, Germany.
| | - Andrea Tipold
- Department of Small Animal Medicine and Surgery, University of Veterinary Medicine Hannover, Bünteweg 9, 30559, Hannover, Germany.
| | - Holger A Volk
- Department of Clinical Science and Services, Royal Veterinary College, Hatfield, AL9 7TA, Hertfordshire, UK.
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Xu MY, Ergene E, Zagardo M, Tracy PT, Wang H, Liu W, Machens NA. Proton MR Spectroscopy in Patients with Structural MRI-Negative Temporal Lobe Epilepsy. J Neuroimaging 2015; 25:1030-7. [PMID: 26011809 DOI: 10.1111/jon.12263] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2015] [Revised: 04/16/2015] [Accepted: 04/18/2015] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND AND PURPOSE With conventional magnetic resonance imaging (MRI), 20-30% of patients with temporal lobe epilepsy (TLE) have negative pathological MRI findings. Further investigations of the role of magnetic resonance spectroscopy (MRS) in the pre-surgical evaluation of patients with MRI-negative TLE are important to avoid intracranial EEG recording and to better understand the mechanism of the epileptogenic process. This study aimed to compare the measurements of N-acetylaspartate (NAA), creatine (Cr), and choline (Cho) in the hippocampi of MRI-negative TLE patients and normal subjects. METHODS Twenty patients with MRI-negative TLE and 10 age-matched healthy control subjects underwent MRI and MRS. The concentrations of NAA, Cr, and Cho and the ratios of NAA/Cr and NAA/(Cr+Cho) were measured. Seven of these 20 patients also underwent surgical treatment for TLE. Their pathological results and surgical outcomes were evaluated. RESULTS In the hippocampi ipsilateral to the seizure side, the NAA/Cr and NAA/(Cr+Cho) ratios were significantly decreased compared with the ratios of the hippocampi contralateral to the seizure side and the normal control hippocampi. There was no significant difference between the hippocampi contralateral to the seizure side and the normal control hippocampi. The pathological results from the patients who underwent temporal lobe resection indicated mild to moderate gliosis and minimal loss of neurons. Five patients were seizure-free during the follow-up period of 9- 47 months (mean 27.7 months). CONCLUSIONS In MRI-negative TLE, significant reductions in the NAA/Cr and NAA/(Cr+Cho) ratios ipsilateral to the seizure side may help lateralize and localize the epileptogenic zone.
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Affiliation(s)
- Michael Y Xu
- Department of Neurology, Illinois Neurologic Institute, University of Illinois College of Medicine, Peoria, IL
| | - Erhan Ergene
- Department of Neurology, Illinois Neurologic Institute, University of Illinois College of Medicine, Peoria, IL
| | - Michael Zagardo
- Department of Radiology, Illinois Neurologic Institute, University of Illinois College of Medicine, Peoria, IL
| | - Patrick T Tracy
- Department of Neurosurgery, Illinois Neurologic Institute, University of Illinois College of Medicine, Peoria, IL
| | - Huaping Wang
- Department of the Center for Outcomes Research, University of Illinois College of Medicine, Peoria, IL
| | - WenChing Liu
- Department of Radiology, Illinois Neurologic Institute, University of Illinois College of Medicine, Peoria, IL
| | - Nancy A Machens
- Department of Neurology, Illinois Neurologic Institute, University of Illinois College of Medicine, Peoria, IL
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Nazem-Zadeh MR, Elisevich KV, Schwalb JM, Bagher-Ebadian H, Mahmoudi F, Soltanian-Zadeh H. Lateralization of temporal lobe epilepsy by multimodal multinomial hippocampal response-driven models. J Neurol Sci 2014; 347:107-18. [PMID: 25300772 DOI: 10.1016/j.jns.2014.09.029] [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] [Received: 07/23/2014] [Revised: 09/16/2014] [Accepted: 09/18/2014] [Indexed: 11/28/2022]
Abstract
PURPOSE Multiple modalities are used in determining laterality in mesial temporal lobe epilepsy (mTLE). It is unclear how much different imaging modalities should be weighted in decision-making. The purpose of this study is to develop response-driven multimodal multinomial models for lateralization of epileptogenicity in mTLE patients based upon imaging features in order to maximize the accuracy of noninvasive studies. METHODS AND MATERIALS The volumes, means and standard deviations of FLAIR intensity and means of normalized ictal-interictal SPECT intensity of the left and right hippocampi were extracted from preoperative images of a retrospective cohort of 45 mTLE patients with Engel class I surgical outcomes, as well as images of a cohort of 20 control, nonepileptic subjects. Using multinomial logistic function regression, the parameters of various univariate and multivariate models were estimated. Based on the Bayesian model averaging (BMA) theorem, response models were developed as compositions of independent univariate models. RESULTS A BMA model composed of posterior probabilities of univariate response models of hippocampal volumes, means and standard deviations of FLAIR intensity, and means of SPECT intensity with the estimated weighting coefficients of 0.28, 0.32, 0.09, and 0.31, respectively, as well as a multivariate response model incorporating all mentioned attributes, demonstrated complete reliability by achieving a probability of detection of one with no false alarms to establish proper laterality in all mTLE patients. CONCLUSION The proposed multinomial multivariate response-driven model provides a reliable lateralization of mesial temporal epileptogenicity including those patients who require phase II assessment.
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Affiliation(s)
- Mohammad-Reza Nazem-Zadeh
- Department of Research Administration, Henry Ford Health System, Detroit, MI 48202, USA; Department of Radiology, Henry Ford Health System, Detroit, MI, 48202, USA.
| | - Kost V Elisevich
- Department of Clinical Neurosciences, Spectrum Health Medical Group, Grand Rapids, MI 49503, USA.
| | - Jason M Schwalb
- Department of Neurosurgery, Henry Ford Health System, Detroit, MI 48202, USA.
| | - Hassan Bagher-Ebadian
- Department of Radiology, Henry Ford Health System, Detroit, MI, 48202, USA; Department of Neurology, Henry Ford Health System, Detroit, MI 48202, USA.
| | - Fariborz Mahmoudi
- Department of Research Administration, Henry Ford Health System, Detroit, MI 48202, USA; Department of Radiology, Henry Ford Health System, Detroit, MI, 48202, USA; Computer and IT engineering Faculty, Islamic Azad University, Qazvin Branch, Iran.
| | - Hamid Soltanian-Zadeh
- Department of Research Administration, Henry Ford Health System, Detroit, MI 48202, USA; Department of Radiology, Henry Ford Health System, Detroit, MI, 48202, USA; Control and Intelligent Processing Center of Excellence (CIPCE), School of Electrical and Computer, University of Tehran, Tehran, Iran.
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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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Zhang J, Liu Q, Mei S, Zhang X, Liu W, Chen H, Xia H, Zhou Z, Wang X, Li Y. Identifying the affected hemisphere with a multimodal approach in MRI-positive or negative, unilateral or bilateral temporal lobe epilepsy. Neuropsychiatr Dis Treat 2014; 10:71-81. [PMID: 24476628 PMCID: PMC3891647 DOI: 10.2147/ndt.s56404] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Patients with non-lesional or bilateral temporal-lobe epilepsy (TLE) are often excluded from surgical treatment. This study investigated focus lateralization in TLE to understand identification of the affected hemisphere with regard to non-lesional or bilateral affection and postsurgical outcome. A total of 24 TLE patients underwent presurgical evaluation with magnetic resonance imaging (MRI), proton magnetic resonance spectroscopy ((1)H-MRS), video-electroencephalogram (video-EEG), and/or intracranial EEG (icEEG), and they were classified as MRI-positive or negative, unilateral or bilateral TLE cases. In patients with positive-MRI, MRI and (1)H-MRS indicated high (100%) concordant lateralization to EEG findings in unilateral TLE, and moderate (75%) concordance to icEEG findings in bilateral TLE; whereas in patients with negative-MRI, (1)H-MRS indicated moderate (60%-75%) concordance to EEG and/or icEEG in unilateral TLE, and relatively low (50%) concordance to icEEG in bilateral TLE. Ninety point nine percent of patients with unilateral TLE and 41.7% of patients with bilateral TLE (including 50% of MRI-negative bilateral TLE) became seizure-free. The MRS findings were not correlated with seizure outcome, while non-seizure-free patients had an insignificantly higher percentage of contralateral N-acetyl aspartate (NAA) reduction compared with seizure-free patients, indicating the relatively low predictive value of (1)H-MRS for surgical outcome. Further, EEG and icEEG findings were significantly correlated with seizure outcome, and for patients with positive MRI, MRI findings were also correlated with seizure outcome, indicating the predictive value of these modalities. The results suggested that a multimodal approach including neuroimaging, EEG, and/or icEEG could identify seizure focus in most cases, and provide surgical options for non-lesional or bilateral TLE patients with a possible good outcome.
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Affiliation(s)
- Jing Zhang
- School of Biomedical Engineering, Capital Medical University, Beijing, People's Republic of China
| | - Qingzhu Liu
- Department of Functional Neurolog and Neurosurgery, Beijing Haidian Hospital, Beijing, People's Republic of China
| | - Shanshan Mei
- Department of Functional Neurolog and Neurosurgery, Beijing Haidian Hospital, Beijing, People's Republic of China
| | - Xiaoming Zhang
- Department of Functional Neurolog and Neurosurgery, Beijing Haidian Hospital, Beijing, People's Republic of China
| | - Weifang Liu
- School of Biomedical Engineering, Capital Medical University, Beijing, People's Republic of China
| | - Hui Chen
- School of Biomedical Engineering, Capital Medical University, Beijing, People's Republic of China
| | - Hong Xia
- School of Biomedical Engineering, Capital Medical University, Beijing, People's Republic of China
| | - Zhen Zhou
- School of Biomedical Engineering, Capital Medical University, Beijing, People's Republic of China
| | - Xiaofei Wang
- Department of Functional Neurolog and Neurosurgery, Beijing Haidian Hospital, Beijing, People's Republic of China
| | - Yunlin Li
- Department of Functional Neurolog and Neurosurgery, Beijing Haidian Hospital, Beijing, People's Republic of China
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Zhang J, Liu W, Chen H, Xia H, Zhou Z, Mei S, Liu Q, Li Y. Multimodal neuroimaging in presurgical evaluation of drug-resistant epilepsy. NEUROIMAGE-CLINICAL 2013; 4:35-44. [PMID: 24282678 PMCID: PMC3840005 DOI: 10.1016/j.nicl.2013.10.017] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/26/2013] [Revised: 09/21/2013] [Accepted: 10/25/2013] [Indexed: 01/12/2023]
Abstract
Intracranial EEG (icEEG) monitoring is critical in epilepsy surgical planning, but it has limitations. The advances of neuroimaging have made it possible to reveal epileptic abnormalities that could not be identified previously and improve the localization of the seizure focus and the vital cortex. A frequently asked question in the field is whether non-invasive neuroimaging could replace invasive icEEG or reduce the need for icEEG in presurgical evaluation. This review considers promising neuroimaging techniques in epilepsy presurgical assessment in order to address this question. In addition, due to large variations in the accuracies of neuroimaging across epilepsy centers, multicenter neuroimaging studies are reviewed, and there is much need for randomized controlled trials (RCTs) to better reveal the utility of presurgical neuroimaging. The results of multiple studies indicate that non-invasive neuroimaging could not replace invasive icEEG in surgical planning especially in non-lesional or extratemporal lobe epilepsies, but it could reduce the need for icEEG in certain cases. With technical advances, multimodal neuroimaging may play a greater role in presurgical evaluation to reduce the costs and risks of epilepsy surgery, and provide surgical options for more patients with drug-resistant epilepsy.
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Affiliation(s)
- Jing Zhang
- School of Biomedical Engineering, Capital Medical University, Beijing 100069, PR China
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Abstract
Neuroimaging in epilepsy is a very large and growing field. Researchers in this area have quickly adopted new methods, resulting in a lively literature. Basic features of common epilepsies are well known, but, outside of the specific area of epilepsy surgery evaluation, new methods evolving in the last few years have had limited new beneficial clinical impact. Here, an overview of the epilepsy neuroimaging literature of the last 5 years, with an emphasis on mesial temporal lobe epilepsy, idiopathic generalized epilepsies, presurgical evaluation and new developments in functional MRI is presented. The need for attention to clinical translation, as well as immediate opportunities and future trends in this field, are discussed.
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Affiliation(s)
- Mark Richardson
- P043 Institute of Psychiatry, De Crespigny Park, London SE5 8AF, UK.
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12
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Richardson M. Current themes in neuroimaging of epilepsy: brain networks, dynamic phenomena, and clinical relevance. Clin Neurophysiol 2010; 121:1153-75. [PMID: 20185365 DOI: 10.1016/j.clinph.2010.01.004] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2009] [Revised: 12/24/2009] [Accepted: 01/05/2010] [Indexed: 11/15/2022]
Abstract
Brain scanning methods were first applied in patients with epilepsy more than 30years ago. A very substantial literature now exists in this field, which is exponentially increasing. Contemporary neuroimaging studies in epilepsy reflect new concepts in the epilepsies, as well as current methodological developments. In particular, this area is emphasising the role of networks in epileptogenicity, the existence of dynamic phenomena which can be captured by imaging, and is beginning to validate the implementation of neuroimaging in the clinic. Here, recent studies of the last 5years are reviewed, covering the full range of neuroimaging methods with SPECT, PET and MRI in epilepsy.
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Affiliation(s)
- Mark Richardson
- P043 Institute of Psychiatry, De Crespigny Park, London SE5 8AF, UK.
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Doelken MT, Mennecke A, Stadlbauer A, Kloska S, Struffert T, Engelhorn T, Thuerauf N, Doerfler A, Stefan H, Hammen T. Multi-voxel magnetic resonance spectroscopy of cerebral metabolites in healthy adults at 3 Tesla. Acad Radiol 2009; 16:1493-501. [PMID: 19781961 DOI: 10.1016/j.acra.2009.07.025] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2009] [Revised: 07/08/2009] [Accepted: 07/23/2009] [Indexed: 11/28/2022]
Abstract
RATIONALE AND OBJECTIVES The objective of this study was to determine how metabolite values (total N-acetyl aspartate [tNAA], glutamate plus glutamine [Glx], total choline [tCho], myoinositol [mI], and total creatine [tCr]) vary across brain regions in healthy subjects. This study was implemented to create an internal reference database for patients with psychiatric disorders and epilepsy. MATERIALS AND METHODS Using the multivoxel technique with a voxelwise phantom calibration on a 3-T magnetic resonance imaging scanner, metabolite levels of 29 healthy controls (13 men, 16 women; average age, 29 years) were obtained from the hippocampi, basal ganglia, insula cortex, cingulum, and precuneus. Additionally, gray and white matter metabolite values were obtained from the frontal and parietal lobes. RESULTS No significant effect of gender was noticed. The total magnitude of variation was greatest for Glx, followed by tNAA, mI, tCho, and tCr. Glx/tCr, Glx, and tCr were increased in gray matter, while tNAA/tCr, tCho/tCr, respectively tNAA and tCho, were elevated in white matter. These findings indicate (1) anterior-to-posterior increases of tNAA/tCr and Glx/tCr, respectively tNAA and Glx, along the midline in gray matter (cingulum); (2) increased tNAA/tCr, respectively tNAA, in white matter in the fiber tracts of the precentral region; (3) an accentuated anterior-to-posterior increase of tCr in the insula cortex; and (4) an anterior-to-posterior decrease of tCho/tCr and tCho in white matter. CONCLUSIONS There are significant metabolic differences within tissue types and within tissue types at different locations; therefore, the spectra and metabolite values presented should provide a useful internal reference for both clinical and research studies.
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Affiliation(s)
- Marc Thorsten Doelken
- Department of Neuroradiology, University of Erlangen-Nuremberg, Schwabachanlage 6, 91054 Erlangen, Germany.
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14
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Doelken M, Stefan H, Pauli E, Stadlbauer A, Struffert T, Engelhorn T, Richter G, Ganslandt O, Doerfler A, Hammen T. 1H-MRS profile in MRI positive- versus MRI negative patients with temporal lobe epilepsy. Seizure 2008; 17:490-7. [DOI: 10.1016/j.seizure.2008.01.008] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2007] [Revised: 01/08/2008] [Accepted: 01/23/2008] [Indexed: 01/09/2023] Open
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Umeoka S, Matsuda K, Baba K, Usui N, Tottori T, Terada K, Usui K, Nakamura F, Inoue Y, Fujiwara T, Mihara T. Usefulness of 123I-iomazenil single-photon emission computed tomography in discriminating between mesial and lateral temporal lobe epilepsy in patients in whom magnetic resonance imaging demonstrates normal findings. J Neurosurg 2007; 107:352-63. [PMID: 17695390 DOI: 10.3171/jns-07/08/0352] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Object
To provide greater accuracy in determining the epileptogenic zone during preoperative evaluation, the authors retrospectively examined 123I-iomazenil single-photon emission computed tomography (IMZ SPECT) studies obtained in patients with temporal lobe epilepsy (TLE) in whom there was no evidence of an abnormality on magnetic resonance (MR) images.
Methods
Twelve patients, seven with mesial TLE (MTLE) and five with lateral TLE (LTLE), satisfied the criteria for inclusion in the study. The IMZ SPECT findings in these patients were reviewed retrospectively, and a comparison was made between findings in patients with MTLE and those in patients with LTLE.
Results
The IMZ SPECT studies demonstrated decreased IMZ uptake in the ipsilateral mesial temporal region and the anterobasal temporal lobe in all patients who had MTLE on only one side. On the other hand, IMZ SPECT examinations revealed low IMZ uptake in the ipsilateral lateral temporal lobe in four of five patients with LTLE in whom abnormal findings were restricted to the lateral neocortex. In the remaining patient with LTLE, abnormally low IMZ uptake was found in both mesial and lateral temporal lobes, although pure LTLE was diagnosed by an invasive electroencephalographic evaluation; this patient's habitual seizures continued even after temporal lobectomy, although his mesial structures were spared.
Conclusions
The authors report characteristics of IMZ SPECT findings that differed between patients with MTLE and those with LTLE. The IMZ SPECT examinations proved useful for preoperative evaluation and, to a certain extent, for discrimination between MTLE and LTLE in cases in which MR imaging demonstrated normal findings. The results of this study suggest that IMZ SPECT findings may reflect localization of the epileptogenic zone.
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Affiliation(s)
- Shuichi Umeoka
- Department of Neurological Surgery, National Epilepsy Center, Shizuoka Institute of Epilepsy and Neurological Disorders, Urushiyama, Shizuoka, Japan.
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Abstract
Over the past two decades, proton magnetic resonance spectroscopy (proton MRS) of the brain has made the transition from research tool to a clinically useful modality. In this review, we first describe the localization methods currently used in MRS studies of the brain and discuss the technical and practical factors that determine the applicability of the methods to particular clinical studies. We also describe each of the resonances detected by localized solvent-suppressed proton MRS of the brain and discuss the metabolic and biochemical information that can be derived from an analysis of their concentrations. We discuss spectral quantitation and summarize the reproducibility of both single-voxel and multivoxel methods at 1.5 and 3-4 T. We have selected three clinical neurologic applications in which there has been a consensus as to the diagnostic value of MRS and summarize the information relevant to clinical applications. Finally, we speculate about some of the potential technical developments, either in progress or in the future, that may lead to improvements in the performance of proton MRS.
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Affiliation(s)
- Yael Rosen
- Department of Radiology, Beth Israel Deaconess Medical Center, Harvard Medical School, 02215 Boston, Massachusetts
| | - Robert E. Lenkinski
- Department of Radiology, Beth Israel Deaconess Medical Center, Harvard Medical School, 02215 Boston, Massachusetts
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