1
|
Sathyan S, Ayers E, Blumen H, Weiss EF, Adhikari D, Stimmel M, Abdulsalam K, Noone M, George RK, Ceide M, Ambrose AF, Wang C, Narayanan P, Sureshbabu S, Shaji KS, Sigamani A, Mathuranath PS, Pradeep VG, Verghese J. Epidemiology of Motoric Cognitive Risk Syndrome in the Kerala Einstein Study: Protocol for a Prospective Cohort Study. JMIR Res Protoc 2023; 12:e49933. [PMID: 37590054 PMCID: PMC10472178 DOI: 10.2196/49933] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Revised: 07/03/2023] [Accepted: 07/04/2023] [Indexed: 08/18/2023] Open
Abstract
BACKGROUND The southern India state of Kerala has among the highest proportion of older adults in its population in the country. An increase in chronic age-related diseases such as dementia is expected in the older Kerala population. Identifying older individuals early in the course of cognitive decline offers the best hope of introducing preventive measures early and planning management. However, the epidemiology and pathogenesis of predementia syndromes at the early stages of cognitive decline in older adults are not well established in India. OBJECTIVE The Kerala Einstein Study (KES) is a community-based cohort study that was established in 2008 and is based in the Kozhikode district in Kerala state. KES aims to establish risk factors and brain substrates of motoric cognitive risk syndrome (MCR), a predementia syndrome characterized by the presence of slow gait and subjective cognitive concerns in individuals without dementia or disability. This protocol describes the study design and procedures for this KES project. METHODS KES is proposing to enroll a sample of 1000 adults ≥60 years old from urban and rural areas in the Kozhikode district of Kerala state: 200 recruited in the previous phase of KES and 800 new participants to be recruited in this project. MCR is the cognitive phenotype of primary interest. The associations between previously established risk factors for dementia as well as novel risk factors (apathy and traumatic brain injury) and MCR will be examined in KES. Risk factor profiles for MCR will be compared between urban and rural residents as well as with individuals who meet the criteria for mild cognitive impairment (MCI). Cognitive and physical function, medical history and medications, sociodemographic characteristics, lifestyle patterns, and activities of daily living will be evaluated. Participants will also undergo magnetic resonance imaging and electrocardiogram investigations. Longitudinal follow-up is planned in a subset of participants as a prelude to future longitudinal studies. RESULTS KES (2R01AG039330-07) was funded by the US National Institutes of Health in September 2019 and received approval from the Indian Medical Council of Research to start the study in June 2021. We had recruited 433 new participants from urban and rural sites in Kozhikode as of May 2023: 41.1% (178/433) women, 67.7% (293/433) rural residents, and 13.4% (58/433) MCR cases. Enrollment is actively ongoing at all the KES recruitment sites. CONCLUSIONS KES will provide new insights into risk factors and brain substrates associated with MCR in India and will help guide future development of regionally specific preventive interventions for dementia. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID) DERR1-10.2196/49933.
Collapse
Affiliation(s)
- Sanish Sathyan
- Department of Neurology, Albert Einstein College of Medicine, Bronx, NY, United States
| | - Emmeline Ayers
- Department of Neurology, Albert Einstein College of Medicine, Bronx, NY, United States
| | - Helena Blumen
- Department of Neurology, Albert Einstein College of Medicine, Bronx, NY, United States
- Department of Medicine, Albert Einstein College of Medicine, Bronx, NY, United States
| | - Erica F Weiss
- Department of Neurology, Albert Einstein College of Medicine, Bronx, NY, United States
| | - Dristi Adhikari
- Department of Neurology, Albert Einstein College of Medicine, Bronx, NY, United States
| | - Marnina Stimmel
- Department of Neurology, Albert Einstein College of Medicine, Bronx, NY, United States
| | | | - Mohan Noone
- Institute of Neurosciences, Baby Memorial Hospital, Kozhikode, India
| | - Roy K George
- Institute of Neurosciences, Baby Memorial Hospital, Kozhikode, India
| | - Mirnova Ceide
- Department of Neurology, Albert Einstein College of Medicine, Bronx, NY, United States
- Department of Psychiatry and Behavioral Sciences, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, NY, United States
| | - Anne Felicia Ambrose
- Department of Neurology, Albert Einstein College of Medicine, Bronx, NY, United States
| | - Cuiling Wang
- Department of Neurology, Albert Einstein College of Medicine, Bronx, NY, United States
- Department of Epidemiology and Population Health, Albert Einstein College of Medicine, Bronx, NY, United States
| | | | | | | | | | - Pavagada S Mathuranath
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bengaluru, India
| | | | - Joe Verghese
- Department of Neurology, Albert Einstein College of Medicine, Bronx, NY, United States
- Department of Medicine, Albert Einstein College of Medicine, Bronx, NY, United States
| |
Collapse
|
2
|
Passaro EA. Neuroimaging in Adults and Children With Epilepsy. Continuum (Minneap Minn) 2023; 29:104-155. [PMID: 36795875 DOI: 10.1212/con.0000000000001242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
OBJECTIVE This article discusses the fundamental importance of optimal epilepsy imaging using the International League Against Epilepsy-endorsed Harmonized Neuroimaging of Epilepsy Structural Sequences (HARNESS) protocol and the use of multimodality imaging in the evaluation of patients with drug-resistant epilepsy. It outlines a methodical approach to evaluating these images, particularly in the context of clinical information. LATEST DEVELOPMENTS Epilepsy imaging is rapidly evolving, and a high-resolution epilepsy protocol MRI is essential in evaluating newly diagnosed, chronic, and drug-resistant epilepsy. The article reviews the spectrum of relevant MRI findings in epilepsy and their clinical significance. Integrating multimodality imaging is a powerful tool in the presurgical evaluation of epilepsy, particularly in "MRI-negative" cases. For example, correlation of clinical phenomenology, video-EEG with positron emission tomography (PET), ictal subtraction single-photon emission computerized tomography (SPECT), magnetoencephalography (MEG), functional MRI, and advanced neuroimaging such as MRI texture analysis and voxel-based morphometry enhances the identification of subtle cortical lesions such as focal cortical dysplasias to optimize epilepsy localization and selection of optimal surgical candidates. ESSENTIAL POINTS The neurologist has a unique role in understanding the clinical history and seizure phenomenology, which are the cornerstones of neuroanatomic localization. When integrated with advanced neuroimaging, the clinical context has a profound impact on identifying subtle MRI lesions or finding the "epileptogenic" lesion when multiple lesions are present. Patients with an identified lesion on MRI have a 2.5-fold improved chance of achieving seizure freedom with epilepsy surgery compared with those without a lesion. This clinical-radiographic integration is essential to accurate classification, localization, determination of long-term prognosis for seizure control, and identification of candidates for epilepsy surgery to reduce seizure burden or attain seizure freedom.
Collapse
|
3
|
Polyanskaya M, Demushkina A, Kostylev F, Vasilyev I, Kholin A, Zavadenko N, Alikhanov A. The presurgical evaluation of patients with drug-resistant epilepsy. Zh Nevrol Psikhiatr Im S S Korsakova 2022; 122:12-20. [DOI: 10.17116/jnevro202212208112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
4
|
Simultaneous feedback control for joint field and motion correction in brain MRI. Neuroimage 2020; 226:117286. [PMID: 32992003 DOI: 10.1016/j.neuroimage.2020.117286] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 07/21/2020] [Accepted: 08/14/2020] [Indexed: 11/23/2022] Open
Abstract
T2*-weighted gradient-echo sequences count among the most widely used techniques in neuroimaging and offer rich magnitude and phase contrast. The susceptibility effects underlying this contrast scale with B0, making T2*-weighted imaging particularly interesting at high field. High field also benefits baseline sensitivity and thus facilitates high-resolution studies. However, enhanced susceptibility effects and high target resolution come with inherent challenges. Relying on long echo times, T2*-weighted imaging not only benefits from enhanced local susceptibility effects but also suffers from increased field fluctuations due to moving body parts and breathing. High resolution, in turn, renders neuroimaging particularly vulnerable to motion of the head. This work reports the implementation and characterization of a system that aims to jointly address these issues. It is based on the simultaneous operation of two control loops, one for field stabilization and one for motion correction. The key challenge with this approach is that the two loops both operate on the magnetic field in the imaging volume and are thus prone to mutual interference and potential instability. This issue is addressed at the levels of sensing, timing, and control parameters. Performance assessment shows the resulting system to be stable and exhibit adequate loop decoupling, precision, and bandwidth. Simultaneous field and motion control is then demonstrated in examples of T2*-weighted in vivo imaging at 7T.
Collapse
|
5
|
Abstract
Candidates for epilepsy surgery must undergo presurgical evaluation to establish whether and how surgical treatment can stop seizures without causing neurological deficits. Various techniques, including MRI, PET, single-photon emission CT, video-EEG, magnetoencephalography and invasive EEG, aim to identify the diseased brain tissue and the involved network. Recent technical and methodological developments, encompassing both advances in existing techniques and new combinations of technologies, are enhancing the ability to define the optimal resection strategy. Multimodal interpretation and predictive computer models are expected to aid surgical planning and patient counselling, and multimodal intraoperative guidance is likely to increase surgical precision. In this Review, we discuss how the knowledge derived from these new approaches is challenging our way of thinking about surgery to stop focal seizures. In particular, we highlight the importance of looking beyond the EEG seizure onset zone and considering focal epilepsy as a brain network disease in which long-range connections need to be taken into account. We also explore how new diagnostic techniques are revealing essential information in the brain that was previously hidden from view.
Collapse
|
6
|
Fitsiori A, Hiremath SB, Boto J, Garibotto V, Vargas MI. Morphological and Advanced Imaging of Epilepsy: Beyond the Basics. CHILDREN (BASEL, SWITZERLAND) 2019; 6:E43. [PMID: 30862078 PMCID: PMC6462967 DOI: 10.3390/children6030043] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/31/2018] [Revised: 02/27/2019] [Accepted: 03/05/2019] [Indexed: 12/26/2022]
Abstract
The etiology of epilepsy is variable and sometimes multifactorial. Clinical course and response to treatment largely depend on the precise etiology of the seizures. Along with the electroencephalogram (EEG), neuroimaging techniques, in particular, magnetic resonance imaging (MRI), are the most important tools for determining the possible etiology of epilepsy. Over the last few years, there have been many developments in data acquisition and analysis for both morphological and functional neuroimaging of people suffering from this condition. These innovations have increased the detection of underlying structural pathologies, which have till recently been classified as "cryptogenic" epilepsy. Cryptogenic epilepsy is often refractory to anti-epileptic drug treatment. In drug-resistant patients with structural or consistent functional lesions related to the epilepsy syndrome, surgery is the only treatment that can offer a seizure-free outcome. The pre-operative detection of the underlying structural condition increases the odds of successful surgical treatment of pharmacoresistant epilepsy. This article provides a comprehensive overview of neuroimaging techniques in epilepsy, highlighting recent advances and innovations and summarizes frequent etiologies of epilepsy in order to improve the diagnosis and management of patients suffering from seizures, especially young patients and children.
Collapse
Affiliation(s)
- Aikaterini Fitsiori
- Unit of Neurodiagnostic, Division of Neuroradiology, Geneva University Hospital, rue Gabrielle-Perret-Gentil 4, 1205 Geneva, Switzerland.
| | | | - José Boto
- Unit of Neurodiagnostic, Division of Neuroradiology, Geneva University Hospital, rue Gabrielle-Perret-Gentil 4, 1205 Geneva, Switzerland.
| | - Valentina Garibotto
- Division of Nuclear Medicine and Molecular Imaging, Geneva University Hospital and Faculty of Medicine, Geneva University, 1205 Geneva, Switzerland.
| | - Maria Isabel Vargas
- Unit of Neurodiagnostic, Division of Neuroradiology, Geneva University Hospital, rue Gabrielle-Perret-Gentil 4, 1205 Geneva, Switzerland.
| |
Collapse
|
7
|
The Role of Susceptibility-Weighted Imaging and Dedicated MRI Protocols in the Diagnostic Evaluation of Patients with Drug-Resistant Epilepsy. ARCHIVES OF NEUROSCIENCE 2018. [DOI: 10.5812/ans.68741] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
8
|
Pittau F, Baud MO, Jorge J, Xin L, Grouiller F, Iannotti GR, Seeck M, Lazeyras F, Vulliémoz S, Vargas MI. MP2RAGE and Susceptibility-Weighted Imaging in Lesional Epilepsy at 7T. J Neuroimaging 2018; 28:365-369. [DOI: 10.1111/jon.12523] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Accepted: 04/27/2018] [Indexed: 01/22/2023] Open
Affiliation(s)
- Francesca Pittau
- Division of Neurology; Geneva University Hospitals; Geneva Switzerland
| | - Maxime O. Baud
- Division of Neurology; Geneva University Hospitals; Geneva Switzerland
| | - João Jorge
- Laboratory for Functional and Metabolic Imaging; École Polytechnique Fédérale de Lausanne; Lausanne Switzerland
| | - Lijing Xin
- Animal Imaging and Technology Core; Center for Biomedical Imaging; École Polytechnique Fédérale de Lausanne; Lausanne Switzerland
| | - Frédéric Grouiller
- Swiss Center for Affective Sciences; University of Geneva; Geneva Switzerland
| | | | - Margitta Seeck
- Division of Neurology; Geneva University Hospitals; Geneva Switzerland
| | - François Lazeyras
- Division of Radiology of Geneva University Hospitals and CIBM; Geneva Switzerland
| | - Serge Vulliémoz
- Division of Neurology; Geneva University Hospitals; Geneva Switzerland
| | - Maria Isabel Vargas
- Division of Neuroradiology of Geneva University Hospitals and Geneva University; Geneva Switzerland
| |
Collapse
|
9
|
Abstract
PURPOSE OF REVIEW This article discusses structural and functional neuroimaging findings in patients with seizures and epilepsy. The indications for neuroimaging in these patients and the potential diagnostic utility of these studies are presented. RECENT FINDINGS Patients presenting with new seizures typically require urgent imaging to rule out a critical underlying cause. MRI is the structural neuroimaging procedure of choice in individuals with epilepsy. Specific epilepsy protocols should be considered to increase the diagnostic yield of neuroimaging in patients with structural lesions associated with focal or generalized seizures. Common epileptogenic pathologic processes include mesial temporal sclerosis, malformations of cortical development, focal encephalomacia, primary brain tumors, vascular malformations, and neurocysticercosis. Functional neuroimaging studies are usually restricted to the evaluation of patients with drug-resistant focal epilepsy who are being considered for surgical treatment. SUMMARY The role of neuroimaging in epilepsy depends on the appropriate clinical indication. In patients without known epilepsy presenting with acute seizures, structural imaging is essential to rule out an underlying etiology (eg, subdural hematoma) that may require a specific therapeutic intervention. In individuals with new or previously uninvestigated epilepsy, MRI serves multiple purposes, including identifying a causative focal lesion and helping to diagnose the epilepsy type. In a significant number of patients with epilepsy, the MRI results are normal or reveal indeterminate findings. For patients with drug-resistant focal epilepsy, functional neuroimaging techniques, such as fludeoxyglucose-positron emission tomography (FDG-PET), ictal single-photon emission computed tomography (SPECT), or functional MRI (fMRI), may assist in surgical planning, especially in patients with MRI-negative epilepsy, whose prognosis for a seizure-free outcome after surgery is worse than for patients with an epileptogenic lesion on structural MRI.
Collapse
|
10
|
Diagnostic performance of susceptibility-weighted magnetic resonance imaging for the detection of calcifications: A systematic review and meta-analysis. Sci Rep 2017; 7:15506. [PMID: 29138506 PMCID: PMC5686169 DOI: 10.1038/s41598-017-15860-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Accepted: 11/03/2017] [Indexed: 12/21/2022] Open
Abstract
Since its introduction, susceptibility-weighted-magnetic resonance imaging (SW-MRI) has shown the potential to overcome the insensitivity of MRI to calcification. Previous studies reporting the diagnostic performance of SW-MRI and magnetic resonance imaging (MRI) for the detection of calcifications are inconsistent and based on single-institution designs. To our knowledge, this is the first meta-analysis on SW-MRI, determining the potential of SW-MRI to detect calcifications. Two independent investigators searched MEDLINE, EMBASE and Web of Science for eligible diagnostic accuracy studies, which were published until March 24, 2017 and investigated the accuracy of SW-MRI to detect calcifications, using computed tomography (CT) as a reference. The QUADAS-2 tool was used to assess study quality and methods for analysis were based on PRISMA. A bivariate diagnostic random-effects model was applied to obtain pooled sensitivities and specificities. Out of the 4629 studies retrieved by systematic literature search, 12 clinical studies with 962 patients and a total of 1,032 calcifications were included. Pooled sensitivity was 86.5% (95%-confidence interval (CI): 73.6–93.7%) for SW-MRI and 36.7% (95%–CI:29.2–44.8%) for standard MRI. Pooled specificities of SW-MRI (90.8%; 95%–CI:81.0–95.8%) and standard MRI (94.2; 95%–CI:88.9–96.7%) were comparable. Results of the present meta-analysis suggest, that SW-MRI is a reliable method for detecting calcifications in soft tissues.
Collapse
|
11
|
Duque KR, Burneo JG. Clinical presentation of neurocysticercosis-related epilepsy. Epilepsy Behav 2017; 76:151-157. [PMID: 28882721 DOI: 10.1016/j.yebeh.2017.08.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/04/2017] [Revised: 07/27/2017] [Accepted: 08/02/2017] [Indexed: 11/15/2022]
Abstract
Neurocysticercosis (NCC) is the most common parasitic infection of the central nervous system and a major risk factor for seizures and epilepsy. Seizure types in NCC vary largely across studies and seizure semiology is poorly understood. We discuss here the studies regarding seizure types and seizure semiology in NCC, and examine the clinical presentation in patients with NCC and drug-resistant epilepsy. We also provide evidence of the role of MRI and EEG in the diagnosis of NCC-related epilepsy. Focal seizures are reported in 60-90% of patients with NCC-related epilepsy, and around 90% of all seizures registered prospectively are focal not evolving to bilateral tonic-clonic seizures. A great number of cases suggest that seizure semiology is topographically related to NCC lesions. Patients with hippocampal sclerosis and NCC have different clinical and neurophysiological characteristics than those with hippocampal sclerosis alone. Different MRI protocols have allowed to better differentiate NCC from other etiologies. Lesions' stages might account on the chances of finding an interictal epileptiform discharge. Studies pursuing the seizure onset in patients with NCC are lacking and they are specially needed to determine both whether the reported events of individual cases are seizures, and whether they are related to the NCC lesion or lesions. This article is part of a Special Issue entitled "Neurocysticercosis and Epilepsy".
Collapse
Affiliation(s)
- Kevin R Duque
- Center for Global Health-Tumbes, Universidad Peruana Cayetano Heredia, Lima, Peru; Hypnos Center for Sleep Medicine, Clínica San Felipe, Lima, Peru.
| | - Jorge G Burneo
- Epilepsy Program, Department of Clinical Neurological Sciences, Schulich School of Medicine, Western University, London, Canada.
| |
Collapse
|
12
|
Tracking inflammation in the epileptic rat brain by bi-functional fluorescent and magnetic nanoparticles. NANOMEDICINE-NANOTECHNOLOGY BIOLOGY AND MEDICINE 2016; 12:1335-45. [DOI: 10.1016/j.nano.2016.01.018] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Revised: 01/07/2016] [Accepted: 01/25/2016] [Indexed: 11/21/2022]
|
13
|
Duncan JS, Winston GP, Koepp MJ, Ourselin S. Brain imaging in the assessment for epilepsy surgery. Lancet Neurol 2016; 15:420-33. [PMID: 26925532 DOI: 10.1016/s1474-4422(15)00383-x] [Citation(s) in RCA: 184] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Revised: 11/22/2015] [Accepted: 12/02/2015] [Indexed: 01/14/2023]
Abstract
Brain imaging has a crucial role in the presurgical assessment of patients with epilepsy. Structural imaging reveals most cerebral lesions underlying focal epilepsy. Advances in MRI acquisitions including diffusion-weighted imaging, post-acquisition image processing techniques, and quantification of imaging data are increasing the accuracy of lesion detection. Functional MRI can be used to identify areas of the cortex that are essential for language, motor function, and memory, and tractography can reveal white matter tracts that are vital for these functions, thus reducing the risk of epilepsy surgery causing new morbidities. PET, SPECT, simultaneous EEG and functional MRI, and electrical and magnetic source imaging can be used to infer the localisation of epileptic foci and assist in the design of intracranial EEG recording strategies. Progress in semi-automated methods to register imaging data into a common space is enabling the creation of multimodal three-dimensional patient-specific datasets. These techniques show promise for the demonstration of the complex relations between normal and abnormal structural and functional data and could be used to direct precise intracranial navigation and surgery for individual patients.
Collapse
Affiliation(s)
- John S Duncan
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, University College London, London, UK; National Hospital for Neurology and Neurosurgery, London, UK; Chalfont Centre for Epilepsy, Chalfont St Peter, Gerrards Cross, UK.
| | - Gavin P Winston
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, University College London, London, UK; National Hospital for Neurology and Neurosurgery, London, UK; Chalfont Centre for Epilepsy, Chalfont St Peter, Gerrards Cross, UK
| | - Matthias J Koepp
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, University College London, London, UK; National Hospital for Neurology and Neurosurgery, London, UK; Chalfont Centre for Epilepsy, Chalfont St Peter, Gerrards Cross, UK
| | - Sebastien Ourselin
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, University College London, London, UK; Translational Imaging Group, Centre for Medical Image Computing, University College London, London, UK; National Hospital for Neurology and Neurosurgery, London, UK
| |
Collapse
|
14
|
Abstract
OBJECTIVE The purpose of this article is to describe an MRI protocol optimized for epilepsy evaluation, common causes of epilepsy visualized on MR images of patients evaluated for medically intractable partial epilepsy, and the basic concepts of advanced imaging techniques in the evaluation of epilepsy. CONCLUSION Epilepsy is one of the most common neurologic disorders in the United States. The long-term seizure-free success of epilepsy surgery is related to the ability to define and completely resect the epileptogenic zone. Detection of structural lesions at preoperative imaging requires not only a dedicated epilepsy protocol but also meticulous examination of the images by the interpreting radiologist with particular attention to subtle abnormalities that might otherwise go unreported.
Collapse
|
15
|
Yang L, Wang S, Yao B, Li L, Xu X, Guo L, Zhao L, Zhang X, Chen W, Chan Q, Wang G. Characterizing the contrast of white matter and grey matter in high-resolution phase difference enhanced imaging of human brain at 3.0 T. Eur Radiol 2014; 25:1068-76. [PMID: 25395065 DOI: 10.1007/s00330-014-3480-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2014] [Revised: 10/28/2014] [Accepted: 10/29/2014] [Indexed: 10/24/2022]
Abstract
OBJECTIVES The purpose of this study was to address the feasibility of characterizing the contrast both between and within grey matter and white matter using the phase difference enhanced (PADRE) technique. METHODS PADRE imaging was performed in 33 healthy volunteers. Vessel enhancement (VE), tissue enhancement (TE), and PADRE images were reconstructed from source images and were evaluated with regard to differentiation of grey-to-white matter interface, the stria of Gennari, and the two layers, internal sagittal stratum (ISS) and external sagittal stratum (ESS), of optic radiation. RESULTS White matter regions showed decreased signal intensity compared to grey matter regions. Discrimination was sharper between white matter and cortical grey matter in TE images than in PADRE images, but was poorly displayed in VE images. The stria of Gennari was observed on all three image sets. Low-signal-intensity bands displayed in VE images representing the optic radiation were delineated as two layers of different signal intensities in TE and PADRE images. Statistically significant differences in phase shifts were found between frontal grey and white matter, as well as between ISS and ESS (p < 0.01). CONCLUSIONS The PADRE technique is capable of identifying grey-to-white matter interface, the stria of Gennari, and ISS and ESS, with improved contrast in PADRE and TE images compared to VE images. KEY POINTS • Phase difference enhanced (PADRE) imaging can yield diverse contrasts between tissues • The PADRE technique utilizes the inherent variety of magnetic susceptibilities • PADRE MR imaging provides better visualization of certain cerebral anatomy in vivo • PADRE imaging is able to delineate the stria of Gennari in the primary visual cortex • PADRE imaging is able to identify the two optic radiation layers.
Collapse
Affiliation(s)
- Li Yang
- Department of Radiology, Shanghai Institute of Medical Imaging, Zhongshan Hospital, Fudan University, Shanghai, 200032, People's Republic of China
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
16
|
Aellen J, Abela E, Buerki SE, Kottke R, Springer E, Schindler K, Weisstanner C, El-Koussy M, Schroth G, Wiest R, Gralla J, Verma RK. Focal hemodynamic patterns of status epilepticus detected by susceptibility weighted imaging (SWI). Eur Radiol 2014; 24:2980-8. [DOI: 10.1007/s00330-014-3284-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2013] [Revised: 05/22/2014] [Accepted: 06/24/2014] [Indexed: 10/24/2022]
|
17
|
Goubran M, Rudko DA, Santyr B, Gati J, Szekeres T, Peters TM, Khan AR. In vivo normative atlas of the hippocampal subfields using multi-echo susceptibility imaging at 7 Tesla. Hum Brain Mapp 2013; 35:3588-601. [PMID: 24339427 DOI: 10.1002/hbm.22423] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2013] [Accepted: 10/16/2013] [Indexed: 11/11/2022] Open
Abstract
OBJECTIVES To generate a high-resolution atlas of the hippocampal subfields using images acquired from 7 T, multi-echo, gradient-echo MRI for the evaluation of epilepsy and neurodegenerative disorders as well as investigating R2* (apparent transverse relaxation rate) and quantitative volume magnetic susceptibility (QS) of the subfields. EXPERIMENTAL DESIGN Healthy control subjects (n=17) were scanned at 7 T using a multi-echo gradient-echo sequence and susceptibility-weighted magnitude images, R2* and QS maps were reconstructed. We defined a hippocampal subfield labeling protocol for the magnitude image produced from the average of all echoes and assessed reproducibility through volume and shape metrics. A group-wise diffeomorphic registration procedure was used to generate an average atlas of the subfields for the whole subject cohort. The quantitative MRI maps and subfield labels were then warped to the average atlas space and used to measure mean values of R2* and QS characterizing each subfield. PRINCIPAL OBSERVATIONS We were able to reliably label hippocampal subfields on the multi-echo susceptibility images. The group-averaged atlas accurately aligns these structures to produce a high-resolution depiction of the subfields, allowing assessment of both quantitative susceptibility and R2* across subjects. Our analysis of variance demonstrates that there are more apparent differences between the subfields on these quantitative maps than the normalized magnitude images. CONCLUSION We constructed a high-resolution atlas of the hippocampal subfields for use in voxel-based studies and demonstrated in vivo quantification of susceptibility and R2* in the subfields. This work is the first in vivo quantification of susceptibility values within the hippocampal subfields at 7 T.
Collapse
Affiliation(s)
- Maged Goubran
- Imaging Research Laboratories, Robarts Research Institute, Western University, London, Ontario, Canada; Biomedical Engineering, Western University, London, Ontario, Canada
| | | | | | | | | | | | | |
Collapse
|
18
|
Kori P, Garg RK, Malhotra HS, Gupta RK, Verma R, Singh MK, Rathore RKS, Gupta PK. Evaluation of cerebral white-matter micro-structural alterations in patients with medically refractory epilepsy using diffusion tensor tractography. Epilepsy Res 2013; 107:82-90. [DOI: 10.1016/j.eplepsyres.2013.08.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2012] [Revised: 07/31/2013] [Accepted: 08/14/2013] [Indexed: 10/26/2022]
|
19
|
Wellmer J, Quesada CM, Rothe L, Elger CE, Bien CG, Urbach H. Proposal for a magnetic resonance imaging protocol for the detection of epileptogenic lesions at early outpatient stages. Epilepsia 2013; 54:1977-87. [DOI: 10.1111/epi.12375] [Citation(s) in RCA: 140] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/13/2013] [Indexed: 01/04/2023]
Affiliation(s)
- Jörg Wellmer
- Ruhr-Epileptology; Department of Neurology; University Hospital Knappschaftskrankenhaus; Bochum Germany
| | - Carlos M. Quesada
- Department of Epileptology & Life and Brain Institute; University Hospital Bonn; Bonn Germany
| | - Lars Rothe
- Ruhr-Epileptology; Department of Neurology; University Hospital Knappschaftskrankenhaus; Bochum Germany
| | - Christian E. Elger
- Department of Epileptology & Life and Brain Institute; University Hospital Bonn; Bonn Germany
| | | | - Horst Urbach
- Department of Neuroradiology; University Hospital Freiburg; Freiburg Germany
| |
Collapse
|
20
|
Rathore C, Thomas B, Kesavadas C, Abraham M, Radhakrishnan K. Calcified neurocysticercosis lesions and antiepileptic drug-resistant epilepsy: a surgically remediable syndrome? Epilepsia 2013; 54:1815-22. [PMID: 24032594 DOI: 10.1111/epi.12349] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/27/2013] [Indexed: 11/30/2022]
Abstract
PURPOSE In contrast to the well-recognized association between acute symptomatic seizures and neurocysticercosis, the association between antiepileptic drug (AED)-resistant epilepsy and calcified neurocysticercosis lesions (CNLs) is poorly understood. We studied the association between AED-resistant epilepsy and CNLs, including the feasibility and outcome of resective surgery. METHODS From the prospective database maintained at our epilepsy center, we reviewed the data of all patients with AED-resistant epilepsy who underwent presurgical evaluation from January 2001 to July 2010 and had CNL on imaging. We used clinical, neuroimaging, and interictal, ictal, and intracranial electroencephalography (EEG) findings to determine the association between CNL and epilepsy. Suitable candidates underwent resective surgery. KEY FINDINGS Forty-five patients fulfilled the inclusion criteria. In 17 patients, CNL was proven to be the causative lesion for AED-resistant epilepsy (group 1); in 18 patients, CNL was associated with unilateral hippocampal sclerosis (HS; group 2); and in 10 patients, CNLs were considered as incidental lesions (group 3). In group 1 patients, CNLs were more common in frontal lobes (12/17), whereas in group 2 patients, CNLs were more commonly located in temporal lobes (11/18; p = 0.002). Group 2 patients were of a younger age at epilepsy onset than those in group 1 (8.9 ± 7.3 vs. 12.6 ± 6.8 years, p = 0.003). Perilesional gliosis was more common among patients in group 1 when compared to group 3 patients (12/17 vs. 1/10; p = 0.006). Fifteen patients underwent resective surgery. Among group 1 patients, four of five became seizure-free following lesionectomy alone. In group 2, four patients underwent anterior temporal lobectomy (ATL) alone, of whom one became seizure-free; five underwent ATL combined with removal of CNL (two of them after intracranial EEG and all of them became seizure-free, whereas one patient underwent lesionectomy alone and did not become seizure-free. SIGNIFICANCE In endemic regions, although rare, CNLs are potential cause for AED-resistant and surgically remediable epilepsy, as well as dual pathology. Presence of perilesional gliosis contributes to epileptogenicity of these lesions. For those patients with CNL and HS, resection of both lesions favors better chance of seizure-free outcome.
Collapse
Affiliation(s)
- Chaturbhuj Rathore
- R. Madhavan Nayar Center for Comprehensive Epilepsy Care, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, Kerala, India
| | | | | | | | | |
Collapse
|
21
|
Toledo M, Sarria-Estrada S, Quintana M, Auger C, Salas-Puig X, Santamarina E, Vert C, Rovira A. 3 TESLA MR imaging in adults with focal onset epilepsy. Clin Neurol Neurosurg 2013; 115:2111-6. [PMID: 23969199 DOI: 10.1016/j.clineuro.2013.07.039] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2013] [Revised: 07/01/2013] [Accepted: 07/27/2013] [Indexed: 12/01/2022]
Abstract
OBJECTIVE The finding of cerebral epileptogenic lesions in magnetic resonance (MR) has demonstrated to be a relevant prognostic factor for potential surgical candidates. In a series of consecutive adults with focal onset epilepsy, we investigated the yield of 3T MR imaging for detecting epileptogenic cerebral lesions. MATERIALS AND METHODS We prospectively recruited 161 adult patients with a diagnosis of focal epilepsy, all of whom underwent standardized MR imaging study performed with a 3T magnet. RESULTS Lesion-related epilepsy was observed in 48% of patients, and 12% of cryptogenic patients showed subtle or non-specific lesions related to the epileptogenic source. The most common findings were focal cortical dysplasia and vascular lesions, followed by mesial temporal sclerosis, tumors, and scars from previous cerebral injuries. Patients older than 72 years were more likely to have vascular epilepsy. CONCLUSIONS Diagnostic assessment using a standardized 3T MR imaging protocol for focal-onset epilepsy detects lesions in nearly half the patients. Our results indicate that elders with focal epilepsy should be searched for vascular lesions.
Collapse
Affiliation(s)
- Manuel Toledo
- Epilepsy Unit, Neurology Department, Hospital Universitari Vall d'Hebron, Universitat Autonoma de Barcelona, Passeig Vall d'Hebron 119-129, 08035 Barcelona, Spain.
| | | | | | | | | | | | | | | |
Collapse
|
22
|
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.
Collapse
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.
| |
Collapse
|
23
|
Dash GK, Radhakrishnan A, Kesavadas C, Abraham M, Sarma PS, Radhakrishnan K. An audit of the presurgical evaluation and patient selection for extratemporal resective epilepsy surgery in a resource-poor country. Seizure 2012; 21:361-6. [DOI: 10.1016/j.seizure.2012.03.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2011] [Revised: 03/08/2012] [Accepted: 03/10/2012] [Indexed: 10/28/2022] Open
|
24
|
[Structural magnetic resonance imaging in epilepsy]. RADIOLOGIA 2012; 54:9-20. [PMID: 22245703 DOI: 10.1016/j.rx.2011.07.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2010] [Revised: 07/07/2011] [Accepted: 07/09/2011] [Indexed: 11/22/2022]
Abstract
Magnetic resonance imaging is the main structural imaging in epilepsy. In patients with focal seizures, detection (and characterization) of a structural lesion consistent with electroclinical data allows therapeutic decisions without having to resort to other more expensive or invasive diagnostic procedures. The identification of some lesions may provide prognostic value, as in the case of Mesial Temporal Sclerosis (MTS) or may contribute to genetic counseling, as in the case of some Malformations of Cortical Development (MCD). The aim of this paper is to review the current state of structural MRI techniques, propose a basic protocol of epilepsy and mention the indications for structural MRI. Also, review the semiology of the main causes of epilepsy, with emphasis on MTS and MCD, by its highest frequency and by the special impact that MRI has shown in dealing with these entities.
Collapse
|
25
|
Rathore C, Thomas B, Kesavadas C, Radhakrishnan K. Calcified neurocysticercosis lesions and hippocampal sclerosis: potential dual pathology? Epilepsia 2012; 53:e60-2. [PMID: 22242912 DOI: 10.1111/j.1528-1167.2011.03386.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In areas where cysticercosis is endemic, calcified neurocysticercosis lesion(s) (CNL) and hippocampal sclerosis (HS) commonly coexist in patients with localization-related epilepsies. To understand the pathogenesis of HS associated with CNL, we compared the characteristics of three groups of patients with antiepileptic drug-resistant epilepsies: CNL with HS, CNL without HS (CNL alone), and HS without CNL (HS alone). In comparison to patients with CNL alone, those with CNL with HS had CNL more frequently located in the ipsilateral temporal lobe. Those with CNL with HS had a lower incidence of febrile seizures, older age at initial precipitating injury and at onset of habitual complex partial seizures, and more frequent clustering of seizures and extratemporal/bitemporal interictal epileptiform discharges as compared to patients with HS alone. Our study illustrates that HS associated with CNL might have a different pathophysiologic basis as compared to classical HS.
Collapse
Affiliation(s)
- Chaturbhuj Rathore
- R. Madhavan Nayar Center for Comprehensive Epilepsy Care, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, Kerala, India
| | | | | | | |
Collapse
|
26
|
|
27
|
Roy B, Verma S, Awasthi R, Rathore R, Venkatesan R, Yoganathan S, Das JM, Prasad K, Gupta R. Correlation of phase values with CT hounsfield and R2* values in calcified neurocysticercosis. J Magn Reson Imaging 2011; 34:1060-4. [DOI: 10.1002/jmri.22744] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
|
28
|
Unnwongse K, Wehner T, Foldvary-Schaefer N. Selecting Patients for Epilepsy Surgery. Curr Neurol Neurosci Rep 2010; 10:299-307. [DOI: 10.1007/s11910-010-0114-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|