Jorge G Burneo

London Health Sciences Centre, London, Ontario, Canada

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Publications (102)412.53 Total impact

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    ABSTRACT: Advances in MRI have the potential to improve surgical treatment of epilepsy through improved identification and delineation of lesions. However, validation is currently needed to investigate histopathological correlates of these new imaging techniques. The purpose of this work is to develop and evaluate a protocol for deformable image registration of in-vivo to ex-vivo resected brain specimen MRI. This protocol, in conjunction with our previous work on ex-vivo to histology registration, completes a registration pipeline for histology to in-vivo MRI, enabling voxel-based validation of novel and existing MRI techniques with histopathology. A combination of image-based and landmark-based 3D registration was used to register in-vivo MRI and the ex-vivo MRI from patients (N=10) undergoing epilepsy surgery. Target registration error (TRE) was used to assess accuracy and the added benefit of deformable registration. A mean TRE of 1.35±0.11 and 1.41±0.33mm was found for neocortical and hippocampal specimens respectively. Statistical analysis confirmed that the deformable registration significantly improved the registration accuracy for both specimens. Image registration of surgically resected brain specimens is a unique application which presents numerous technical challenges and that have not been fully addressed in previous literature. Our computed TRE are comparable to previous attempts tackling similar applications, as registering in-vivo MRI to whole brain or serial histology. The presented registration pipeline finds dense and accurate spatial correspondence between in-vivo MRI and histology and allows for the spatially-local and quantitative assessment of pathological correlates in MRI. Copyright © 2014. Published by Elsevier B.V.
    Journal of Neuroscience Methods 12/2014; 241. · 1.96 Impact Factor
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    ABSTRACT: Objective To investigate the histopathological correlates of quantitative relaxometry and DTI and determine their efficacy in epileptogenic lesion detection for pre-operative evaluation of focal epilepsy. Methods We correlated quantitative relaxometry and DTI with histological features of neuronal density and morphology in 55 regions of the temporal lobe neocortex, selected from 13 patients who underwent epilepsy surgery. We made use of a validated non-rigid image registration protocol to obtain accurate correspondences between in-vivo MRI and histology images. Results We found T1 to be a predictor of neuronal density in the neocortical GM using linear mixed effects models with random effects for subjects. FA was a predictor of neuronal density of large-caliber neurons only (pyramidal cells, layers 3/5). Comparing multivariate to univariate mixed effects models with nested univariate demonstrated that employing T1 and FA together provided a significantly better fit than T1 or FA alone in predicting density of large-caliber neurons. Correlations with clinical variables revealed significant positive correlations between neuronal density with age (rs = 0.726, pfwe = 0.021). This study is the first to relate in-vivo T1 and FA values to the proportion of neurons in GM. Interpretation Our results suggest that quantitative T1 mapping and DTI may have a role in pre-operative evaluation of focal epilepsy and can be extended to identify gray matter pathology in a variety of neurological disorders. This article is protected by copyright. All rights reserved. Copyright © 2014 American Neurological Association.
    Annals of neurology. 11/2014;
  • Asuri N. Prasad, Jorge G. Burneo, Bradley Corbett
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    ABSTRACT: Purpose The purpose of this study was to analyze national survey data to provide estimates of prevalence of epilepsy and associated developmental disabilities and comorbid conditions. Methods We analyzed data from Cycle 3 of Canada's National Longitudinal Survey of Children and Youth. The NLSCY captured, socio-demographic information, as well as age, sex, education, ethnicity, household income, chronic health related conditions from birth to 15 years old. The main survey question intended to identify “epilepsy”, “cerebral palsy”, “intellectual disability”, “learning disability”, and “emotional and nervous difficulties” in the population of children surveyed. Prevalence was based on the national cross-sectional sample and used 1000 bootstrap weights to account for survey design factors. Results Cycle 3 of the NLSCY had the largest number of patients with diagnosed epilepsy. Prevalence figures (n/1000) for epilepsy and cerebral palsy (EPI_CP), epilepsy and intellectual disability (EPI_ID), epilepsy and learning disability (EPI_LD), and epilepsy and emotional nervous difficulties (EPI_EMO_NERV) were 1.1, 1.17, 2.58 and 1.34 respectively. Amongst children with epilepsy, 43.17% reported the presence of one or more of the above comorbid conditions. Conclusion These results provide an initial prevalence estimate of comorbid conditions with epilepsy in Canadian children. In a high proportion of children with epilepsy, the PMK had reported at least one comorbid disorder. These findings carry implications for health care utilization and long-term outcomes. We discuss methodological aspects related to the ascertainment of epilepsy in both surveys, and to the validity and implications of our findings.
    Seizure 11/2014; · 2.06 Impact Factor
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    ABSTRACT: Purpose To assess the mortality related to epilepsy in Latin America Methods We searched MEDLINE, EMBASE, and LILACS from inception to December 2013 for articles evaluating mortality in patients with epilepsy in Latin America. Studies were included if they evaluated any mortality outcome, included a population of subjects with recurrent seizures or epilepsy, and contained original data analysis. Results The search strategy yielded 177 publications in MEDLINE and EMBASE, and 59 publications in LILACS; of which 18 met inclusion criteria for our overall review of epilepsy and mortality in Latin America. Most excluded studies did not report the mortality or lacked original data. We also included two references obtained from 2 non-systematic reviews fulfilling our inclusion criteria, and able to provide data for our analyses. Five studies reported Standardized Mortality Ratio (SMR), and demonstrated that people with epilepsy had a higher risk of death than the general population. The SMRs reported in two community based studies were 1.34 and 2.45. Conclusion The information about mortality in epilepsy in Latin America is very scarce. Comparisons cannot be made among studies due to methodological differences. More studies are needed.
    Seizure 10/2014; · 2.06 Impact Factor
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    ABSTRACT: Malformations of cortical development (MCD) are an increasingly recognized cause of medically intractable epilepsy. We assessed the role of fMRI in evaluating the motor and somatosensory cortices, as well as if there is possible reorganization of these vital areas in patients with polymicrogyria.
    Clinical Neurology and Neurosurgery 07/2014; 122C:29-33. · 1.25 Impact Factor
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    The Canadian journal of neurological sciences. Le journal canadien des sciences neurologiques 07/2014; 41(4):413-420. · 1.60 Impact Factor
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    ABSTRACT: We compared clinical characteristics of seizures at ischemic stroke presentation (SSP) to seizures during hospitalization post ischemic stroke (SDH), and their impacts on stroke outcome, using the Registry of the Canadian Stroke Network (RCSN) database. This cohort study included consecutive patients from the RCSN who had an acute ischemic stroke between July 2003 and March 2008. Outcome measures included morbidity, mortality, length of hospital stay, and discharge disposition. Clinical variables for either SSP or SDH were investigated and the stroke outcome was stratified by stroke severity. The study included 10,261 patients with ischemic strokes: 157 patients (1.53%) had SSP and 208 patients (2.03%) had SDH. Compared to stroke patients without seizures, patients with SSP and SDH were younger, had more severe strokes (p < 0.001), a higher admission rate to the intensive care unit (p < 0.001), higher morbidity, and higher mortality (p < 0.05). SSP was associated with female sex and less limb weakness, while SDH was associated with pneumonia and the presence of hemineglect. Importantly, patients with less severe strokes had higher morbidity and mortality (p < 0.005) if SDH occurred. Variables predicting overall mortality were SDH, older age, higher Charlson-Deyo index, more severe strokes, and nonalert status on arrival (all p < 0.001). SSP and SDH have different characteristics. SDH indicates a poorer prognosis in patients. Increased awareness of SSP and efforts to prevent SDH may be important in improving outcomes following clinical stroke care.
    Neurology 01/2014; · 8.30 Impact Factor
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    Jorge G Burneo, Jose E Cavazos
    Epilepsy Currents 01/2014; 14(1 Suppl):23-8. · 2.95 Impact Factor
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    ABSTRACT: Objective Malformations of cortical development (MCD) are an increasingly recognized cause of medically intractable epilepsy. We assessed the role of fMRI in evaluating the motor and somatosensory cortices, as well as if there is possible reorganization of these vital areas in patients with polymicrogyria. Methods We included 2 patients with polymicrogyria and epilepsy. Somatosensory and motor cortices were assessed with a 4 T fMRI. These findings were compared with direct cortical stimulation. Results Localization of the sensorimotor cortices was adequately identified by fMRI. These vital areas did not reorganize outside the malformation of cortical development. Conclusion fMRI is a tool that can allow identification of these vital areas of the brain in a non-invasive manner. Practice implications Adequate localization of the sensorimotor cortices is important for optimal patient selection, surgical strategy, and to determine the maximal extent of the resection. The clinical implications for such understanding are not limited to it; these findings should help researchers understand more of the neurobiology of MCDs and even possibly clues to the mechanisms of epileptogenesis associated with such malformations.
    Clinical Neurology and Neurosurgery. 01/2014; 122:29–33.
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    ABSTRACT: Seizure recurrence after epilepsy surgery has been classified as either early or late depending on the recurrence time after operation. However, time of recurrence is variable and has been arbitrarily defined in the literature. We established a mathematical model for discriminating patients with early or late seizure recurrence, and examined differences between these two groups. A historical cohort of 247 consecutive patients treated surgically for temporal lobe epilepsy was identified. In patients who recurred, postoperative time until seizure recurrence was examined using an receiver-operating characteristic (ROC) curve to determine the best cutoff for predicting long-term prognosis, dividing patients in those with early and those with late seizure recurrence. We then compared the groups in terms of a number of clinical, electrophysiologic, and radiologic variables. Seizures recurred in 107 patients (48.9%). The ROC curve demonstrated that 6 months was the ideal time for predicting long-term surgical outcome with best accuracy, (area under the curve [AUC] = 0.761; sensitivity = 78.8%; specificity = 72.1%). We observed that patients with seizure recurrence during the first 6 months started having seizures at younger age (odds ratio [OR] = 6.03; 95% confidence interval [CI] = 1.06-11.01; p = 0.018), had a worse outcome (OR = 6.85; 95% CI = 2.54-18.52; p = 0.001), needed a higher number of antiepileptic medications (OR = 2.07; 95% CI = 1.16-9.34; p = 0.013), and more frequently had repeat surgery (OR = 9.59; 95% CI = 1.18-77.88; p = 0.021). Patients with late relapse more frequently had seizures associated with trigger events (OR = 9.61; 95% CI = 3.52-26.31; p < 0.01). Patients with early or late recurrence of seizures have different characteristics that might reflect diversity in the epileptogenic zone and epileptogenicity itself. These disparities might help explain variable patterns of seizure recurrence after epilepsy surgery.
    Epilepsia 11/2013; 54(11):1933-41. · 4.58 Impact Factor
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    ABSTRACT: OBJECTIVE: To review the evidence base for different treatment strategies in intraparenchymal neurocysticercosis in adults and children. METHOD: A literature search of Medline, EMBASE, LILACS, and the Cochrane Database from 1980 to 2008, updated in 2012, resulted in the identification of 10 Class I or Class II trials of cysticidal drugs administered with or without corticosteroids in the treatment of neurocysticercosis. RESULTS: The available data demonstrate that albendazole therapy, administered with or without corticosteroids, is probably effective in decreasing both long-term seizure frequency and the number of cysts demonstrable radiologically in adults and children with neurocysticercosis, and is well-tolerated. There is insufficient information to assess the efficacy of praziquantel. RECOMMENDATIONS: Albendazole plus either dexamethasone or prednisolone should be considered for adults and children with neurocysticercosis, both to decrease the number of active lesions on brain imaging studies (Level B) and to reduce long-term seizure frequency (Level B). The evidence is insufficient to support or refute the use of steroid treatment alone in patients with intraparenchymal neurocysticercosis (Level U).
    Neurology 10/2013; 81(16):1474-1476. · 8.30 Impact Factor
  • Jorge G Burneo, David Steven
    The Canadian journal of neurological sciences. Le journal canadien des sciences neurologiques 07/2013; 40(4):443-444. · 1.60 Impact Factor
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    ABSTRACT: Neurocysticercosis (NCC) is the main risk factor for late-onset seizures in many Taenia solium endemic countries and is also increasingly recognized in high income countries, where it was once thought to have been eliminated. The course and outcome of NCC-associated seizures and epilepsy are poorly understood. Substrates underlying NCC-associated seizures and epilepsy are unknown. Another unknown is if there is an association between NCC and hippocampal sclerosis (HS) and if it leads to intractable epilepsy. We review evidence regarding the structural basis of seizures and epilepsy in NCC and its association with HS. There are only a limited number of prospective studies of NCC-associated seizures and epilepsy. From these, it can be inferred that the risk of seizure recurrence is high following a first seizure, even though seizures are well-controlled with antiepileptic drugs. The single most important risk factor for ongoing or recurrent seizures is the persistence of either degenerating or residual calcified cysticercus cysts in the brain parenchyma on follow-up imaging studies. Medically intractable epilepsy requiring surgical treatment appears to be rare in people with NCC. In few cases that have been operated, gliosis around the cysticerci is the principal pathologic finding. Reports of the association between NCC and HS might be categorized into those in which the calcified cysticercus is located within the hippocampus and those in which the calcified cysticercus is located remote from the hippocampus. The former are convincing cases of medically intractable epilepsy with good seizure control following hippocampal resection. In the remaining, it is unclear whether a dual pathology relationship exists between HS and the calcified cysticercus. Carefully planned, follow-up studies incorporating high-resolution and quantitative imaging are desirable in order to clarify the outcome, the structural basis of NCC-associated epilepsy, and also its association with HS.
    Epilepsia 05/2013; 54(5):783-92. · 4.58 Impact Factor
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    ABSTRACT: We report the achievements obtained, over a period of 4years, by the collaborative partnering effort of the Epilepsy Program at Western University in Canada and the Instituto of Ciencias Neurologicas in Lima, Peru, building an epilepsy program in Peru.
    Epilepsy & Behavior 01/2013; 26(1):96-9. · 2.06 Impact Factor
  • The Canadian journal of neurological sciences. Le journal canadien des sciences neurologiques 01/2013; 40(1):85-8. · 1.60 Impact Factor
  • Epilepsy Currents 01/2013; 13(5):232-235. · 2.95 Impact Factor
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    ABSTRACT: We developed novel methodology for investigating the use of quantitative relaxometry (T1, T2) and diffusion tensor imaging (DTI) for lateralization in temporal lobe epilepsy. Patients with mesial temporal sclerosis confirmed by pathology (N = 8) and non-MTS unilateral temporal lobe epilepsy (N = 6) were compared against healthy controls (N = 19) using voxel-based analysis restricted to the anterior temporal lobes, and laterality indices for each MRI metric (T1, T2, fractional anisotropy (FA), mean diffusivity, axial and radial diffusivity) were computed based on the proportion of significant voxels on each side. The diffusivity metrics were the most lateralizing MRI metrics in MTS and non-MTS subsets, with significant differences also seen with FA, T1 and T2. Patient-specific multi-modal laterality indices were also computed and were shown to clearly separate the left-onset and right-onset patients. Marked differences between left-onset and right-onset patients were also observed, with left-onset patients exhibiting stronger laterality indices. Finally, neocortical abnormalities were found to be more common in the non-MTS patients. These preliminary results on a small sample size support the further investigation of quantitative MRI and multi-modal image analysis in clinical determination of seizure onset. The presence of more neocortical abnormalities in the non-MTS group suggests a role in seizure onset or propagation and motivates the investigation of more sensitive histopathological analysis to detect and delineate potentially subtle neocortical pathology.
    Epilepsy research 01/2013; · 2.48 Impact Factor
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    ABSTRACT: ABSTRACT: Epilepsy surgery is a highly effective and durable treatment for specific types of drug resistant epilepsy such as temporal lobe epilepsy. assessment of outcomes is essential in epilepsy surgery, which is an irreversible intervention for a chronic condition. Excellent short-term results of resective epilepsy surgery have been established. In the last years more information regarding long term outcomes have been published. This article reviews the best available evidence about the best measures to assess outcomes and the most important evidence. The outcomes reviewed in this article are the following: seizure outcome, social and psychiatric outcomes, complications and mortality
    The Canadian journal of neurological sciences. Le journal canadien des sciences neurologiques 12/2012; 36(6):S25-29. · 1.60 Impact Factor
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    ABSTRACT: An abstract is unavailable. This article is available as HTML full text and PDF.
    The Canadian journal of neurological sciences. Le journal canadien des sciences neurologiques 11/2012; 39(6):830-2. · 1.60 Impact Factor
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    ABSTRACT: OBJECTIVES: Despite evidence that epilepsy surgery is more effective than medical therapy, significant delays between seizure intractability and surgery exist. We aimed to develop a new Web-based methodology to assist physicians in identifying patients who might benefit from an epilepsy surgery evaluation. METHODS: The RAND/UCLA appropriateness method was used. Clinical scenarios were developed based on eligibility criteria from previously published surgical series. Thirteen national experts rated the scenarios for their appropriateness for an epilepsy surgery evaluation based on published evidence. All scenarios were rerated after a face-to-face meeting following a modified Delphi process. Appropriate scenarios were rerated for necessity to determine referral priority. RESULTS: Of the final 2646 scenarios, 20.6% (n = 544) were appropriate, 17.2% (n = 456) uncertain, and 61.5% (n = 1626) inappropriate for a surgical evaluation. Of the appropriate cases, 55.9% (n = 306) were rated as very high priority. Not attempting AED treatment was always rated as inappropriate for a referral. Trial of 2 AEDs was usually rated as appropriate unless seizure-free or not fully investigated Based on these data, a Web-based decision tool (www.epilepsycases.com) was created. CONCLUSIONS: Using the available evidence through 2008 and expert consensus, we developed a Web-based decision tool that provides a guide for determining candidacy for epilepsy surgery evaluations. The tool needs clinical validation, and will be updated and revised regularly. This rendition of the tool is most appropriate for those over age 12 years with focal epilepsy. The Rand/UCLA appropriate methodology might be considered in the development of guidelines in other areas of epilepsy care.
    Neurology 08/2012; 79(11):1084-1093. · 8.30 Impact Factor

Publication Stats

1k Citations
412.53 Total Impact Points

Institutions

  • 2007–2014
    • London Health Sciences Centre
      • Department of Clinical Neurological Sciences
      London, Ontario, Canada
    • The University of Edinburgh
      Edinburgh, Scotland, United Kingdom
  • 2004–2014
    • The University of Western Ontario
      • • Department of Epidemiology and Biostatistics
      • • Department of Clinical Neurological Sciences
      London, Ontario, Canada
  • 2012–2013
    • Western University
      London, Ontario, Canada
    • Chinook Regional Hospital
      Lethbridge, Alberta, Canada
  • 2009
    • University of Toronto
      • Institute of Health Policy, Management and Evaluation
      Toronto, Ontario, Canada
    • The University of Calgary
      • Department of Clinical Neurosciences
      Calgary, Alberta, Canada
  • 2001–2009
    • University of Alabama at Birmingham
      • • Department of Pediatrics
      • • Department of Neurology
      Birmingham, Alabama, United States
  • 2006
    • Government of Ontario, Canada
      Guelph, Ontario, Canada