62 results on '"Blackmon K"'
Search Results
2. Perceptions of Dietetics Students Regarding College Weight Gain
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Burnett, D., Blackmon, K., and Evans, R.
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- 2020
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3. Septal nuclei enlargement in human temporal lobe epilepsy without mesial temporal sclerosis.
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Butler T, Zaborszky L, Wang X, McDonald CR, Blackmon K, Quinn BT, Dubois J, Carlson C, Barr WB, French J, Kuzniecky R, Halgren E, Devinsky O, Thesen T, Butler, Tracy, Zaborszky, Laszlo, Wang, Xiuyuan, McDonald, Carrie R, Blackmon, Karen, and Quinn, Brian T
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- 2013
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4. Cortical thickness changes associated with depression in temporal lobe epilepsy
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Butler<ce:sup loc='post">⁎</ce:sup>, T., McDonald, C., Blackmon, K., Halgren, E., and Barr, W.
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- 2012
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5. Water-Soluble Copolymers. XX. Copolymers of Acrylamide with Sodium 3-(N-Propyl)Acrylamido-3-Methylbutanoate: Solution Properties.
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McCormick, C. L., Blackmon, K. P., and Elliott, D. L.
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- 1986
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6. Water-Soluble Copolymers. XIX. Copolymers of Acrylamide with Sodium 3-(N-Propyl)acrylamido-3-Methylbutanoate: Synthesis and Characterization.
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McCormick, C. L. and Blackmon, K. P.
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- 1986
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7. Cortical thickness changes associated with depression in temporal lobe epilepsy
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⁎, T., McDonald, C., Blackmon, K., Halgren, E., and Barr, W.
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- 2012
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8. Dementia risk reduction in the African context: Multi-national implementation of multimodal strategies to promote healthy brain aging in Africa (the Africa-FINGERS project).
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Udeh-Momoh CT, Maina R, Anazodo UC, Akinyemi R, Atwoli L, Baker L, Bassil D, Blackmon K, Bosire E, Chemutai G, Crivelli L, Eze LU, Ibanez A, Kafetsouli D, Karikari TK, Khakali L, Kumar M, Lengyel I, de Jager Loots CA, Mangialasche F, Mbugua S, Merali Z, Mielke M, Mostert C, Muthoni E, Nesic-Taylor O, Ngugi A, Nguku S, Ogunniyi A, Ogunyemi A, Okonkwo OC, Okubadejo N, Perneczky R, Peto T, Riang'a RM, Saleh M, Sayed S, Shah J, Shah S, Solomon A, Thesen T, Trepel D, Ucheagwu V, Valcour V, Waa S, Watermeyer T, Yokoyama J, Zetterberg H, and Kivipelto M
- Abstract
Dementia prevention in Africa is critically underexplored, despite the continent's high prevalence of modifiable risk factors. With a predominantly young and middle-aged population, Africa presents a prime opportunity to implement evidence-based strategies that could significantly reduce future dementia cases and mitigate its economic impact. The multinational Africa-FINGERS program offers an innovative solution, pioneering culturally sensitive, multidomain interventions tailored to the unique challenges of the region. Leveraging insights from landmark global studies such as Worldwide-FINGERS and Alzheimer's Disease Neuroimaging Initiative, the program employs a multideterminant precision prevention framework, grounded in community based systems dynamics. Africa-FINGERS further integrates cutting-edge state-of-the-art multimodal biomarker evaluations tailored to regional contexts, with the goal of advancing brain health and establishing a global standard for dementia prevention. This groundbreaking initiative highlights the potential for scalableand sustainable interventions, thus is poised to transform dementia risk reduction efforts across the continent. HIGHLIGHTS: Dementia rates are escalating in Africa, largely due to longer life spans and increased prevalence of modifiable risk factors. Yet, few regional interventions have directly targeted lifestyle factors to reduce dementia risk. The multinational Africa-FINGERS study will address this gap by adapting the successful FINGERS lifestyle intervention to African populations. Africa-FINGERS will pioneer a culturally informed, multidomain dementia risk reduction intervention in the African region through feasibility dementia prevention trials in rural and urban sites across Kenya and Nigeria in the first instance, enrolling 600 at-risk adults (≥ 50 years). The program adopts participatory research methods to develop culturally appropriate interventions and build infrastructure to evaluate dementia biomarkers from ante and post mortem samples. A cost-effectiveness analysis will be conducted to guide the strategic implementation of Africa-FINGERS into regional health systems. The Africa-FINGERS strategy aligns with the Worldwide-FINGERS framework and integrates the global Alzheimer's Disease Neuroimaging Initiative approach, emphasizing multimodal analysis., (© 2024 The Author(s). Alzheimer's & Dementia published by Wiley Periodicals LLC on behalf of Alzheimer's Association.)
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- 2024
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9. The Grenada Learning and Memory Scale: Psychometric features and normative data in Caribbean preschool children.
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Blackmon K, Evans R, Mohammed L, Burgen KS, Ingraham E, Punch B, Isaac R, Murray T, Noel J, Belmar-Roberts C, Waechter R, and Landon B
- Abstract
Objective: Neuropsychological assessment of preschool children is essential for early detection of delays and referral for intervention prior to school entry. This is especially pertinent in low- and middle-income countries (LMICs), which are disproportionately impacted by micronutrient deficiencies and teratogenic exposures. The Grenada Learning and Memory Scale (GLAMS) was created for use in limited resource settings and includes a shopping list and face-name association test. Here, we present psychometric and normative data for the GLAMS in a Grenadian preschool sample., Methods: Typically developing children between 36 and 72 months of age, primarily English speaking, were recruited from public preschools in Grenada. Trained Early Childhood Assessors administered the GLAMS and NEPSY-II in schools, homes, and clinics. GLAMS score distributions, reliability, and convergent/divergent validity against NEPSY-II were evaluated., Results: The sample consisted of 400 children (190 males, 210 females). GLAMS internal consistency, inter-rater agreement, and test-retest reliability were acceptable. Principal components analysis revealed two latent factors, aligned with expected verbal/visual memory constructs. A female advantage was observed in verbal memory. Moderate age effects were observed on list learning/recall and small age effects on face-name learning/recall. All GLAMS subtests were correlated with NEPSY-II Sentence Repetition, supporting convergent validity with a measure of verbal working memory., Conclusions: The GLAMS is a psychometrically sound measure of learning and memory in Grenadian preschool children. Further adaptation and scale-up to global LMICs are recommended.
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- 2024
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10. Review of epilepsy care in the Democratic Republic of the Congo.
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Tshimbombu TN, Shin M, Thesen T, Mesu'a Kabwa L, Blackmon K, Kashama JMKW, Jobst BC, Fontaine D, Olarinde I, and Okitundu-Luwa E-Andjafono D
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- Animals, Humans, Democratic Republic of the Congo epidemiology, Risk Factors, Onchocerciasis complications, Onchocerciasis epidemiology, Onchocerca volvulus physiology, Epilepsy drug therapy
- Abstract
Epilepsy imposes a substantial burden on the Democratic Republic of Congo (DRC). These challenges encompass the lack of comprehensive disease surveillance, an unresolved understanding of its pathophysiology, economic barriers limiting access to essential care, the absence of epilepsy surgical capabilities, and deeply ingrained societal stigmas. Notably, the national prevalence of epilepsy remains undetermined, with research primarily concentrating on infectious factors like Onchocerca volvulus, leaving other potential causes underexplored. Most patients lack insurance, incurring out-of-pocket expenses that often lead them to opt for traditional medicine rather than clinical care. Social stigma, perpetuated by common misconceptions, intensifies the social isolation experienced by individuals living with epilepsy. Additionally, surgical interventions are unavailable, and the accessibility of anti-seizure medications and healthcare infrastructure remains inadequate. Effectively tackling these interrelated challenges requires a multifaceted approach, including conducting research into region-specific factors contributing to epilepsy, increasing healthcare funding, subsidizing the costs of treatment, deploying mobile tools for extensive screening, launching awareness campaigns to dispel myths and reduce stigma, and promoting collaborations between traditional healers and medical practitioners to enhance local understanding and epilepsy management. Despite the difficulties, significant progress can be achieved through sustained and compassionate efforts to understand and eliminate the barriers faced by epilepsy patients in the region. This review outlines essential steps for alleviating the epilepsy burden in the DRC. PLAIN LANGUAGE SUMMARY: There are not enough resources to treat epilepsy in the DRC. PWEs struggle with stigma and the lack of money. Many of them still use traditional medicine for treatment and hold wrong beliefs about epilepsy. That is why there is a need for more resources to make the lives of PWEs better in the DRC., (© 2024 The Authors. Epilepsia Open published by Wiley Periodicals LLC on behalf of International League Against Epilepsy.)
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- 2024
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11. Is preserved consciousness during seizures associated with quality of life among patients with drug-resistant epilepsy?
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Koay JM, Sabsevitz DS, Ritaccio A, Feyissa AM, Tatum W, and Blackmon K
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- Adult, Humans, Quality of Life, Consciousness physiology, Prospective Studies, Seizures complications, Seizures psychology, Epilepsy psychology, Epilepsies, Partial drug therapy, Drug Resistant Epilepsy complications
- Abstract
Drug-resistant epilepsy is associated with reduced quality of life (QoL) due to a myriad of disease-related and psychosocial factors. Although consciousness during seizures is a core feature of seizure classification, its impact on QoL in people with epilepsy (PWE) is not well understood. This study aimed to address this gap by comparing QoL between PWE with focal aware (FA) versus impaired awareness (FIA) seizures. Sixty-nine adults with epilepsy completed the Quality of Life in Epilepsy-31 (QoLIE-31) inventory as part of their pre-surgical neuropsychological evaluation (FA: n = 26, FIA: n = 43). There was no group difference in seizure burden as defined by the proportion of comorbid focal to bilateral tonic-clonic seizures (FA:65.4 %; FIA: 79.1 %). People with FA seizures reported lower overall QoL than people with FIA seizures; sub-scale analyses revealed that seizure worry drives this effect. There was no difference in QoL between people with motor and non-motor FA seizures. Results suggest that FA seizures are burdensome on the QoL of PWE. FA seizures may contribute to seizure worry due to preserved awareness of aversive peri-ictal phenomenon. Findings suggest that clinical efforts should continue to be made to optimize seizure control in people with breakthrough FA seizures. Prospective longitudinal monitoring of QoL in trials of consciousness-targeting neurostimulation therapy is needed to determine if QoL changes as a function of improved peri-ictal consciousness following treatment., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Inc. All rights reserved.)
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- 2024
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12. Who should pay the bill for the mental health crisis in Africa?
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Mostert CM, Nesic O, Udeh-Momoh C, Khan M, Thesen T, Bosire E, Trepel D, Blackmon K, Kumar M, and Merali Z
- Abstract
Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
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- 2023
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13. Case study of invalid to valid shift in cognitive performance following successful treatment of psychogenic nonepileptic seizure events.
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Drane DL, Hewitt KC, Price ME, Rush BK, Blackmon K, Okada N, Shade T, Valentin E, Vinson J, Rosen P, and Loring DW
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- Humans, Female, Middle Aged, Cognitive Dysfunction etiology, Cognitive Dysfunction therapy, Cognitive Dysfunction physiopathology, Psychophysiologic Disorders therapy, Electroencephalography, Seizures therapy, Neuropsychological Tests standards
- Abstract
Patients with psychogenic nonepileptic seizure (PNES) who fail performance validity testing (PVT) may appear to produce non-valid cognitive profiles. Consequently, they may not get referred to treatment and events persist, with worsening disability and high resource utilization. As a result, we report pre- and post-treatment neuropsychological evaluation findings in a 59-year-old woman with a confirmed diagnosis of PNES established using video-EEG monitoring. At pre-treatment baseline neuropsychological evaluation, PNES events occurred weekly to daily. Performance was impaired across PVTs and across multiple cognitive domains. After behavioral intervention specific to PNES, these events substantially reduced in frequency to rare stress-induced flares. Post-treatment neuropsychological evaluation revealed marked improvement of most cognitive and behavioral scores from baseline, and valid PVT scores. We review predisposing, precipitating, and perpetuating factors for PNES and cognitive impairment in this case and discuss the patient's outcome from treatment. Effectively managing PNES events and dissociative tendencies while reducing unnecessary pharmacological interventions appears to have allowed this patient to function closer to her optimal state. This case illustrates the complexity of Functional Neurologic Disorder (FND) clinical presentation and challenges the assumption that suboptimal neuropsychological performance predicts poor treatment engagement and outcome. We showcase the reversibility of PNES and cognitive manifestations of FND using targeted psychotherapeutic interventions, which resulted in reduced disability and associated healthcare costs, as well as re-engagement in life.
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- 2023
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14. Incidence and risk factors associated with seizures in cerebral amyloid angiopathy.
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Freund BE, Sanchez-Boluarte SS, Blackmon K, Day GS, Lin M, Khan A, Feyissa AM, Middlebrooks EH, and Tatum WO 4th
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- Female, Humans, Cerebral Hemorrhage complications, Retrospective Studies, Incidence, Magnetic Resonance Imaging, Risk Factors, Seizures etiology, Seizures complications, Inflammation complications, Siderosis, Cerebral Amyloid Angiopathy complications, Cerebral Amyloid Angiopathy epidemiology
- Abstract
Background and Purpose: Cerebral amyloid angiopathy (CAA) is a common cause of intracranial hemorrhage (ICH), which is a risk factor for seizures. The incidence and risk factors of seizures associated with a heterogeneous cohort of CAA patients have not been studied., Methods: We conducted a retrospective study of patients with CAA treated at Mayo Clinic Florida between 1 January 2015 and 1 January 2021. CAA was defined using the modified Boston criteria version 2.0. We analyzed electrophysiological and clinical features, and comorbidities including lobar ICH, nontraumatic cortical/convexity subarachnoid hemorrhage (cSAH), superficial siderosis, and inflammation (CAA with inflammation [CAA-ri]). Cognition and mortality were secondary outcomes. Univariate and multivariate analyses were performed to determine risk of seizures relative to clinical presentation., Results: Two hundred eighty-four patients with CAA were identified, with median follow-up of 35.7 months (interquartile range = 13.5-61.3 months). Fifty-six patients (19.7%) had seizures; in 21 (37.5%) patients, seizures were the index feature leading to CAA diagnosis. Seizures were more frequent in females (p = 0.032) and patients with lobar ICH (p = 0.002), cSAH (p = 0.030), superficial siderosis (p < 0.001), and CAA-ri (p = 0.005), and less common in patients with microhemorrhage (p = 0.006). After controlling for age and sex, lobar ICH (odds ratio [OR] = 2.1, 95% confidence interval [CI] = 1.1-4.2), CAA-ri (OR = 3.8, 95% CI = 1.4-10.3), and superficial siderosis (OR = 3.7, 95% CI = 1.9-7.0) were independently associated with higher odds of incident seizures., Conclusions: Seizures are common in patients with CAA and are independently associated with lobar ICH, CAA-ri, and superficial siderosis. Our results may be applied to optimize clinical monitoring and management for patients with CAA., (© 2023 European Academy of Neurology.)
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- 2023
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15. Neurophenotypes of COVID-19: Risk factors and recovery outcomes.
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Prabhakaran D, Day GS, Munipalli B, Rush BK, Pudalov L, Niazi SK, Brennan E, Powers HR, Durvasula R, Athreya A, and Blackmon K
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Coronavirus disease 2019 (COVID-19) infection is associated with risk of persistent neurocognitive and neuropsychiatric complications. It is unclear whether the neuropsychological manifestations of COVID-19 present as a uniform syndrome or as distinct neurophenotypes with differing risk factors and recovery outcomes. We examined post-acute neuropsychological profiles following SARS-CoV-2 infection in 205 patients recruited from inpatient and outpatient populations, using an unsupervised machine learning cluster analysis, with objective and subjective measures as input features. This resulted in three distinct post-COVID clusters. In the largest cluster (69%), cognitive functions were within normal limits, although mild subjective attention and memory complaints were reported. Vaccination was associated with membership in this "normal cognition" phenotype. Cognitive impairment was present in the remaining 31% of the sample but clustered into two differentially impaired groups. In 16% of participants, memory deficits, slowed processing speed, and fatigue were predominant. Risk factors for membership in the "memory-speed impaired" neurophenotype included anosmia and more severe COVID-19 infection. In the remaining 15% of participants, executive dysfunction was predominant. Risk factors for membership in this milder "dysexecutive" neurophenotype included disease-nonspecific factors such as neighborhood deprivation and obesity. Recovery outcomes at 6-month follow-up differed across neurophenotypes, with the normal cognition group showing improvement in verbal memory and psychomotor speed, the dysexecutive group showing improvement in cognitive flexibility, and the memory-speed impaired group showing no objective improvement and relatively worse functional outcomes compared to the other two clusters. These results indicate that there are multiple post-acute neurophenotypes of COVID-19, with different etiological pathways and recovery outcomes. This information may inform phenotype-specific approaches to treatment., Competing Interests: The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: GS Day's research is supported by NIH [K23AG064029, U01AG057195, U19AG032438], the Alzheimer's Association, and Chan Zuckerberg Initiative. He serves as a consultant for Parabon Nanolabs Inc, as a Topic Editor [Dementia] for DynaMed (EBSCO), and as the Clinical Director of the Anti-NMDA Receptor Encephalitis Foundation [Inc, Canada; uncompensated]. He is the co-Project PI for a clinical trial in anti-NMDAR encephalitis, which receives support from Horizon Pharmaceuticals. He has developed educational materials for PeerView Media, Inc, and Continuing Education Inc. He owns stock in ANI pharmaceuticals. Dr. Day's institution has received support from EliLilly for Dr. Day's development and participation in an educational event promoting early diagnosis of symptomatic Alzheimer disease. The remaining authors have nothing to disclose., (© 2023 Published by Elsevier Inc.)
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- 2023
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16. Does Intra-Uterine Exposure to the Zika Virus Increase Risks of Cognitive Delay at Preschool Ages? Findings from a Zika-Exposed Cohort from Grenada, West Indies.
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Fernandes M, Evans R, Cheng M, Landon B, Noël T, Macpherson C, Cudjoe N, Burgen KS, Waechter R, LaBeaud AD, and Blackmon K
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- Pregnancy, Infant, Newborn, Female, Humans, Child, Preschool, Infant, Child, Grenada epidemiology, Cognition, Zika Virus, Zika Virus Infection complications, Zika Virus Infection epidemiology, Zika Virus Infection diagnosis, Microcephaly epidemiology, Microcephaly etiology, Microcephaly diagnosis, Pregnancy Complications, Infectious, Nervous System Malformations
- Abstract
Maternal infection with Zika virus (ZIKV) is associated with a distinct pattern of birth defects, known as congenital Zika syndrome (CZS). In ZIKV-exposed children without CZS, it is often unclear whether they were protected from in utero infection and neurotropism. Early neurodevelopmental assessment is essential for detecting neurodevelopmental delays (NDDs) and prioritizing at-risk children for early intervention. We compared neurodevelopmental outcomes between ZIKV-exposed and unexposed children at 1, 3 and 4 years to assess exposure-associated NDD risk. A total of 384 mother-child dyads were enrolled during a period of active ZIKV transmission (2016-2017) in Grenada, West Indies. Exposure status was based on laboratory assessment of prenatal and postnatal maternal serum. Neurodevelopment was assessed using the Oxford Neurodevelopment Assessment, the NEPSY
® Second Edition and Cardiff Vision Tests, at 12 ( n = 66), 36 ( n = 58) and 48 ( n = 59) months, respectively. There were no differences in NDD rates or vision scores between ZIKV-exposed and unexposed children. Rates of microcephaly at birth (0.88% vs. 0.83%, p = 0.81), and childhood stunting and wasting did not differ between groups. Our results show that Grenadian ZIKV-exposed children, the majority of whom were without microcephaly, had similar neurodevelopmental outcomes to unexposed controls up to at least an age of 4 years.- Published
- 2023
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17. Is formal scoring better than just looking? A comparison of subjective and objective scoring methods of the Rey Complex Figure Test for lateralizing temporal lobe epilepsy.
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LeMonda BC, MacAllister W, Morrison C, Vaurio L, Blackmon K, Maiman M, Liu A, Liberta T, and Bar WB
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- Adult, Female, Functional Laterality, Humans, Magnetic Resonance Imaging methods, Neuropsychological Tests, Research Design, Epilepsy, Temporal Lobe diagnostic imaging
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Objective Neuropsychologists labor over scoring the Rey Complex Figure Test (RCFT), a measure of visuospatial functioning and nonverbal memory. Compelling arguments suggest that pathognomonic signs of the RCFT are observable to the "naked eye." Standard scoring systems are insensitive to lateralizing temporal lobe epilepsy (TLE) and alternative "qualitative" scoring systems are ineffective and time-consuming. Method: We examined accuracy of TLE lateralization using subjective classifications and standard scoring. Participants were 84 TLE patients (53 female; mean age
= 36yrs) and 46 controls (27 female; mean age = 27.5). The former were classified as right (n = 41) or left (n = 43) TLE by neurologists using EEG and MRI studies. RCFT were scored using standard scoring with cut-offs of z ≤ -2 classified as impaired and were rated as "characteristic" of RTLE (Ugly) or LTLE (Not Ugly) performance by neuropsychologists. Accuracy of seizure lateralization for both methods was examined. Results: Neuropsychologists' ratings accuracy were at or below chance. Standard scoring criteria showed chance or slightly better lateralization prediction. Standard scoring predicted RTLE laterality more accurately than subjective ratings for copy trials; standard scoring was no better at lateralizing RTLE with delays. Subjective ratings were better at distinguishing TLE patients from controls. Conclusion: Findings highlight concerns regarding the usefulness of the RCFT in TLE lateralization, regardless of scoring approach.- Published
- 2022
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18. Neurocognitive screening in patients following SARS-CoV-2 infection: tools for triage.
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Blackmon K, Day GS, Powers HR, Bosch W, Prabhakaran D, Woolston D, and Pedraza O
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- Cross-Sectional Studies, Hospitalization, Humans, SARS-CoV-2, Triage, COVID-19 complications, COVID-19 diagnosis
- Abstract
Background: Cognitive complaints are common in patients recovering from Coronavirus Disease 2019 (COVID-19), yet their etiology is often unclear. We assess factors that contribute to cognitive impairment in ambulatory versus hospitalized patients during the sub-acute stage of recovery., Methods: In this cross-sectional study, participants were prospectively recruited from a hospital-wide registry. All patients tested positive for SARS-CoV-2 infection using a real-time reverse transcriptase polymerase-chain-reaction assay. Patients ≤ 18 years-of-age and those with a pre-existing major neurocognitive disorder were excluded. Participants completed an extensive neuropsychological questionnaire and a computerized cognitive screen via remote telemedicine platform. Rates of subjective and objective neuropsychological impairment were compared between the ambulatory and hospitalized groups. Factors associated with impairment were explored separately within each group., Results: A total of 102 patients (76 ambulatory, 26 hospitalized) completed the symptom inventory and neurocognitive tests 24 ± 22 days following laboratory confirmation of SARS-CoV-2 infection. Hospitalized and ambulatory patients self-reported high rates of cognitive impairment (27-40%), without differences between the groups. However, hospitalized patients showed higher rates of objective impairment in visual memory (30% vs. 4%; p = 0.001) and psychomotor speed (41% vs. 15%; p = 0.008). Objective cognitive test performance was associated with anxiety, depression, fatigue, and pain in the ambulatory but not the hospitalized group., Conclusions: Focal cognitive deficits are more common in hospitalized than ambulatory patients. Cognitive performance is associated with neuropsychiatric symptoms in ambulatory but not hospitalized patients. Objective neurocognitive measures can provide essential information to inform neurologic triage and should be included as endpoints in clinical trials., (© 2022. The Author(s).)
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- 2022
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19. Addressing racial inequities in neuropsychological assessment requires international prescriptive standards, not demographically adjusted norms.
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Fernandes M, Ayede AI, and Blackmon K
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- Humans, Neuropsychological Tests
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- 2022
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20. Improving neurodevelopment in Zika-exposed children: A randomized controlled trial.
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Waechter R, Burgen KS, Punch B, Evans R, Blackmon K, Noël T, Fernandes M, and Landon B
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- Child, Child, Preschool, Female, Grenada, Humans, Infant, Pregnancy, Microcephaly epidemiology, Pregnancy Complications, Infectious epidemiology, Zika Virus, Zika Virus Infection complications, Zika Virus Infection epidemiology, Zika Virus Infection prevention & control
- Abstract
Background: While microcephaly is a significant adverse outcome of prenatal exposure to the Zika virus (ZIKV), subtle malformations of cortical development (MCD) have been observed in Zika-exposed children (ZEC), including delays in language, cognition, and motor domains, and visual acuity deficits. Interventions within the first 1,000 days of life can significantly improve developmental outcomes. This study examined a 12-week Responsive Caregiving Intervention on neurodevelopmental outcomes in 24-30-month-old ZEC., Methodology/principal Findings: A randomized controlled trial was implemented in Grenada, West Indies using an existing ZIKV cohort surveillance study. When children in that study turned 24 months, baseline child neurodevelopmental measures and caregiver interviews were administered. Caregivers who agreed to participate in the 12-week Responsive Caregiving Intervention, implemented when children were 24-30 months of age, were randomly assigned to the Intervention or Waitlist Control group. Children in both groups were re-assessed on the neurodevelopmental measures post-intervention., Conclusions/significance: 233 children from the ZIKV surveillance study met inclusion criteria, of which n = 80 declined participation, n = 42 did not complete the Intervention, and n = 72 missed follow-up assessments given strict timelines in the study design. The final sample for analysis was N = 13 children in the Intervention group and N = 26 children in the Control group. A GEE model analysis showed significantly higher language (p = 0.021) and positive behaviour (p = 0.005) scores for children in the Intervention group compared to the Control group. The Intervention had a medium effect on child language (d = 0.66) and a large effect on positive behaviour (d = 0.83). A 12-week Responsive Caregiving Intervention Programme significantly improves language and positive behaviour scores in 30-month-old normocephalic children who were exposed to ZIKV in utero. The programme provides an option for mothers of ZIKV-exposed children who are seeking an evidence-based neurodevelopmental intervention regardless of known impact of the virus on cortical formation., Trial Registration: The study was registered with clinicaltrials.gov (NCT04697147)., Competing Interests: The authors have declared that no competing interests exist.
- Published
- 2022
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21. Neurodevelopment in normocephalic children with and without prenatal Zika virus exposure.
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Blackmon K, Evans R, Fernandes M, Landon B, Noel T, Macpherson C, Cudjoe N, Burgen KS, Punch B, Krystosik A, Grossi-Soyster EN, LaBeaud AD, and Waechter R
- Subjects
- Adult, Child Development, Child, Preschool, Cohort Studies, Female, Humans, Infant, Male, Microcephaly epidemiology, Pregnancy, Prospective Studies, West Indies, Zika Virus, Brain growth & development, Infectious Disease Transmission, Vertical, Pregnancy Complications, Infectious virology, Prenatal Exposure Delayed Effects virology, Zika Virus Infection transmission
- Abstract
Objective: Zika virus (ZIKV) targets neural stem cells in the developing brain. However, the majority of ZIKV-exposed children are born without apparent neurological manifestations. It remains unclear if these children were protected from ZIKV neurotropism or if they harbour subtle pathology that is disruptive to brain development. We assess this by comparing neurodevelopmental outcomes in normocephalic ZIKV-exposed children relative to a parallel control group of unexposed controls., Design: Cohort study., Setting: Public health centres in Grenada, West Indies., Patients: 384 mother-child pairs were enrolled during a period of active ZIKV transmission (April 2016-March 2017) and prospectively followed up to 30 months. Child exposure status was based on laboratory assessment of prenatal and postnatal maternal serum., Main Outcome Measures: The INTERGROWTH-21st Neurodevelopment Assessment (INTER-NDA) package and Cardiff Vision Tests, administered and scored by research staff masked to child's exposure status., Results: A total of 131 normocephalic ZIKV exposed (n=68) and unexposed (n=63) children were assessed between 22 and 30 months of age. Approximately half of these children completed vision testing. There were no group differences in sociodemographics. Deficits in visual acuity (31%) and contrast sensitivity (23%) were apparent in the ZIKV-exposed infants in the absence of cognitive, motor, language or behavioural delays., Conclusions: Overall neurodevelopment is likely to be unaffected in ZIKV-exposed children with normal head circumference at birth and normal head growth in the first 2 years of life. However, the visual system may be selectively vulnerable, which indicates the need for vision testing by 3 years of age., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2022. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)
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- 2022
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22. A systems-level analysis highlights microglial activation as a modifying factor in common epilepsies.
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Altmann A, Ryten M, Di Nunzio M, Ravizza T, Tolomeo D, Reynolds RH, Somani A, Bacigaluppi M, Iori V, Micotti E, Di Sapia R, Cerovic M, Palma E, Ruffolo G, Botía JA, Absil J, Alhusaini S, Alvim MKM, Auvinen P, Bargallo N, Bartolini E, Bender B, Bergo FPG, Bernardes T, Bernasconi A, Bernasconi N, Bernhardt BC, Blackmon K, Braga B, Caligiuri ME, Calvo A, Carlson C, Carr SJA, Cavalleri GL, Cendes F, Chen J, Chen S, Cherubini A, Concha L, David P, Delanty N, Depondt C, Devinsky O, Doherty CP, Domin M, Focke NK, Foley S, Franca W, Gambardella A, Guerrini R, Hamandi K, Hibar DP, Isaev D, Jackson GD, Jahanshad N, Kälviäinen R, Keller SS, Kochunov P, Kotikalapudi R, Kowalczyk MA, Kuzniecky R, Kwan P, Labate A, Langner S, Lenge M, Liu M, Martin P, Mascalchi M, Meletti S, Morita-Sherman ME, O'Brien TJ, Pariente JC, Richardson MP, Rodriguez-Cruces R, Rummel C, Saavalainen T, Semmelroch MK, Severino M, Striano P, Thesen T, Thomas RH, Tondelli M, Tortora D, Vaudano AE, Vivash L, von Podewils F, Wagner J, Weber B, Wiest R, Yasuda CL, Zhang G, Zhang J, Leu C, Avbersek A, Thom M, Whelan CD, Thompson P, McDonald CR, Vezzani A, and Sisodiya SM
- Subjects
- Animals, Brain, Endothelial Cells, Mice, Seizures, Epilepsy metabolism, Microglia metabolism
- Abstract
Aims: The causes of distinct patterns of reduced cortical thickness in the common human epilepsies, detectable on neuroimaging and with important clinical consequences, are unknown. We investigated the underlying mechanisms of cortical thinning using a systems-level analysis., Methods: Imaging-based cortical structural maps from a large-scale epilepsy neuroimaging study were overlaid with highly spatially resolved human brain gene expression data from the Allen Human Brain Atlas. Cell-type deconvolution, differential expression analysis and cell-type enrichment analyses were used to identify differences in cell-type distribution. These differences were followed up in post-mortem brain tissue from humans with epilepsy using Iba1 immunolabelling. Furthermore, to investigate a causal effect in cortical thinning, cell-type-specific depletion was used in a murine model of acquired epilepsy., Results: We identified elevated fractions of microglia and endothelial cells in regions of reduced cortical thickness. Differentially expressed genes showed enrichment for microglial markers and, in particular, activated microglial states. Analysis of post-mortem brain tissue from humans with epilepsy confirmed excess activated microglia. In the murine model, transient depletion of activated microglia during the early phase of the disease development prevented cortical thinning and neuronal cell loss in the temporal cortex. Although the development of chronic seizures was unaffected, the epileptic mice with early depletion of activated microglia did not develop deficits in a non-spatial memory test seen in epileptic mice not depleted of microglia., Conclusions: These convergent data strongly implicate activated microglia in cortical thinning, representing a new dimension for concern and disease modification in the epilepsies, potentially distinct from seizure control., (© 2021 The Authors. Neuropathology and Applied Neurobiology published by John Wiley & Sons Ltd on behalf of British Neuropathological Society.)
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- 2022
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23. Artificial intelligence for classification of temporal lobe epilepsy with ROI-level MRI data: A worldwide ENIGMA-Epilepsy study.
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Gleichgerrcht E, Munsell BC, Alhusaini S, Alvim MKM, Bargalló N, Bender B, Bernasconi A, Bernasconi N, Bernhardt B, Blackmon K, Caligiuri ME, Cendes F, Concha L, Desmond PM, Devinsky O, Doherty CP, Domin M, Duncan JS, Focke NK, Gambardella A, Gong B, Guerrini R, Hatton SN, Kälviäinen R, Keller SS, Kochunov P, Kotikalapudi R, Kreilkamp BAK, Labate A, Langner S, Larivière S, Lenge M, Lui E, Martin P, Mascalchi M, Meletti S, O'Brien TJ, Pardoe HR, Pariente JC, Xian Rao J, Richardson MP, Rodríguez-Cruces R, Rüber T, Sinclair B, Soltanian-Zadeh H, Stein DJ, Striano P, Taylor PN, Thomas RH, Elisabetta Vaudano A, Vivash L, von Podewills F, Vos SB, Weber B, Yao Y, Lin Yasuda C, Zhang J, Thompson PM, Sisodiya SM, McDonald CR, and Bonilha L
- Subjects
- Artificial Intelligence, Brain diagnostic imaging, Brain pathology, Hippocampus diagnostic imaging, Hippocampus pathology, Humans, Magnetic Resonance Imaging, Sclerosis pathology, Support Vector Machine, Epilepsy, Temporal Lobe diagnostic imaging, Epilepsy, Temporal Lobe pathology
- Abstract
Artificial intelligence has recently gained popularity across different medical fields to aid in the detection of diseases based on pathology samples or medical imaging findings. Brain magnetic resonance imaging (MRI) is a key assessment tool for patients with temporal lobe epilepsy (TLE). The role of machine learning and artificial intelligence to increase detection of brain abnormalities in TLE remains inconclusive. We used support vector machine (SV) and deep learning (DL) models based on region of interest (ROI-based) structural (n = 336) and diffusion (n = 863) brain MRI data from patients with TLE with ("lesional") and without ("non-lesional") radiographic features suggestive of underlying hippocampal sclerosis from the multinational (multi-center) ENIGMA-Epilepsy consortium. Our data showed that models to identify TLE performed better or similar (68-75%) compared to models to lateralize the side of TLE (56-73%, except structural-based) based on diffusion data with the opposite pattern seen for structural data (67-75% to diagnose vs. 83% to lateralize). In other aspects, structural and diffusion-based models showed similar classification accuracies. Our classification models for patients with hippocampal sclerosis were more accurate (68-76%) than models that stratified non-lesional patients (53-62%). Overall, SV and DL models performed similarly with several instances in which SV mildly outperformed DL. We discuss the relative performance of these models with ROI-level data and the implications for future applications of machine learning and artificial intelligence in epilepsy care., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)
- Published
- 2021
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24. Epilepsy surveillance in normocephalic children with and without prenatal Zika virus exposure.
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Blackmon K, Waechter R, Landon B, Noël T, Macpherson C, Donald T, Cudjoe N, Evans R, Burgen KS, Jayatilake P, Oyegunle V, Pedraza O, Abdel Baki S, Thesen T, Dlugos D, Chari G, Patel AA, Grossi-Soyster EN, Krystosik AR, and LaBeaud AD
- Subjects
- Anticonvulsants therapeutic use, Carbamazepine therapeutic use, Cohort Studies, Electroencephalography, Epilepsy etiology, Female, Grenada epidemiology, Humans, Immunoglobulin G blood, Infant, Male, Pregnancy, Pregnancy Complications, Infectious virology, Prospective Studies, Zika Virus isolation & purification, Zika Virus Infection complications, Zika Virus Infection congenital, Epilepsy epidemiology, Pregnancy Complications, Infectious epidemiology, Zika Virus Infection diagnosis
- Abstract
Children with Congenital Zika Syndrome and microcephaly are at high risk for epilepsy; however, the risk is unclear in normocephalic children with prenatal Zika virus (ZIKV) exposure [Exposed Children (EC)]. In this prospective cohort study, we performed epilepsy screening in normocephalic EC alongside a parallel group of normocephalic unexposed children [Unexposed Children (UC)]. We compared the incidence rate of epilepsy among EC and UC at one year of life to global incidence rates. Pregnant women were recruited from public health centers during the ZIKV outbreak in Grenada, West Indies and assessed for prior ZIKV infection using a plasmonic-gold platform that measures IgG antibodies in serum. Normocephalic children born to mothers with positive ZIKV results during pregnancy were classified as EC and those born to mothers with negative ZIKV results during and after pregnancy were classified as UC. Epilepsy screening procedures included a pediatric epilepsy screening questionnaire and video electroencephalography (vEEG). vEEG was collected using a multi-channel microEEG® system for a minimum of 20 minutes along with video recording of participant behavior time-locked to the EEG. vEEGs were interpreted independently by two pediatric epileptologists, who were blinded to ZIKV status, via telemedicine platform. Positive screening cases were referred to a local pediatrician for an epilepsy diagnostic evaluation. Epilepsy screens were positive in 2/71 EC (IR: 0.028; 95% CI: 0.003-0.098) and 0/71 UC. In both epilepsy-positive cases, questionnaire responses and interictal vEEGs were consistent with focal, rather than generalized, seizures. Both children met criteria for a clinical diagnosis of epilepsy and good seizure control was achieved with carbamazepine. Our results indicate that epilepsy rates are modestly elevated in EC. Given our small sample size, results should be considered preliminary. They support the use of epilepsy screening procedures in larger epidemiological studies of children with congenital ZIKV exposure, even in the absence of microcephaly, and provide guidance for conducting epilepsy surveillance in resource limited settings., Competing Interests: I have read the journal's policy and the authors of this manuscript have the following competing interests: Dr. Samah G. Abdel Baki reports support from Bio-Signal Group Corporation and other grants outside the submitted work. In addition, Dr. Baki has a patent 61/554,743 pending and a U.S. patent 13/284,886. None of the other authors have competing interests to disclose.
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- 2020
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25. Focal epilepsy features in a child with Congenital Zika Syndrome.
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Jayatilake P, Oyegunle V, Waechter R, Landon B, Fernandes M, Cudjoe N, Evans R, Noël T, Macpherson C, Donald T, Abdelbaki SG, Mandalaneni K, Dlugos D, Chari G, Patel AA, Grossi-Soyster EN, Desiree LaBeaud A, and Blackmon K
- Abstract
Zika virus (ZIKV) is a mosquito-borne, single-stranded DNA flavivirus that is teratogenic and neurotropic. Similar to the teratogenic effects of other TORCH infections, ZIKV infection during pregnancy can have an adverse impact on fetal and neonatal development. Epilepsy is detected in 48-96% of children with Congenital Zika Syndrome (CZS) and microcephaly. Early epilepsy surveillance is needed in children with prenatal ZIKV exposure; yet, most ZIKV-endemic regions do not have specialist epilepsy care. Here, we describe the demographic, clinical, imaging, and EEG characteristics of a 2-year-old child with CZS and microcephaly who presented with focal epileptiform activity, suboptimal growth, and severe neurodevelopmental delays. Administration of a brief seizure questionnaire by allied health professionals to the patient's caregiver helped to characterize the child's seizure semiology and differentiate focal from generalized seizure features. A telemedicine EEG interpretation platform provided valuable diagnostic information for the patient's local pediatrician to integrate into her treatment plan. This case illustrates that CZS can present with focal epilepsy features and that a telemedicine approach can be used to bridge the gap between epilepsy specialists and local care providers in resource limited ZIKV-endemic regions to achieve better seizure control in children with CZS., Competing Interests: The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: SB reports support from Bio-Signal Group Co. and the following patents pending: 61/554,743; 13/284,886. None of the other authors have any conflicts of interest to disclose., (© 2020 The Author(s).)
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- 2020
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26. Cortical gray-white matter blurring and declarative memory impairment in MRI-negative temporal lobe epilepsy.
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Blackmon K, Barr WB, Morrison C, MacAllister W, Kruse M, Pressl C, Wang X, Dugan P, Liu AA, Halgren E, Devinsky O, and Thesen T
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- Adult, Cognition physiology, Female, Humans, Magnetic Resonance Imaging methods, Male, Middle Aged, Neuropsychological Tests, Sclerosis pathology, Temporal Lobe physiopathology, Cerebral Cortex pathology, Epilepsy, Temporal Lobe physiopathology, Gray Matter pathology, Hippocampus pathology, Memory Disorders pathology, White Matter pathology
- Abstract
Magnetic resonance imaging (MRI)-negative temporal lobe epilepsy (TLE) may be a distinct syndrome from TLE with mesial temporal sclerosis (TLE-MTS). Imaging and neuropsychological features of TLE-MTS are well-known; yet, these features are only beginning to be described in MRI-negative TLE. This study examined whether a quantitative measure of cortical gray and white matter blurring (GWB) was elevated in the temporal lobes ipsilateral to the seizure onset zone of individuals with MRI-negative TLE relative to TLE-MTS and healthy controls (HCs) and whether GWB elevations were associated with neuropsychological comorbidity. Gray-white matter blurring from 34 cortical regions and hippocampal volumes were quantified and compared across 28 people with MRI-negative TLE, 15 people with TLE-MTS, and 51 HCs. Declarative memory was assessed with standard neuropsychological tests and the intracarotid amobarbital procedure (IAP). In the group with MRI-negative TLE (left and right onsets combined), hippocampal volumes were within normal range but GWB was elevated, relative to HCs, across several mesial and lateral temporal lobe regions ipsilateral to the seizure onset zone. Gray-white matter blurring did not differ between the groups with TLE-MTS and HC or between the groups with TLE-MTS and MRI-negative TLE. The group with MRI-negative TLE could not be distinguished from the group with TLE-MTS on any of the standard neuropsychological tests; however, ipsilateral hippocampal volumes and IAP memory scores were lower in the group with TLE-MTS than in the group with MRI-negative TLE. The group with left MRI-negative TLE had lower general cognitive abilities and verbal fluency relative to the HC group, which adds to the characterization of neuropsychological comorbidities in left MRI-negative TLE. In addition, ipsilateral IAP memory performance was reduced relative to contralateral memory performance in MRI-negative TLE, indicating some degree of ipsilateral memory dysfunction. There was no relationship between hippocampal volume and IAP memory scores in MRI-negative TLE; however, decreased ipsilateral IAP memory scores were correlated with elevated GWB in the ipsilateral superior temporal sulcus of people with left MRI-negative TLE. In sum, GWB elevations in the ipsilateral temporal lobe of people with MRI-negative TLE suggest that GWB may serve as a marker for reduced structural integrity in regions in or near the seizure onset zone. Although mesial temporal abnormalities might be the major driver of memory dysfunction in TLE-MTS, a loss of structural integrity in lateral temporal lobe regions may contribute to IAP memory dysfunction in MRI-negative TLE., (Copyright © 2019 Elsevier Inc. All rights reserved.)
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- 2019
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27. Hippocampal volumetric integrity in mesial temporal lobe epilepsy: A fast novel method for analysis of structural MRI.
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Hakimi M, Ardekani BA, Pressl C, Blackmon K, Thesen T, Devinsky O, Kuzniecky RI, and Pardoe HR
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- Adult, Female, Humans, Male, Middle Aged, Young Adult, Epilepsy, Temporal Lobe diagnostic imaging, Hippocampus diagnostic imaging, Image Processing, Computer-Assisted methods, Magnetic Resonance Imaging methods
- Abstract
Objective: We investigate whether a rapid and novel automated MRI processing technique for assessing hippocampal volumetric integrity (HVI) can be used to identify hippocampal sclerosis (HS) in patients with mesial temporal lobe epilepsy (mTLE) and determine its performance relative to hippocampal volumetry (HV) and visual inspection., Methods: We applied the HVI technique to T1-weighted brain images from healthy control (n = 35), mTLE (n = 29), non-HS temporal lobe epilepsy (TLE, n = 44), and extratemporal focal epilepsy (EXTLE, n = 25) subjects imaged using a standardized epilepsy research imaging protocol and on non-standardized clinically acquired images from mTLE subjects (n = 40) to investigate if the technique is translatable to clinical practice. Performance of HVI, HV, and visual inspection was assessed using receiver operating characteristic (ROC) analysis., Results: mTLE patients from both research and clinical groups had significantly reduced ipsilateral HVI relative to controls (effect size: -0.053, 5.62%, p = 0.002 using a standardized research imaging protocol). For lateralizing mTLE, HVI had a sensitivity of 88% compared with a HV sensitivity of 92% when using specificity equal to 70%., Conclusions: The novel HVI approach can effectively detect HS in clinical populations, with an average image processing time of less than a minute. The fast processing speed suggests this technique could have utility as a quantitative tool to assist with imaging-based diagnosis and lateralization of HS in a clinical setting., (Copyright © 2019 Elsevier B.V. All rights reserved.)
- Published
- 2019
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28. Hippocampal Contributions to Model-Based Planning and Spatial Memory.
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Vikbladh OM, Meager MR, King J, Blackmon K, Devinsky O, Shohamy D, Burgess N, and Daw ND
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- Adult, Case-Control Studies, Decision Making, Female, Hippocampus diagnostic imaging, Hippocampus physiology, Hippocampus physiopathology, Humans, Male, Spatial Learning physiology, Task Performance and Analysis, Anterior Temporal Lobectomy, Epilepsy, Temporal Lobe surgery, Hippocampus surgery, Spatial Memory physiology
- Abstract
Little is known about the neural mechanisms that allow humans and animals to plan actions using knowledge of task contingencies. Emerging theories hypothesize that it involves the same hippocampal mechanisms that support self-localization and memory for locations. Yet limited direct evidence supports the link between planning and the hippocampal place map. We addressed this by investigating model-based planning and place memory in healthy controls and epilepsy patients treated using unilateral anterior temporal lobectomy with hippocampal resection. Both functions were impaired in the patient group. Specifically, the planning impairment was related to right hippocampal lesion size, controlling for overall lesion size. Furthermore, although planning and boundary-driven place memory covaried in the control group, this relationship was attenuated in patients, consistent with both functions relying on the same structure in the healthy brain. These findings clarify both the neural mechanism of model-based planning and the scope of hippocampal contributions to behavior., (Copyright © 2019 Elsevier Inc. All rights reserved.)
- Published
- 2019
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29. Understanding perirhinal contributions to perception and memory: Evidence through the lens of selective perirhinal damage.
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Inhoff MC, Heusser AC, Tambini A, Martin CB, O'Neil EB, Köhler S, Meager MR, Blackmon K, Vazquez B, Devinsky O, and Davachi L
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- Adolescent, Adult, Female, Hippocampus pathology, Hippocampus physiology, Humans, Judgment, Male, Neuropsychological Tests, Perirhinal Cortex pathology, Recognition, Psychology physiology, Young Adult, Facial Recognition physiology, Memory physiology, Perirhinal Cortex physiology
- Abstract
Although a memory systems view of the medial temporal lobe (MTL) has been widely influential in understanding how memory processes are implemented, a large body of work across humans and animals has converged on the idea that the MTL can support various other decisions, beyond those involving memory. Specifically, recent work suggests that perception of and memory for visual representations may interact in order to support ongoing cognition. However, given considerations involving lesion profiles in neuropsychological investigations and the correlational nature of fMRI, the precise nature of representations supported by the MTL are not well understood in humans. In the present investigation, three patients with highly specific lesions to MTL were administered a task that taxed perceptual and mnemonic judgments with highly similar face stimuli. A striking double dissociation was observed such that I.R., a patient with a cyst localized to right posterior PRc, displayed a significant impairment in perceptual discriminations, whereas patient A.N., an individual with a lesion in right posterior parahippocampal cortex and the tail of the right hippocampus, and S.D., an individual with bilateral hippocampal damage, did not display impaired performance on the perceptual task. A.N. and S.D. did, however, show impairments in memory performance, whereas patient I.R. did not. These results causally implicate right PRc in successful perceptual oddity judgments, however they suggest that representations supported by PRc are not necessary for correct mnemonic judgments, even in situations of high featural overlap., (Copyright © 2019 Elsevier Ltd. All rights reserved.)
- Published
- 2019
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30. Resting state functional connectivity patterns associated with pharmacological treatment resistance in temporal lobe epilepsy.
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Pressl C, Brandner P, Schaffelhofer S, Blackmon K, Dugan P, Holmes M, Thesen T, Kuzniecky R, Devinsky O, and Freiwald WA
- Subjects
- Adult, Anticonvulsants adverse effects, Brain drug effects, Female, Humans, Image Processing, Computer-Assisted, Magnetic Resonance Imaging, Male, Middle Aged, Neural Pathways drug effects, Oxygen blood, Retrospective Studies, Brain diagnostic imaging, Drug Resistant Epilepsy diagnostic imaging, Epilepsy, Temporal Lobe diagnostic imaging, Neural Pathways diagnostic imaging, Rest
- Abstract
There are no functional imaging based biomarkers for pharmacological treatment response in temporal lobe epilepsy (TLE). In this study, we investigated whether there is an association between resting state functional brain connectivity (RsFC) and seizure control in TLE. We screened a large database containing resting state functional magnetic resonance imaging (Rs-fMRI) data from 286 epilepsy patients. Patient medical records were screened for seizure characterization, EEG reports for lateralization and location of seizure foci to establish uniformity of seizure localization within patient groups. Rs-fMRI data from patients with well-controlled left TLE, patients with treatment-resistant left TLE, and healthy controls were analyzed. Healthy controls and cTLE showed similar functional connectivity patterns, whereas trTLE exhibited a significant bilateral decrease in thalamo-hippocampal functional connectivity. This work is the first to demonstrate differences in neural network connectivity between well-controlled and treatment-resistant TLE. These differences are spatially highly focused and suggest sites for the etiology and possibly treatment of TLE. Altered thalamo-hippocampal RsFC thus is a potential new biomarker for TLE treatment resistance., (Copyright © 2018 Elsevier B.V. All rights reserved.)
- Published
- 2019
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31. Focal Cortical Anomalies and Language Impairment in 16p11.2 Deletion and Duplication Syndrome.
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Blackmon K, Thesen T, Green S, Ben-Avi E, Wang X, Fuchs B, Kuzniecky R, and Devinsky O
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- Adolescent, Adult, Autistic Disorder diagnostic imaging, Cerebral Cortex diagnostic imaging, Chi-Square Distribution, Child, Chromosome Deletion, Chromosome Disorders diagnostic imaging, Chromosomes, Human, Pair 16 genetics, Female, Humans, Intellectual Disability diagnostic imaging, Language Disorders diagnostic imaging, Language Disorders genetics, Male, Middle Aged, Severity of Illness Index, Tomography Scanners, X-Ray Computed, Young Adult, Autistic Disorder complications, Chromosome Disorders complications, Chromosome Duplication genetics, Intellectual Disability complications, Language Disorders etiology, Malformations of Cortical Development complications, Malformations of Cortical Development genetics
- Abstract
Individuals with copy number variants (CNV) in the 16p11.2 chromosomal region are at high risk for language disorders. We investigate whether the extent and location of focal cortical anomalies are associated with language impairment in individuals with 16p11.2 CNVs. High-resolution T1-weighted MRI scans from 30 16p11.2 deletion (16p-del), 25 16p11.2 duplication (16p-dup), and 90 noncarrier controls (NCC) were analyzed to derive personalized cortical anomaly maps through single-case cortical thickness (CT) comparison to age-matched normative samples. Focal cortical anomalies were elevated in both 16p-del and 16p-dup and their total extent was inversely correlated with Full-Scale IQ. Clusters of abnormally thick cortex were more extensive in the 16p-del group and clusters of abnormally thin cortex were more extensive in the 16p-dup group. Abnormally thick clusters were more extensive in left lateral temporal and bilateral postcentral and mesial occipital regions in 16p-del. Focal cortical anomalies in the left middle temporal region and pars opercularis (Broca's region) of children with 16-del were associated with lower scores on a comprehensive language evaluation. Results extend neuroanatomical findings in 16p11.2 syndrome to include spatially heterogenous focal cortical anomalies that appear to disrupt language ability in accordance with the functional specialization of left frontotemporal regions.
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- 2018
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32. Parieto-frontal gyrification and working memory in healthy adults.
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Green S, Blackmon K, Thesen T, DuBois J, Wang X, Halgren E, and Devinsky O
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- Adolescent, Adult, Aged, Female, Humans, Magnetic Resonance Imaging, Male, Middle Aged, Young Adult, Frontal Lobe diagnostic imaging, Memory, Short-Term, Parietal Lobe diagnostic imaging
- Abstract
Gyrification of the cortical mantle is a dynamic process that increases with cortical surface area and decreases with age. Increased gyrification is associated with higher scores on cognitive tasks in adults; however, the degree to which this relationship is independent of cortical surface area remains undefined. This study investigates whether regional variation in gyrification is associated with domain-general and domain-specific cognition. Our hypothesis is that increased local gyrification confers a functional advantage that is independent of surface area. To quantify regional gyrification, we computed the local gyrification index (LGI) at each vertex and averaged across a bilateral parietal-frontal region associated with general intelligence and reasoning (Jung and Haier 2007). A sample of 48 healthy adults (24 males/24 females; ages 18-68 years) completed a high-resolution 3 T T1-weighted MRI and standardized administration of the Wechsler Adult Intelligence Scale (WAIS). We found a positive correlation between cortical gyrification and working memory, which remained significant after controlling for cortical surface area. Results suggest that a higher degree of local cortical folding confers a functional advantage that is independent from surface area and evident for more dynamic or "fluid" cognitive processes (i.e., working memory) rather than over-learned or "crystallized" cognitive processes.
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- 2018
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33. Structural brain abnormalities in the common epilepsies assessed in a worldwide ENIGMA study.
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Whelan CD, Altmann A, Botía JA, Jahanshad N, Hibar DP, Absil J, Alhusaini S, Alvim MKM, Auvinen P, Bartolini E, Bergo FPG, Bernardes T, Blackmon K, Braga B, Caligiuri ME, Calvo A, Carr SJ, Chen J, Chen S, Cherubini A, David P, Domin M, Foley S, França W, Haaker G, Isaev D, Keller SS, Kotikalapudi R, Kowalczyk MA, Kuzniecky R, Langner S, Lenge M, Leyden KM, Liu M, Loi RQ, Martin P, Mascalchi M, Morita ME, Pariente JC, Rodríguez-Cruces R, Rummel C, Saavalainen T, Semmelroch MK, Severino M, Thomas RH, Tondelli M, Tortora D, Vaudano AE, Vivash L, von Podewils F, Wagner J, Weber B, Yao Y, Yasuda CL, Zhang G, Bargalló N, Bender B, Bernasconi N, Bernasconi A, Bernhardt BC, Blümcke I, Carlson C, Cavalleri GL, Cendes F, Concha L, Delanty N, Depondt C, Devinsky O, Doherty CP, Focke NK, Gambardella A, Guerrini R, Hamandi K, Jackson GD, Kälviäinen R, Kochunov P, Kwan P, Labate A, McDonald CR, Meletti S, O'Brien TJ, Ourselin S, Richardson MP, Striano P, Thesen T, Wiest R, Zhang J, Vezzani A, Ryten M, Thompson PM, and Sisodiya SM
- Subjects
- Adult, Brain pathology, Correlation of Data, Cross-Sectional Studies, Epilepsy diagnostic imaging, Female, Humans, Image Processing, Computer-Assisted, International Cooperation, Magnetic Resonance Imaging, Male, Meta-Analysis as Topic, Brain diagnostic imaging, Brain Mapping, Epilepsy pathology
- Abstract
Progressive functional decline in the epilepsies is largely unexplained. We formed the ENIGMA-Epilepsy consortium to understand factors that influence brain measures in epilepsy, pooling data from 24 research centres in 14 countries across Europe, North and South America, Asia, and Australia. Structural brain measures were extracted from MRI brain scans across 2149 individuals with epilepsy, divided into four epilepsy subgroups including idiopathic generalized epilepsies (n =367), mesial temporal lobe epilepsies with hippocampal sclerosis (MTLE; left, n = 415; right, n = 339), and all other epilepsies in aggregate (n = 1026), and compared to 1727 matched healthy controls. We ranked brain structures in order of greatest differences between patients and controls, by meta-analysing effect sizes across 16 subcortical and 68 cortical brain regions. We also tested effects of duration of disease, age at onset, and age-by-diagnosis interactions on structural measures. We observed widespread patterns of altered subcortical volume and reduced cortical grey matter thickness. Compared to controls, all epilepsy groups showed lower volume in the right thalamus (Cohen's d = -0.24 to -0.73; P < 1.49 × 10-4), and lower thickness in the precentral gyri bilaterally (d = -0.34 to -0.52; P < 4.31 × 10-6). Both MTLE subgroups showed profound volume reduction in the ipsilateral hippocampus (d = -1.73 to -1.91, P < 1.4 × 10-19), and lower thickness in extrahippocampal cortical regions, including the precentral and paracentral gyri, compared to controls (d = -0.36 to -0.52; P < 1.49 × 10-4). Thickness differences of the ipsilateral temporopolar, parahippocampal, entorhinal, and fusiform gyri, contralateral pars triangularis, and bilateral precuneus, superior frontal and caudal middle frontal gyri were observed in left, but not right, MTLE (d = -0.29 to -0.54; P < 1.49 × 10-4). Contrastingly, thickness differences of the ipsilateral pars opercularis, and contralateral transverse temporal gyrus, were observed in right, but not left, MTLE (d = -0.27 to -0.51; P < 1.49 × 10-4). Lower subcortical volume and cortical thickness associated with a longer duration of epilepsy in the all-epilepsies, all-other-epilepsies, and right MTLE groups (beta, b < -0.0018; P < 1.49 × 10-4). In the largest neuroimaging study of epilepsy to date, we provide information on the common epilepsies that could not be realistically acquired in any other way. Our study provides a robust ranking of brain measures that can be further targeted for study in genetic and neuropathological studies. This worldwide initiative identifies patterns of shared grey matter reduction across epilepsy syndromes, and distinctive abnormalities between epilepsy syndromes, which inform our understanding of epilepsy as a network disorder, and indicate that certain epilepsy syndromes involve more widespread structural compromise than previously assumed., (© The Author(s) (2018). Published by Oxford University Press on behalf of the Guarantors of Brain.)
- Published
- 2018
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34. Material specificity of memory deficits in children with temporal tumors and seizures: A case series.
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Whitman L, Scharaga EA, Blackmon K, Wiener J, Bender HA, Weiner HL, and MacAllister WS
- Subjects
- Adolescent, Brain Neoplasms complications, Brain Neoplasms diagnostic imaging, Child, Female, Humans, Intelligence physiology, Male, Memory Disorders diagnostic imaging, Memory Disorders etiology, Neuropsychological Tests, Seizures complications, Seizures diagnostic imaging, Brain Neoplasms psychology, Memory physiology, Memory Disorders psychology, Seizures psychology, Temporal Lobe diagnostic imaging
- Abstract
In adults, left temporal lobe pathology is typically associated with verbal memory deficits, whereas right temporal lobe pathology is thought to produce visual memory deficits in right-handed individuals. However, in children and adolescents with temporal lobe pathology, conclusions regarding material specificity of memory deficits remain unclear. The goal of the present case series is to examine the profile of verbal and visual memory impairment in children with temporal lobe tumors. Three patients with identified right temporal tumors and three patients with left temporal tumors are included. The Wide Range Assessment of Memory and Learning-Second Edition (WRAML-2) was administered as part of a larger neuropsychological battery. As anticipated, participants with right temporal lesions showed impaired visual memory relative to intact verbal memory. Interestingly, although the discrepancies between verbal and visual indices were less extreme, those with left temporal lesions showed a similar memory profile. These seemingly counterintuitive findings among left temporal tumor patients likely reflect less hemispheric specialization in children in comparison to adults and the fact that early developmental lesions in the left hemisphere may lead to functional reorganization of language-based skills.
- Published
- 2017
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35. Musical hallucinations: a brief review of functional neuroimaging findings.
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Bernardini F, Attademo L, Blackmon K, and Devinsky O
- Subjects
- Brain physiopathology, Functional Neuroimaging, Hallucinations physiopathology, Humans, Magnetoencephalography, Tomography, Emission-Computed, Single-Photon, Brain diagnostic imaging, Hallucinations diagnostic imaging, Music
- Abstract
Musical hallucinations are uncommon phenomena characterized by intrusive and frequently distressful auditory musical percepts without an external source, often associated with hypoacusis, psychiatric illness, focal brain lesion, epilepsy, and intoxication/pharmacology. Their physiological basis is thought to involve diverse mechanisms, including "release" from normal sensory or inhibitory inputs as well as stimulation during seizures, or they can be produced by functional or structural disorders in diverse cortical and subcortical areas. The aim of this review is to further explore their pathophysiology, describing the functional neuroimaging findings regarding musical hallucinations. A literature search of the PubMed electronic database was conducted through to 29 December 2015. Search terms included "musical hallucinations" combined with the names of specific functional neuroimaging techniques. A total of 18 articles, all clinical case reports, providing data on 23 patients, comprised the set we reviewed. Diverse pathological processes and patient populations with musical hallucinations were included in the studies. Converging data from multiple studies suggest that the superior temporal sulcus is the most common site and that activation is the most common mechanism. Further neurobiological research is needed to clarify the pathophysiology of musical hallucinations.
- Published
- 2017
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36. Structural brain changes in medically refractory focal epilepsy resemble premature brain aging.
- Author
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Pardoe HR, Cole JH, Blackmon K, Thesen T, and Kuzniecky R
- Subjects
- Adult, Brain diagnostic imaging, Electroencephalography, Epilepsies, Partial drug therapy, Female, Follow-Up Studies, Humans, Image Processing, Computer-Assisted, Magnetic Resonance Imaging, Male, Middle Aged, Neuropsychological Tests, Young Adult, Aging, Premature pathology, Brain pathology, Drug Resistant Epilepsy pathology, Epilepsies, Partial pathology
- Abstract
Objective: We used whole brain T1-weighted MRI to estimate the age of individuals with medically refractory focal epilepsy, and compared with individuals with newly diagnosed focal epilepsy and healthy controls. The difference between neuroanatomical age and chronological age was compared between the three groups., Methods: Neuroanatomical age was estimated using a machine learning-based method that was trained using structural MRI scans from a large independent healthy control sample (N=2001). The prediction model was then used to estimate age from MRI scans obtained from newly diagnosed focal epilepsy patients (N=42), medically refractory focal epilepsy patients (N=94) and healthy controls (N=74)., Results: Individuals with medically refractory epilepsy had a difference between predicted brain age and chronological age that was on average 4.5 years older than healthy controls (p=4.6×10
-5 ). No significant differences were observed in newly diagnosed focal epilepsy. Earlier age of onset was associated with an increased brain age difference in the medically refractory group (p=0.034)., Significance: Medically refractory focal epilepsy is associated with structural brain changes that resemble premature brain aging., (Copyright © 2017 Elsevier B.V. All rights reserved.)- Published
- 2017
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37. Amygdala enlargement: Temporal lobe epilepsy subtype or nonspecific finding?
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Reyes A, Thesen T, Kuzniecky R, Devinsky O, McDonald CR, Jackson GD, Vaughan DN, and Blackmon K
- Subjects
- Adult, Amygdala physiopathology, Electroencephalography methods, Epilepsy, Temporal Lobe physiopathology, Female, Humans, Magnetic Resonance Imaging methods, Male, Middle Aged, Temporal Lobe physiopathology, Amygdala pathology, Epilepsy, Temporal Lobe pathology, Temporal Lobe pathology
- Abstract
Objective: Amygdala enlargement (AE) is observed in patients with temporal lobe epilepsy (TLE), which has led to the suggestion that it represents a distinct TLE subtype; however, it is unclear whether AE is found at similar rates in other epilepsy syndromes or in healthy controls, which would limit its value as a marker for focal epileptogenicity., Methods: We compared rates of AE, defined quantitatively from high-resolution T1-weighted MRI, in a large multi-site sample of 136 patients with nonlesional localization related epilepsy (LRE), including TLE and extratemporal (exTLE) focal epilepsy, 34 patients with idiopathic generalized epilepsy (IGE), and 233 healthy controls (HCs)., Results: AE was found in all groups including HCs; however, the rate of AE was higher in LRE (18.4%) than in IGE (5.9%) and HCs (6.4%). Patients with unilateral LRE were further evaluated to compare rates of concordant ipsilateral AE in TLE and exTLE, with the hypothesis that rates of ipsilateral AE would be higher in TLE. Although ipsilateral AE was higher in TLE (19.4%) than exTLE (10.5%), this difference was not significant. Furthermore, among the 25 patients with unilateral LRE and AE, 13 (52%) had either bilateral AE or AE contralateral to seizure onset., Conclusion: Results suggest that AE, as defined with MRI volumetry, may represent an associated feature of nonlesional localization related epilepsy with limited seizure onset localization value., (Copyright © 2017 Elsevier B.V. All rights reserved.)
- Published
- 2017
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38. Parahippocampal and Entorhinal Resection Extent Predicts Verbal Memory Decline in an Epilepsy Surgery Cohort.
- Author
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Liu A, Thesen T, Barr W, Morrison C, Dugan P, Wang X, Meager M, Doyle W, Kuzniecky R, Devinsky O, and Blackmon K
- Subjects
- Adolescent, Adult, Entorhinal Cortex pathology, Entorhinal Cortex surgery, Female, Follow-Up Studies, Humans, Magnetic Resonance Imaging, Male, Memory Disorders pathology, Middle Aged, Parahippocampal Gyrus pathology, Parahippocampal Gyrus surgery, Retrospective Studies, Young Adult, Anterior Temporal Lobectomy adverse effects, Entorhinal Cortex physiopathology, Epilepsy, Temporal Lobe surgery, Memory Disorders physiopathology, Mental Recall physiology, Parahippocampal Gyrus physiopathology, Verbal Learning physiology
- Abstract
The differential contribution of medial-temporal lobe regions to verbal declarative memory is debated within the neuroscience, neuropsychology, and cognitive psychology communities. We evaluate whether the extent of surgical resection within medial-temporal regions predicts longitudinal verbal learning and memory outcomes. This single-center retrospective observational study involved patients with refractory temporal lobe epilepsy undergoing unilateral anterior temporal lobe resection from 2007 to 2015. Thirty-two participants with Engel Class 1 and 2 outcomes were included (14 left, 18 right) and followed for a mean of 2.3 years after surgery (±1.5 years). Participants had baseline and postsurgical neuropsychological testing and high-resolution T1-weighted MRI scans. Postsurgical lesions were manually traced and coregistered to presurgical scans to precisely quantify resection extent of medial-temporal regions. Verbal learning and memory change scores were regressed on hippocampal, entorhinal, and parahippocampal resection volume after accounting for baseline performance. Overall, there were no significant differences in learning and memory change between patients who received left and right anterior temporal lobe resection. After controlling for baseline performance, the extent of left parahippocampal resection accounted for 27% (p = .021) of the variance in verbal short delay free recall. The extent of left entorhinal resection accounted for 37% (p = .004) of the variance in verbal short delay free recall. Our findings highlight the critical role that the left parahippocampal and entorhinal regions play in recall for verbal material.
- Published
- 2017
- Full Text
- View/download PDF
39. Resting-state functional MRI distinguishes temporal lobe epilepsy subtypes.
- Author
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Reyes A, Thesen T, Wang X, Hahn D, Yoo D, Kuzniecky R, Devinsky O, and Blackmon K
- Subjects
- Adolescent, Adult, Aged, Amygdala diagnostic imaging, Case-Control Studies, Electroencephalography, Epilepsy, Temporal Lobe pathology, Female, Functional Laterality, Hippocampus diagnostic imaging, Humans, Male, Middle Aged, Retrospective Studies, Video Recording, Young Adult, Epilepsy, Temporal Lobe classification, Epilepsy, Temporal Lobe diagnostic imaging, Image Processing, Computer-Assisted, Magnetic Resonance Imaging methods, Rest
- Abstract
Objective: We assessed whether presurgical resting state functional magnetic resonance imaging (fMRI) provides information for distinguishing temporal lobe epilepsy (TLE) with mesial temporal sclerosis (TLE-MTS) from TLE without MTS (TLE-noMTS)., Methods: Thirty-four patients with TLE and 34 sex-/age-matched controls consented to a research imaging protocol. MTS status was confirmed by histologic evaluation of surgical tissue (TLE-MTS = 16; TLE-noMTS = 18). The fractional amplitude of low-frequency fluctuations (fALFFs) in the blood oxygen level-dependent (BOLD) resting-state fMRI signal, a marker of local metabolic demand at rest, was averaged at five regions of interest (ROIs; hippocampus, amygdala, frontal, occipital, and temporal lobe), along with corresponding volume and cortical thickness estimates. ROIs were labeled ipsilateral or contralateral according to seizure lateralization and compared across TLE-MTS, TLE-noMTS, and healthy controls (HCs). MTS status was regressed on ipsilateral hippocampal volume and fALFF to test for independent contributions., Results: The TLE-MTS group had reduced fALFF in the ipsilateral amygdala and hippocampus; whereas, the TLE-noMTS group had marginally reduced fALFF in the ipsilateral amygdala but not hippocampus. These results were consistently obtained with and without application of global signal regression (GSR). Ipsilateral hippocampal volume contributed to 37% of the variance in MTS status (p < 0.001) and fALFF contributed an additional 10% (p = 0.021). Two MTS cases were accurately classified with fALFF but not volume, and three were accurately classified with volume but not fALFF. At the lobar level, fALFF (with GSR) was reduced in the ipsilateral temporal and bilateral frontal lobes of patients with TLE-MTS and bilateral frontal lobes of patients with TLE-noMTS in the context of normal cortical thickness., Significance: This study indicates that resting-state fMRI provides complementary functional information for MTS classification. Findings validate fALFF as a measure of regional brain integrity in TLE and highlight the value of using multi-modal imaging to provide independent diagnostic information in presurgical epilepsy evaluations., (Wiley Periodicals, Inc. © 2016 International League Against Epilepsy.)
- Published
- 2016
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40. Prefrontal lobe structural integrity and trail making test, part B: converging findings from surface-based cortical thickness and voxel-based lesion symptom analyses.
- Author
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Miskin N, Thesen T, Barr WB, Butler T, Wang X, Dugan P, Kuzniecky R, Doyle W, Devinsky O, and Blackmon K
- Subjects
- Adult, Aged, Female, Humans, Magnetic Resonance Imaging, Male, Middle Aged, Organ Size, Tomography, X-Ray Computed, Trail Making Test, Young Adult, Brain Diseases diagnostic imaging, Brain Diseases psychology, Mental Processes, Prefrontal Cortex diagnostic imaging
- Abstract
Surface-based cortical thickness (CT) analyses are increasingly being used to investigate variations in brain morphology across the spectrum of brain health, from neurotypical to neuropathological. An outstanding question is whether individual differences in cortical morphology, such as regionally increased or decreased CT, are associated with domain-specific performance deficits in healthy adults. Since CT studies are correlational, they cannot establish causality between brain morphology and cognitive performance. A direct comparison with classic lesion methods is needed to determine whether the regional specificity of CT-cognition correlations is similar to that observed in patients with brain lesions. We address this question by comparing the neuroanatomical overlap of effects when 1) whole brain vertex-wise CT is tested as a correlate of performance variability on a commonly used neuropsychological test of executive function, Trailmaking Test Part B (TMT-B), in healthy adults and 2) voxel-based lesion-symptom mapping (VBLSM) is used to map lesion location to performance decrements on the same task in patients with frontal lobe lesions. We found that reduced performance on the TMT-B was associated with increased CT in bilateral prefrontal regions in healthy adults and that results spatially overlapped in the left dorsomedial prefrontal cortex with findings from the VBLSM analysis in patients with frontal brain lesions. Findings indicate that variations in the structural integrity of the left dorsomedial prefrontal lobe, ranging from individual CT differences in healthy adults to structural lesions in patients with neurological disorders, are associated with poor performance on the TMT-B. These converging results suggest that the left dorsomedial prefrontal region houses a critical region for the complex processing demands of TMT-B, which include visuomotor tracking, sequencing, and cognitive flexibility.
- Published
- 2016
- Full Text
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41. Treatment Resistant Epilepsy in Autism Spectrum Disorder: Increased Risk for Females.
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Blackmon K, Bluvstein J, MacAllister WS, Avallone J, Misajon J, Hedlund J, Goldberg R, Bojko A, Mitra N, Giridharan R, Sultan R, Keller S, and Devinsky O
- Subjects
- Adolescent, Adult, Child, Child, Preschool, Comorbidity, Female, Humans, Male, Prospective Studies, Risk, Sex Distribution, Young Adult, Autism Spectrum Disorder epidemiology, Epilepsy epidemiology
- Abstract
The male:female ratio in autism spectrum disorder (ASD) averages greater than 4:1 while the male:female ratio of ASD with epilepsy averages less than 3:1. This indicates an elevated risk of epilepsy in females with ASD; yet, it is unknown whether phenotypic features of epilepsy and ASD differ between males and females with this comorbidity. The goal of this study is to investigate sex differences in phenotypic features of epilepsy and ASD in a prospective sample of 130 children and young adults with an initial ASD diagnosis and subsequent epilepsy diagnosis. All participants were characterized by standardized diagnostic inventories, parent/caregiver completed questionnaires, and medical/academic record review. Diagnostic classifications of epilepsy, ASD, and intellectual disability were performed by board certified neurologists and a pediatric neuropsychologist. Results demonstrated a lower male:female ratio (1.8:1) in individuals with ASD and treatment-resistant epilepsy relative to those with ASD and treatment-responsive epilepsy (4.9:1), indicating a higher risk of treatment-resistant epilepsy in females. Mild neuroimaging abnormalities were more common in females than males and this was associated with increased risk of treatment-resistance. In contrast, ASD symptom severity was lower in females compared with males. Findings distinguish females with ASD and epilepsy as a distinct subgroup at higher risk for a more severe epilepsy phenotype in the context of a less severe ASD phenotype. Increased risk of anti-epileptic treatment resistance in females with ASD and epilepsy suggests that comprehensive genetic, imaging, and neurologic screening and enhanced treatment monitoring may be indicated for this subgroup. Autism Res 2016, 9: 311-320. © 2015 International Society for Autism Research, Wiley Periodicals, Inc., (© 2015 International Society for Autism Research, Wiley Periodicals, Inc.)
- Published
- 2016
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42. Periventricular white matter abnormalities and restricted repetitive behavior in autism spectrum disorder.
- Author
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Blackmon K, Ben-Avi E, Wang X, Pardoe HR, Di Martino A, Halgren E, Devinsky O, Thesen T, and Kuzniecky R
- Subjects
- Adolescent, Adult, Child, Female, Gray Matter pathology, Humans, Male, Neuropsychological Tests, Severity of Illness Index, Young Adult, Autism Spectrum Disorder pathology, Autism Spectrum Disorder psychology, Brain pathology, Cerebral Ventricles pathology, Magnetic Resonance Imaging methods, White Matter pathology
- Abstract
Malformations of cortical development are found at higher rates in autism spectrum disorder (ASD) than in healthy controls on postmortem neuropathological evaluation but are more variably observed on visual review of in-vivo MRI brain scans. This may be due to the visually elusive nature of many malformations on MRI. Here, we utilize a quantitative approach to determine whether a volumetric measure of heterotopic gray matter in the white matter is elevated in people with ASD, relative to typically developing controls (TDC). Data from a primary sample of 48 children/young adults with ASD and 48 age-, and gender-matched TDCs, selected from the Autism Brain Imaging Data Exchange (ABIDE) open-access database, were analyzed to compare groups on (1) blinded review of high-resolution T1-weighted research sequences; and (2) quantitative measurement of white matter hypointensity (WMH) volume calculated from the same T1-weighted scans. Groupwise WMH volume comparisons were repeated in an independent, multi-site sample (80 ASD/80 TDC), also selected from ABIDE. Visual review resulted in equivalent proportions of imaging abnormalities in the ASD and TDC group. However, quantitative analysis revealed elevated periventricular and deep subcortical WMH volumes in ASD. This finding was replicated in the independent, multi-site sample. Periventricular WMH volume was not associated with age but was associated with greater restricted repetitive behaviors on both parent-reported and clinician-rated assessment inventories. Thus, findings demonstrate that periventricular WMH volume is elevated in ASD and associated with a higher degree of repetitive behaviors and restricted interests. Although the etiology of focal WMH clusters is unknown, the absence of age effects suggests that they may reflect a static anomaly.
- Published
- 2015
- Full Text
- View/download PDF
43. Cortical Gray-White Matter Blurring and Cognitive Morbidity in Focal Cortical Dysplasia.
- Author
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Blackmon K, Kuzniecky R, Barr WB, Snuderl M, Doyle W, Devinsky O, and Thesen T
- Subjects
- Adolescent, Adult, Cerebral Cortex pathology, Female, Humans, Image Processing, Computer-Assisted, Magnetic Resonance Imaging, Male, Malformations of Cortical Development classification, Middle Aged, Retrospective Studies, Young Adult, Cognition Disorders etiology, Gray Matter pathology, Malformations of Cortical Development complications, Malformations of Cortical Development pathology, White Matter pathology
- Abstract
Focal cortical dysplasia (FCD) is a malformation of cortical development that is associated with high rates of cognitive morbidity. However, the degree to which specific irregularities of dysplastic tissue directly impact cognition remains unknown. This study investigates the relationship between blurring of the cortical gray and white matter boundary on magnetic resonance imaging (MRI) and global cognitive abilities in FCD. Gray-white blurring (GWB) is quantified by sampling the non-normalized T1 image intensity contrast above and below the gray and white matter interface along the cortical mantle. Spherical averaging is used to compare resulting GWB for patients with histopathologically verified FCD with matched controls. Whole-brain correlational analyses are used to investigate the relationship between blurring and general cognitive abilities, controlling for epilepsy duration. Results show that cognitive performance is reduced in patients with FCD relative to controls. Patients show increased GWB in bilateral temporal, parietal, and frontal regions. Furthermore, increased GWB in these regions is linearly related to decreased cognition and mediates group differences in cognitive performance. These findings demonstrate that GWB is a marker of reduced cognitive efficiency in FCD that can potentially be used to probe general and domain-specific cognitive functions in other neurological disorders., (© The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.)
- Published
- 2015
- Full Text
- View/download PDF
44. Structural MRI biomarkers of shared pathogenesis in autism spectrum disorder and epilepsy.
- Author
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Blackmon K
- Subjects
- Brain growth & development, Child, Humans, Autism Spectrum Disorder pathology, Biomarkers, Epilepsy pathology, Magnetic Resonance Imaging methods
- Abstract
Etiological factors that contribute to a high comorbidity between autism spectrum disorder (ASD) and epilepsy are the subject of much debate. Does epilepsy cause ASD or are there common underlying brain abnormalities that increase the risk of developing both disorders? This review summarizes evidence from quantitative MRI studies to suggest that abnormalities of brain structure are not necessarily the consequence of ASD and epilepsy but are antecedent to disease expression. Abnormal gray and white matter volumes are present prior to onset of ASD and evident at the time of onset in pediatric epilepsy. Aberrant brain growth trajectories are also common in both disorders, as evidenced by blunted gray matter maturation and white matter maturation. Although the etiological factors that explain these abnormalities are unclear, high heritability estimates for gray matter volume and white matter microstructure demonstrate that genetic factors assert a strong influence on brain structure. In addition, histopathological studies of ASD and epilepsy brain tissue reveal elevated rates of malformations of cortical development (MCDs), such as focal cortical dysplasia and heterotopias, which supports disruption of neuronal migration as a contributing factor. Although MCDs are not always visible on MRI with conventional radiological analysis, quantitative MRI detection methods show high sensitivity to subtle malformations in epilepsy and can be potentially applied to MCD detection in ASD. Such an approach is critical for establishing quantitative neuroanatomic endophenotypes that can be used in genetic research. In the context of emerging drug treatments for seizures and autism symptoms, such as rapamycin and rapalogs, in vivo neuroimaging markers of subtle structural brain abnormalities could improve sample stratification in human clinical trials and potentially extend the range of patients that might benefit from treatment. This article is part of a Special Issue entitled "Autism and Epilepsy"., (Copyright © 2015 Elsevier Inc. All rights reserved.)
- Published
- 2015
- Full Text
- View/download PDF
45. The corpus callosum and recovery of working memory after epilepsy surgery.
- Author
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Blackmon K, Pardoe HR, Barr WB, Ardekani BA, Doyle WK, Devinsky O, Kuzniecky R, and Thesen T
- Subjects
- Adolescent, Adult, Epilepsy metabolism, Female, Humans, Longitudinal Studies, Magnetic Resonance Imaging, Male, Middle Aged, Retrospective Studies, Wechsler Scales, Young Adult, Corpus Callosum anatomy & histology, Corpus Callosum physiology, Epilepsy diagnosis, Epilepsy surgery, Memory, Short-Term physiology, Recovery of Function physiology
- Abstract
Objective: For patients with medically intractable focal epilepsy, the benefit of epilepsy surgery must be weighed against the risk of cognitive decline. Clinical factors such as age and presurgical cognitive level partially predict cognitive outcome; yet, little is known about the role of cross-hemispheric white matter pathways in supporting postsurgical recovery of cognitive function. The purpose of this study is to determine whether the presurgical corpus callosum (CC) midsagittal area is associated with pre- to postsurgical change following epilepsy surgery., Methods: In this observational study, we retrospectively identified 24 adult patients from an epilepsy resection series who completed preoperative high-resolution T1 -weighted magnetic resonance imaging (MRI) scans, as well as pre- and postsurgical neuropsychological testing. The total area and seven subregional areas of the CC were measured on the midsagittal MRI slice using an automated method. Standardized indices of auditory-verbal working memory and delayed memory were used to probe cognitive change from pre- to postsurgery. CC total and subregional areas were regressed on memory-change scores, after controlling for overall brain volume, age, presurgical memory scores, and duration of epilepsy., Results: Patients had significantly reduced CC area relative to healthy controls. We found a positive relationship between CC area and change in working memory, but not delayed memory; specifically, the larger the CC, the greater the postsurgical improvement in working memory (β = 0.523; p = 0.009). Effects were strongest in posterior CC subregions. There was no relationship between CC area and presurgical memory scores., Significance: Findings indicate that larger CC area, measured presurgically, is related to improvement in working memory abilities following epilepsy surgery. This suggests that transcallosal pathways may play an important, yet little understood, role in postsurgical recovery of cognitive functions., (Wiley Periodicals, Inc. © 2015 International League Against Epilepsy.)
- Published
- 2015
- Full Text
- View/download PDF
46. Cortical thickness abnormalities associated with dyslexia, independent of remediation status.
- Author
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Ma Y, Koyama MS, Milham MP, Castellanos FX, Quinn BT, Pardoe H, Wang X, Kuzniecky R, Devinsky O, Thesen T, and Blackmon K
- Subjects
- Adolescent, Brain Mapping methods, Child, Female, Humans, Image Interpretation, Computer-Assisted methods, Magnetic Resonance Imaging, Male, Cerebral Cortex pathology, Dyslexia pathology
- Abstract
Abnormalities in cortical structure are commonly observed in children with dyslexia in key regions of the "reading network." Whether alteration in cortical features reflects pathology inherent to dyslexia or environmental influence (e.g., impoverished reading experience) remains unclear. To address this question, we compared MRI-derived metrics of cortical thickness (CT), surface area (SA), gray matter volume (GMV), and their lateralization across three different groups of children with a historical diagnosis of dyslexia, who varied in current reading level. We compared three dyslexia subgroups with: (1) persistent reading and spelling impairment; (2) remediated reading impairment (normal reading scores), and (3) remediated reading and spelling impairments (normal reading and spelling scores); and a control group of (4) typically developing children. All groups were matched for age, gender, handedness, and IQ. We hypothesized that the dyslexia group would show cortical abnormalities in regions of the reading network relative to controls, irrespective of remediation status. Such a finding would support that cortical abnormalities are inherent to dyslexia and are not a consequence of abnormal reading experience. Results revealed increased CT of the left fusiform gyrus in the dyslexia group relative to controls. Similarly, the dyslexia group showed CT increase of the right superior temporal gyrus, extending into the planum temporale, which resulted in a rightward CT asymmetry on lateralization indices. There were no group differences in SA, GMV, or their lateralization. These findings held true regardless of remediation status. Each reading level group showed the same "double hit" of atypically increased left fusiform CT and rightward superior temporal CT asymmetry. Thus, findings provide evidence that a developmental history of dyslexia is associated with CT abnormalities, independent of remediation status.
- Published
- 2014
- Full Text
- View/download PDF
47. Comments on Hughes JR. A review of recent reports on autism: 1000 studies published in 2007. Epilepsy & behavior 2008;13:425-437 and Hughes JR. Update on autism: a review of 1300 reports published in 2008. Epilepsy & behavior 2009;16:569-589.
- Author
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Besag FM and Blackmon K
- Subjects
- Female, Humans, Male, Autistic Disorder etiology, Autistic Disorder physiopathology, Autistic Disorder therapy, Publications statistics & numerical data
- Published
- 2014
- Full Text
- View/download PDF
48. Thalamic functional connectivity predicts seizure laterality in individual TLE patients: application of a biomarker development strategy.
- Author
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Barron DS, Fox PT, Pardoe H, Lancaster J, Price LR, Blackmon K, Berry K, Cavazos JE, Kuzniecky R, Devinsky O, and Thesen T
- Subjects
- Adolescent, Adult, Area Under Curve, Child, Child, Preschool, Female, Humans, Image Interpretation, Computer-Assisted methods, Infant, Magnetic Resonance Imaging, Male, ROC Curve, Young Adult, Brain Mapping methods, Epilepsy, Temporal Lobe physiopathology, Functional Laterality physiology, Neural Pathways physiopathology
- Abstract
Noninvasive markers of brain function could yield biomarkers in many neurological disorders. Disease models constrained by coordinate-based meta-analysis are likely to increase this yield. Here, we evaluate a thalamic model of temporal lobe epilepsy that we proposed in a coordinate-based meta-analysis and extended in a diffusion tractography study of an independent patient population. Specifically, we evaluated whether thalamic functional connectivity (resting-state fMRI-BOLD) with temporal lobe areas can predict seizure onset laterality, as established with intracranial EEG. Twenty-four lesional and non-lesional temporal lobe epilepsy patients were studied. No significant differences in functional connection strength in patient and control groups were observed with Mann-Whitney Tests (corrected for multiple comparisons). Notwithstanding the lack of group differences, individual patient difference scores (from control mean connection strength) successfully predicted seizure onset zone as shown in ROC curves: discriminant analysis (two-dimensional) predicted seizure onset zone with 85% sensitivity and 91% specificity; logistic regression (four-dimensional) achieved 86% sensitivity and 100% specificity. The strongest markers in both analyses were left thalamo-hippocampal and right thalamo-entorhinal cortex functional connection strength. Thus, this study shows that thalamic functional connections are sensitive and specific markers of seizure onset laterality in individual temporal lobe epilepsy patients. This study also advances an overall strategy for the programmatic development of neuroimaging biomarkers in clinical and genetic populations: a disease model informed by coordinate-based meta-analysis was used to anatomically constrain individual patient analyses.
- Published
- 2014
- Full Text
- View/download PDF
49. Mood, anxiety, and incomplete seizure control affect quality of life after epilepsy surgery.
- Author
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Hamid H, Blackmon K, Cong X, Dziura J, Atlas LY, Vickrey BG, Berg AT, Bazil CW, Langfitt JT, Walczak TS, Sperling MR, Shinnar S, and Devinsky O
- Subjects
- Adult, Anxiety etiology, Depression etiology, Epilepsy surgery, Female, Humans, Male, Middle Aged, Postoperative Period, Prospective Studies, Psychiatric Status Rating Scales, Seizures surgery, Treatment Outcome, Anxiety psychology, Depression psychology, Epilepsy psychology, Quality of Life psychology, Seizures psychology
- Abstract
Objective: We examined the complex relationship between depression, anxiety, and seizure control and quality of life (QOL) outcomes after epilepsy surgery., Methods: Seven epilepsy centers enrolled 373 patients and completed a comprehensive diagnostic workup and psychiatric and follow-up QOL evaluation. Subjects were evaluated before surgery and then at 3, 6, 12, 24, 48, and 60 months after surgery. Standardized assessments included the Quality of Life in Epilepsy Inventory-89, Beck Depression Inventory (BDI), and Beck Anxiety Inventory (BAI). A mixed-model repeated-measures analysis was used to analyze associations of depression, anxiety, seizure outcome, and seizure history with overall QOL score and QOL subscores (cognitive distress, physical health, mental health, epilepsy-targeted) prospectively., Results: The groups with excellent and good seizure control showed a significant positive effect on the overall QOL compared to the groups with fair and poor seizure control. The BDI and BAI scores were both highly and negatively associated with overall QOL; increases in BDI and BAI scores were associated with decreased overall QOL score., Conclusions: Depression and anxiety are strongly and independently associated with worse QOL after epilepsy surgery. Interestingly, even partial seizure control, controlling for depression and anxiety levels, improved QOL. Management of mood and anxiety is a critical component to postsurgical care.
- Published
- 2014
- Full Text
- View/download PDF
50. Cortical thickness abnormalities associated with depressive symptoms in temporal lobe epilepsy.
- Author
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Butler T, Blackmon K, McDonald CR, Carlson C, Barr WB, Devinsky O, Kuzniecky R, DuBois J, French J, Halgren E, and Thesen T
- Subjects
- Adult, Electroencephalography, Female, Humans, Image Processing, Computer-Assisted, Magnetic Resonance Imaging, Male, Psychiatric Status Rating Scales, Cerebral Cortex pathology, Depression etiology, Epilepsy, Temporal Lobe complications, Epilepsy, Temporal Lobe pathology
- Abstract
Depression in patients with temporal lobe epilepsy (TLE) is highly prevalent and carries significant morbidity and mortality. Its neural basis is poorly understood. We used quantitative, surface-based MRI analysis to correlate brain morphometry with severity of depressive symptoms in 38 patients with TLE and 45 controls. Increasing severity of depressive symptoms was associated with orbitofrontal cortex (OFC) thinning in controls, but with OFC thickening in TLE patients. These results demonstrate distinct neuroanatomical substrates for depression with and without TLE, and suggest a unique role for OFC, a limbic region for emotional processing strongly interconnected with medial temporal structures, in TLE-related depressive symptoms., (Copyright © 2011 Elsevier Inc. All rights reserved.)
- Published
- 2012
- Full Text
- View/download PDF
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