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Blackmon, Karen

https://orcid.org/0000-0002-2665-7807

Mayo Clinic

Mayo Clinic

Citations 10

Towards precision well-being in medical education
Marrero, Wesley J. , Konopasky, Abigail J., Duncan, Matthew , Blackmon, Karen , Blackmon, Karen E, Thesen, Thomas

Medical Teacher | May 29, 2024 | Volume: 47 | Issue: 4 | Pages: 630-634

10.1080/0142159x.2024.2357279 Get It

Case study of invalid to valid shift in cognitive performance following successful treatment of psychogenic nonepileptic seizure events
Drane, Daniel L. , Price, Michele E., Rush, Beth K., Blackmon, Karen , Okada, Noah , Shade, Taylor, Valentin, Edward, Vinson, Joseph, Rosen, Phyllis, Hewitt, Kelsey C. , Valentin, Edward, Loring, David W.

Journal of Clinical and Experimental Neuropsychology | March 27, 2024 | Volume: 45 | Issue: 10 | Pages: 1024-1038

10.1080/13803395.2024.2335600 Get It

Review of epilepsy care in the Democratic Republic of the Congo
Tshimbombu, Tshibambe Nathanael , Kabwa, Luabeya Mesu’a, Blackmon, Karen , Kashama, Jean Marie, Jobst, Barbara C. , Fontaine, Dominique , Olarinde, Immanuel, E‐Andjafono, Daniel Okitundu‐Luwa, Tshimbombu, Tshibambe N , Jobst, Barbara , Shin, Minkyung, Thesen, Thomas , Olarinde, Immanuel O. , E‐Andjafono, Daniel Okitundu Luwa

Epilepsia Open | January 20, 2024 | Volume: 9 | Issue: 2 | Pages: 467-474

10.1002/epi4.12904 Get It

AbstractEpilepsy 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 summaryThere 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.
Incidence and risk factors associated with seizures in cerebral amyloid angiopathy
Freund, Brin , Sánchez, Sofía S. , Blackmon, Karen , Day, Gregory S. , Khan, Aafreen , Feyissa, Anteneh M. , Middlebrooks, Erik H. , Tatum, William O. , Freund, Brin E , Feyissa, A M , Tatum, William O , Middlebrooks, Erik H , Day, Gregory S , Sanchez-Boluarte, Sofia S , Lin, Michelle

European Journal of Neurology | May 31, 2023 | Volume: 30 | Issue: 12 | Pages: 3682-3691

10.1111/ene.15903 Get It

AbstractBackground and purposeCerebral 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.MethodsWe 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.ResultsTwo 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.ConclusionsSeizures 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.
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
Fernandes, Michelle , Evans, Roberta , Cheng, Mira , Landon, Barbara, Noël, Trevor, Macpherson, C. N. L. , Cudjoe, Nikita, Burgen, Kemi S. , Waechter, Randall , LaBeaud, A. Desirée , Blackmon, Karen

Viruses | May 31, 2023 | Volume: 15 | Issue: 6 | Pages: 1290

10.3390/v15061290 Get It

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.
Neurophenotypes of COVID-19: risk factors and recovery outcomes
Prabhakaran, Divya , Day, Gregory S. , Munipalli, Bala, Rush, Beth K., Pudalov, Lauren, Niazi, Shehzad K. , Brennan, Emily, Durvasula, Ravi, Athreya, Arjun, Blackmon, Karen , Powers, Harry R , Blackmon, Karen , Day, Gregory S , Powers, Harry R.

No container title available | February 20, 2023 | Volume: No volume available | Issue: No issue available | Pages: No page available

10.21203/rs.3.rs-2363210/v2 Get It

Abstract Coronavirus disease 2019 (COVID-19) infection is associated with risk of persistent neurocognitive and neuropsychiatric complications, termed “long COVID”. 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 long COVID, with different etiological pathways and recovery outcomes. This information may inform phenotype-specific approaches to treatment.
Examining the role of the uncinate fasciculus in proper noun naming: awake brain tumor resections and stereo EEG targeted electrical stimulation multiple case study
Koay, Jun Min , Blackmon, Karen , Middlebrooks, Erik H. , Quiñones‐Hinojosa, Alfredo , Chaichana, Kaisorn L. , Grewal, Sanjeet S. , Sabsevitz, David S. , Blackmon, Karen E, Feyissa, Anteneh M. , Grewal, Sanjeet , Middlebrooks, Erik H

Neurocase | December 22, 2022 | Volume: 28 | Issue: 5 | Pages: 439-447

10.1080/13554794.2022.2160261 Get It

Neurophenotypes of COVID-19: risk factors and recovery trajectories
Prabhakaran, Divya , Day, Gregory S. , Munipalli, Bala, Rush, Beth K., Pudalov, Lauren, Niazi, Shehzad K. , Brennan, Emily, Durvasula, Ravi, Athreya, Arjun, Blackmon, Karen , Day, Gregory S , Powers, Harry

No container title available | December 21, 2022 | Volume: No volume available | Issue: No issue available | Pages: No page available

10.21203/rs.3.rs-2363210/v1 Get It

Abstract Coronavirus disease 2019 (COVID-19) infection is associated with risk of persistent neurocognitive and neuropsychiatric complications, termed “long COVID”. 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 trajectories. We examined post-acute outcomes 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 neuropsychological measures as input features. This resulted in three distinct post-COVID clusters. In the largest cluster (69%), cognitive functions were within normal limits (“normal cognition” neurophenotype), although mild subjective attention and memory complaints were reported. 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 processed 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 trajectories at 6-month follow-up differed across neurophenotypes, with the normal cognition group showing stability, the dysexecutive group showing improvement, and the memory-speed impaired group showing persistent processing speed deficits and fatigue, as well as worse functional outcomes. These results indicate that there are multiple post-acute neurophenotypes of long COVID, with different etiological pathways and recovery trajectories. This information may inform phenotype-specific approaches to treatment.
Neurocognitive Screening in Patients Following SARS-CoV-2 Infection: Tools for Triage
Blackmon, Karen , Day, Gregory S. , Bosch, Wendelyn , Prabhakaran, Divya , Woolston, Dixie J., Pedraza, Otto , Powers, Harry Ross, Woolston, Dixie, Day, Gregory S , Powers, Harry Ross

No container title available | February 7, 2022 | Volume: No volume available | Issue: No issue available | Pages: No page available

10.21203/rs.3.rs-1127420/v1 Get It

Abstract Background and purpose 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 Participants were prospectively recruited from a hospital-wide registry. All patients tested positive for SARS-CoV-2 infection using a real-time reverse transcriptase polymerasechain-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 SARSCoV-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.
A systems‐level analysis highlights microglial activation as a modifying factor in common epilepsies
Altmann, André , Ryten, Mina , Nunzio, Martina Di , Ravizza, Teresa , Reynolds, Regina H. , Somani, Alyma, Bacigaluppi, Marco , Iori, Valentina , Sapia, Rossella Di , Cerovic, Milica , Palma, Eleonora , Ruffolo, Gabriele , Botía, Juan A. , Absil, Julie , Alhusaini, Saud , Alvim, Marina K. M. , Auvinen, Pia, Bartolini, Emanuele , Bender, Benjamin , Bergo, Felipe P. G. , Bernardes, Tauana, Bernasconi, Andrea , Bernasconi, Neda , Bernhardt, Boris C. , Blackmon, Karen , Braga, Bárbara , Caligiuri, Maria Eugenia , Calvo, Anna, Carr, Sarah J. A. , Cavalleri, Gianpiero L. , Chen, Jian , Chen, Shuai , Cherubini, Andrea , Concha, Luis , David, Philippe, Delanty, Norman, Depondt, Chantal, Doherty, Colin P. , Domín, Martin , Foley, Sonya , França, Wendy, Gambardella, Antonio , Guerrini, Renzo , Hamandi, Khalid , Hibar, Derrek P., Isaev, Dmitry , Jahanshad, Neda , Kälviäinen, Reetta , Keller, Simon S. , Kotikalapudi, Raviteja , Kwan, Patrick , Langner, Sönke , Lenge, Matteo , Martin, Pascal , Meletti, Stefano , Morita‐Sherman, Marcia , Pariente, José C. , Richardson, Mark P. , Rummel, Christian , Saavalainen, Taavi, Semmelroch, Mira , Striano, Pasquale, Thesen, Thomas , Thomas, Rhys H. , Tondelli, Manuela , Vaudano, Anna Elisabetta , Vivash, Lucy , Podewils, Felix von , Wagner, Jan , Weber, Bernd , Wiest, Roland , Yasuda, Clarissa Lin , Zhang, Junsong , Group, ENIGMA‐Epilepsy Working, Leu, Costin , Avberšek, Andreja , Whelan, Christopher D. , Thompson, Paul M. , McDonald, Carrie R. , Di Sapia, Rossella , Bender, Benjamin , Severino, Mariasavina , Thom, Maria , Yasuda, Clarissa L , Doherty, Colin P , Cavalleri, Gianpiero L , Weber, Bernd , Thompson, Paul M , Richardson, Mark P , Guerrini, Renzo , Thomas, Rhys H , Leu, Costin , Tolomeo, Daniele , Micotti, Edoardo , Bargalló, Núria , Carlson, Chad , Cendes, Fernando , Devinsky, Orrin , Focke, Niels K. , Jackson, Graeme D. , Kochunov, Peter V , Kowalczyk, Magdalena A. , Kuzniecky, Ruben , Labate, Angelo , Liu, Min , Mascalchi, Mario , Morita, Márcia Elisabete , O’Brien, Terence J. , Rodríguez‐Cruces, Raúl , Tortora, Domenico , Zhang, Guohao , Group, ENIGMA‐Epilepsy Working, Vezzani, Annamaria , Sisodiya, Sanjay

Neuropathology and Applied Neurobiology | August 13, 2021 | Volume: 48 | Issue: 1 | Pages: No page available

10.1111/nan.12758 Get It

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.