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INTRODUCTION: The prognostic significance of tailored resection guided with intraoperative electrocorticography (iECoG) in frontal lobe epilepsy surgery has not been fully elucidated. OBJECTIVES: To analyze influence of preresection and postresection iECoG patterns on long-term seizure control of adults with frontal lobe epilepsy undergoing epilepsy surgery. METHODS: We retrospectively analyzed 27 patients undergoing epilepsy surgery from two centers with preresection and postresection iECoG and reported clinical variables, preresection and postresection iECoG patterns, and outcome using the Engel Outcome Scale. Descriptive statistics, Kaplan-Meier, the logistic regression model, and analysis of variance tests were used. RESULTS: Fifteen males (55.6%), a mean and mode follow-up after surgery of 43 (range 2-117) and 19 months, respectively. At 6 months, seizure frequency outcome according to Engel Scale was I 74.1% (20/27), II 7.4% (2/27), III 3.7% (1/27), and IV 14.8% (4/27). We found that 51.9% (14/27) and 40.8% (11/27) of patients without residual epileptiform discharges in postresective iECoG become seizure-free at 6 and 12 months of follow-up, respectively, compared with other postresective iECoG patterns. CONCLUSIONS: Disregarding the presence of lack of residual epileptiform discharges (interictal epileptiform discharges) after resection, Engel I outcome was seen between 74.1% and 63% at 6- and 12-month postresection follow-up, suggesting the outcome might be in relation with other factors.
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Objective: Characterize the neurophysiological effects of mild hypothermia on stroke and spreading depolarizations (SDs) in gyrencephalic brains. Methods: Left middle cerebral arteries (MCAs) of six hypothermic and six normothermic pigs were permanently occluded (MCAo). Hypothermia began 1 h after MCAo and continued throughout the experiment. ECoG signals from both frontoparietal cortices were recorded. Five-minute ECoG epochs were collected 5 min before, at 5 min, 4, 8, 12, and 16 h after MCAo, and before, during, and after SDs. Power spectra were decomposed into fast (alpha, beta, and gamma) and slow (delta and theta) frequency bands. Results: In the vascular insulted hemisphere under normothermia, electrodes near the ischemic core exhibited power decay across all frequency bands at 5 min and the 4th hour after MCAo. The same pattern was registered in the two furthest electrodes at the 12th and 16th hour. When mild hypothermia was applied in the vascular insulted hemispheres, the power decay was generalized and seen even in electrodes with uncompromised blood flow. During SD analysis, hypothermia maintained increased delta and beta power during the three phases of SDs in the furthest electrode from the ischemic core, followed by the second furthest and third electrode in the beta band during preSD and postSD segments. However, in hypothermic conditions, the third electrode showed lower delta, theta, and alpha power. Conclusion: Mild hypothermia attenuates all frequency bands in the vascularly compromised hemisphere, irrespective of the cortical location. During SD formation, it preserves power spectra more significantly in electrodes further from the ischemic core.
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PURPOSE: There is a lack of clinical and epidemiological knowledge about nonconvulsive status epilepticus (NCSE) in developing countries including Mexico, which has the highest prevalence of epilepsy in the Americas. Our aim was to describe the clinical findings, EEG features, and outcomes of NCSE in a tertiary center in Mexico. METHODS: We conducted a retrospective case series study (2010-2020) including patients (≥15 years old) with NCSE according to the modified Salzburg NCSE criteria 2015 with at least 6 months of follow-up. We extracted the clinical data (age, sex, history of epilepsy, antiseizure medications, clinical manifestations, triggers, and etiology), EEG patterns of NCSE, and outcome. Descriptive statistics and multinomial logistic regression were used. RESULTS: One hundred thirty-four patients were analyzed; 74 (54.8%) women, the total mean age was 39.5 (15-85) years, and 71% had a history of epilepsy. Altered state of consciousness was found in 82% (including 27.7% in coma). A generalized NCSE pattern was the most common (32.1%). The NCSE etiology was mainly idiopathic (56%), and previous uncontrolled epilepsy was the trigger in 48% of patients. The clinical outcome was remission with clinical improvement in 54.5%. Multinomial logistic regression showed that the patient's age (P = 0.04), absence of comorbidities (P = 0.04), history of perinatal hypoxia (P = 0.04), absence of clinical manifestations (P = 0.01), and coma (P = 0.03) were negatively correlated with the outcome and only the absence of generalized slowing in the EEG (P = 0.001) had a significant positive effect on the prognosis. CONCLUSIONS: Age, history of perinatal hypoxia, coma, and focal ictal EEG pattern influence negatively the prognosis of NCSE.
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Epilepsia , Estado Epiléptico , Gravidez , Humanos , Feminino , Adulto , Adolescente , Masculino , México/epidemiologia , Coma , Países em Desenvolvimento , Estudos Retrospectivos , Estado Epiléptico/diagnóstico , Estado Epiléptico/epidemiologia , Estado Epiléptico/terapia , Prognóstico , Hipóxia , EletroencefalografiaRESUMO
The burden of epilepsy in the Latin America and the Caribbean (LAC) region causes a profound regional impact on the health care system and significantly contributes to the global epilepsy burden. As in many other resource-limited settings worldwide, health care professionals and patients with epilepsy in LAC countries face profound challenges due to a combination of factors, including high disease prevalence, stigmatization of epilepsy, disparities in access to care, limited resources, substantial treatment gaps, insufficient training opportunities for health care providers, and a diverse patient population with varying needs. This article presents an overview of the epidemiology of epilepsy and discusses the principal obstacles to epilepsy care and key contributors to the epilepsy diagnosis and treatment gap in the LAC region. We conclude by highlighting various initiatives across different LAC countries to improve epilepsy care in marginalized communities, listing strategies to mitigate treatment gaps and facilitate better health care access for patients with epilepsy by enhancing the epilepsy workforce.
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Epilepsia , Acessibilidade aos Serviços de Saúde , Humanos , Região do Caribe/epidemiologia , América Latina/epidemiologia , PrevalênciaRESUMO
Cluster headache (CH) is one of the worst primary headaches that remain underdiagnosed and inappropriately treated. There are recent advances in the understanding of this disease and available treatments. This paper aims to review CH's recent clinical and pathophysiological findings, diagnosis, and treatment. We performed a narrative literature review on the socio-demographics, clinical presentations, pathophysiological findings, and diagnosis and treatment of CH. CH affects 0.1% of the population with an incidence of 2.07-9.8/100,00 person-years-habitants, a mean prevalence of 53/100,000 inhabitants (3-150/100,000 inhabitants). The male-to-female ratio remains inconclusive, as the ratio of 4.3:1 has recently been modified to 1.3-2.6, possibly due to previous misdiagnosis in women. Episodic presentation is the most frequent (80%). It is a polygenetic and multifactorial entity that involves dysfunction of the trigeminovascular system, the trigeminal autonomic reflex, and the hypothalamic networks. An MRI of the brain is mandatory to exclude secondary etiologies. There are effective and safe pharmacological treatments oxygen, sphenopalatine, and great occipital nerve block, with the heterogeneity of clinical trial designs for patients with CH divided into acute, transitional, or bridge treatment (prednisone) and preventive interventions. In conclusion, CH remains underdiagnosed, mainly due to a lack of awareness within the medical community, frequently causing a long delay in reaching a final diagnosis. Recent advances in understanding the principal risk factors and underlying pathophysiology exist. There are new therapeutic possibilities that are effective for CH. Indeed, a better understanding of this challenging pathology will continue to be a subject of research, study, and discoveries in its diagnostic and therapeutic approach.
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AIMS: To evaluate the knowledge, attitudes, and practical skills of students submitted to a 6-week intensive training in epilepsy compared to students without any training but mandatory neurology classes. METHODS: It is a case-control study. After completing a 6-week intensive Academic, Clinical, and Research Program in epilepsy, TUMSs answered a validated Knowledge Attitudes and Practices (KAP) questionnaire. The control group, composed of undergraduate students who shared the same age, academic year, and compulsory hours for learning about epilepsy as TUMSs, was also assessed through the KAP instrument. Answers from both groups were submitted to Fisher exact and the χ2 test to observe differences among groups. Descriptive statistics were also performed. RESULTS: TUMSs displayed better results in theoretical knowledge such as the definition and causes of epilepsy, and the application of paraclinical studies essential for diagnosing epilepsy. From their perspective, people with epilepsy encounter restricted opportunities for preserving their social life and employment and they are more prone to workplace accidents. They are convinced that facing epilepsy presents a notable risk due to the difficulties linked with diagnosis, considering epilepsy a challenging disease for general practitioners to identify and follow up. Likewise, they exhibited improvement in treatment adjustment and treatment monitoring of patients with epilepsy, mainly in pregnancy cases. Finally, they had greater knowledge about what to do when they witness a person experiencing a seizure. CONCLUSION: Our study showed that a 6-week intensive education program in epilepsy increased the knowledge and practical skills and changed the attitude toward patients with epilepsy of undergraduate students.
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Epilepsia , Estudantes de Medicina , Humanos , Estudos de Casos e Controles , Epilepsia/terapia , Convulsões , Escolaridade , Inquéritos e Questionários , Conhecimentos, Atitudes e Prática em SaúdeRESUMO
Cluster headache (CH) is the most common and devastating autonomic headache with multiple and recent advances in treatment. However, it usually goes unrecognized and is found to have a delayed and inappropriate treatment. This paper aims to review the current therapeutic options for patients with CH. We conducted a narrative literature review on the treatments available for this condition using the American Academy of Neurology (AAN) classification of therapeutic evidence. We found effective and safe pharmacological and non-pharmacological therapies with heterogeneity of clinical trial designs for patients with CH, and they are divided into three phases, namely, transitional, acute, and preventive interventions. Prednisone (A) is the most studied treatment in the transitional phase; acute attacks are treated using triptans (A), oxygen (A), and non-invasive transcutaneous vagal nerve stimulation (A). Verapamil (A) and monoclonal antibodies (possible A) are considered the first options in preventive treatments, followed by multiple pharmacological and non-pharmacological options in prophylactic treatments. In conclusion, numerous effective and safe treatments are available in treating patients with episodic, chronic, and pharmacoresistant CH according to the clinical profile of each patient.
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Introduction. Monogenic mutations as the cause of recurrent ischemic cerebral small-vessel disease with leukodystrophy are rare. COL4A1 gene mutations are a relatively new etiology of cerebrovascular lesions in young adults; however, any patient has been reported from Latin America. Case Presentation. We presented a Mexican young female with leukodystrophy and recurrent stroke secondary to COL4A1 monogenic mutation. Discussion/Conclusion. COL4A1 monogenic mutations are associated with cerebral small-vessel disease and other systemic manifestations. To date, there is little evidence to justify the treatment and prevention of recurrent strokes in patients with this mutation.
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PURPOSE: We conducted an observational study to investigate the opinions of neurologists and psychiatrists all around the world who are taking care of patients with seizures [epilepsy and functional seizures (FS)]. METHODS: Practicing neurologists and psychiatrists from around the world were invited to participate in an online survey. On 29th September 2022, an e-mail including a questionnaire was sent to the members of the International Research in Epilepsy (IR-Epil) Consortium. The study was closed on 1st March 2023. The survey, conducted in English, included questions about physicians' opinions about FS and anonymously collected data. RESULTS: In total, 1003 physicians from different regions of the world participated in the study. Both neurologists and psychiatrists identified "seizures" as their preferred term. Overall, the most preferred modifiers for "seizures" were "psychogenic" followed by "functional" by both groups. Most participants (57.9%) considered FS more difficult to treat compared to epilepsy. Both psychological and biological problems were considered as the underlying cause of FS by 61% of the respondents. Psychotherapy was considered the first treatment option for patients with FS (79.9%). CONCLUSION: Our study represents the first large-scale attempt of investigating physicians attitudes and opinions about a condition that is both frequent and clinically important. It shows that there is a broad spectrum of terms used by physicians to refer to FS. It also suggests that the biopsychosocial model has gained its status as a widely used framework to interpret and inform clinical practice on the management of patients.
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Epilepsia , Psiquiatria , Humanos , Neurologistas/psicologia , Inquéritos e Questionários , Epilepsia/terapia , Epilepsia/etiologia , Atitude , Eletroencefalografia/efeitos adversosRESUMO
PURPOSE: Pediatric intraoperative neurophysiological monitoring (IONM) has been shown to be effective in preventing and reversing postoperative neurological deficits in developed countries. There are currently no published studies from developing countries that describe neurophysiological findings and postoperative outcomes. Our study aims to address these gaps in children undergoing neurosurgical procedures in a single center. METHODS: We conducted a retrospective study of case series of children who underwent IONM (2014-2020) in the State of Mexico, Mexico. Sociodemographic characteristics, IONM modalities, changes during procedures, and short-term and long-term postoperative results were recorded. Descriptive statistics were used. RESULTS: We included 35 patients (≤18 years of age), 57% (20/35) boys. A relative increase of up to 5 times in the use of IONM is observed from 2014 (5.7%) to 2020 (25.7%) in our center. The most frequent preoperative pathologies were located at the infratentorial cranium (40%), followed by the spine and spinal cord (37.1%). The IONM modalities were as follows: free-running EMG 94.3%, transcranial electrical stimulation motor-evoked potentials 91.4%, somatosensory-evoked potentials 85.7%, triggered EMG 28.6%, EEG 25.7%, and visual-evoked potentials 5.7%. Only in 8.3%, we did not obtain sufficient evoked potential baseline signals. At 24 hours postoperatively true negatives were 100%. Long-term follow-up was completed in 22/35 (63%) at 3 months, 12/35 (34.2%) at 6 months, and 5/35 (14.3%) at 12 months with progressive motor and sensory improvement. CONCLUSIONS: Pediatric multimodal IONM in neurosurgeries from a single center in a developing country is mainly used in pathologies of the posterior fossa, spine, and spinal cord, with true negatives in 100% of those monitored, preventing and avoiding postoperative sequelae.
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BACKGROUND: Epilepsy is the most common major neurological disorder that affects people of all ages. The prevalence varies from one country to another and even between different areas, due to a lack of access to medical care for reasons related to limited resources. OBJECTIVE: Epilepsy is a worldwide public health problem that affects more deeply populations living in developing countries such as Mexico, where more aggressive health policies based on epidemiological data are needed; however, this information is scarce and the evolution of this data over time remains unclear. The aim of the present study is to provide an overview of the epidemiology of epilepsy in Mexico from 1970 to 2020. METHODS: We searched descriptive epidemiological studies on epilepsy in rural and urban regions of Mexico from 1970 to 2020. Available data on the sociodemographic characteristics, prevalence, and incidence data were extracted. Finally, the abstract, full-text review, and data abstraction were conducted in duplicate and reported using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Descriptive statistics was also used. RESULTS: Overall, 11 underrepresented and heterogeneous epidemiological studies were included. In total, the prevalence of epilepsy in Mexico is 3.9 to 41:1,000 inhabitants; 3.9 to 41 per 1,000 persons in rural regions, and 3.49 to 44.3 per 1,000 persons in urban regions. None of these studies addressed the incidence of epilepsy. The prevalence of epilepsy in Mexico has remained unchanged during the last 5 decades. CONCLUSIONS: Our results confirm a high prevalence of epilepsy in both urban and rural settings in Mexico that remain unchanged during the last 5 decades. All studies included in the present review showed multiple methodological limitations. New and robust epidemiological studies are needed to delineate the epidemiological profile of epilepsy in Mexico.
ANTECEDENTES: La epilepsia es el trastorno neurológico más común que afecta a individuos de todas las edades. La prevalencia varía entre paises e incluso entre diferentes áreas del mismo pais debido a la falta de acceso a la atención médica. OBJECTIVO: La epilpesía es un problema de salud pública mundial que afecta de manera más importante a los países en desarrollo como México, donde hacen falta políticas en salud y datos epidemiológicos, para conocer el impacto real de esta enfermedad. El objetivo de este estudio es brindar una visión general de la epidemiología de la epilepsia en México (1970-2020). MéTODOS: Se realizo unas búsquedas bibliografica de estudios epidemiológicos descriptivos sobre epilepsia en regiones rurales y urbanas de México desde 1970 a 2020. Se extrajeron los datos disponibles sobre las características sociodemográficas, prevalencia e incidencia. Finalmente, el resumen, la revisión completa del texto y la extracción de datos se realizaron por duplicado y se informaron utilizando PRISMA. Se utilizo estadística descriptiva. RESULTADOS: Se incluyeron 11 estudios epidemiológicos heterogeéneos. En total la prevalencia de epilepsia en México es 3.9-41: 1000 habitantes; 3,9 a 41 por 1000 personas en las regiones rurales y 3,49 a 44,3 por 1000 personas en las regiones urbanas. Ninguno de estos estudios abordó la incidencia de epilepsia. La prevalencia de la epilepsia en México se ha mantenido sin cambios durante las últimas cinco décadas. CONCLUSIONES: Nuestros resultados confirman una alta prevalencia de epilepsia en las areas urbanas y rurales de México que se mantiene sin cambios durante las últimas cinco décadas. Todos los estudios incluidos en esta revisión mostraron múltiples limitaciones metodológicas. Se necesitan estudios epidemiológicos nuevos y sólidos para delinear el perfil epidemiológico de la epilepsia en México.
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Epilepsia , Humanos , México/epidemiologia , Epilepsia/epidemiologia , Saúde Pública , Prevalência , IncidênciaRESUMO
Electroencephalogram (EEG) interpretation plays a critical role in the clinical assessment of neurological conditions, most notably epilepsy. However, EEG recordings are typically analyzed manually by highly specialized and heavily trained personnel. Moreover, the low rate of capturing abnormal events during the procedure makes interpretation time-consuming, resource-hungry, and overall an expensive process. Automatic detection offers the potential to improve the quality of patient care by shortening the time to diagnosis, managing big data and optimizing the allocation of human resources towards precision medicine. Here, we present MindReader, a novel unsupervised machine-learning method comprised of the interplay between an autoencoder network, a hidden Markov model (HMM), and a generative component: after dividing the signal into overlapping frames and performing a fast Fourier transform, MindReader trains an autoencoder neural network for dimensionality reduction and compact representation of different frequency patterns for each frame. Next, we processed the temporal patterns using a HMM, while a third and generative component hypothesized and characterized the different phases that were then fed back to the HMM. MindReader then automatically generates labels that the physician can interpret as pathological and non-pathological phases, thus effectively reducing the search space for trained personnel. We evaluated MindReader's predictive performance on 686 recordings, encompassing more than 980 h from the publicly available Physionet database. Compared to manual annotations, MindReader identified 197 of 198 epileptic events (99.45%), and is, as such, a highly sensitive method, which is a prerequisite for clinical use.
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Eletroencefalografia , Epilepsia , Humanos , Eletroencefalografia/métodos , Epilepsia/diagnóstico , Redes Neurais de Computação , Análise de Fourier , Aprendizado de Máquina não SupervisionadoRESUMO
Mendelian Susceptibility to Mycobacterial Disease describes a spectrum of inherited defects, of which complete deficiency of the interleukin-12 receptor ß subunit 1 (IL-12Rß1) is the most common cause. This condition results in a predisposition to severe disease caused by mycobacteria. We report a case of disseminated multidrug-resistant tuberculosis with extensive central nervous system affection with SARS-CoV-2 co-infection, in a 4-year-old child with IL-12Rß1 complete deficiency.
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COVID-19 , Coinfecção , Tuberculose Resistente a Múltiplos Medicamentos , Pré-Escolar , Humanos , Predisposição Genética para Doença , SARS-CoV-2 , Receptores de Interleucina-12RESUMO
Abstract Background Epilepsy is the most common major neurological disorder that affects people of all ages. The prevalence varies from one country to another and even between different areas, due to a lack of access to medical care for reasons related to limited resources. Objective Epilepsy is a worldwide public health problem that affects more deeply populations living in developing countries such as Mexico, where more aggressive health policies based on epidemiological data are needed; however, this information is scarce and the evolution of this data over time remains unclear. The aim of the present study is to provide an overview of the epidemiology of epilepsy in Mexico from 1970 to 2020. Methods We searched descriptive epidemiological studies on epilepsy in rural and urban regions of Mexico from 1970 to 2020. Available data on the sociodemographic characteristics, prevalence, and incidence data were extracted. Finally, the abstract, full-text review, and data abstraction were conducted in duplicate and reported using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Descriptive statistics was also used. Results Overall, 11 underrepresented and heterogeneous epidemiological studies were included. In total, the prevalence of epilepsy in Mexico is 3.9 to 41:1,000 inhabitants; 3.9 to 41 per 1,000 persons in rural regions, and 3.49 to 44.3 per 1,000 persons in urban regions. None of these studies addressed the incidence of epilepsy. The prevalence of epilepsy in Mexico has remained unchanged during the last 5 decades. Conclusions Our results confirm a high prevalence of epilepsy in both urban and rural settings in Mexico that remain unchanged during the last 5 decades. All studies included in the present review showed multiple methodological limitations. New and robust epidemiological studies are needed to delineate the epidemiological profile of epilepsy in Mexico.
Resumen Antecedentes La epilepsia es el trastorno neurológico más común que afecta a individuos de todas las edades. La prevalencia varía entre paises e incluso entre diferentes áreas del mismo pais debido a la falta de acceso a la atención médica. Objectivo La epilpesía es un problema de salud pública mundial que afecta de manera más importante a los países en desarrollo como México, donde hacen falta políticas en salud y datos epidemiológicos, para conocer el impacto real de esta enfermedad. El objetivo de este estudio es brindar una visión general de la epidemiología de la epilepsia en México (1970-2020). Métodos Se realizo unas búsquedas bibliografica de estudios epidemiológicos descriptivos sobre epilepsia en regiones rurales y urbanas de México desde 1970 a 2020. Se extrajeron los datos disponibles sobre las características sociodemográficas, prevalencia e incidencia. Finalmente, el resumen, la revisión completa del texto y la extracción de datos se realizaron por duplicado y se informaron utilizando PRISMA. Se utilizo estadística descriptiva. Resultados Se incluyeron 11 estudios epidemiológicos heterogeéneos. En total la prevalencia de epilepsia en México es 3.9-41: 1000 habitantes; 3,9 a 41 por 1000 personas en las regiones rurales y 3,49 a 44,3 por 1000 personas en las regiones urbanas. Ninguno de estos estudios abordó la incidencia de epilepsia. La prevalencia de la epilepsia en México se ha mantenido sin cambios durante las últimas cinco décadas. Conclusiones Nuestros resultados confirman una alta prevalencia de epilepsia en las areas urbanas y rurales de México que se mantiene sin cambios durante las últimas cinco décadas. Todos los estudios incluidos en esta revisión mostraron múltiples limitaciones metodológicas. Se necesitan estudios epidemiológicos nuevos y sólidos para delinear el perfil epidemiológico de la epilepsia en México.
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PURPOSE: Animal and proof-of-principle human studies suggest that cathodal transcranial direct current stimulation may suppress seizures in drug-resistant focal epilepsy. The present study tests the safety, tolerability, and effect size of repeated daily cathodal transcranial direct current stimulation in epilepsy have not been established, limiting development of clinically meaningful interventions. METHODS: We conducted a 2-center, open-label study on 20 participants with medically refractory, focal epilepsy, aged 9 to 56 years (11 women and 9 children younger than18 years). Each participant underwent 10 sessions of 20 minutes of cathodal transcranial direct current stimulation over 2 weeks. Multielectrode montages were designed using a realistic head model-driven approach to conduct an inhibitory electric field to the target cortical seizure foci and surrounding cortex to suppress excitability and reduce seizure rates. Patients recorded daily seizures using a seizure diary 8 weeks prior, 2 weeks during, and 8 to 12 weeks after the stimulation period. RESULTS: The median seizure reduction was 44% relative to baseline and did not differ between adult and pediatric patients. Three patients experienced an increase in seizure frequency of >50% during the stimulation period; in one, a 36% increase in seizure frequency persisted through 12 weeks of follow-up. Otherwise, participants experienced only minor adverse events-the most common being scalp discomfort during transcranial direct current stimulation. CONCLUSIONS: This pilot study supports the safety and efficacy of multifocal, personalized, multichannel, cathodal transcranial direct current stimulation for adult and pediatric patients with medication-refractory focal epilepsy, although identifies a possibility of seizure exacerbation in some. The data also provide insight into the effect size to inform the design of a randomized, sham-stimulation controlled trial.
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Epilepsia Resistente a Medicamentos , Epilepsias Parciais , Estimulação Transcraniana por Corrente Contínua , Adulto , Criança , Feminino , Humanos , Epilepsia Resistente a Medicamentos/terapia , Epilepsias Parciais/terapia , Projetos Piloto , Convulsões , Estimulação Transcraniana por Corrente Contínua/efeitos adversosRESUMO
Aim: To describe the spatial and temporal electrocorticographic (ECoG) changes after middle cerebral artery occlusion (MCAo), including those caused by spreading depolarization (SD) in the pig brain. Methods: The left middle cerebral arteries (MCAs) were clipped in six pigs. The clipping procedure lasted between 8 and 12 min, achieving a permanent occlusion (MCAo). Five-contact ECoG stripes were placed bilaterally over the frontoparietal cortices corresponding to the irrigation territory of the MCA and anterior cerebral artery (ACA). ECoG recordings were performed around 24 h: 1 h before and 23 h after the MCAo, and SDs were quantified. Five-minute ECoG signal segments were sampled before, 5 min, and 4, 8, and 12 h after cerebral artery occlusion and before, during, and after the negative direct current shift of the SDs. The power spectrum of the signals was decomposed into delta, theta, alpha, beta, and gamma bands. Descriptive statistics, Wilcoxon matched-pairs signed-rank tests, and Friedman tests were performed. Results: Electrodes close to the MCAo showed instant decay in all frequency bands and SD onset during the first 5 h. Electrodes far from the MCAo exhibited immediate loss of fast frequencies and progressive decline of slow frequencies with an increased SD incidence between 6 and 14 h. After 8 h, the ACA electrode reported a secondary reduction of all frequency bands except gamma and high SD incidence within 12-17 h. During the SD, all electrodes showed a decline in all frequency bands. After SD passage, frequency band recovery was impaired only in MCA electrodes. Conclusion: ECoG can identify infarct progression and secondary brain injury. Severe disturbances in all the frequency bands are generated in the cortices where the SDs are passing by.
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The problem of whether we can execute free acts or not is central in philosophical thought, and it has been studied by numerous scholars throughout the centuries. Recently, neurosciences have entered this topic contributing new data and insights into the neuroanatomical basis of cognitive processes. With the advent of connectomics, a more refined landscape of brain connectivity can be analysed at an unprecedented level of detail. Here, we identify the connectivity network involved in the movement process from a connectomics point of view, from its motivation through its execution until the sense of agency develops. We constructed a "volitional network" using data derived from the Brainnetome Atlas database considering areas involved in volitional processes as known in the literature. We divided this process into eight processes and used Graph Theory to measure several structural properties of the network. Our results show that the volitional network is small-world and that it contains four communities. Nodes of the right hemisphere are contained in three of these communities whereas nodes of the left hemisphere only in two. Centrality measures indicate the nucleus accumbens is one of the most connected nodes in the network. Extensive connectivity is observed in all processes except in Decision (to move) and modulation of Agency, which might correlate with a mismatch mechanism for perception of Agency.