Electroencephalographic findings in asymptomatic relatives of patients with juvenile myoclonic epilepsy: relationship with the degree of kinship.

INTRODUCTION: A prevalence of 1 to 71% of electroencephalogram (EEG) abnormalities has been reported in asymptomatic relatives of patients with juvenile myoclonic epilepsy (JME). OBJECTIVE: To determine the frequency of EEG abnormalities in asymptomatic relatives of patients with JME according to the degree of kinship. METHODS: Prospective, analytical study. First-, second, and third-degree relatives of patients with JME who agreed to participate and signed informed consent were included. The analysis was descriptive, bivariate. RESULTS: 209 asymptomatic relatives were included, out of which 115 (55%) were females and 94 (45%) were males, with a mean age of 35.9 ± 16.9 (range between 6 and 73 years). Forty-four (21.1%) relatives had abnormal EEGs. First-degree relatives (12%) had abnormalities more frequently in comparison with second- and third-degree relatives (p = 0.007). CONCLUSIONS: EEG abnormalities were observed in one third of asymptomatic relatives. It is important to highlight that there were more alterations among first-degree relatives. In the future, these findings might enable for the risk of clinically developing the disease to be estimated and for genetic counseling to be provided.

INTRODUCCIÓN: Se ha reportado de 1 a 71 % de prevalencia de anormalidades en el electroencefalograma (EEG) de familiares asintomáticos de pacientes con epilepsia mioclónica juvenil (EMJ). OBJETIVO: Determinar la frecuencia de anormalidades en el EEG en familiares asintomáticos de pacientes con EMJ de acuerdo con el grado de parentesco. MÉTODOS: Estudio prospectivo y analítico. Se incluyeron familiares de primer, segundo y tercer grado de pacientes con EMJ, quienes aceptaron participar y firmaron el consentimiento informado. El análisis fue descriptivo bivariado. RESULTADOS: Se incluyeron 209 familiares asintomáticos, 115 (55 %) mujeres y 94 (45 %) hombres, con edad media de 35.9 ± 16.9 (rango entre seis y 73 años); 44 familiares (21.1 %) tuvieron EEG anormal. Los familiares de primer grado (12 %) cursaron con mayor frecuencia con anormalidades en comparación con los de segundo y tercer grado (p = 0.007). CONCLUSIONES: Se observaron anormalidades en el EEG de una tercera parte de los familiares asintomáticos. Es importante resaltar que existieron más alteraciones entre los familiares de primer grado. En un futuro, estos hallazgos permitirán estimar el riesgo de desarrollar la enfermedad clínicamente y brindar consejo genético.

HaNDL syndrome: Correlation between focal deficits topography and EEG or SPECT abnormalities in a series of 5 new cases. / Síndrome HaNDL: correlación entre la topografía del déficit neurológico y las alteraciones en electroencefalograma y SPECT en una serie de 5 nuevos casos.

INTRODUCTION: Transient headache and neurological deficits with cerebrospinal fluid lymphocytosis (HaNDL) is characterised by migraine-like headache episodes accompanied by neurological deficits consisting of motor, sensory, or aphasic symptoms. Electroencephalogram (EEG) and single photon emission computed tomography (SPECT) may show focal abnormalities that correspond to the neurological deficits. We aim to evaluate the correlation between focal deficit topography and EEG or SPECT abnormalities in 5 new cases. PATIENTS: We retrospectively reviewed patients attended in a tertiary hospital (January 2010-May 2014) and identified 5 patients (3 men, 2 women) with a mean age of 30.6 ± 7.7 (21-39) years. They presented 3.4 ± 2.6 episodes of headache (range, 2-8) of moderate to severe intensity and transient neurological deficits over a maximum of 5 weeks. Pleocytosis was detected in CSF in all cases (70 to 312 cells/mm3, 96.5-100% lymphocytes) with negative results from aetiological studies. RESULTS: At least one EEG was performed in 4 patients and SPECT in 3 patients. Patient 1: 8 episodes; 4 left hemisphere, 3 right hemisphere, and 1 brainstem; 2 EEGs showing left temporal and bilateral temporal slowing; normal SPECT. Patient 2: 2 episodes, left hemisphere and right hemisphere; SPECT showed decreased left temporal blood flow. Patient 3: 3 left hemisphere deficits; EEG with bilateral frontal and temporal slowing. Patient 4: 2 episodes with right parieto-occipital topography and right frontal slowing in EEG. Patient 5: 2 episodes, right hemisphere and left hemisphere, EEG with right temporal slowing; normal SPECT. CONCLUSION: The neurological deficits accompanying headache in HaNDL demonstrate marked clinical heterogeneity. SPECT abnormalities and most of all EEG abnormalities were not uncommon in our series and they did not always correlate to the topography of focal déficits.

[Safety study of long-term video-electroencephalogram monitoring]. / Estudio de seguridad en la monitorización por vídeo-electroencefalograma prolongado.

INTRODUCTION: The increased morbidity and mortality and poorer quality of life associated with drug-resistant epilepsy justify admitting patients to epilepsy monitoring units (EMU). These units employ methods that promote the occurrence of seizures, which involves a risk of secondary adverse events. The aim of our study is to characterise and quantify these adverse events in a Spanish EMU. MATERIALS AND METHODS: A descriptive, longitudinal and retrospective study of patients admitted consecutively to our EMU. Patients admitted due to status epilepticus, clusters of seizures, or as participants in a clinical trial were excluded. RESULTS: We included 175 patients, of whom 92.1% (161) did not suffer any adverse events. Status epilepticus was present in 3.4% (6); 1.7% (3) had traumatic injury, 1.7% (3) had interictal or postictal psychosis, and 1.1% (2) had cardiorespiratory impairment. There were no risk factors associated with these adverse events. CONCLUSIONS: The most frequently-identified adverse events were status epilepticus, traumatic injury, interictal or postictal psychosis, and cardiorespiratory disorders. The frequency of these adverse events was similar to that seen in international literature. The complications detected do not contraindicate VEEGM.

Assessment of the diagnostic utility of the electroencephalogram in pediatric emergencies.

INTRODUCTION: We analyze the diagnostic utility of urgent EEG (electroencephalogram) performed in children under 16 years of age in our center. MATERIAL AND METHODS: Descriptive, retrospective, observational study of consecutive patients from 0 to 16 years of age, who underwent an urgent EEG for any reason, from January to December 2022. RESULTS: Of the 388 patients, 70 were children: 37 (52.85%) women, and 33 (47.14%) men. Average age: 6.27 ±â€¯4.809. Of the 70 patients, 6 (8.57%) had previous epilepsy. Reasons for consultation: 17 febrile seizures, 10 first focal seizures, 10 first TCG seizures, 6 paroxysmal episodes, 6 absences, 3 myoclonus of extremities, 3 syncope, 2 SE, 2 visual alterations, 2 low level of consciousness, 2 cyanosis, 2 suspected meningitis or encephalitis, 1 choking, 1 atypical headache, 1 chorea, 1 presyncope, 1 language delay. Of the 70 patients, 47 had a normal EEG (67.14%). Of the 47 patients with a normal EEG, 10 were diagnosed with epilepsy, and 3 of them began receiving antiepileptic treatment upon discharge. None of the patients with suspected syncope or paroxysmal disorder (17 patients, 24.28%) had EEG abnormalities. Of the 17 patients with atypical febrile seizures, 3 had EEG abnormalities. CONCLUSIONS: A third of the EEG records performed in the Emergency Department showed alterations, probably due to the time taken. Almost half of the patients with suspected epilepsy or EE showed EEG abnormalities, which confirmed the diagnosis in these cases and encouraged the clinician to start drug treatment. No case with a high suspicion of epilepsy was dismissed due to the normality of the EEG recording in our series. No patient diagnosed with syncope or paroxysmal disorder had EEG abnormalities. Nearly a quarter of patients with atypical febrile seizures showed EEG abnormalities. We barely register cases of status epilepticus, probably due to the degree of complexity of our center.

[Subtle and subclinical neurological findings in patients with SARS-CoV-2]. / Hallazgos sutiles y subclínicos neurológicos en pacientes con SARS-CoV-2.

Background: There are severe neurological conditions in patients with COVID-19, such as: cerebrovascular disease, Guillain-Barré syndrome, encephalitis, acute hemorrhagic necrotizing encephalopathy and myelitis. Objective: We describe that the patient with SARS-CoV 2 with respiratory symptoms has subtle or subclinical neurological manifestations. Material and methods: Observational, cross-sectional, analytical study, which included patients aged 18-65 years with respiratory symptoms and a confirmed diagnosis of COVID-19. Intubated patients with chronic neurodegenerative diseases or pre-existing neurological compromise were excluded. Semiology of the headache and neurological examination were performed; Serum levels of glucose, protein, electrolytes, lactate, C-reactive protein, lactic dehydrogenase, and D-dimer were measured. Cerebrospinal fluid (CSF) analysis and electroencephalogram (EEG) were also performed in patients who accepted the risks. Results: A high prevalence of subtle neurological manifestations was found in patients with COVID-19 with only a respiratory clinical picture. Headache, anosmia, dysgeusia, and hypopalesthesia predominated in the early stages, with frequent abnormal findings in the CSF (>70%) and less frequently in the EEG (<20%). Conclusions: Headache, anosmia, dysgeusia and hypoesthesia were frequent at the beginning of the infection, together with abnormal findings in CSF and EEG, without other neurological symptoms or neurological disease.

Introducción: existen condiciones neurológicas severas en pacientes con COVID-19, como: enfermedad cerebrovascular, síndrome de Guillain-Barré, encefalitis, encefalopatía necrotizante hemorrágica aguda y mielitis. Objetivo: describimos que el paciente con SARS-CoV-2 con síntomas respiratorios tiene manifestaciones neurológicas sutiles o subclínicas. Material y métodos: estudio observacional, transversal, analítico, que incluyó pacientes de 18-65 años con síntomas respiratorios y diagnóstico de COVID-19 confirmado. Se excluyeron pacientes intubados, con enfermedades neurodegenerativas crónicas o compromiso neurológico preexistente. Se realizó semiología de la cefalea y exploración neurológica; Se midieron los niveles séricos de glucosa, proteínas, electrolitos, lactato, proteína C reactiva, deshidrogenasa láctica y dímero D. También se realizaron análisis de líquido cefalorraquídeo (LCR) y un electroencefalograma (EEG) en los pacientes que aceptaron los riesgos. Resultados: se encontró alta prevalencia de manifestaciones neurológicas sutiles en pacientes con COVID-19 con solo cuadro clínico respiratorio. Cefalea, anosmia, disgeusia e hipopalestesia predominaron en las primeras etapas, con hallazgos anormales frecuentes en el LCR (>70%) y con menos frecuencia en el EEG (<20%). Conclusiones: la cefalea, anosmia, disgeusia e hipoestesia fueron frecuentes al inicio de la infección, junto con hallazgos anormales en LCR y EEG, sin otros síntomas neurológicos ni enfermedad neurológica.

Seizures in the Emergency Department: clinical and diagnostic data from a series of 153 patients.

INTRODUCTION: Seizures are a frequent reason for admission to emergency departments and require early, precise diagnosis and treatment. The objective of this study was to describe the clinical and prognostic characteristics of a series of patients with seizures attended at our hospital's emergency department. METHODS: We performed a retrospective, observational study of all patients with seizures who were admitted to our hospital's emergency department and attended by the on-call neurology service between February and August 2017. RESULTS: We included 153 patients, representing 9.9% of all neurological emergency department admissions. The median age was 58 years, 52.3% of patients were women, and 51% had history of epilepsy. Onset was focal in 82.4% of cases, and the most frequent aetiology was cerebrovascular disease (24.2%). Twelve patients (7.8%) developed status epilepticus, which was associated with higher scores on the ADAN scale (P < .001) and with history of refractory epilepsy (P = .002). The in-hospital mortality rate was 3.7%, and in-hospital mortality was associated with older age (P = .049) and status epilepticus (P = .018). Eighty percent of patients with no history of epilepsy were diagnosed with epilepsy at the emergency department; all started treatment. The kappa coefficient for epilepsy diagnosis in the emergency department compared to diagnosis after one year of follow-up by the epilepsy unit was 0.45 (diagnosis was modified in 20% of patients). CONCLUSIONS: Seizures are a frequent neurological emergency with potential complications and considerable morbidity and mortality rates. In patients with no known history of epilepsy, the condition may be diagnosed in the emergency department, but follow-up at specialised epilepsy units is recommended.

Implications of starting antiepileptic treatment prior to electroencephalography in first epileptic seizures.

INTRODUCTION: This study aimed to determine whether the administration of antiepileptic drugs (AED) alters the likelihood of detecting epileptiform abnormalities in electroencephalographies (EEG) performed early after a first epileptic seizure. METHODS: We performed a retrospective, observational study including patients with a first seizure attended at our centre's emergency department between July 2014 and November 2019. We collected clinical data, as well as technical data on the acquisition and interpretation of the EEG performed within the first 72 hours after the seizure, and the factors related with seizure recurrence. RESULTS: We recruited 155 patients with a mean (SD) age of 48.6 (22.5) years; 61.3% were men. Regarding seizure type, 51% presented tonic-clonic seizures of unknown onset and 12% presented focal to bilateral tonic-clonic seizures. Thirty-nine patients (25.2%) received AED treatment before the EEG was performed: 33 received a non-benzodiazepine AED and 6 received a benzodiazepine. Epileptiform abnormalities were observed in 29.7% of patients. Previous administration of AEDs was not significantly associated with the probability of detecting interictal epileptiform abnormalities (P = .25) or with the risk of recurrence within 6 months (P = .63). CONCLUSIONS: Administration of AEDs before an early EEG following a first seizure does not decrease the likelihood of detecting epileptiform abnormalities. These findings suggest that starting AED treatment immediately in patients with a high risk of early recurrence does not imply a reduction in the diagnostic accuracy of the test.

Components of event-related potentials and borderline personality disorder: a meta-analysis.

Background: Borderline personality disorder (BPD) is characterized by symptoms associated with difficulties in emotion regulation, altered self-image, impulsivity, and instability in personal relationships. A relationship has been found between BPD symptoms and altered neuropsychological processes. Studies of event-related potentials (ERP) measured with electroencephalogram (EEG) have found neural correlates related to BPD symptoms. Of note is the P300 component, considered a potential mental health biomarker for trauma-associated disorders. However, no meta-analysis has been found to demonstrate this relationship.Objectives: To evaluate the relationship between the P300 component and BPD symptoms. To evaluate the relationship of other ERP components with BPD symptoms.Methods: The method and procedure were adjusted to the PRISMA checklist. The search was performed in three databases: WOS, Scopus and PubMed. A Random Effects Model was used to perform the analysis of the studies. In addition, a meta-regression was performed with % women, Gini and GDP. Finally, a descriptive analysis of the main results found between P300, other ERP components (LPP, P100 and ERN/Ne) and BPD symptoms was performed.Results: From a review of 485 articles, a meta-analysis was performed with six articles that met the inclusion criteria. A moderate, positive relationship was found between the P300 component and BPD symptoms (REM = .489; p < .001). It was not possible to perform meta-analyses for other ERP components (LPP, P100 and ERN/Ne) due to the low number of articles found.Conclusion: The idea that P300 could be considered for use as a biomarker to identify altered neural correlates in BPD is reinforced. In addition, a moderating effect of inequality (Gini) was detected.

The P300 component of event-related potentials could be considered for use as a possible biomarker to identify altered neural correlates in Borderline Personality Disorder.There is support for the proposition that an altered P300 would be present in disorders related to exposure to traumatic events.P300 could be used to evaluate the therapeutic processes associated with the clinical symptoms of Borderline Personality Disorder.

Posttraumatic growth EEG neuromarkers: translational neural comparisons with resilience and PTSD in trauma-exposed healthy adults.

Background: Supporting wellbeing beyond symptom reduction is necessary in trauma care. Research suggests increased posttraumatic growth (PTG) may promote wellbeing more effectively than posttraumatic stress disorder (PTSD) symptom reduction alone. Understanding neurobiological mechanisms of PTG would support PTG intervention development. However, most PTG research to-date has been cross-sectional data self-reported through surveys or interviews.Objective: Neural evidence of PTG and its coexistence with resilience and PTSD is limited. To advance neural PTG literature and contribute translational neuroscientific knowledge necessary to develop future objectively measurable neural-based PTG interventions.Method: Alpha frequency EEG and validated psychological inventories measuring PTG, resilience, and PTSD symptoms were collected from 30 trauma-exposed healthy adults amidst the COVID-19 pandemic. EEG data were collected using custom MNE-Python software, and a wireless OpenBCI 16-channel dry electrode EEG headset. Psychological inventory scores were analysed in SPSS Statistics and used to categorise the EEG data. Power spectral density analyses, t-tests and ANOVAs were conducted within EEGLab to identify brain activity differentiating high and low PTG, resilience, and PTSD symptoms.Results: Higher PTG was significantly differentiated from low PTG by higher alpha power in the left centro-temporal brain area around EEG electrode C3. A trend differentiating high PTG from PTSD was also indicated in this same location. Whole-scalp spectral topographies revealed alpha power EEG correlates of PTG, resilience and PTSD symptoms shared limited, but potentially meaningful similarities.Conclusion: This research provides the first comparative neural topographies of PTG, resilience and PTSD symptoms in the known literature. Results provide objective neural evidence supporting existing theory depicting PTG, resilience and PTSD as independent, yet co-occurring constructs. PTG neuromarker alpha C3 significantly delineated high from low PTG and warrants further investigation for potential clinical application. Findings provide foundation for future neural-based interventions and research for enhancing PTG in trauma-exposed individuals.

Objective translational study designed to increase neural understanding of posttraumatic growth (PTG) and provide a basis for future neural-based interventions to enhance PTG.Results provide neural evidence of PTG as an independent construct that coexists, and shares limited neural relatedness with resilience and PTSD symptoms.Increased PTG was significantly related to higher alpha power in the left centro-temporal brain area around EEG electrode C3: This finding warrants further investigation for potential clinical application.

Implications of initiating antiseizure drugs prior to the performance of EEG in first epileptic seizures. / Implicaciones de iniciar fármacos antiepilépticos previo a la realización de EEG en primeras crisis epilépticas.

INTRODUCTION: This study aimed to determine whether the administration of antiepileptic drugs (AED) alters the likelihood of detecting epileptiform abnormalities in electroencephalographies (EEG) performed early after a first epileptic seizure. METHOD: We performed a retrospective, observational study including patients with a first seizure attended at our centre's emergency department between July 2014 and November 2019. We collected clinical data, as well as technical data on the acquisition and interpretation of the EEG performed within the first 72hours after the seizure, and the factors related with seizure recurrence. RESULTS: We recruited 155 patients with a mean (SD) age of 48.6 (22.5) years; 61.3% were men. Regarding seizure type, 51% presented tonic-clonic seizures of unknown onset and 12% presented focal to bilateral tonic-clonic seizures. Thirty-nine patients (25.2%) received AED treatment before the EEG was performed: 33 received a non-benzodiazepine AED and 6 received a benzodiazepine. Epileptiform abnormalities were observed in 29.7% of patients. Previous administration of AEDs was not significantly associated with the probability of detecting interictal epileptiform abnormalities (P=.25) or with the risk of recurrence within 6 months (P=.63). CONCLUSIONS: Administration of AEDs before an early EEG following a first seizure does not decrease the likelihood of detecting epileptiform abnormalities. These findings suggest that starting AED treatment immediately in patients with a high risk of early recurrence does not imply a reduction in the diagnostic accuracy of the test.

Seizures in the Emergency Department: Clinical and diagnostic data from a series of 153 patients. / Crisis epilépticas en urgencias: aspectos clínicos y diagnósticos de una serie de 153 pacientes.

INTRODUCTION: Seizures are a frequent reason for admission to emergency departments and require early, precise diagnosis and treatment. The objective of this study was to describe the clinical and prognostic characteristics of a series of patients with seizures attended at our hospital's emergency department. METHODS: We performed a retrospective, observational study of all patients with seizures who were admitted to our hospital's emergency department and attended by the on-call neurology service between February and August 2017. RESULTS: We included 153 patients, representing 9.9% of all neurological emergency department admissions. The median age was 58 years, 52.3% of patients were women, and 51% had history of epilepsy. Onset was focal in 82.4% of cases, and the most frequent aetiology was cerebrovascular disease (24.2%). Twelve patients (7.8%) developed status epilepticus, which was associated with higher scores on the ADAN scale (P<.001) and with history of refractory epilepsy (P=.002). The in-hospital mortality rate was 3.7%, and in-hospital mortality was associated with older age (P=.049) and status epilepticus (P=.018). Eighty percent of patients with no history of epilepsy were diagnosed with epilepsy at the emergency department; all started treatment. The kappa coefficient for epilepsy diagnosis in the emergency department compared to diagnosis after one year of follow-up by the epilepsy unit was .45 (diagnosis was modified in 20% of patients). CONCLUSIONS: Seizures are a frequent neurological emergency with potential complications and considerable morbidity and mortality rates. In patients with no known history of epilepsy, the condition may be diagnosed in the emergency department, but follow-up at specialised epilepsy units is recommended.

Usefulness of electroencephalography for the management of epilepsy in emergency departments. / Utilidad del electroencefalograma en el manejo de la epilepsia en el Servicio de Urgencias.

INTRODUCTION: Electroencephalography (EEG) is an essential diagnostic tool in epilepsy. Its use in emergency departments (ED) is usually restricted to the diagnosis and management of non-convulsive status epilepticus (NCSE). However, EDs may also benefit from EEG in the context of other situations in epilepsy. METHODS: We conducted a retrospective observational study using the clinical histories of patients treated at our hospital's ED for epileptic seizures and suspicion of NCSE and undergoing EEG studies in 2015 and 2016. We collected a series of demographic and clinical variables. RESULTS: Our sample included 87 patients (mean age of 44 years). Epileptic seizures constituted the most common reason for consultation: 59.8% due to the first episode of epileptic seizures (FES), 27.6% due to recurrence, and 12.6% due to suspected NCSE. Interictal epileptiform discharges (IED) were observed in 38.4% of patients reporting FES and in 33.3% of those with a known diagnosis of epilepsy. NCSE was confirmed by EEG in 36.4% of all cases of suspected NCSE. Presence of IED led to administration of or changes in long-term treatment in 59.8% of the patients. CONCLUSIONS: EEG is a useful tool for seizure management in EDs, not only for severe, sudden-onset clinical situations such as NCSE but also for diagnosis in cases of non-affiliated epilepsy and in patients experiencing the first episode of epilepsy.

Neuromonitoreo con electroencefalograma procesado, más que profundidad anestésica / Neuromonitoring with processed electroencephalogram, more than anesthetic depth

Resumen: El neuromonitoreo intraoperatorio con electroencefalograma (EEG) y electroencefalograma procesado (pEEG) permite la evaluación de cambios en la actividad eléctrica cerebral generados por los anestésicos, además de prevenir eventos adversos como recuerdo intraoperatorio, sobredosis farmacológica, compromiso hemodinámico y/o neurológico, delirio y disfunción cognitiva postoperatoria. Sin embargo, la actividad eléctrica cortical puede estar modulada y ser afectada por alteraciones fisiopatológicas, independientemente del efecto de los fármacos anestésicos, por lo que, tanto el EEG como el pEEG pueden ser auxiliares en el diagnóstico oportuno de trastornos metabólicos, hipóxicos, supresión de la actividad eléctrica cerebral, estados epilépticos no convulsivos, hipertensión intracraneal, hipoperfusión o isquemia cerebral. El neuromonitoreo de rutina con el monitor disponible es recomendable con el fin de mejorar nuestra experiencia en su uso para una anestesia personalizada y de precisión, estableciendo estado de profundidad anestésica y dosis farmacológica óptima para el mantenimiento de los mecanismos implicados en la autorregulación de la perfusión cerebral, mejor comprensión de la fisiología, función cerebral y su interacción con los anestésicos e impacto hemodinámico del paciente neuroquirúrgico y no neuroquirúrgico, identificando signos precoces de posibles complicaciones derivadas del procedimiento o por efecto farmacológico y su rápida resolución.

Abstract: Intraoperative neuromonitoring with electroencephalogram (EEG) and processed electroencephalogram (pEEG) allows the evaluation of changes in brain electrical activity and unconsciousness generated by anesthetics, as well as preventing adverse events such as intraoperative recall, drug overdose, hemodynamic and/or neurological compromise, delirium and postoperative cognitive dysfunction. However, cortical electrical activity can be modulated and affected by pathophysiological alterations, independently of the effect of anesthetic drugs, both EEG and pEEG can be helpful in the timely diagnosis of metabolic, hypoxic, and suppression of electrical activity disorders brain, non-convulsive status epilepticus, intracranial hypertension, hypoperfusion or cerebral ischemia. Routine neuromonitoring with the available monitor is recommended in order to improve our experience in order to achieve a patient personalized and precise anesthesia level, arriving to an optimal dose for the maintenance of the mechanisms involved in the autoregulation of cerebral perfusion, understanding brain physiology, function as well as its interaction with drugs and hemodynamic impact to neurosurgical and non-neurosurgical patients, identifying early signs of possible complications derived from the procedure or due to pharmacological effect and their rapid resolution.

Critical view of the effect site modelling of propofol. / Visión crítica de la modelación del efecto de propofol.

Target controlled infusion (TCI) of Propofol has been the subject of discussion during its 20 years of use, including the validity of the models that represent the course of the effect, such as: Are the different EEG indexes representative of the effect? Is the reactivity of the EEG index used to build models comparable to each other? What is the real reacting time of each monitor? Is the ke0 influenced by the infusion speed? Is the ke0 or the time to peak effect affected by age? How valid are the current Emax models? Are the induction and wakening simple mirror phenomenon as they are represented in the E max models? This review discusses issues related to the complexity and difficulty in obtaining a representation of the effect, and the lack of agreed definitions to be able to construct representative models of the temporary installation of the effect of Propofol for its use in TCI.

Preventive Detection of Driver Drowsiness from EEG Signals using Fuzzy Expert Systems / Detección Preventiva de la Somnolencia del Conductor a partir de Señales EEG Mediante Sistemas Expertos Difusos

Abstract Currently, the percentage of traffic accidents has increased, and according to statistics, this percentage will continue to increase every year, so it is necessary to develop new technologies to prevent this kind of accidents. This paper presents a drowsiness detection system based on electroencephalogram (EEG) signals using a pair of channels (Fp1 and Fp2) applied to drivers before entering their vehicles. First, this model detects the relationship between the area under the curve (AUC) of alpha brain waves, an effective parameter for detecting drowsiness. Then, the extracted information is passed to a fuzzy expert system (FES) that classifies the subject's state as "alert" or "sleepy"; the criterion used was a threshold and training with subjective levels. The proposed system was compared with neural network models, such as support vector machine (SVM), K nearest neighbors (KNN), and random forest (RF). Measurements of one hundred and twenty minutes were performed on each of the ten drivers for two days to test the system. The tests confirm that this system is suitable for preventive measures and that the fuzzy system is superior to traditional neural network methods.

Resumen Actualmente, el porcentaje de accidentes de tráfico ha aumentado, y según las estadísticas, este porcentaje seguirá aumentando cada año, por lo que es necesario desarrollar nuevas tecnologías para prevenir este tipo de accidentes. Este trabajo presenta un sistema de detección de somnolencia basado en señales de electroencefalograma (EEG) utilizando un par de canales (Fp1 y Fp2) aplicado a los conductores antes de entrar en sus vehículos. En primer lugar, este modelo detecta la relación entre el área bajo la curva (AUC) de las ondas cerebrales alfa, un parámetro eficaz para detectar la somnolencia. A continuación, la información extraída se pasa a un sistema experto difuso (FES) que clasifica el estado del sujeto como "alerta" o "somnoliento"; el criterio utilizado fue un umbral y el entrenamiento con niveles subjetivos. El sistema propuesto se comparó con modelos de redes neuronales, como la máquina de vectores de soporte (SVM), K vecinos más cercanos (KNN) y el bosque aleatorio (RF). Se realizaron mediciones de ciento veinte minutos en cada uno de los diez conductores durante dos días para probar el sistema. Las pruebas confirman que este sistema es adecuado para las medidas preventivas y que el sistema difuso es superior a los métodos tradicionales de redes neuronales.

Study of the Length of time Window in Emotion Recognition based on EEG Signals / Estudio de la Longitud de Ventana de Tiempo en el Reconocimiento de Emociones Basado en Señales EEG

Abstract The objective of this research is to present a comparative analysis using various lengths of time windows (TW) during emotion recognition, employing machine learning techniques and the portable wireless sensing device EPOC+. In this study, entropy will be utilized as a feature to evaluate the performance of different classifier models across various TW lengths, based on a dataset of EEG signals extracted from individuals during emotional stimulation. Two types of analyses were conducted: between-subjects and within-subjects. Performance measures such as accuracy, area under the curve, and Cohen's Kappa coefficient were compared among five supervised classifier models: K-Nearest Neighbors (KNN), Support Vector Machine (SVM), Logistic Regression (LR), Random Forest (RF), and Decision Trees (DT). The results indicate that, in both analyses, all five models exhibit higher performance in TW ranging from 2 to 15 seconds, with the 10 seconds TW particularly standing out for between-subjects analysis and the 5-second TW for within-subjects; furthermore, TW exceeding 20 seconds are not recommended. These findings provide valuable guidance for selecting TW in EEG signal analysis when studying emotions.

Resumen El objetivo de esta investigación es presentar un análisis comparativo empleando diversas longitudes de ventanas de tiempo (VT) durante el reconocimiento de emociones, utilizando técnicas de aprendizaje automático y el dispositivo de sensado inalámbrico portátil EPOC+. En este estudio, se utilizará la entropía como característica para evaluar el rendimiento de diferentes modelos clasificadores en diferentes longitudes de VT, basándose en un conjunto de datos de señales EEG extraídas de individuos durante la estimulación de emociones. Se llevaron a cabo dos tipos de análisis: entre sujetos e intra-sujetos. Se compararon las medidas de rendimiento, tales como la exactitud, el área bajo la curva y el coeficiente de Cohen's Kappa, de cinco modelos clasificadores supervisados: K-Nearest Neighbors (KNN), Support Vector Machine (SVM), Logistic Regression (LR), Random Forest (RF) y Decision Trees (DT). Los resultados indican que, en ambos análisis, los cinco modelos presentan un mayor rendimiento en VT de 2 a 15 segundos, destacándose especialmente la VT de 10 segundos para el análisis entre los sujetos y 5 segundos intrasujetos; además, no se recomienda utilizar VT superiores a 20 segundos. Estos hallazgos ofrecen una orientación valiosa para la elección de las VT en el análisis de señales EEG al estudiar las emociones.

[Continuous spike-waves during slow-wave sleep: Experience during 20 years]. / Patrón punta-onda continua en el sueño lento: nuestra experiencia durante 20 años.

INTRODUCTION: Continuous spikes and waves during slow sleep (CSWS) is an EEG pattern that appears during childhood, and is often associated with cognitive impairment. It can appear in the course of epileptic syndromes, as well as in benign epilepsy. The aim of this study is to analyse epidemiological and clinical characteristic of patients with CSWS, in order to describe possible predictive factors in their outcome. METHODS: A retrospective study was conducted on paediatric patients with CSWS treated in a third-level hospital from November 1997 to November 2017. RESULTS: The study included 25 patients (68% male), of whom 76% had abnormalities in the neuroimaging or suffered from psychomotor development disorder (secondary CSWS). The rest were healthy, or diagnosed with idiopathic epilepsy. The mean age of onset of CSWS was 6.7 years, but earlier in the secondary CSWS cases. Symptoms were present during the CSWS episode in 72% of cases. All of them were treated with antiepileptic drugs, which were effective in 36%. CSWS stopped in 72%, and remission was longer if the CSWS onset occurred at an older age. One-third (33%) presented with sequelae, mostly cognitive and behavioural alterations. Outcome was poorer in those with secondary CSWS and, in those whose CSWS started at an earlier age and lasted longer. CONCLUSION: The CSWS pattern, although rare, is still a therapeutic challenge. A close follow-up of the patients with epilepsy is important, especially if associated with cognitive impairment, in order to establish an early diagnosis and treatment.

Factores asociados a epilepsia farmacorresistente en niños atendidos en un hospital de referencia nacional / Factors associated with drug-resistant epilepsy in children treated at a national referral hospital

Antecedentes: Según la Organización Mundial de la Salud (OMS) cerca de 70 millones de personas en el mundo padecen epilepsia. Los países de medianos y bajos ingresos presentan 70-80% de los casos; se estima que afecta 4-13% de los niños hasta los 16 años, de los cuales la epilepsia farmacorresistente (EFR) se desarrolla en 10-23%. Objetivo: Determinar factores de riesgo asociados a EFR en pacientes pediátricos atendidos en Hospital María, Especialidades Pediátricas (HMEP), Tegucigalpa, marzo 2017-marzo 2022. Métodos: Estudio de casos-controles. A partir del total de pacientes menores de 18 años con diagnóstico de epilepsia atendidos en el Servicio de Neurología HMEP, se definió Caso como pacientes con diagnóstico de EFR y Controles como pacientes con epilepsia no farmacorresistente (ENFR). A partir de expedientes clínicos, se evaluaron factores sociodemográficos, antecedentes personales y familiares, factores clínicos, estudios de imagen y electroencefalograma. El estudio fue aprobado por el Comité de Ética Institucional. Resultados: Se analizaron 81 casos y 162 controles. La edad más afectada en casos fue preescolar (35.8%), en controles fue edad escolar (41.4%). El sexo masculino presentó similar distribución en ambos grupos (51.8% y 51.2%). La procedencia rural fue más frecuente en los casos que en controles (58.0% versus 48.8%). Se identificaron los siguientes factores asociados a EFR: Antecedentes familiares de epilepsia (ORa 2.32, IC95%1.22­4.41, p=0.01), alteración focal en examen físico (ORa 2.23, IC95%1.10­4.55, p=0.02), neurodesarrollo anormal (ORa 2.78, IC95%1.18­6.54, p=0.02). Discusión: El control adecuado de las crisis epilépticas incide directamente en la calidad de vida y sobrevida de los pacientes. La identificación correcta de los niños con epilepsia con los factores asociados identificados en este estudio, que coinciden con lo descrito internacionalmente, permitirá hacer un mejor tamizaje y priorizar la referencia temprana a un neurólogo pediatra contribuyendo a mejorar la calidad de vida de los pacientes...(AU)

Grado de concordancia en una serie de informes de electroencefalogramas ambulatorios del Departamento de Neurofisiología Clínica del Hospital de Clínicas / Coefficient of agreement in a series of reports for ambulatory electroencephalograms at the clinical neurophisiology department of Clinicas Hospital / Grau de concordância em uma série de relatórios de eletroencefalogramas ambulatoriais do Departamento de Neurofisiologia Clínica do Hospital de Clínicas

El electroencefalograma (EEG) es una técnica neurofisiológica encargada de analizar la actividad cerebral utilizada con fines diagnósticos en la epilepsia, pero también en pacientes con encefalopatías agudas y crónicas no epilépticas. Su interpretación debe realizarse por médicos especializados en el área con una formación correcta, actualizada y homogénea para evitar conclusiones disimiles y términos en desuso. Para conocer dentro de una unidad de Neurofisiología Clínica de manera objetiva cómo se interpreta un EEG y su concordancia, comparamos una serie de estudios de EEG ambulatorios a través del grado de concordancia o Kappa entre los observadores. Creemos que es importante conocer las similitudes o diferencias inter observador a fines de corregir los problemas observados y mejorar la calidad asistencial.

An electroencephalogram (EEG) is a neurophysiological technique that measures electrical activity in the brain for diagnostic purposes in epilepsy, and in patients with nonepileptic acute and chronic encelopathies. This test must be performed by physicians who are specialized in the area and have the appropriate updated and uniform training, in order to avoid dissimilar conclusions and outdated terms. We compared a series of ambulatory EEG by analyzing the Kappa or coefficient of agreement rate among observers to objectively learn how an EEG is interpreted and about agreement rates at the Neurophisiology Clinic. We believe it is important to learn about interobserver similarities and differences to allow for the correction of problems noticed and improve the quality of care. Coefficient of agreement in a series of reports for ambulatory electroencephalograms at the clinical neurophisiology department of Clinicas Hospital.

O eletroencefalograma (EEG) é uma técnica neurofisiológica utilizada no estudo da atividade cerebral utilizada no diagnóstico em epilepsia, mas também em pacientes com encefalopatias não epilépticas agudas e crônicas. Sua interpretação deve ser realizada por médicos especialistas na área com formação correta, atualizada e homogênea para evitar conclusões díspares e termos obsoletos. Para conhecer como um EEG e sua concordância são interpretados objetivamente dentro de uma unidade de Neurofisiologia Clínica, comparamos uma série de estudos EEG ambulatoriais através do grau de concordância ou Kappa entre observadores. Acreditamos que é importante conhecer as semelhanças ou diferenças interobservadores para corrigir os problemas observados e melhorar a qualidade do atendimento.

Marcadores Neurales como Indicadores de Funciones Predictivas en Pacientes con Traumatismo Cerebral Moderado a Severo / Neural Markers as Indicators of Predictive Functions in Patients with Moderate to Severe Brain Trauma

Introducción. El traumatismo encéfalo craneano moderado a severo (TEC-MS) es una condición compleja que cambia la estructura y función del cerebro, afectando a personas de distintas edades. Los problemas cognitivos y motores son la mayor causa de discapacidad en individuos con TEC-MS crónico. Sin embargo, muchas de estas dificultades no son visibles de inmediato clasificándose como una "Epidemia silenciosa". Las principales alteraciones reportadas por los pacientes tienen relación con problemas de la memoria, atención y lentitud psicomotora, los cuales tienen un impacto en su independencia y funcionalidad. Objetivo. Este estudio tiene por objetivo discutir y revisar la evidencia disponible acerca de la capacidad de los pacientes crónicos con TEC-MS para generar predicciones en diferentes niveles de procesamiento cerebral. Métodos. Para esto, utilizamos desde las neurociencias el modelo teórico del código predictivo para explicar las respuestas neurofisiológicas adquiridas bajo un paradigma de predicción auditiva. Esta información es complementada con el reporte de datos preliminares de sujetos con TEC-MS y sujetos control, con el fin de ilustrar los aspectos teóricos discutidos. Conclusiones. Esto podría contribuir a una mejor comprensión de los mecanismos neurales detrás de los déficits cognitivos en esta población, aportando una perspectiva que nos oriente al desarrollo de nuestras estrategias terapéuticas.

Background. Moderate to severe traumatic brain injury (TBI-MS) is a complex condition that changes the structure and function of the brain, affecting people of different ages. Cognitive and motor problems are the major cause of disability in individuals with chronic ECT-MS. However, many of these difficulties are not immediately visible, classifying them as a "Silent Epidemic." The main alterations reported by patients are related to problems with memory, attention and psychomotor slowness, which have an impact on their independence and functionality. Objetive. This study aims to discuss and review the available evidence about the ability of chronic ECT-MS patients to generate predictions at different levels of brain processing. Methods. For this, we use the theoretical model of the predictive code from neuroscience to explain the neurophysiological responses acquired under an auditory prediction paradigm. This information is complemented with the report of preliminary data from subjects with ECT-MS and control subjects, in order to illustrate the theoretical aspects discussed. Conclusions. This could contribute to a better understanding of the neural mechanisms behind cognitive deficits in this population, providing a perspective that guides us in the development of our therapeutic strategies.