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1.
Anesth Analg ; 132(4): e50-e55, 2021 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-33560660

RESUMO

Many general anesthetics potentiate gamma-aminobutyric acid (GABA) A receptors but their neuroanatomic sites of action are less clear. GABAergic neurons in the rostromedial tegmental nucleus (RMTg) send inhibitory projections to multiple arousal-promoting nuclei, but the role of these neurons in modulating consciousness is unknown. In this study, designer receptors exclusively activated by designer drugs (DREADDs) were targeted to RMTg GABAergic neurons of Vgat-ires-Cre mice. DREADDs expression was found in the RMTg and other brainstem regions. Activation of these neurons decreased movement and exploratory behavior, impaired motor coordination, induced electroencephalogram (EEG) oscillations resembling nonrapid eye movement (NREM) sleep without loss of righting and reduced the dose requirement for sevoflurane-induced unconsciousness. These results suggest that GABAergic neurons in the RMTg and other brainstem regions promote sedation and facilitate sevoflurane-induced unconsciousness.


Assuntos
Anestésicos Inalatórios/farmacologia , Comportamento Animal/efeitos dos fármacos , Tronco Encefálico/efeitos dos fármacos , Estado de Consciência/efeitos dos fármacos , Neurônios GABAérgicos/efeitos dos fármacos , Receptores Acoplados a Proteínas-G/metabolismo , Sevoflurano/farmacologia , Sono/efeitos dos fármacos , Animais , Tronco Encefálico/metabolismo , Ondas Encefálicas/efeitos dos fármacos , Comportamento Exploratório/efeitos dos fármacos , Feminino , Neurônios GABAérgicos/metabolismo , Masculino , Camundongos Transgênicos , Atividade Motora/efeitos dos fármacos
2.
Br J Anaesth ; 126(2): 445-457, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33461725

RESUMO

Electroencephalographic (EEG) activity is used to monitor the neurophysiology of the brain, which is a target organ of general anaesthesia. Besides its use in evaluating hypnotic states, neurophysiologic reactions to noxious stimulation can also be observed in the EEG. Recognising and understanding these responses could help optimise intraoperative analgesic management. This review describes three types of changes in the EEG induced by noxious stimulation when the patient is under general anaesthesia: (1) beta arousal, (2) (paradoxical) delta arousal, and (3) alpha dropout. Beta arousal is an increase in EEG power in the beta-frequency band (12-25 Hz) in response to noxious stimulation, especially at lower doses of anaesthesia drugs in the absence of opioids. It is usually indicative of a cortical depolarisation and increased cortical activity. At higher concentrations of anaesthetic drug, and with insufficient opioids, delta arousal (increased power in the delta band [0.5-4 Hz]) and alpha dropout (decreased alpha power [8-12 Hz]) are associated with noxious stimuli. The mechanisms of delta arousal are not well understood, but the midbrain reticular formation seems to play a role. Alpha dropout may indicate a return of thalamocortical communication, from an idling mode to an operational mode. Each of these EEG changes reflect an incomplete modulation of pain signals and can be mitigated by administration of opioid or the use of regional anaesthesia techniques. Future studies should evaluate whether titrating analgesic drugs in response to these EEG signals reduces postoperative pain and influences other postoperative outcomes, including the potential development of chronic pain.


Assuntos
Analgésicos/administração & dosagem , Anestesia Geral , Anestésicos Gerais/administração & dosagem , Ondas Encefálicas/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Eletroencefalografia , Monitorização Neurofisiológica Intraoperatória , Nociceptividade/efeitos dos fármacos , Limiar da Dor/efeitos dos fármacos , Dor Pós-Operatória/prevenção & controle , Encéfalo/fisiopatologia , Relação Dose-Resposta a Droga , Humanos , Dor Pós-Operatória/fisiopatologia , Estimulação Física , Valor Preditivo dos Testes , Fatores de Tempo , Resultado do Tratamento
3.
Neurology ; 96(9): 439-448, 2021 03 02.
Artigo em Inglês | MEDLINE | ID: mdl-33408149

RESUMO

For the past 2 decades, high-frequency oscillations (HFOs) have been enthusiastically studied by the epilepsy community. Emerging evidence shows that HFOs harbor great promise to delineate epileptogenic brain areas and possibly predict the likelihood of seizures. Investigations into HFOs in clinical epilepsy have advanced from small retrospective studies relying on visual identification and correlation analysis to larger prospective assessments using automatic detection and prediction strategies. Although most studies have yielded promising results, some have revealed significant obstacles to clinical application of HFOs, thus raising debate about the reliability and practicality of HFOs as clinical biomarkers. In this review, we give an overview of the current state of HFO research and pinpoint the conceptual and methodological issues that have hampered HFO translation. We highlight recent insights gained from long-term data, high-density recordings, and multicenter collaborations and discuss the open questions that need to be addressed in future research.


Assuntos
Eletroencefalografia , Epilepsia/diagnóstico , Epilepsia/fisiopatologia , Biomarcadores , Ondas Encefálicas , Humanos , Convulsões/fisiopatologia
4.
Int J Mol Sci ; 21(24)2020 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-33321734

RESUMO

Neurosteroids are a family of compounds that are synthesized in principal excitatory neurons and glial cells, and derive from the transformation of cholesterol into pregnenolone. The most studied neurosteroids-allopregnanolone and allotetrahydrodeoxycorticosterone (THDOC)-are known to modulate GABAA receptor-mediated transmission, thus playing a role in controlling neuronal network excitability. Given the role of GABAA signaling in epileptic disorders, neurosteroids have profound effects on seizure generation and play a role in the development of chronic epileptic conditions (i.e., epileptogenesis). We review here studies showing the effects induced by neurosteroids on epileptiform synchronization in in vitro brain slices, on epileptic activity in in vivo models, i.e., in animals that were made epileptic with chemoconvulsant treatment, and in epileptic patients. These studies reveal that neurosteroids can modulate ictogenesis and the occurrence of pathological network activity such as interictal spikes and high-frequency oscillations (80-500 Hz). Moreover, they can delay the onset of spontaneous seizures in animal models of mesial temporal lobe epilepsy. Overall, this evidence suggests that neurosteroids represent a new target for the treatment of focal epileptic disorders.


Assuntos
Anticonvulsivantes/uso terapêutico , Epilepsia do Lobo Temporal/fisiopatologia , Neuroesteroides/uso terapêutico , Animais , Anticonvulsivantes/farmacologia , Ondas Encefálicas/efeitos dos fármacos , Epilepsia do Lobo Temporal/tratamento farmacológico , Epilepsia do Lobo Temporal/metabolismo , Humanos , Neuroesteroides/farmacologia , Transmissão Sináptica/efeitos dos fármacos
5.
Artigo em Inglês | MEDLINE | ID: mdl-33017931

RESUMO

Affective personality traits have been associated with a risk of developing mental and cognitive disorders and can be informative for early detection and management of such disorders. However, conventional personality trait detection is often biased and unreliable, as it depends on the honesty of the subjects when filling out the lengthy questionnaires. In this paper, we propose a method for objective detection of personality traits using physiological signals. Subjects are shown affective images and videos to evoke a range of emotions. The electrical activity of the brain is captured using EEG during this process and the multi-channel EEG data is processed to compute the inter-hemispheric asynchrony of the brainwaves. The most discriminative features are selected and then used to build a machine learning classifier, which is trained to predict 16 personality traits. Our results show high predictive accuracy for both image and video stimuli individually, and an improvement when the two stimuli are combined, achieving a 95.49% accuracy. Most of the selected discriminative features were found to be extracted from the alpha frequency band. Our work shows that personality traits can be accurately detected with EEG data, suggesting possible use in practical applications for early detection of mental and cognitive disorders.


Assuntos
Ondas Encefálicas , Eletroencefalografia , Encéfalo/diagnóstico por imagem , Aprendizado de Máquina , Personalidade
6.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 2999-3002, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33018636

RESUMO

Mental stress is a prevalent issue in the modern society and a prominent contributing factor to various physical and psychological diseases. This paper investigates the feasibility of detecting different stress levels using electroencephalography (EEG), and evaluates the effectiveness of various stress-relief methods. EEG data were collected from 25 subjects while they were at rest and under 3 different levels of stress induced by mental arithmetic tasks. Nine features that correlate with stress from existing literature were extracted. Subsequently, discriminative features were selected by Fisher Ratio and used to train a Linear Discriminant Analysis classifier. Results from 10-fold cross-validation yielded averaged intra-subject classification accuracy of 85.6% for stress versus rest, 7l.2% for two levels of stress and rest, and 58.4% for three levels of stress and rest. The results showed high promise of using EEG to detect level of stress, and the features selected showed that Beta brain waves (13-30HZ) and prefrontal relative Gamma power are most discriminative. Five different stress-relief methods were then evaluated, and the method of hugging a pillow was found to be the most effective measure relatively in decreasing the stress level detected using EEG. These results show promise of future research in real-time stress detection and reduction using EEG for stress management and relief.


Assuntos
Ondas Encefálicas , Eletroencefalografia , Análise Discriminante , Humanos , Matemática , Estresse Psicológico/diagnóstico
7.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 3208-3211, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33018687

RESUMO

This paper presents comparison of brain connectivity estimators of distracted drivers and non-distracted drivers based on statistical analysis. Twelve healthy volunteers with more than one year of driving experience participated in this experiment. Lane-keeping tasks and the Math problem-solving task were introduced in the experiment and EEGs (electroencephalogram) were used to record the brain waves. Granger-Geweke causality (GGC), directed transfer function (DTF) and partial directed coherence (PDC) brain connectivity estimation methods were used in brain connectivity analysis. Correlation test and a student's t-test were conducted on the connectivity matrixes. Results show a significant difference between the mean of distracted drivers and non-distracted driver's brain connectivity matrixes. GGC and DTF methods student's t-tests shows a p-value below 0.05 with the correlation coefficients varying from 0.62 to 0.38. PDC connectivity estimation method does not show a significant difference between the connectivity matrixes means unless it is compared with lane keeping task and the normal driving task. Furthermore, it shows a strong positive correlation between the connectivity matrixes.


Assuntos
Ondas Encefálicas , Direção Distraída , Encéfalo , Mapeamento Encefálico , Eletroencefalografia , Humanos
8.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 5224-5227, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33019162

RESUMO

This paper is concerned with a study of hyperglycemia on four patients with type 1 diabetes at night time. We investigated the association between hyperglycemic episodes and electroencephalogram (EEG) signals using data from the central and occipital areas. The power spectral density of the brain waves was estimated to compare the difference between hyperglycemia and euglycemia using the hyperglycemic threshold of 8.3 mmol/L. The statistical results showed that alpha and beta bands were more sensitive to hyperglycemic episodes than delta and theta bands. During hyperglycemia, whereas the alpha power increased significantly in the occipital lobe (P<0.005), the power of the beta band increased significantly in all observed channels (P<0.01). Using the Pearson correlation, we assessed the relationship between EEG signals and glycemic episodes. The estimated EEG power levels of the alpha band and the beta band produced a significant correlation against blood glucose levels (P<0.005). These preliminary results show the potential of using EEG signals as a biomarker to detect hyperglycemia.


Assuntos
Ondas Encefálicas , Diabetes Mellitus Tipo 1 , Hiperglicemia , Glicemia , Eletroencefalografia , Humanos , Hiperglicemia/diagnóstico
9.
J Vis Exp ; (162)2020 08 20.
Artigo em Inglês | MEDLINE | ID: mdl-32894266

RESUMO

Brainwaves amplitude obtained from electroencephalography (EEG) has been well-recognized as a basis for cognitive capacity, memory, and learning on animals and humans. Adult neurogenesis mechanism is also linked to memory and learning improvement. Traditionally, researchers used to assess learning and memory parameters in rodent models by behavioral tasks. Therefore, the simultaneous monitoring of behavioral changes and EEG is particularly interesting in correlating data between brain activity and task-related behaviors. However, most of the equipment required to perform both studies are either complex, expensive, or uses a wired setup network that hinders the natural animals' movement. In this study, EEG was recorded with a wireless electrophysiology device along with the execution of a novel object recognition task (NORT). The animal's behavior was monitored simultaneously by a video tracking system. Both recordings were analyzed offline by their timestamps which were synched to link EEG signals with the animal's actions. Subjects consist of adult Wistar rats after medium-term environmental enrichment treatment. Six skull screw electrodes were fixed in pairs on both hemispheres over frontal, central, and parietal regions and were referenced to an electrode located posterior of the nasal bone. NORT protocol consists of exposing the animal to two identical objects for 10 min. After 2 h and 24 h, one of the objects was replaced with a novel one. Exploration time for each object was monitored by a behavioral tracking software (BTS) and EEG data recording. The analysis of the EEG synced with behavioral data consists of estimations of alpha and beta relative band power and comparisons between novel object recognition versus familiar object exploration, between three experimental stages. In this manuscript, we have discussed electrodes manufacturing process, epidural electrodes implantation surgery, environmental enrichment protocol, NORT protocol, BTS setup, EEG - BTS coupling for simultaneous monitoring in real-time, and EEG data analysis based on automatic events detection.


Assuntos
Comportamento Animal/fisiologia , Eletroencefalografia/métodos , Hipocampo/fisiologia , Memória/fisiologia , Tecnologia sem Fio , Animais , Ondas Encefálicas/fisiologia , Eletrodos Implantados , Eletroencefalografia/instrumentação , Hipocampo/citologia , Hipocampo/crescimento & desenvolvimento , Masculino , Neurogênese , Ratos , Ratos Wistar
11.
Neurology ; 95(16): e2235-e2245, 2020 10 20.
Artigo em Inglês | MEDLINE | ID: mdl-32753439

RESUMO

OBJECTIVE: To examine whether fast ripples (FRs) are an accurate marker of the epileptogenic zone, we analyzed overnight stereo-EEG recordings from 43 patients and hypothesized that FR resection ratio, maximal FR rate, and FR distribution predict postsurgical seizure outcome. METHODS: We detected FRs automatically from an overnight recording edited for artifacts and visually from a 5-minute period of slow-wave sleep. We examined primarily the accuracy of removing ≥50% of total FR events or of channels with FRs to predict postsurgical seizure outcome (Engel class I = good, classes II-IV = poor) according to the whole-night and 5-minute analysis approaches. Secondarily, we examined the association of low overall FR rates or absence or incomplete resection of 1 dominant FR area with poor outcome. RESULTS: The accuracy of outcome prediction was highest (81%, 95% confidence interval [CI] 67%-92%) with the use of the FR event resection ratio and whole-night recording (vs 72%, 95% CI 56%-85%, for the visual 5-minute approach). Absence of channels with FR rates >6/min (p = 0.001) and absence or incomplete resection of 1 dominant FR area (p < 0.001) were associated with poor outcome. CONCLUSIONS: FRs are accurate in predicting epilepsy surgery outcome at the individual level when overnight recordings are used. Absence of channels with high FR rates or absence of 1 dominant FR area is a poor prognostic factor that may reflect suboptimal spatial sampling of the epileptogenic zone or multifocality, rather than an inherently low sensitivity of FRs. CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that FRs are accurate in predicting epilepsy surgery outcome.


Assuntos
Ondas Encefálicas , Encéfalo/fisiopatologia , Eletroencefalografia , Epilepsia/diagnóstico , Epilepsia/cirurgia , Adolescente , Adulto , Epilepsia/fisiopatologia , Feminino , Humanos , Masculino , Sensibilidade e Especificidade , Resultado do Tratamento , Adulto Jovem
12.
Br J Anaesth ; 125(3): 330-335, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32653082

RESUMO

BACKGROUND: Anaesthetic drugs may cause neuroapoptosis in children and are routinely used off-label in specific age groups. Techniques that reduce anaesthetic drug dose requirements in children may thus enhance the safety of paediatric sedation or anaesthesia. Brainwave entrainment, notably in the form of auditory binaural beats, has been shown to have sedative effects in adults. We evaluated the influence of brainwave entrainment on propofol dose requirements for sedation in children. METHODS: We randomised 49 boys scheduled for sub-umbilical surgery under caudal blockade to an entrainment or a control group. Small differences in pitch were applied to each ear to create binaural beats, supplemented by synchronous visual stimuli, within the electroencephalographic frequency bands seen during relaxation and (rapid eye movement/non-rapid eye movement) sleep. After establishment of caudal block, propofol infusion was started at 5 mg kg-1 h-1. Intraoperatively, the infusion rate was adjusted every 5 min depending on the sedation state judged by the bispectral index (BIS). The infusion rate was decreased by 1 mg kg-1 h-1 if BIS was <70, and was increased if BIS was >70, heart rate increased by 20%, or if there were other signs of inadequate sedation. RESULTS: Mean propofol infusion rates were 3.0 (95% confidence interval [CI]: 2.4-3.6) mg kg-1 h-1vs 4.2 (95% CI: 3.6-4.8) mg kg-1 h-1 in the entrainment and control groups, respectively (P<0.01). BIS values were similar in the two groups. CONCLUSIONS: Brainwave entrainment effectively reduced the propofol infusion rates required for sedation in children undergoing surgery with regional anaesthesia. Further studies are needed to investigate the possibility of phasing out propofol infusions completely during longer surgical procedures and optimising the settings of brainwave stimulation. CLINICAL TRIAL REGISTRATION: DRKS00005064.


Assuntos
Estimulação Acústica/métodos , Anestésicos Intravenosos/administração & dosagem , Ondas Encefálicas/fisiologia , Estimulação Luminosa/métodos , Propofol/administração & dosagem , Procedimentos Cirúrgicos Operatórios , Criança , Pré-Escolar , Relação Dose-Resposta a Droga , Eletroencefalografia , Humanos , Lactente , Masculino
13.
Neurophysiol Clin ; 50(3): 155-165, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32653111

RESUMO

OBJECTIVES: Although rare, neurological manifestations in SARS-CoV-2 infection are increasingly being reported. We conducted a retrospective systematic study to describe the electroencephalography (EEG) characteristics in this disease, looking for specific patterns. METHODS: EEGs performed in patients with positive PCR for SARS-CoV-2 between 25/03/2020 and 06/05/2020 in the University Hospital of Bicêtre were independently reviewed by two experienced neurologists. We used the American Clinical Neurophysiology Society's terminology for the description of abnormal patterns. EEGs were classified into five categories, from normal to critically altered. Interobserver reliability was calculated using Cohen's kappa coefficient. Medical records were reviewed to extract demographics, clinical, imaging and biological data. RESULTS: Forty EEGs were reviewed in 36 COVID-19 patients, 18 in intensive care units (ICU) and 22 in medicine units. The main indications were confusion or fluctuating alertness for 23 (57.5%) and delayed awakening after stopping sedation in ICU in six (15%). EEGs were normal to mildly altered in 23 (57.5%) contrary to the 42.5% where EEG alterations were moderate in four (10%), severe in eight (20%) and critical in five (12.5%). Generalized periodic discharges (GPDs), multifocal periodic discharges (MPDs) or rhythmic delta activity (RDA) were found in 13 recordings (32.5%). EEG alterations were not stereotyped or specific. They could be related to an underlying morbid status, except for three ICU patients with unexplained encephalopathic features. CONCLUSION: In this first systematic analysis of COVID-19 patients who underwent EEG, over half of them presented a normal recording pattern. EEG alterations were not different from those encountered in other pathological conditions.


Assuntos
Betacoronavirus , Confusão/etiologia , Infecções por Coronavirus/complicações , Recuperação Demorada da Anestesia/etiologia , Eletroencefalografia , Pneumonia Viral/complicações , Adulto , Idoso , Idoso de 80 Anos ou mais , Nível de Alerta/fisiologia , Betacoronavirus/isolamento & purificação , Ondas Encefálicas/fisiologia , Doenças Cardiovasculares/complicações , Doenças Cardiovasculares/fisiopatologia , Comorbidade , Confusão/fisiopatologia , Infecções por Coronavirus/fisiopatologia , Infecções por Coronavirus/psicologia , Sedação Profunda , Recuperação Demorada da Anestesia/fisiopatologia , Demência/complicações , Demência/fisiopatologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pandemias , Pneumonia Viral/fisiopatologia , Pneumonia Viral/psicologia , Reação em Cadeia da Polimerase , /fisiopatologia , Estudos Retrospectivos
15.
Med. intensiva (Madr., Ed. impr.) ; 44(5): 301-309, jun.-jul. 2020. ilus, tab, graf
Artigo em Espanhol | IBECS | ID: ibc-193190

RESUMO

La monitorización es crucial en el cuidado del paciente crítico. Detecta disfunciones orgánicas y provee orientación en el abordaje terapéutico. Los intensivistas monitorizan habitualmente la función de varios sistemas orgánicos y el cerebro no es la excepción. La monitorización EEG continuo es una vía no invasiva e ininterrumpida para valorar la actividad eléctrica cortical con aceptable resolución espacial y excelente resolución temporal. La efectividad diagnóstica del estado epiléptico no convulsivo como causa de compromiso de la consciencia no explicable por otras causas se ha incrementado con el empleo del EEG continuo; sin embargo, no es la única indicación para valorar la actividad eléctrica cortical cerebral. Este manuscrito intenta resumir las indicaciones, modos de empleo y metodología para el empleo del monitoreo electroencefalográfico continuo en la unidad de cuidados intensivos con la finalidad que el intensivista se familiarice con el mismo


Monitoring is a crucial part of the care of the critically ill patient. It detects organ dysfunction and provides guidance on the therapeutic approach. Intensivists closely monitor the function of various organ systems, and the brain is no exception. Continuous EEG monitoring is a noninvasive and uninterrupted way of assessing cerebral cortical activity with good spatial and excellent temporal resolution. The diagnostic effectiveness of non-convulsive status epilepticus as a cause of unexplained consciousness disorder has increased the use of continuous EEG monitoring in the neurocritical care setting. However, non-convulsive status epilepticus is not the only indication for the assessment of cerebral cortical activity. This study summarizes the indications, usage and methodology of continuous EEG monitoring in the intensive care unit, with the aim of allowing practitioners to become familiarized the technique


Assuntos
Humanos , Eletroencefalografia/métodos , Cuidados Críticos , Isquemia Encefálica/diagnóstico por imagem , Encefalopatias/diagnóstico por imagem , Ondas Encefálicas/efeitos da radiação , Isquemia Encefálica/fisiopatologia , Sedação Profunda , Morte Encefálica/diagnóstico por imagem
16.
PLoS One ; 15(6): e0224053, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32497075

RESUMO

This study explored brain responses to images that exploit incongruity as a creative technique, often used in advertising (i.e., surrealistic images). We hypothesized that these images would reveal responses akin to cognitive conflict resulting from incongruent trials in typical laboratory tasks (i.e., Stroop Task). Indeed, in many surrealistic images, common visual elements are juxtaposed to create un-ordinary associations with semantically conflicting representations. We expected that these images engage the conflict processing network that has been described in cognitive neuroscience theories. We addressed this hypothesis by measuring the power of mid-frontal Theta oscillations using EEG while participants watched images through a social media-like interface. Incongruent images, compared to controls, produced a significant Theta power increase, as predicted from the cognitive conflict theory. We also found increased memory for incongruent images one week after exposure, compared to the controls. These findings provide evidence for the incongruent images to effectively engage the viewer's cognitive control and boost memorability. The results of this study provide validation of cognitive theories in real-life scenarios (i.e., surrealistic ads or art) and offer insights regarding the use of neural correlates as effectiveness metrics in advertising.


Assuntos
Cognição , Percepção Visual/fisiologia , Adolescente , Adulto , Ondas Encefálicas , Feminino , Voluntários Saudáveis , Humanos , Masculino , Memória , Adulto Jovem
17.
J Occup Health ; 62(1): e12121, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32515890

RESUMO

OBJECTIVES: It is common to find doctors working long and odd hours and many at times without rest and sleep. Despite the evidence of adverse risk, jeopardizing patient safety under the hands of fatigue doctors under such working hours has not changed in many places. It has argued that with such training and subsequent experience, such issues with patient safety reduce. Fatigue too is argued as subjective, as those who can withstand the stress still perform. Nevertheless, undeniably working under fatigue is not safe for both the patient and the doctor. This study is a novel attempt to explore and objectify the state of fatigue using quantitative EEG among post-call doctors. METHOD: Seven volunteer post-call doctors were recruited to go through an EEG recording before and after their on-call rotation while at rest and subsequently while carrying out Stroop Test, putting their cognitive function at work. RESULTS: The doctors have worked up to 33 hours in a row and have had sleep of an average of 1.5 hours. It is found that during task there is a statistically significant increase in theta (frontal and occipital regions) and beta (occipital region) band power while at task post-call. Alpha band power is increased in the frontal and reduced in other regions. Correlation with Stroop Test results indicated that those who have higher alpha, beta, and lower relative theta powers at the frontal region at post-call rest have higher percentage of correct congruent trials. CONCLUSION: The results objectively imply that these fatigue doctors are under more strain while carrying out a task and corresponds to the implicated regions of brain stimulated by the task accordingly.


Assuntos
Ondas Encefálicas , Eletroencefalografia , Fadiga/fisiopatologia , Médicos , Tolerância ao Trabalho Programado/fisiologia , Adulto , Feminino , Humanos , Masculino
18.
PLoS One ; 15(5): e0232530, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32384091

RESUMO

BACKGROUND: Clinical and animal studies have found that anxiety and depression are significantly more common after acute myocardial infarction (AMI). The medial prefrontal cortex (PFC) has a dual role: in higher brain functions and in cardiovascular control, making it a logical candidate for explaining the perceived bidirectional heart-brain connection. We used parallel Electrocardiography (ECG) and Electrocorticography (ECoG) registration to investigate AMI-induced changes in medial PFC bioelectrical activity in a rat model of AMI. MATERIALS AND METHODS: Adult male Wistar albino rats were used in the study. Gold-plated recording electrodes were implanted over the frontal cortex for ECoG recording. ECG was recorded via two holter electrodes attached on the skin of the back fixed in place by a jacket. Induction of AMI was performed by isoprenaline (150 mg/kg, i.p.). ECoG and ECG signals were registered at baseline, during 3 hours after isoprenaline administration and at 24 hours after isoprenaline administration. RESULTS: Significant increases of theta, alpha, and beta electroencephalographic (EEG) band power were observed in different time intervals after isoprenaline administration. Significant increase of theta band peak frequency was also observed during the first hour after isoprenaline administration. No statistically significant differences in band-power activity were found between the pre-isoprenaline measurements and 24 hours after administration. CONCLUSION: Our results demonstrate significant increases in EEG band power of alpha beta and theta bands during isoprenaline-induced AMI model. These are the first findings to connect heart damage during isoprenaline- induced AMI to disturbances in the cortical bioelectrical activity.


Assuntos
Isoproterenol/farmacologia , Infarto do Miocárdio/fisiopatologia , Córtex Pré-Frontal/fisiopatologia , Animais , Ondas Encefálicas/fisiologia , Modelos Animais de Doenças , Eletrocardiografia , Eletrocorticografia , Eletroencefalografia , Masculino , Infarto do Miocárdio/induzido quimicamente , Ratos , Ratos Wistar
20.
J Neurosci ; 40(24): 4673-4684, 2020 06 10.
Artigo em Inglês | MEDLINE | ID: mdl-32371605

RESUMO

Spindles and slow oscillations (SOs) both appear to play an important role in memory consolidation. Spindle and SO "nesting," or the temporal overlap between the two events, is believed to modulate consolidation. However, the neurophysiological processes modified by nesting remain poorly understood. We thus recorded activity from the primary motor cortex of 4 male sleeping rats to investigate how SO and spindles interact to modulate the correlation structure of neural firing. During spindles, primary motor cortex neurons fired at a preferred phase, with neural pairs demonstrating greater neural synchrony, or correlated firing, during spindle peaks. We found a direct relationship between the temporal proximity between SO and spindles, and changes to the distribution of neural correlations; nesting was associated with narrowing of the distribution, with a reduction in low- and high-correlation pairs. Such narrowing may be consistent with greater exploration of neural states. Interestingly, after animals practiced a novel motor task, pairwise correlations increased during nested spindles, consistent with targeted strengthening of functional interactions. These findings may be key mechanisms through which spindle nesting supports memory consolidation.SIGNIFICANCE STATEMENT Our analysis revealed changes in cortical spiking structure that followed the waxing and waning of spindles; firing rates increased, spikes were more phase-locked to spindle-band local field potential, and synchrony across units peaked during spindles. Moreover, we showed that the degree of nesting between spindles and slow oscillations modified the correlation structure across units by narrowing the distribution of pairwise correlations. Finally, we demonstrated that engaging in a novel motor task increased pairwise correlations during nested spindles. These phenomena suggest key mechanisms through which the interaction of spindles and slow oscillations may support sensorimotor learning. More broadly, this work helps link large-scale measures of population activity to changes in spiking structure, a critical step in understanding neuroplasticity across multiple scales.


Assuntos
Ondas Encefálicas/fisiologia , Consolidação da Memória/fisiologia , Córtex Motor/fisiologia , Neurônios/fisiologia , Sono/fisiologia , Animais , Eletroencefalografia , Masculino , Ratos , Fases do Sono/fisiologia
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