RESUMO
Consciousness transiently fades away during deep sleep, more stably under anesthesia, and sometimes permanently due to brain injury. The development of an index to quantify the level of consciousness across these different states is regarded as a key problem both in basic and clinical neuroscience. We argue that this problem is ill-defined since such an index would not exhaust all the relevant information about a given state of consciousness. While the level of consciousness can be taken to describe the actual brain state, a complete characterization should also include its potential behavior against external perturbations. We developed and analyzed whole-brain computational models to show that the stability of conscious states provides information complementary to their similarity to conscious wakefulness. Our work leads to a novel methodological framework to sort out different brain states by their stability and reversibility, and illustrates its usefulness to dissociate between physiological (sleep), pathological (brain-injured patients), and pharmacologically-induced (anesthesia) loss of consciousness.
Assuntos
Encéfalo/fisiologia , Estado de Consciência , Encéfalo/diagnóstico por imagem , Biologia Computacional , Estado de Consciência/classificação , Estado de Consciência/fisiologia , Humanos , Aprendizado de Máquina , Imageamento por Ressonância Magnética , Sono/fisiologia , Vigília/classificação , Vigília/fisiologiaRESUMO
OBJECTIVE: To describe neurological status and associated factors of survivors after cardiac arrest, upon discharge, and at 6 and 12 month follow-up. METHODS: A cohort, prospective, descriptive study conducted in an emergency room. Patients who suffered cardiac arrest and survived were included. A one-year consecutive sample, comprising 285 patients and survivors (n=16) followed up for one year after discharge. Neurological status was assessed by the Cerebral Performance Category before the cardiac arrest, upon discharge, and at 6 and 12 months after discharge. The following factors were investigated: comorbidities, presence of consciousness upon admission, previous cardiac arrest, witnessed cardiac arrest, location, cause and initial rhythm of cardiac arrest, number of cardiac arrests, interval between collapse and start of cardiopulmonary resuscitation, and between collapse and end of cardiopulmonary resuscitation, and duration of cardiopulmonary resuscitation. RESULTS: Of the patients treated, 4.5% (n=13) survived after 6 and 12 months follow-up. Upon discharge, 50% of patients remained with previous Cerebral Performance Category of the cardiac arrest and 50% had worsening of Cerebral Performance Category. After 6 months, 53.8% remained in the same Cerebral Performance Category and 46.2% improved as compared to discharge. After 12 months, all patients remained in the same Cerebral Performance Category of the previous 6 months. There was no statistically significant association between neurological outcome during follow-up and the variables assessed. CONCLUSION: There was neurological worsening at discharge but improvement or stabilization in the course of a year. There was no association between Cerebral Performance Category and the variables assessed.
Assuntos
Encefalopatias/etiologia , Parada Cardíaca/complicações , Sobreviventes , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Encefalopatias/fisiopatologia , Reanimação Cardiopulmonar/estatística & dados numéricos , Estudos de Coortes , Estado de Consciência/classificação , Serviço Hospitalar de Emergência , Feminino , Seguimentos , Escala de Coma de Glasgow/estatística & dados numéricos , Parada Cardíaca/mortalidade , Parada Cardíaca/terapia , Hospitais de Ensino , Humanos , Masculino , Pessoa de Meia-Idade , Exame Neurológico , Alta do Paciente , Prognóstico , Estudos Prospectivos , Fatores de Tempo , Resultado do Tratamento , Adulto JovemRESUMO
ABSTRACT Objective: To describe neurological status and associated factors of survivors after cardiac arrest, upon discharge, and at 6 and 12 month follow-up. Methods: A cohort, prospective, descriptive study conducted in an emergency room. Patients who suffered cardiac arrest and survived were included. A one-year consecutive sample, comprising 285 patients and survivors (n=16) followed up for one year after discharge. Neurological status was assessed by the Cerebral Performance Category before the cardiac arrest, upon discharge, and at 6 and 12 months after discharge. The following factors were investigated: comorbidities, presence of consciousness upon admission, previous cardiac arrest, witnessed cardiac arrest, location, cause and initial rhythm of cardiac arrest, number of cardiac arrests, interval between collapse and start of cardiopulmonary resuscitation, and between collapse and end of cardiopulmonary resuscitation, and duration of cardiopulmonary resuscitation. Results: Of the patients treated, 4.5% (n=13) survived after 6 and 12 months follow-up. Upon discharge, 50% of patients remained with previous Cerebral Performance Category of the cardiac arrest and 50% had worsening of Cerebral Performance Category. After 6 months, 53.8% remained in the same Cerebral Performance Category and 46.2% improved as compared to discharge. After 12 months, all patients remained in the same Cerebral Performance Category of the previous 6 months. There was no statistically significant association between neurological outcome during follow-up and the variables assessed. Conclusion: There was neurological worsening at discharge but improvement or stabilization in the course of a year. There was no association between Cerebral Performance Category and the variables assessed. .
RESUMO Objetivo: Identificar a condição neurológica e os fatores associados de sobreviventes pós-parada cardiorrespiratória na alta hospitalar, após 6 e 12 meses de seguimento. Métodos: Estudo de coorte, prospectivo e descritivo, realizado em um pronto-socorro. Foram incluídos pacientes em parada cardiorrespiratória que sobreviveram à alta. A amostra foi consecutiva por um ano, sendo composta por 285 pacientes, e os sobreviventes (n=16) foram acompanhados por um ano após alta. O estado neurológico foi avaliado pela Categoria de Performance Cerebral antes da parada, na alta, 6 e 12 meses após alta. Foram investigados os seguintes fatores: comorbidades, presença de consciência na admissão, parada cardiorrespiratória prévia, parada cardiorrespiratória testemunhada, local, causa e ritmo inicial da parada, número de paradas, intervalo entre colapso e início da ressuscitação cardiopulmonar, e entre colapso e término da ressuscitação, e duração da ressuscitação. Resultados: Dos pacientes atendidos, 4,5% (n=13) sobreviveram após 6 e 12 meses de seguimento. Na alta, 50% dos pacientes permaneceram com Categoria de Performance Cerebral prévia à parada, e 50% tiveram piora da mesma. Após 6 meses, 53,8% permaneceram com mesma Categoria de Performance Cerebral, e 46,2% tiveram melhora em relação à alta. Após 12 meses, a totalidade dos pacientes permaneceu com mesma Categoria de Performance Cerebral em relação aos 6 meses anteriores. Não houve associação estatisticamente significativa entre evolução neurológica durante o seguimento e variáveis de interesse. Conclusão: Observou-se piora neurológica na alta, mas houve melhora ou estabilização no decorrer de 1 ano. Não foi encontrada associação entre Categoria de Performance Cerebral e variáveis de interesse. .
Assuntos
Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem , Encefalopatias/etiologia , Parada Cardíaca/complicações , Sobreviventes , Encefalopatias/fisiopatologia , Estudos de Coortes , Reanimação Cardiopulmonar/estatística & dados numéricos , Estado de Consciência/classificação , Serviço Hospitalar de Emergência , Seguimentos , Escala de Coma de Glasgow/estatística & dados numéricos , Hospitais de Ensino , Parada Cardíaca/mortalidade , Parada Cardíaca/terapia , Exame Neurológico , Alta do Paciente , Prognóstico , Estudos Prospectivos , Fatores de Tempo , Resultado do TratamentoRESUMO
Kraepelin's concept of clarity of awareness (lucidity) had a stable signification during more than hundred years. It is the basis of most of current theories of disturbed consciousness. However, two alternative definitions that arise in Buenos Aires produce confusion due to their conceptual overlap. We discuss these definitions and propose a classification of disorders of consciousness that rely on traditional point of view.
Assuntos
Conscientização , Estado de Consciência , Conscientização/classificação , Estado de Consciência/classificação , Humanos , Terminologia como AssuntoRESUMO
In this article I propose a definition of "consciousness" and three general conditions for it. Based on these premises. I identify five distinct degrees of consciousness related to the activity of brain subsystems, and their modalities of interaction with the body and environment of animals.