RESUMEN
BACKGROUND: A terrible pandemic, Covid-19, has captivated scientists to investigate if SARS-CoV-2 virus infects the central nervous system (CNS). A crucial question is if acute respiratory distress syndrome (ARDS), the main cause of death in this pandemic, and often refractory to treatments, can be explained by respiratory center dysfunction. OBJECTIVE: To discuss that ARDS can be caused by SARS-CoV-2 infection of the respiratory center in the brainstem. MATERIALS AND METHODS: I reviewed literature about SARS-CoV-2 mechanisms to infect the respiratory center in the brainstem. RESULTS AND CONCLUSIONS: An increasing amount of reports demonstrates that neurotropism is a common feature of coronavirus, which have been found in the brains of patients and experimental models, where the brainstem was severely infested. Recent studies have provided tremendous indication of the incidence of acute respiratory failure due to SARS-CoV-2 infection of the brainstem. SARS-CoV-2 might infect the CNS through the olfactory bulb, spreading from the olfactory nerves to the rhinencephalon, and finally reaching the brainstem. Hence, the virus infection causes respiratory center dysfunctions, leading to ARDS in COVID-19 patients. I conclude that acute ARDS in Covid-19 can be caused by SARS-CoV-2 invasion of brainstem respiratory center, suggesting the needs of more specific and aggressive treatments, with the direct participation of neurologists and neurointensivists.
Asunto(s)
Infecciones por Coronavirus/fisiopatología , Neumonía Viral/fisiopatología , Centro Respiratorio/fisiopatología , Síndrome de Dificultad Respiratoria/fisiopatología , Betacoronavirus , Tronco Encefálico/fisiopatología , Tronco Encefálico/virología , COVID-19 , Humanos , Hipoxia/fisiopatología , Pandemias , Centro Respiratorio/virología , SARS-CoV-2 , Tropismo ViralRESUMEN
We studied autistics by quantitative EEG spectral and coherence analysis during three experimental conditions: basal, watching a cartoon with audio (V-A), and with muted audio band (VwA). Significant reductions were found for the absolute power spectral density (PSD) in the central region for delta and theta, and in the posterior region for sigma and beta bands, lateralized to the right hemisphere. When comparing VwA versus the V-A in the midline regions, we found significant decrements of absolute PSD for delta, theta and alpha, and increments for the beta and gamma bands. In autistics, VwA versus V-A tended to show lower coherence values in the right hemisphere. An impairment of visual and auditory sensory integration in autistics might explain our results.
Asunto(s)
Percepción Auditiva/fisiología , Trastorno Autístico/fisiopatología , Ondas Encefálicas/fisiología , Percepción Visual/fisiología , Estimulación Acústica , Parpadeo/fisiología , Estudios de Casos y Controles , Preescolar , Electroencefalografía , Expresión Facial , Femenino , Humanos , Masculino , Estimulación LuminosaRESUMEN
OBJECTIVE: To assess the autonomic nervous system (ANS) in coma by heart rate variability (HRV). METHODS: Sixteen comatose patients and 22 normal subjects with comparable ages and genders were studied. Patients were classified in two subgroups according to the Glasgow Coma Scale (GCS). Time, frequency, and informational HRV domain indices were calculated. RESULTS: A notable reduction of HRV was found in patients. Regarding the time domain indices, the triangular index, and the Delta_RRs, were significantly reduced in the subgroup with GCS=3. Absolute power for the whole frequency spectrum decreased whenever GCS scores were lower. A significant decrement was found for absolute power of the VLF and LF bands in the subgroup of GCS=3, and although it was lower for the HF band in these patients, those changes were not statistically significantly different. The LF/HF ratio and the Shannon´s entropy indices were significantly reduced in the subgroup with GCS=3. Our results are discussed regarding the progressive dysfunction the ANS networks when coma deepens. CONCLUSIONS: The HRV procedure is a powerful tool to assess the ANS in comatose patients. SIGNIFICANCE: HRV is a minimally invasive, low-cost methodology, suitable for assessing the ANS in coma.
Asunto(s)
Sistema Nervioso Autónomo/fisiopatología , Coma/diagnóstico , Frecuencia Cardíaca/fisiología , Anciano , Anciano de 80 o más Años , Coma/fisiopatología , Electrocardiografía , Femenino , Escala de Coma de Glasgow , Humanos , Masculino , Persona de Mediana Edad , PronósticoRESUMEN
The purpose of this study was to explore the relationship between electroencephalogram (EEG) phase reset in autism spectrum disorder (ASD) subjects as compared to age matched control subjects. The EEG was recorded from 19 scalp locations from 54 autistic subjects and 241 control subjects ranging in age from 2.6 years to 11 years. Complex demodulation was used to compute instantaneous phase differences between all pairs of electrodes and the 1st and 2nd derivatives were used to measure phase reset by phase shift duration and phase lock duration. In both short (6 cm) and long (21-24 cm) inter-electrode distances phase shift duration in ASD subjects was significantly shorter in all frequency bands but especially in the alpha-1 frequency band (8-10 Hz) (p < .0001). Phase lock duration was significantly longer in the alpha-2 frequency band (10-12 Hz) in ASD subjects (p < .0001). An anatomical gradient was present with the occipital-parietal regions the most significant. The findings in this study support the hypothesis that neural resource recruitment occurs in the lower frequency bands and especially the alpha-1 frequency band while neural resource allocation occurs in the alpha-2 frequency band. The results are consistent with a general GABA inhibitory neurotransmitter deficiency resulting in reduced number and/or strength of thalamo-cortical connections in autistic subjects.