RESUMO
STUDY OBJECTIVES: Physiological adaptation to high altitude hypoxia may be impaired in Andeans with significant European ancestry. The respiratory 'burden' of sleep may challenge adaptation, leading to relative nocturnal hypoxia. Developmental aspects of sleep-related breathing in high-altitude native children have not previously been reported. We aimed to determine the influence of development on diurnal-nocturnal oxyhemoglobin differences in children living at high altitude. METHODS: This was a cross-sectional, observational study. Seventy-five healthy Bolivian children aged 6 mo to 17 y, native to low altitude (500 m), moderate high altitude (2,500 m), and high altitude (3,700 m) were recruited. Daytime resting pulse oximetry was compared to overnight recordings using Masimo radical oximeters. Genetic ancestry was determined from DNA samples. RESULTS: Children had mixed European/Amerindian ancestry, with no significant differences between altitudes. Sixty-two participants had ≥ 5 h of nocturnal, artifact-free data. As predicted, diurnal mean oxyhemoglobin saturation decreased across altitudes (infants and children, both P < 0.001), with lowest diurnal values at high altitude in infants. At high altitude, there was a greater drop in nocturnal mean oxyhemoglobin saturation (infants, P < 0.001; children, P = 0.039) and an increase in variability (all P ≤ 0.001) compared to low altitude. Importantly, diurnal to nocturnal altitude differences diminished (P = 0.036), from infancy to childhood, with no further change during adolescence. CONCLUSIONS: Physiological adaptation to high-altitude living in native Andeans is unlikely to compensate for the significant differences we observed between diurnal and nocturnal oxyhemoglobin saturation, most marked in infancy. This vulnerability to sleep-related hypoxia in early childhood has potential lifespan implications. Future studies should characterize the sleep- related respiratory physiology underpinning our observations.
Assuntos
Aclimatação/fisiologia , Altitude , Desenvolvimento Infantil , Hipóxia/metabolismo , Oxiemoglobinas/metabolismo , Sono/fisiologia , Aclimatação/genética , Adolescente , Desenvolvimento do Adolescente , Doença da Altitude , Bolívia , Criança , Pré-Escolar , Estudos Transversais , Europa (Continente)/etnologia , Feminino , Humanos , Hipóxia/genética , Lactente , Masculino , Oximetria , Respiração , Sono/genéticaRESUMO
The brain is highly sensitive to environmental hypoxia. Little is known, however, about the neuropsychological effects of high altitude residence in the developing brain. We recently described only minor changes in processing speed in native Bolivian children and adolescents living at approximately 3700 m. However, evidence for loss of cerebral autoregulation above this altitude (4000 m) suggests a potential threshold of hypoxia severity over which neuropsychological functioning may be compromised. We conducted physiological and neuropsychological assessments in 62 Bolivian children and adolescents living at La Paz (â¼3700 m) and El Alto (â¼4100 m) in order to address this issue. Groups were equivalent in terms of age, gender, social class, schooling, parental education and genetic admixture. Apart from percentage of hemoglobin saturated with oxygen in arterial blood (%SpO(2)), participants did not differ in their basal cardiac and cerebrovascular performance as explored by heart rate, mean arterial pressure, end-tidal carbon dioxide, and cerebral blood flow velocity at the basilar, anterior, middle and posterior cerebral arteries. A comprehensive neuropsychological assessment was administered, including tests of executive functions, attention, memory and psychomotor performance. Participants living at extreme altitude showed lower levels of performance in all executive tests (Cohen effect size = -0.91), whereas all other domains remained unaffected by altitude of residence. These results are compatible with earlier physiological evidence of a transitional zone for cerebral autoregulation at an altitude of 4000 m. We now show that above this threshold, the developing brain is apparently increasingly vulnerable to neuropsychological deficit.
Assuntos
Altitude , Encéfalo/fisiologia , Fenômenos Fisiológicos Cardiovasculares , Função Executiva/fisiologia , Aclimatação/fisiologia , Adolescente , Atenção/fisiologia , Bolívia , Encéfalo/embriologia , Encéfalo/fisiopatologia , Sistema Cardiovascular , Criança , Feminino , Homeostase/fisiologia , Humanos , Hipóxia/sangue , Hipóxia/fisiopatologia , Masculino , Memória/fisiologia , Testes Neuropsicológicos , Oxigênio , Desempenho Psicomotor/fisiologiaRESUMO
Mario A. Bunge is one of the most prominent philosophers and humanists of our time. His vast record of publications has covered, among others, episte-mology, ontology, ethics, philosophy of natural and social sciences, philosophy of technology, and philosophy of mind. A topic that intersects many of these areas and is recurrent in Bunge's work is causality. His analyses of the causal principle, and the redefinition of determinism into near-determinism have been applied to different philosophical issues that range from the causal role of neuronal functioning to the laws of social phenomena. Bunge has criticized functionalism, cognitivism, computationalism, behaviourism, and idealism in their attempt to explain human and non-human behaviour. This article results from an extensive interview held with Dr. Bunge in which we discussed a variety of conceptual issues related to the notions of causality and explanation in psychology.
RESUMO
Millions of people currently live at altitudes in excess of 2500 metres, where oxygen supply is limited, but very little is known about the development of brain and behavioural function under such hypoxic conditions. We describe the physiological, cognitive and behavioural profile of a large cohort of infants (6-12 months), children (6-10 years) and adolescents (13-16 years) who were born and are living at three altitude locations in Bolivia ( approximately 500 m, approximately 2500 m and approximately 3700 m). Level of haemoglobin oxygen saturation and end-tidal carbon dioxide were significantly lower in all age groups living above 2500 metres, confirming the presence of hypoxia and hypocapnia, but without any detectable detriment to health. Infant measures of neurodevelopment and behaviour yielded comparable results across altitude groups. Neuropsychological assessment in children and adolescent groups indicated a minor reduction in psychomotor speed with increasing altitude, with no effect of age. This may result from slowing of underlying brain activity in parallel with reduced cerebral metabolism and blood flow, evidenced here by reduced cerebral blood flow velocity, particularly in the basilar artery, in children and adolescents. The proportion of European, Native American and African genetic admixture was comparable across altitude groups, suggesting that adaptation to high altitude in these children occurred in response to chronic hypoxic exposure irrespective of ethnic origin. Thus, psychomotor slowing is proposed to be an adaptive rather than a deficient trait, perhaps enabling accuracy of mental activity in hypoxic conditions.
Assuntos
Adaptação Biológica/fisiologia , Altitude , Desenvolvimento Infantil , Desempenho Psicomotor/fisiologia , Adolescente , Fatores Etários , Análise de Variância , Antropometria , Velocidade do Fluxo Sanguíneo , Bolívia , Dióxido de Carbono/sangue , Cérebro/irrigação sanguínea , Cérebro/diagnóstico por imagem , Criança , Estudos Transversais , Hemoglobinas/química , Humanos , Lactente , Testes Neuropsicológicos , Oxigênio/sangue , Ultrassonografia Doppler TranscranianaAssuntos
Altitude , Mortalidade/tendências , Idoso , Bolívia , Feminino , Humanos , Masculino , Estudos Retrospectivos , Taxa de SobrevidaRESUMO
OBJECTIVE: To conduct a cross-national validation of the Scales for Outcomes in Parkinson's Disease-PsychoSocial questionnaire (SCOPA-PS) in four Latin American Countries. METHODS: Data quality (missing items), scale assumptions (item-test correlation), internal consistency (Cronbach's alpha, item homogeneity), factor structure, content validity, and precision (standard error of measurement, SEM) of the scale were explored, as was convergent validity with motor symptoms (Clinical Impression of Severity Index [CISI-PD], Scales for Outcomes in Parkinson's Disease-Motor Scale), emotional status (Hospital Anxiety and Depression Scale) and health-related quality of life (Parkinson Disease Questionnaire-39). Known-groups validity was studied by category of severity, based on Hoehn and Yahr staging (HY), CISI-PD, and disease duration. RESULTS: Three hundred thirty-one Parkinson's disease (PD) patients with usable data participated (mean age 64.7 years; 42.3% female; mean PD duration 8.5 years; HY, 1 to 5). Data quality (missing items <10%), scale assumptions (item-total correlation = 0.43 - 0.71) and internal consistency of SCOPA-PS (Cronbach's alpha = 0.87; item homogeneity = 0.38) were satisfactory. Factor analysis suggested a unifactorial structure. High convergent validity was found for depression (r(S) = 0.61), anxiety (r(S) = 0.62), and health-related quality of life (r(S) = 0.82). Known-groups validity analyses indicated a gradual influence of severity category and disease duration on SCOPA-PS scores (P < 0.0001). SEM value was 8.24 (7 to 12 in previous studies). These magnitudes may be indicative of the threshold for a real change and a minimum important difference. CONCLUSIONS: The Latin American versions of the SCOPA-PS displayed appropriate psychometric attributes.
Assuntos
Competência Cultural , Diversidade Cultural , Doença de Parkinson/psicologia , Qualidade de Vida , Estresse Psicológico , Adaptação Psicológica , Idoso , Ansiedade , Comparação Transcultural , Depressão , Análise Fatorial , Feminino , Humanos , Internacionalidade , Idioma , Masculino , Pessoa de Meia-Idade , Doença de Parkinson/tratamento farmacológico , Psicometria , Análise de Regressão , Reprodutibilidade dos Testes , Índice de Gravidade de Doença , Perfil de Impacto da Doença , América do Sul , Estresse Psicológico/etiologia , Inquéritos e Questionários , Resultado do TratamentoRESUMO
Se presentan de forma abreviada, los efectos de la altitud sobre la fisiología cerebral, con especial énfasis durante la exposición aguda en el funcionamiento neuropsicológico. También, sobre el sistema senso-perceptivo, la aptitud psicomotora y otras funciones cognitivas superiores, incluyendo la memoria y el lenguaje. La hipoxia relacionada con la anemia falciforme así como el nacimiento a gran altitud se discuten como un modelo potencial de repercusión sobre la función neuropsicológica bajo hipoxia. La literatura sugiere que existe un patrón de deterioro cognitivo leve e inespecífico asociado a la exposición aguda a grandes altitudes. Finalmente, se discutieron los efectos de la hipoxia crónica asociada a la altitud y se exponen nuevos datos acerca del efecto residual, tras el abandono de un ambiente hipóxico. La literatura disponible sugiere un posible rol de la hipoxia sobre la sustancia blanca como factor subyacente a estos hallazgos. Los estudios son escasos en este ámbito; no obstante, condiciones de hipoxia patológica sugieren la necesidad de investigaciones futuras en esta área.
This paper reviews the effects of high altitude on brain function, focussing on neuropsychological outcome following acute exposure to high altitude hypoxia. Domains of sensor-perceptual and psycho-motor function are considered along performance on more complex cognitive tasks requiring memory and language. Conditions of pathological hypoxia including sickle cell disease and birth-related hypoxia are briefly discussed as models for the potential effect of high altitude residence on neuropsychological functioning. Currently, research on a potentially different neuropsychological profile of high altitude residents is lacking. The literature suggests a profile of generalised and mild neuropsychological impairment due to acute exposure to high altitude, but a number of limitations are identified. More research is needed to determine a potentially regular pattern of neuropsychological impairment. In particular, it is of interest to determine whether there is a pattern of residual neuropsychological impairment after descent from high altitude. Finally, effects of chronic hypoxia due to altitude are discussed. Available literature suggests a potential effect of hypoxia over white matter as an underlying factor accounting for the neuropsychological effects. There is lack of evidence in this area; however, conditions of pathological hypoxia suggest that further research efforts should be made.