Development of aptitude at altitude

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 (∼500 m, ∼2500 m and ∼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.Alexandra M. Hogan, Javier Virues-Ortega, Ana Baya Botti, Romola Bucks, John W. Holloway, Matthew J. Rose-Zerilli, Lyle J. Palmer, Rebecca J. Webster, Torsten Baldeweg, and Fenella J. Kirkha

Leucoencefalopatia multifocal progressiva confirmada por PCR para vírus JC no líquor: relato de caso Progressive multifocal leukoencephalopathy confirmed by PCR: case report

Relatamos um caso de leucoencefalopatia multifocal progressiva, doença infecciosa desmielinizante do sistema nervoso central, seguido de revisão da literatura. Comenta-se a importância diagnóstica dos métodos de imagem, bem como da análise do líquor e da técnica de reação em cadeia da polimerase (PCR). Até o presente momento, não há terapia efetiva para a condição, com sobrevida média de 1-6 meses nos pacientes não tratados; evolução favorável pode ocorrer no subgrupo de pacientes que obtém melhora da imunidade com o uso de terapia anti-retroviral.<br>A case of progressive multifocal leukoencephalopathy (PML) is presented, with literature review. PML diagnosis and its differential diagnosis are presented, with emphasis on neuroradiology, cerebrospinal fluid analysis and polymerase chain reaction studies. The prognosis of PML is usually poor, with a median survival of 1-6 months. There is yet no proven effective treatment for this condition; HAART has become the standard of care for these patients