Neurosurgery
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Cerebral autoregulation maintains a relatively stable cerebral blood flow over a range of perfusion pressures. During exercise, regional cerebral blood flow may be elevated in particular areas of the brain. This case report presents the impact of aerobic exercise on intracranially measured pressure and brain tissue oxygenation in an adult human. ⋯ Our results suggest that cerebral autoregulation appears to maintain constant cerebral oxygen tension during exercise. Further, we note transient cerebral hyperoxygenation at the onset of exercise as autoregulation "turns on" and at the termination of exercise. We present a quantitative interpretation of the post-exercise hyperoxygenation phase based on Fick's principle. We are the first to demonstrate cortical hyperoxygenation in a human breathing natural air without oxygen supplementation.