Gravitational Ischemia in the Brain: How Interfering with Its Release May Predispose to Either Alzheimer’s- or Parkinson’s-like Illness, Treatable with Hyperbaric Oxygen

The physiological mechanisms for releasing and resolving gravitational ischemia in the brain, and their susceptibility to malfunction, may play an important role in a variety of neurological illnesses. An astronaut on a space walk in a micro-gravity environment may be susceptible to neuro-ocular symptoms associated with unopposed gravity-resistance mechanisms for partially preventing gravitational ischemia in the brain, and for attenuating its impact—mechanisms which may be required for normal brain physiology on Earth. Astronauts on the International Space Station typically breathe a mixture of gasses similar in composition to what they breathed on Earth, following the 1967 death of three astronauts, including Ed White, by fire on the Apollo 1 spacecraft, which was carrying 100% oxygen. For the last decade, astronauts have been studied extensively by flight physicians regarding the commonly experienced symptoms of VIIP, or ‘visual impairment and intracranial pressure’ syndrome. In this paper, we compare VIIP syndrome to the neuro-ocular and Parkinson’s-like symptoms which occurred during and after the 1918–1919 influenza pandemic. The common denominator may be gravitational ischemia in the brain, and the mirror-imaging failed mechanisms for its release (in influenza) versus unopposed gravity-resistance mechanisms (in astronauts). Some research has suggested that astronauts may benefit from breathing oxygen concentrations somewhat higher than 20%, and under slightly elevated pressure. These may possibly prevent maladaptive mechanisms leading to Alzheimer’s- or Parkinson’s-like illness by compensating for impaired mechanisms for releasing and resolving gravitational ischemia in the brain.