Subatmospheric decompression: neurological and behavioural studies

Several studies in animals over the past decade have shown that prolonged exposures to pressures within the range 226 mm Hg to 160 mm Hg (30,000 to 37,500 ft) are likely to lead to brain damage. This often results in neurological and behavioural disturbance, which may be subtle and reversible or gross and ultimately fatal. The appearance of these impairments is often delayed until several hours or even days after exposure. Immediate survival does not necessarily ensure recovery. In contrast, decompression to pressures below 160 mm Hg or above 226 mm Hg are unlikely to have adverse effects if the exposure is survived. The most probable outcomes of such decompressions are death or uneventful recovery.