By Dr. Brian McDonough, Medical Editor

PHILADELPHIA (CBS) – Pilots who fly at high altitudes are at increased risk of developing abnormalities in their brains. High altitude pilots are at risk of decompression syndrome — characterized by slowed thought, confusion, and even permanent memory loss.

Researchers at the University of Texas in San Antonio and US Air Force School of Aerospace studied 193 healthy subjects, half whom were air force pilots — the other half were not. When they scanned their brains they found that the pilots had three times more “white matter hyperintensities” – in other words, a defect in the brain that shows up as a white spot on an MRI scan.

Even when decompression sickness was not an issue, the pilots showed signs of risk.