How does decompression sickness affect the brain?

Bubble brain. Literally, nitrogen 80% of air is pressured into the blood stream and embolizes to body parts the brain is more sensitive to flow interruption than muscle, and other organs.
Air embolism. The brain is damaged due to lack of oxygen caused by bubbles in the arterial circulation. The bubbles lodge in the small arteries, preventing blood from getting to the brain. The brain can only tolerate lack of oxygen for 5 to 6 minutes, after which it starts to die (stroke).