My husband had suffered an axonal brain injury when thrown from a horse, causing injury to his frontal lobe(multi-tasking, memory region). Eight months later while driving, he saw black and white vertical lines in his vision, and the next thing he knew somebody was yelling in his truck, Is anyone alive in there? He had cross ed the median on the freeway, side-swiped a hughe truck, crossed back over the median and flipped the truck we don;t even knwo how many times. What would cause black and white vertical lines in his vision?