Doctors in Moscow have discovered a 60-year-old man with only half a brain, according to the British Daily Mail website.
Doctors said the CT scan, which had been performed for the man after his stroke, showed a black hole in the right part of his brain.
The man grew up without health problems, while rare cases caused the parts of the brain to severely handicap and die at an early age, but the condition of this man "very unique," according to doctors.
Doctors suggested that the congenital defect developed when the man was a fetus in his mother's womb, and the technology would not be able to reveal his condition at the time.
The remaining right hemisphere of the brain has all the functions of the brain.