A man with a brain significantly smaller than average managed to live an entirely normal life working as a civil servant. When the 44-year-old man's brain was scanned, it showed that a huge fluid-filled chamber took up most of his skull. French researchers say it left room for only a thin sheet of actual brain tissue. "He was a married father of two children, and worked as a civil servant," Dr Lionel Feuillet of the Universite de la Mediterranee in Marseille said in the Lancet medical journal. When Dr Feuillet's staff took his medical history, they discovered he had had a shunt inserted into his head to drain away water on the brain as a child. The researchers were shocked when scans showed a "massive enlargement" of the lateral ventricles - chambers, usually small in size, that hold the fluid that acts as a cushion for the brain. Intelligence tests showed the man had an IQ of 75, below the average score of 100 but not enough to classify him as mentally retarded or disabled. "What I find amazing to this day is how the brain can deal with something which you think should not be compatible with life," said Dr Max Muenke, a brain specialist at the National Human Genome Research Institute. "If something happens very slowly over quite some time, maybe over decades, the different parts of the brain take up functions that would normally be done by the part that is pushed to the side."