Former Defence Minister and Janata Dal (United) leader George Fernandes today underwent a neurosurgery at All India Institute of Medical Sciences (AIIMS).George was admitted to the hospital on December 5 after a severe headache. The doctors examining him found fluid obstructing one of the nerves in his brain. A team of doctors led by senior neurosurgeon Dr VS Mehta today drained out the fluid from the nerve. His condition is stable and he is recovering, doctors at the hospital said.According to sources in the hospital, George has been kept under observation in the Intensive Care Unit (ICU) for a day. He will be shifted to the general ward on Sunday and discharged within a week, they said.