The boy, known as Alex, was born with a rare disorder called Sturge-Weber syndrome which caused him to suffer epileptic seizures which could not be treated with drugs. In addition, he was only able to utter one word - "mama" - and one or two vowel sounds.
Surgeons decided the fits could only be controlled by removing the left hemisphere of Alex's brain. Although the procedure sounds drastic it is carried out on about 10 patients a year. Children treated in this way can lead a nearly normal life, but have lower than average intelligence.
The operation on Alex was performed by Christopher Adams, a consultant neurosurgeon at the Radcliffe Infirmary in Oxford. Almost immediately the seizures disappeared and after four months Alex suddenly began to speak. He is now an articulate 15-year-old and his progress is being followed by researchers from the Institute of Child Health in London.
His case, highlighted in New Scientist magazine, has caused a stir among child psychologists because many experts hold that articulate speech cannot be learnt after the age of five or six.
Dr Elizabeth Isaacs, one of the institute team, said: "There's a lot of controversy and discussion about the acquisition of language ... Here you have a child who at the age of nine started to speak and very quickly developed well-annunciated speech and a wide vocabulary. Obviously this means you cannot say language can never be developed beyond five or six."Reuse content