George Milne, 36, was convicted of assaulting 43-year-old Mark Docherty to his permanent disfigurement and to the danger of his life by repeatedly punching him.
Doctors say that the best prognosis that Mr Docherty can hope for is spending the rest of his life in a wheelchair.
He can only communicate with his eyes and by pointing and is unlikely to ever walk again.
The assault took place at Baird Place, Bellshill, on August 29, last year.
Judge John Beckett QC said: "This incident caused severe brain injury to Mr Docherty."