At 65, nurse Cathy Irvine has put off retirement and is working night shifts to help provide around-the-clock care in her home for her 36-year-old son Robin Irvine.
"He cannot stand or walk without the aid of a mechanic lifter or people helping him," she said.
Ms Irvine told the ABC he had difficulty speaking, swallowing and seeing.
The sustained assault in his cell, included being "stomped on" by a fellow inmate and resulted in extensive brain bleeds requiring surgery, fractured eye sockets, a broken nose. His mother said "it looked like he suffered a stroke at the same time".
Ms Irvine told the ABC no help came for an hour-and-a-half.
In 2015 Mr Irvine was sentenced to nine months' jail for negligent driving after he crashed into a cyclist, causing the woman's death.
He was refused bail pending an appeal and within a week-and-a-half in prison he was assaulted by a prisoner with a violent criminal history.
We should remember when we call for custodial sentences that prison can be life altering