After two surgeries - one to cut his vertebrae to create more space for his spinal cord, and one to insert a catheter - Andy Beech remains in Whangarei Hospital but will be sent to the Auckland Spinal Rehabilitation Unit in Otara.
His orthopaedic surgeon, Dr Johnny Manson, said he was likely to recover, but often the legs would recover better than the arms in people with the syndrome.
"You wouldn't wish this problem on anyone."
Barry Beech said his brother, who does not work because he had autism spectrum disorder, and suffered from epilepsy, believes his brother simply didn't see the kerb.
"He'd been stable for months," he said.
"We were just having lunch and he'd been fine - just his normal self.
"The kerb overshot the end of the crossing by a foot and a half. He was just walking along the crossing behind me and just tripped right on the edge of it - he didn't get a chance to put his hands out or anything. It could have happened to anybody."
Since the fall, McDonald's has shortened, rounded off and painted the kerb.
When contacted by the Herald last week, a WorkSafe spokesman said the report of the incident received from McDonald's indicated the only injury was a broken nose and therefore no further action was taken.
But after information was received by the Herald about Andy's more serious condition, the spokesman said further enquiries would be made, including a visit to the site.
"WorkSafe New Zealand is still making follow up inquiries. No decision has yet been taken whether or not to launch a formal investigation," the spokesman said this week.
McDonald's spokesman Simon Kenny told the Herald the company had asked Barry to sign a privacy waiver so they could pay a contracted doctor to review Andy's medical records to help with their internal investigation, and so they could provide the correct information to both WorkSafe and ACC.
"We can do a more full and thorough investigation if we do have that information."
He said it was a very unfortunate accident.
A spokeswoman for the Whangarei District Council said staff had inspected the site and found McDonald's "identified the safety issue for their customers and have taken sensible measures to widen the gap in their barrier [kerb] to ensure it lines up with their crossing".