He has been in intensive care at Tallahassee Memorial Hospital since then, but his family is hoping he will be able to make the trip home to New York from Florida later this week.
Chiachia's brother, Daniel, said that Darren took his first unsteady steps yesterday.
They hoped he could return by air ambulance to Buffalo, where he would begin rehabilitation at a brain injury recovery unit.
His family said that Darren's cognitive functioning remains more guarded. "He is confused and illogical, but optimism remains," they said yesterday.