Michael Jarry's school board insisted on the helmet to prevent the youngster from spitting on the other children who take the same minibus to school.
His mother, Sandra Luce, agreed in October to allow Michael to be harnessed into the seat by an E-Z vest - a special jacket often used to transport children with cognitive disabilities. But she drew the line at the helmet and visor, saying that her son is not physically capable of spitting.
"I will not agree to have my son transported to school in Montreal like he is Hannibal Lecter," she said. "Michael is not an animal."
Michael, who learned to read and write last year, and can set and clean up the dinner-table at home, lives in Cheteauguay, 25 miles south of Montreal.
His journey to school takes up to two hours, and the bus picks up several other mentally and physically handicapped children in wheelchairs on the way.
The school board would not comment on an individual case, but its "drastic solution" has been questioned by Quebec's Office of People with Disabilities.
Carmen Lahaie, president of Autisme Montreal, said a helmet and visor were not necessary. The problem lay with the length of journey and lack of trained monitors. "If the kid is OK at home, then the problem is with the transport," she said.
* Bowing to public pressure, Canada's soft-drink manufacturers have agreed to remove soda-pop from dispensing machines in primary and middle schools.
The industry decision was welcomed by both politicians and health groups, who have pointed to the easy availability of soft drinks as a cause of the tripling of Canada's childhood obesity rate, from 11.4 per cent to 29.3 per cent, in the past 30 years.
The sugar-laden soft drinks will be replaced by water, 100 per cent fruit juices and sports drinks.