Commonwealth Games silver medallist Stephanie Inglis remains in a coma following the accident last week.
According to friends ,the 27-year-old from Inverness is still in a critical condition.
Doctors have warned that any possible recovery will involve significant rehabilitation and time.
Friends said she had responded to some eye tests but the next 48 hours remained crucial.
Stephanie won a judo silver medal at the Glasgow 2014 Commonwealth Games.
The accident in Vietnam is reported to have happened when her skirt caught in the wheel of the motorbike.
She was being taxied by motorbike to a school in Ha Long, where she had been teaching English for the past four months.
Family friend and judo athlete Khalid Gehlan started a funding appeal after it emerged that Ms Inglis's travel insurance had expired due to the length of her stay in Vietnam.
It has raised more than Â£180,000.
The Scottish judo star who suffered head injuries in a motorbike accident in Vietnam has shown "small signs" of improvement, friends have said.