A four-year-old girl from Cornwall with a severe form of epilepsy has undergone a dramatic improvement within days of starting a radical diet programme.
Sarah Laslett wears a helmet to protect her from falls
But cash for the pilot scheme, which could help other sufferers, is due to run out and an appeal has been launched for £25,000 to keep it going.
Sarah Laslett, from Morval near Looe, has Myoclomic Astatic epilepsy.
The rare, drug-resistant form of epilepsy triggers scores of blackouts and seizures every day.
The attacks started eight months ago and mean Sarah has to wear a helmet when she is playing.
But in the past week, 90% of the seizures have stopped thanks to a complex diet made up of 80% fat.
Her treatment, the ketogenic diet, is part of a clinical trial at Great Ormond Street Hospital for Children in London.
However, it is so finely balanced it has to be carefully calculated by experts who are on hand for advice and support.
Sarah's family is trying to raise £25,000 to continue the trial for another year and help other children like Sarah.
Her mother Alex said: "The diet does involve a lot of work.
"When I first started preparing it, I spent about five hours a day in the kitchen.
"The diet is so carefully balanced and only works if you get it exactly right."
As Sarah burns off the fat, her body produces ketones, which protect her against seizures.
But the benefits are worth the hard work.
Mrs Laslett said: "Watching your child being injured continuously is torture.
"She is a completely different child on the diet. It is our old Sarah back."
Trial dietician Liz Neal said: "We need to show the benefits over a large enough sample to make the study scientifically strong enough.
"We can then go out to the scientific world at large and say, 'this is a controlled study and the diet works'.
"That's why we need the ongoing funding."
Cheques should be made payable to: Great Ormond Street Hospital for Children NHS Trust - EO3.
Send it, together with a note confirming that the cheque is a donation for the Ketogenic Diet Study, to Sarah's GP, Dr D Goss, Sarah's Appeal, Old Bridge Surgery, Station Road, East Looe, Cornwall, PL13 1HA.