A 10-year-old girl with dystonia - a condition which left her head touching the small of her back - has returned home after surgery.
Natasha suffered severe muscle spasms which bent her backwards
Natasha Young, from Haywards Heath, West Sussex, had the pioneering operation in southern France.
The treatment involved implanting electrodes in her brain to eradicate incorrect messages sent to her muscles.
Natasha developed the condition 18 months ago - her parents say she has already shown a vast improvement.
After surgery in France, Natasha can sit up and look forwards
The schoolgirl, who enjoyed horse riding and skiing before she became ill, had suffered severe muscle spasms forcing her back to curl backwards and leaving her bed-ridden.
Now, after treatment in France, she is able to sit up and look forwards.
Allie Young, Natasha's mother, said: "She's not stopped smiling. She's now pain free and she feels better. She's able to lie flat on her back.
"She can actually see things. Before, she had her head back all the time.
"She can actually see to sit normally, to watch a DVD or see something on the television and it's just changed her life already - it's fantastic."
At home after her stay in hospital, Natasha said: "I've missed my pets especially my hamster, Katy."
Her father, David Young, said: "You can see the excitement in her face when she does things and you can see this big smile."
Natasha was treated in Montpellier by surgeon Professor Philippe Coubes who has pioneered the technique for tackling the condition.
Pulses from the electrodes target the parts sending out the incorrect messages and "switch them off".
Her parents took her to France after consultant Dr Jean-Pierre Lin, at Guy's and St Thomas' Hospital in London, recommended the treatment.