People may say, why did you put your daughter forward? I've always said from day one that I had nothing to lose but everything to gain

Stephen Forber

She quickly deteriorated from a happy, active young woman, to a bed-ridden invalid requiring constant care.

Rachel could not recognise members of her family, stand noise or sunlight or feed or dress herself.

Her father Stephen contacted Professor Stanley Prusiner, who invited her to his San Francisco clinic to become the first human to try Quinacrine.

She started taking it in August and within three months she was able to get out of bed, walk unaided and even swim without support.

'Nothing to lose'

When Rachel started taking the drug her father said he knew it was a last chance.

Mr Forber said: "I spoke to Rachel's neurosurgeon who told me that the drug hadn't even been tested on animals. I said, 'I know'.

"People may say, why did you put your daughter forward? I've always said from day one that I had nothing to lose but everything to gain.

"When I signed the consent form for the treatment, what could I lose?"