Forty-one per cent of those who said they did have enough information about drug treatments still did not take a disease-modifying treatment.

BBC: Multiple sclerosis patients are missing out on drugs

But what counts in drug litigation is the information that goes to doctors, who are in charge of prescribing medicines.

ECONOMIST: Big trouble for Merck

She has also written to Health Secretary Jeremy Hunt, enclosing information and personal stories about the children who need the drug and the difficulties they face.

BBC: Ellie Nickless