British neurosurgeon Professor Steven Gill is trying to halt, or even reverse, the development of the progressive neurological condition Parkinson's with an experimental drug: GDNF. Medical trials for the drug were the subject of the BBC Two documentary The Parkinson's Drug Trial: a Miracle Cure? Filmed over six years, the show follows some of the 42 people taking part in this groundbreaking study. Even though the results so far seem to be inconclusive, some subjects report miraculous changes in their range of movement and quality of life. So can GDNF bring hope to the 10 million people affected by Parkinson's worldwide? IFrame The Parkinson's Drug Trial: a Miracle Cure? will screen on Sky TV's BBC Earth channel on Saturday 9 November at 9:20pm.?