Footnotes

• Competing interests SA receives research support from the Motor Neurone Disease Association, UK, MND Scotland, Silvia Aitken Charitable Trust and the University of Edinburgh. She has also received support from the Wellcome Trust, UK. She has received salary support from the University of Edinburgh and NHS Lothian and travel expenses and honoraria for speaking and education activities not funded by industry. The views expressed here are those of the author.

• Provenance and peer review Commissioned; internally peer reviewed.