[1] NHS Lothian, Dept Clin Neurosci, Edinburgh, Midlothian, Scotland
[2] Euan Macdonald Ctr MND Res, Edinburgh, Midlothian, Scotland
[3] Anne Rowling Regenerat Neurol Clin, Edinburgh, Midlothian, Scotland
[4] Univ Edinburgh, Ctr Clin Brain Sci, Chancellors Bldg,49 Little France Crescent, Edinburgh EH16 4SB, Midlothian, Scotland
[5] Clin Audit Res & Evaluat Motor Neurone Dis, Edinburgh, Midlothian, Scotland