1. Department of Neurology, Bashkir State Medical University, Ufa, Russia
2. Department of Neurology, G.G. Kuvatov Republican Clinical Hospital, Ufa, Russia
3. Faculty of Medicine and Health Sciences, University of East Anglia, Norwich, UK
4. Euan MacDonald Centre for Motor Neuron Disease Research, University of Edinburgh, Edinburgh, UK
5. Alzheimer Scotland Dementia Research Centre, University of Edinburgh, Edinburgh, UK, and
6. Cambridgeshire and Peterborough NHS Foundation Trust, Cambridge, UK