1. Department of Neurology, Oregon Health & Science University (OHSU), Portland, Oregon, USA.
2. Veterans Affairs Portland Health Care System, Portland, Oregon, USA.
3. Department of Anesthesiology and Perioperative Medicine, Oregon Health & Science University (OHSU), Portland, Oregon, USA.
4. School of Nursing, Linfield University, Portland, Oregon, USA.
5. Department of Behavioral Neuroscience, Oregon Health & Science University (OHSU), Portland, Oregon, USA.
6. Oregon Institute of Occupational Health Sciences, Oregon Health & Science University (OHSU), Portland, Oregon, USA.
7. Department of Medicine, Oregon Health & Science University (OHSU), Portland, Oregon, USA.
8. Department of Neurological Surgery, Oregon Health & Science University (OHSU), Portland, Oregon, USA.